Front cover

KVI PhD theses in 2008

Editors Hans BeijersCatherine Rigollet

Editorial assistance Amarins Petitiaux

Printing Grafisch Centrum, Facilitair Bedrijf, RuG

Preface

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In December 2008 KVIcelebrated its 40th an-niversary and MuhsinHarakeh’s 60th birth-day with guests from allover the world.

The Kernfysisch Versneller Instituut (KVI) celebrated in 2008 its 40thanniversary. In the 1960s Professor Brinkman could successfullyrealize his vision to establish an institute for nuclear physics in theNorth of the Netherlands with an accelerator as its central facility. Theinstitute became known for both its successful fundamental scienceand its applied research conducted under one roof.

Under the leadership of Professor Siemssen the institute grew into aworldwide recognized center for forefront nuclear physics with experi-ments at its own Philips cyclotron and in international collaborationwith colleagues from all over the world. Next to experiments in nuclearphysics an atomic physics group was attracted to conduct collisionresearch with highly charged heavy ions and an independent theorygroup of worldwide recognition was established the successes of whichincludes the introduction of the now widely used interacting bosonmodel. Also applications found their place at KVI. A research line wasstarted to study and monitor environmental radioactivity. The firstPositron Emission Tomography (PET) machine of the Netherlands wasset up in collaboration with medical partners from the local universityhospital.

In the last decade of the past millennium Professor Malfliet navigatedthe institute through a period when the old Philips cyclotron washonorably retired and a novel superconducting cyclotron, AGOR,was designed and constructed in close collaboration with Frenchcolleagues from the Nuclear Physics Laboratory in Orsay, to be finallyinstalled at KVI. Few-body Physics was introduced as a new researchfield at KVI. An open international atmosphere and high qualityeducation of students and young scientists has always been centralat KVI. Consequently the first international research school for PhDstudents, FANTOM, was established in collaboration with partnersfrom Belgium, France, Germany and Sweden. It will keep its uniqueindependent identity also within the faculty-wide graduate schoolwhich is now established in Groningen.

Professor Harakeh took the lead from the inauguration of the AGORcyclotron to set up a modern subatomic phyics program at the newmachine. Next to nuclear structure few body forces were studied us-ing new instruments among which the Big Bite Spectrometer (BBS)and the Big Instrument for Nuclear Analysis (BINA) at AGOR. Alsothe international collaboration operating the Two Armed Photon Spec-trometer (TAPS) in which KVI scientists participated exploited beamsof AGOR and other European major accelerators. The numerous suc-cessful nuclear physics experiments include investigations of nuclearstructure and as a particular example d-2He reactions involving nucleiof relevance to searches for neutrinoless double β-decay. The high-est precision until today could be achieved. At the beginning of thisdecade a new research line started which emphasizes the role of fun-damental symmetries and forces using Trapped radioactive Isotopesas µicrolaboratories for fundamental Physics (TRIµP), a subject whichhad been studied at KVI since long, but at a smaller scale. Such testsof our basic understanding of physical laws, today summarized as theStandard Model, is complementary to experiments at the highest en-ergy accelerators.

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Today the TRIµP research line is the main user of the AGOR cyclotron,which also delivers beams for research on the interaction of radiationwith matter, including biological material. The TRIµP facility consist-ing of a target station, a novel magnetic double separator, devicesto cool the produced radioactive isotopes and finally store them asneutral atoms in optical traps was fuly completed after a seven yearconstruction period and commissioned. Several experiments couldbe conducted already with productive international colleagues fromEurope and the United States of America. The TRIµP research pro-gram receives significant funds from the Dutch funding agency FOM.It was very positively evaluated at the end of 2008 by a high rankedinternational panel and the Dutch FOM commission for COndensedMatter and Optical Physics (COMOP) and can therefore continueits research program as planned. In this year, Rob Timmermansand Gerco Onderwater were successful with a FOM projectruimteapplication to study CPT and Lorentz violation in weak interactions,which exploits the unique features of the TRIµP facility by observingweak effects in the decays of spin-precessing polarized radioactiveisotopes.

Nuclear Physics with the traditional instruments at KVI is restricted tothird party funded experiments. In the past year a strategic partner-ship with the German Helmholtz-Center for Heavy Ion Research (GSI)had grown in its second year to its full designed size and makes KVIscientists partners in hadron Physics within the PANDA collaboration,in nuclear Physics within the NUSTAR collaboration and in the atomicphysics HITRAP project. In this context also accelerator componentsare designed and constructed for the international FAIR project tocome at the GSI location in Darmstadt, Germany.

In 2008 the new research line Astro-Particle Physics at KVI couldbook important progress. Olaf Scholten won a subsidy from NWOfor a research project where in the signals nearby radio telescope atWesterborg radios ignals are searched for which are expected fromultrahigh neutrinos which react with the moon (NUMOON). Furtherthe Pierre Auger Laboratory in Argentina was inaugurated by a largeinternational collaboration within which KVI, supported by Dutchcolleagues from NIKHEF and the Radboud University in Nijmegen,has the lead for the detection of cosmic air showers by radio waves,a novel detector part which enhances greatly this instrument. Thisexperimental program aims at understanding cosmic rays at thehighest ever observed single elementary particle energies.

It is a pleasure to mention tokens of appreciation based on personalperformance which several KVI scientists have received. ProfessorMuhsin Harakeh, whose term as director of the institute ended 31December 2008 after 13 years of service was decorated with RoyalHonours as Officier in de Orde van Oranje Nassau. The adjunct pro-fessors Ronnie Hoekstra and Nasser Kalantar-Nayestanaki were ap-pointed Full Professors at the University of Groningen with chairsfor Experimental Atomic Physics (physics of highly charged ions andtheir interactions with matter) and Experimental Nuclear Physics (few-body systems and fundamental forces). Laura Tolos won a RosalindFranklin Fellowship from the University of Groningen and started her

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research at KVI in the field of theoretical hadron physics in connec-tion with the PANDA activities. Bijaya Sahoo received an NWO VENIfellowship for theoretical research on atomic parity violation as a high-precision test of the unified electroweak theory which strengthens thejoint theoretical and experimental TRIµP project on single ion parityviolation. Duurt Johan van der Hoek won the Kamerlingh-Onnes Price2008 as the best undergraduate student. Further, seven graduatestudents could be promoted to doctors in Mathematical and NaturalSciences. In the teaching sector Rob Timmermans was ranked bythe RuG students as the best physics teacher of the year and OscarVersolato as the best physics teaching assistant.

In the coming years KVI, a center of excellence in atomic and sub-atomic physics, will concentrate on two main goals: First, research tounravel secrets of fundamental symmetries and forces and, second,applications of the state of the art technology and methods whichwe design in the course of our basic research. In particular, a majorresearch line will be formed and devoted to the interaction of radiationwith matter. This brings together the independently successful re-search lines at AGOR and at the Low Energy Ion Facility (LEIF) of theAtomic Physics group. Irradiations of technical materials with highenergy particles occurs at AGOR. Radiobiological experiments areconducted together with scientists from the University Medical Centerin Groningen(UMCG) in which biological materials are subjected tohigh energy proton and ion beams. The breakup of trapped biologicalmolecules in in controlled ion collisions with low energy ions is studiedat LEIF. As a major goal, KVI is strongly promoting particle therapyas a method of cancer treatment together with its local partner theUMCG and collaborating institutions in the whole of the Netherlands.KVI in particular endorses a strong radiobiology research programwith particle beams which accompanies patient treatment. Here KVIcan take advantage of its already established program in this fieldwith strong international partners.

Together with all my colleagues at KVI I am expecting fruitful resultsfrom our challenging research projects. We have accepted the chal-lenges imposed on science by concentrating our work on the fieldswhere we are strong. The KVI staff is looking forward to having youas soon as curious guests in our laboratory and perhaps soon aspartners in our future activities.

Groningen, May 2009 Klaus Jungmann

Contents

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TRIµP 9AGOR and Related Projects 21Nuclear and Hadronic Physics 35Astro Particle Physics 65Life Inspired Physics 77Theory 85Atomic Physics 93Personnel 99Scientific Output 103

TRIµP

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TRIµ: Trapping radioactive atoms and ions 10Production of Ra isotopes in the 206Pb + 12C reaction 11Spectroscopy of Barium in a magneto-optical trap 12Simple frequency offset locking device for lasers 13Lasers for Radium atom and ion spectroscopy 14Laser spectroscopy of neutral Radium 15Progress on TRIX: Trapped Radium Ion eXperiments 16High precision polarimetry for deuteron EDM search 17First observation of optically trapped 21Na 18Measuring the 8B neutrino spectrum 19Status of the lifetime measurement of 19Ne 20

TRIµP: Trapping radioactive atomsand ions

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H.W. Wilschut

Blue light prepared forion cooling

With the completion of the facilitythe emphasis is now on trappingradioactive atoms and ions. Ahighlight of this year is thereforethe first observed fluorescence oftrapped 21Na in the collector trap.It enables the next step which isthe transfer of the atoms into thesecond MOT chamber and to de-tect the 21Na β decay.The search of a permanent elec-tric dipole moment (EDM) and thenew project the measure atomicparity violation in the Ra ion, itwas necessary to find a methodto produce different Ra isotopes.In the first contribution of thischapter it is shown that Ra canproduced just like Na in inversekinematic while the thermal ion-izer is also effective in producingthe low energy secondary beamfor both Na and Ra. In this waythe most important isotopes forthe TRIµP group can be made innearly identical configuration ofthe equipment.Progress in trapping Ra and Raions and the preparations interms of necessary (diode) laserdevelopments has been consider-able. In particular the absolutevalue for the main transition linefor cooling and trapping in 225Rawas found. Related progress intheory is reported in the theorysection.After a difficult start in produc-

ing a secondary beam of 8B theexperiment of the collaboration ofR. Raabe could be concluded suc-cessfully thanks to the efforts ofthe cyclotron group.Important for the developmentof the atomic theory of Ra wasthe NWO-VENI fellowship (2008-2011) obtained by B.K. Sahooworking in the theory group.R.G.R. Timmermans and C.J.G.Onderwater obtained a grant inthe ”FOM projectruimte” for ”test-ing Lorentz invariance in theweak interaction”. We were proudthat D.J. van der Hoek, gradu-ate student in the TRIµP group,received the Kamerlingh Onnesprize for best cum laude studentof the academic year 2006-2007.At the end of the yearthe midterm review of theTRIµP/AGOR program took place.Members of the review commit-tee were Professors D.J. Morris-sey (chair), Michigan State Uni-versity, USA, H.-J. Kluge, GSI,Darmstadt and University of Hei-delberg, Germany, W. Marciano,Brookhaven National Laboratory,USA and G.J.M. Meijer, Fritz-Haber-Institut, Germany. Thecommittee gave a strong recom-mendation to continue the pro-gram and remain focussed onthe core theme of the program:the search for physics beyond theStandard Model.

Figure1 : Most of the TRIµP group members at the occasion of thethesis seminar of S. De

Production of Ra isotopes in the206Pb+12C reaction

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P.D. Shidling, H. Fraiquin, G.S. Giri, D.J. van der Hoek, L. Huisman, K. Jungmann,W.L. Kruithof, M. Sohani, O.O. Versolato, L. Willmann, H.W. Wilschut

Photo of the dispersivefocal plane chamber ofthe dual magnetic sepa-rator (top). Charge statedistribution of the pri-mary beam in the dis-persive focal plane afterpassing through thick(black line) and thin(Red line) target (bot-tom). The blue line cor-responds to the momen-tum distribution of ra-dium products.

Short lived radium (Ra) isotopeswill be used for the study of timereversal violation and atomic par-ity violation. The TRIµP facilityemploys the in-flight method forproduction and separation of ra-dioactive isotopes using the dualmagnetic separator. We use thismethod also to produce Ra iso-topes around 213Ra via low-energyfusion-evaporation reactions ininverse kinematic.

A 206Pb beam of 8 MeV/u from theAGOR cyclotron bombarded anamorphous diamond target of 4mg/cm2 thickness [1]. With thisthick diamond target the beamcharge states were not resolved(see side figure (black curve)). Us-ing a thin Al target of 270 µg/cm2

thickness the charge states wereclearly resolved and nine beamcharge states were observed (seeside figure (red bars)). Optimizedmagnetic settings of the separa-tor for radium were 8% lower thanthe primary beam and thereforethe radium was not fully sepa-rated from the primary beam dueto the presence of some chargestates of beam at this settings(see side figure (blue curve)).Up to three charge states canbe transported to the final focalplane of the separator because ofits acceptance. Ra isotopes andthe remnant primary beam at theexit of the separator were stoppedin an Al catcher foil of 80 µm,which was mounted in front ofa silicon detector. Detector andfoil were at an angle of 45o allow-ing to measure α particles fromRa decay. In this mode the ini-tial tuning of the separator wasmade. The highly energetic Raisotopes (MeV) were converted tolow energy (keV) secondary beamwith the thermal ionizer (TI). Lowenergy Ra ions extracted from the

TI were stopped on a 1.8 µm Alfoil in front of a silicon detec-tor placed after the thermal ion-izer. 212Ra (Eα=6.9 MeV)) 213Ra(Eα=6.623 and 6.713 MeV) 214Ra(Eα=7.137 MeV) are all alphaemitters. Decay of the 212,213,214Raisotopes was observed in the de-tector. Figure 1 shows the typicalalpha spectrum. Decays of Raand of daughter nuclei are visi-ble. The resolution is limited dueto the Al catcher foil. Furtheridentification was obtained fromthe characteristic lifetime of theisotopes.

Figure1 : Alpha spectrum ob-served after the decay of Ra iso-topes

213Ra, 214Ra are of our particularinterest; they are produced at arate of 500 and 100 counts/perparticle nA of primary beam, re-spectively. We note that the pro-duction method used for Ra canbe exploited also for the produc-tion and separation of actinideisotopes.

[1] Obtained from Dr. Ste-fan K. Zeisler, Vinder Jaggi,Applied Technology Group,Canada TRIUMF.

Spectroscopy of Barium in amagneto-optical trap

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S. De, U. Dammalapati, K. Jungmann, M. Stokroos, L. Willmann

τ3F2 =

160(10) µs

0 1 2

0.7

0.8

0.9

1

Time [ms]

MO

T F

luo

resc

en

ce

on

off

Laser @ 667.7nm

Lifetime of the 5d6p 3F2

state in Ba measuredwith a trapped sampleas a sensitive test ofatomic structure calcu-lations.

The search for permanent elec-tric dipole moments (EDMs) inthe heavy alkaline earth metal ra-dium is part of a worldwide ef-fort to find new sources of CP-violation, which could explain e.g.the matter-antimatter asymme-try in the universe. The ex-ploitation of the intrinsic sensitiv-ity of Ra requires improved un-derstanding of the atomic struc-ture of such multi-electron sys-tems on the experimental as wellas theoretical side. Experimentaldata on radium is scarce but thelighter earth-alkali metal bariumcan be used for comparison withrecent atomic structure calcula-tions. Particularly sensitive arelifetimes of highly excited statesand their decay branching ratios.New calculations for Ba and Rahave reached now an accuracy topredict the properties of higher ly-ing excited states [1]. Such statesare accessible in our setup formagneto optical trapping (MOT)of Ba [2].

6s2 1S0

6s6p 1P1

1

0

3D3

6s5d

3D23D1

1D2

35d6p 3D

2

1

5d2 3F2

6s6p 3P

λ1=553.7 nm

λIR1= 1107.8 nm

λIR2= 1130.6 nm λIR3 =

1500.4 nm

λ3= 667.7 nm

λ2= 659.7 nm

λB=

413.3 nm

2

Figure1 : Energy level diagramfor Ba.

Ba atoms are collected in a MOTfor about 1s. The populationin the MOT is a few 105 atomsand the trap lifetime is more than1 s. The trapping scheme forBa requires seven lasers at thesame time and produces an al-most equal distribution of thetrapped atoms over five states(6s2 1S0, 6s6p 1P1, 6s5d 1D2, 3D1

and 3D2). A short laser pulse of1ms duration at wavelengths λ2

and λ3 transfers the population ofthe 6s5d 3D1 and 3D2 states intothe excited 5d6p 3D1 state, whichhas a lifetime of 17.4(5)ns. Theatoms decay in equal parts to the6s2 1S0 ground state and to the5d6p 3F2 state. Up to 30% of theMOT population were transferredto the 5d6p 3F2 level, which wasobserved by the decrease of flu-orescence from the MOT at thewavelength λ1. After the laserpulse at wavelengths λ2 and λ3

the MOT fluorescence increasedagain because of the decay of the5d6p 3F2 state back into one ofthe five states of the laser coolingcycle. The characteristics timescale for the increase of the MOTfluorescence is given by the life-time of the 5d6p 3F2 state. Alifetime τ = 160(20)µs was deter-mined, which is in good agree-ment with the recent calculationof 190 µs [1].The atoms low temperature en-sured that they stayed inside theMOT region during this measure-ment cycle. The only loss arosefrom the decay to the metastable6s5d 3D3 state, which is notpart of the laser cooling cycle.A decay fraction from the 5d6p3F2 state to the 6s5d 3D3 stateof 5.4(1.7)% was determined inagreement with the calculation.The results demonstrate the re-liability of the new atomic struc-ture calculations which are in-dispensable for evaluation of thesensitivity of Ra isotopes towardsEDMs.

[1] V.A.Dzuba, V.V. Flambaum,J. Phys. B: At. Mol. Opt.Phys. 40, 227 (2007).

[2] S. De, U. Dammalapati,K. Jungmann, L. Willmann,Phys. Rev. A79 in print(2009).

Simple frequency offset locking devicefor lasers

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R. v. Wooning, S. De, D.J. v.d. Hook, K. Jungmann, W. Kruithof, L. Willmann

Front plate of the fre-quency offset lockingmodule.

The development of techniquesfor the stabilization of lasers isone of the core activities for thelaser laboratory within the TRIµPfacility. The control of an offsetfrequency between two lasers ofup to several GHz is a commontask in many of the experiments.A simple versatile solution isdemonstrated for a frequency off-set lock controller, where the fre-quency offset can be set by anexternal radio frequency refer-ence with the accuracy of a rf-synthesizer. The advantage ofthe system is the possibility tochange the frequency offset in afast and simple way. In the caseof laser cooling and trapping of Nathe offset frequency is 1.72 GHzfor 23Na and 1.85 GHz for 21Na.We applied a commercially avail-able phase-locked loop controller(PLL) for the stabilization of twolasers.A frequency difference betweentwo lasers is measured by a fastphoto-diode. About 1 mW of lightfrom each of the two lasers isoverlapped on the photo-diode.The dc part of the output sig-nal is proportional to the opti-cal power in the two laser beamswhile the rf part is determined bythe difference frequency between

the two lasers. The rf signal isaround ≈ 50 dBm and the signalto noise is better than 50 dB andthe bandwidth of available diodescan be as large as several tens ofGHz.The frequency of any laser canbe controlled by an analog voltagewhich changes, e.g. the laser cav-ity length by a piezo-electric el-ement or the driving current inthe case of a diode laser. In or-der to control the frequency off-set which is measured by the fastphoto diode the frequency differ-ence in the radio frequency rangehas to be converted into a con-trol voltage for the laser. Thisis done with the PLL evaluationboard ADF4007 from Analog De-vices. Advantages are the largefrequency range of the PLL (10MHz to 7GHz) and the high band-width of the error signal of typi-cally 100 kHz.The designed laser locking boardwas implemented in an exper-iment which aims to study β-decays in trapped sodium (Na)and in an experiment whereatomic barium (Ba) is laser cooledand trapped in a magneto-opticaltrap in preparation of a search fora permanent electric dipole mo-ment.

Figure1 : Output signal from the charge pumpof the frequency difference detector for differentmodulation depth of the reference frequency.

Lasers for Radium atom andion spectroscopy

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O. Boll, G. Giri, A. Groot, K. Jungmann, B. Santra, L. Willmann, O. Versolato

Saturated absorp-tion signal from theR(116)(9-2) transitionin molecular 127I2 near714.3nm recorded withan extended cavitydiode laser.

The TRIµP laser facility is con-tinuously increasing and improv-ing lasers and laser technol-ogy for the experimental searchesfor fundamental symmetry viola-tions. In particular, experimentsexploiting radium in its neutralform as well as an ion requiredevelopments of lasers at newwavelengths. The extended cav-ity diode laser technology (ECDL)which was developed within theTRIµP facility plays a central role.It permits the fast response tonew experimental requirementsand benefits from the increasingrange of available wavelength andimproved output power levels oflaser diodes.Laser light for the 7s2 1S0 →7s7p 3P1 intercombination transi-tion in the Ra atom at 714.3nmis required for a second stagelaser cooling of this atom. Thelaser light can be produced byTi::Sapphire lasers. Recentlylaser diodes at the wavelength708nm (HL7001MG/02MG laserdiode, Hitachi), which were de-signed for biomedical researchbecame available. The laser canbe tuned up to 716nm in anECDL configuration with a 1800lines/mm VIS holographic grat-ing from Edmund Optics. TheECDL produces an output powerof up to 40 mW, which is suffi-cient for a magneto optical trap-ping of Ra on the intercombina-tion transition.Amplitude modulated satura-tion absorption spectroscopy ofmolecular I2 was performed tostudy the tunability and fre-quency stability of the ECDL. TheR(116)(9-2) transition in molecu-lar 127I2 is about 1GHz below thetransition frequency in 225Ra. Itcan be used as an absolute ref-

erence for Ra. The resolved hy-perfine structure of the transi-tion is shown in the figure. Theoutermost right peak (a15) at13 999.2459 cm−1 [1] was de-termined to be 702(20) MHz be-low the 1S0 → 3P1 intercombina-tion line [2]. The single hyper-fine transition is a well suited forlocking the ECDL for long termstability of the laser frequency.Further, two lasers for the spec-troscopy of trapped radium ionsare ready for the experiment (seecontribution Ra+). Here we havebuilt an aquamarine ECDL at468.4 nm for the 7s 2S1/2 → 7p2P1/2 transition from the groundstate. However, a second laser isrequired for the laser cooling ofradium ions due to the decay ofthe excited state to the long livedmetastable 6 2D3/2 state. Thislaser drives the 6 2D3/2 → 7 2P1/2

transition at 1079.2 nm. It isbased on a QFBGLD-1080 singlemode laser diode (Toptica) in aECDL configuration. Of particu-lar importance is the choice of thefeedback grating. A holographicgrating with 1200 lines/mm (Ed-mund Optics) resulted in goodfrequency tuning properties andoutput powers of up to 40 mW ofpower. The ECDL has been set upin an aluminum housing in orderto increase the long term stabil-ity of the laser, which will be op-erated in the TRIµP experimentalhall.

[1] S. Gerstenkorn et al., At-las Du Spectre D’AbsorptionDe la Molecule D’Iode (Labo-ratoire Aime Cotten, Orsay,France, 1982).

[2] N.D. Scielzo et al., Phys.Rev. Lett. A 73, 010501(R)(2006).

Laser spectroscopy of neutral Radium

15

B. Santra, A. Groot, K. Jungmann, L. Willmann, H.W. Wilschut

Upper plot: The 1S0

- 1P1 (F=1/2 - F’=3/2transition in 225Ra at482.7 nm. The purpleline indicates the pre-dicted position of thetransitions. Lower: theabsorption spectrum ofmolecular 130Te2 as anabsolute frequency ref-erence.

Atomic radium offers severalunique possibilities for searchesfor fundamental symmetry viola-tions, e.g. searches for perma-nent electric dipole moments ormeasurements of atomic parityviolation. Such experiments re-quire laser cooling and trappingof these isotopes. With the ad-vent of atomic radium sources atthe TRIµP facility we performedspectroscopy of the strong 7s2 1S0

- 7s7p 1P1 transition which canbe used for efficient laser cool-ing (Fig. 1). An accuracy of thisfrequency with an uncertainty ofthe order of the natural linewidthof 30 MHz of this transition isneeded.

Figure1 : Low lying energy levelsof atomic Radium.

The spectrum of 226Ra wasrecorded in 1933 using a gratingspectrometer and 96 lines wereidentified on the photographicplates [1]. From this measure-ment the level scheme of Ra wasderived (Fig. 1). The absolutefrequency of 7s2 1S0 - 7s7p 1P1

transition in 226Ra is reported to621041.4(2.4) GHz [1]. Later, theISOLDE collaboration at CERNperformed collinear laser spec-troscopy to determine the hyper-fine splittings and the isotopeshifts with for a wide range ofisotopes [2], but no improvement

on the absolute frequency deter-mination was reported. The iso-tope shift between 225Ra(I=1/2)and 226Ra(I=0) is 2.236(21) GHzand the hyperfine structure split-ting of the transition in 225Ra is4195.8(3.8) GHz [2].In preparation of laser coolingand trapping of Ra laser spec-troscopy on a weak atomic beamof 225Ra has been performed. Theflux of atoms was a few 104

cm−2s−1. The laser beam at thewavelength 482.7 nm is orthogo-nal to the direction of the atomicbeam to reduce the Doppler ef-fect. Light at this wavelengthis provided by frequency dou-bling of light at 965.4nm froma Ti:Sapphire laser in a tem-perature stabilized KNbO3 crys-tal. Several mW of blue light wasavailable for the experiment. Thefluorescence light from the atomsis passed through a narrow bandinterference filter (480nm, 10nmwidth) and imaged on a photo-multiplier tube. The absolutefrequency of the laser light isdetermined by absorption spec-troscopy on molecular 130Te2 (seeside Fig.). The fluorescence sig-nal from the 1S0−1P1 (F=1/2 -F’=3/2) hyperfine component ofthe transition was observed about600 MHz below the central valueof the literature value, but withinthe uncertainty. The absolute fre-quency of the transition is deter-mined to 621042.14(3) GHz fromthis first measurement. The fre-quency accuracy is improved by afactor of 80, which is sufficient forthe requirements for laser cool-ing.

[1] Rasmussen, Z. Phys. 86, 24(1933).

[2] Ahmad,et al., ISOLDE col-laboration, Physics Letters B133(1-2), 47 (1983).

Progress on TRIX: Trapped Radium IoneXperiments

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O. Boll, O. Dermois, G.S. Giri, L. Huisman, K. Jungmann, B.K. Sahoo, I. Smid,M. Stokroos, D.J.M. Tilman, R.G.E. Timmermans, O.O. Versolato, L.W. Wansbeek,L. Willmann

Recently commissionedion trap designed forhigh precision fields

A dual experiment is beingset up for atomic parity non-conservation (APNC) and an all-optical frequency standard. Bothexperiments are based on pre-cision spectroscopy on a singletrapped radium ion. One single-trapped and laser cooled radiumion is an ideal candidate to in-vestigate APNC and as such canserve as a low energy test ofthe Standard Model of particlephysics. We aim for a precisionmeasurement of the electroweakmixing angle by probing the dif-ferential light shift of the 7S Zee-man sublevels (see Figure 1). ThisStark shift is caused by the in-teraction of the ion with an off-resonant laser light field. Withan almost identical set-up ultra-narrow transitions in this ion canbe exploited for an all optical,high stability clock.

This year, we have set up a newdedicated laser laboratory. Here,all necessary wavelengths forbarium and radium ion detectionand laser cooling are available.Ba+ is used mainly to get hands-on working experience on theplanned experiments with Ra+,because Ba+ is readily availableand is isoelectrical to Ra+. A fre-quency doubling cavity was built

for power enhancement of the493nm light required for coolingtransition of Ba+. Further char-acterization of the collector trapwas one of the central point of re-search this year. Unloading timeof the trap (τ ) and temperature ofthe ion cloud (T) were studied asa function of different experimen-tal conditions.

A single ion trap (precision trap)was constructed in-house andwas commissioned. It has a pre-cise hyperbolic shape to producethe best trapping potential. Thetrap electrodes were gold coated.In the near future, we will try tosee laser cooling of barium ionsin this trap. An ion transportsystem for loading ions from thecollector trap to the precision traphas been constructed in the me-chanical workshop and will becommissioned in the near future.

Meanwhile, successful produc-tion and subsequent efficientslowing down of several isotopesof Ra have been accomplished.For radium ion spectroscopy, anew beamline in the A-cell is be-ing designed and built. Thisbeamline, with associated ion op-tics is expected to be completedbefore the summer of 2009.

Figure1 : Level scheme of Ra+ and concept of differential light shift

High precision polarimetryfor deuteron EDM search

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K. Jungmann, W. Kruithof, C.J.G. Onderwater, M. da Silva e Silva, O.O. Versolato;V. Dzhordzhadze, A. Imig, D. Lazarus, W. Morse, Y. Semertzidis (BNL); E. Stephen-son (IUCF).

New EDDA electronics

The quest for physics beyondthe Standard Model constitutesone of the main endeavours inphysics research. Among the dif-ferent approaches is the searchfor EDMs, predicted by the Stan-dard Model to be practically zero.The deuteron is a promising can-didate particle to search for anEDM. Besides being theoreticallyattractive [1] its small anoma-lous magnetic moment makes it asuitable candidate for an exper-iment based on the frozen spinmethod [2]. We develop a highlyefficient polarimeter necessary forsuch an experiment [3].Our approach involves both sim-ulations and dedicated experi-ments. A data-driven deuteron-carbon scattering model was de-velopped to optimize the operat-ing point and serve as a basis foran analytical model to predict andunderstand systematic errors. Tovalidate our models, experimentswere conducted at COSY-Julichusing the EDDA detector, whichresembles the envisioned setup.The existing electronics and dataacquisition system were replacedby KVI-developed ones. In tworuns with pD ' 1 GeV/c the over-

all efficiency and analyzing powerof the polarimeter were deter-mined, yielding η ' 1.5% and A '0.05 and η ' 0.1% and A ' 0.2,respectively. Different triggeringconditions allowed to vary the dy-namic range of the system, show-ing essentially no loss in perfor-mance, while severely cutting thedata rate. Preliminary analysisshowed a reduced sensitivity tosystematic errors from the first tothe second run.Continuous monitoring capabil-ity was demonstrated by trackingthe polarization through an RF-induced spin flip. First steps wereset to demonstrate the ability toobserve polarization changes atthe level of 10−5 induced by asmall time-dependent solenoid.

[1] C.P. Liu and R. Timmer-mans, Phys. Rev. C 70,055501(2004).

[2] F.J.M. Farley et al., Phys.Rev.Lett.93, 052001(2004).

[3] M. da Silva e Silva et al., The18th International Sympo-sium on Spin Physics Con-ference Proceedings(2009).

Figure1 : Asymmetry monitoring for vector (left)and tensor (right) polarization components

First observation of optically trapped 21Na

18

O. Boll, G. Giri, A. Groot, D.J. van der Hoek, R. Hoekstra, K. Jungmann,W.L. Kruithof, B. Santra, P. Schakel, P.D. Shidling, L. Slatius, M. Sohani,D.J.M. Tilman, O.O. Versolato, L. Willmann, H.W. Wilschut, R.H.L. van Wooning

Impression of a 23NaMOT cloud in the cham-ber with the reaction mi-croscope. Stray light il-luminates some of thestructures of the micro-scope.

One of the important steps in theTRIµP program is to stop rareisotopes in an atomic trap anddo precision experiments on theirdecay process. In 2008 we suc-ceeded in optically detecting 21Nain a magneto optical trap (MOT).A radioactive 21Na beam with 2.8keV energy was transported ontoa thin Zr neutralizer foil. By heat-ing this foil the 21Na atoms leavethe foil. They can then be cap-tured in a MOT. Prior to this runthe efficiency for trapping stable23Na ions was studied as functionof various parameters such as theZr foil temperature.For monitoring the number of21Na particles arriving at the neu-tralizer gamma detectors are usedto detect the 511 keV annihila-tion radiation from the 21Na de-cay, Figure 1 shows this γ rate.A dip in the signal can be seenwhen the neutralizer pulses (redline) and the particles are re-leased from the neutralizer. Thebuild-up time constant when theneutralizer is off (blue line) corre-sponds to the lifetime of the 21Na.

Figure1 : The γ rate from the neu-tralizer.

Figure 2 shows the signal fromthe PMT looking at the MOT cloudin the middle of the glass cell.

During heating of the neutralizerthe fluorescence increases, theMOT lifetime is short due to pres-sure increase associated with theheating. The background countrate is from the stray light in theglass cell.

Figure2 : Optical signal of 21Na.

The proof of optical trapping ofradioactive 21Na completes thesetup of the TRIµP facility. Thetrapping efficiency will be im-proved further. The particleswill be transferred to a sec-ond chamber, where the β-decayproducts can be analyzed forβ − ν correlations. The re-coil ions will be measured ina reaction microscope which in-cludes a position-sensitive multi-channel plate. The direction ofthe positrons is obtained from a∆E detector. The energy is mea-sured in a full E β detector. Thisallows to fully reconstruct thekinematic of the decay. This sec-ond chamber is ready to be com-missioned with 21Na. The transfersystem between the chambers iscurrently being designed and setup. In this system the atoms willbe pushed with a laser beam fromthe collector MOT to the detectionchamber.

Measuring the 8B neutrino spectrum

19

J. Buscher1, R. Raabe2,1, M. Alcorta3, J. Aysto4, B. Bastin1, M. J. G. Borge3,M. Carmona-Gallardo3, T. E. Cocolios1, J. Cruz5, P. Dendooven6, L. Fraile7,H.O.U. Fynbo8, D. Galaviz3,9, L.R. Gasques9, G.S. Giri6, M. Huyse1, S. Hyldegaard8,K. Jungmann6, O. Kirsebom8, W. L. Kruithof6, M. Lantz10, A. Perea3, K. Riisager8,A. Saastamoinen4, B. Santra6, P. D. Shidling6, M. Sohani6, O. Tengblad3,E. Traykov1,6, D.J. van der Hoek6, P. Van Duppen1, O.O. Versolato6, H.W. Wilschut6.1Instituut voor Kern- en Stralingsfysica, K.U.Leuven, Belgium2GANIL, Caen, France3Instituto de Estructura de la Materia, CSIC, Madrid, Spain4Department of Physics, University of Jyvaskyla, Finland5Dep. Fısica, FCT, Universidade Nova de Lisboa, Portugal6Kernfysisch Versneller Instituut, Rijksuniversiteit Groningen, The Netherlands7Departamento Fısica Atomica, Universidad Complutense, Madrid, Spain8Department of Physics and Astronomy, University of Aarhus, Denmark9Centro de Fısica Nuclear da Universidade de Lisboa, Portugal10Fundamental Fysik, Chalmers Tekniska Hogskola, Goteborg, Sweden

Spectrum of the sum en-ergy of the β-delayedα particles emitted inthe decay of 8B Thepeak at ≈280 keV isdue to the decay of thecontaminant 9C nuclei,which will be separatedin the analysis using∆E-E identification. Theinsert is a picture of theimplantation detector.

The solar-neutrino detectorsSuper-Kamiokande, SNO andICARUS are primarily sensitiveto electron neutrinos νe from theβ-decay of 8B. Neutrino oscilla-tions are invoked to explain thepresence of νµ,τ components inthe measured flux. Such a so-lution implies the distortion ofthe measured spectrum of solarneutrinos with respect to the un-perturbed one. Thanks to theincreasing accuracy of the solarneutrino measurements, the dif-ferences between the two spectracan be used to set constraints onthe parameters of neutrino oscil-lations.The β-decay of 8B proceeds to abroad 2+ continuum structure inthe 8Be daughter, which immedi-ately breaks up into two α par-ticles. The neutrino spectrum isreconstructed from the energy ofthe α particles. The measurementis particularly delicate at low en-ergy, where systematic errors be-come important.With the aim of improving onthe existing data, we performeda measurement at the TRIµP fa-cility at KVI. The 8B nuclei wereproduced by impinging with a 55MeV/nucleon 12C beam deliveredby the AGOR cyclotron on a 5mm-thick 12C target. The TRIµPseparator was tuned to optimizethe selection of the 8B ions, which

were then implanted in a finelysegmented silicon detector. Ion-by-ion identification was achievedby a combination of time-of-flightand energy loss techniques, usinga thin ∆E detector placed in frontof the implantation detector. De-cays of 8B were selected as thoseevents following an implantationof a 8B nucleus in the same pixel.With this method the full energyof the emitted α particles is recov-ered with almost 100% efficiencydown to the detection threshold(≈200 keV). An internal calibra-tion was performed using the β-delayed α particles emitted in thedecay of 20Na ions, which werealso separately implanted in thedetector. The stability was regu-larly monitored using standard αsources.A preliminary spectrum of themeasured α particles from the8B decay is shown in the fig-ure. The results look very promis-ing, with better statistics and amuch lower threshold than previ-ous measurements.For the extraction of the neutrinospectrum, the β-particles energysumming needs be taken into ac-count. The measurement of theβ-decay of the mirror 8Li nucleus,performed with the same methodat TRIUMF (Canada), will helpevaluating this and other system-atic effects.

Status of the lifetime measurement of 19Ne

20

L. Broussard, M. Busch, B. Carlin, A. Crowell, H.O. Back, C. Howell, J. Faircloth,P. Mulkey, R.W. Pattie Jr., A.R. Young (TUNL); P.G. Dendooven, D.J.v.d. Hoek,K. Jungmann, W.L. Kruithof, C.J.G. Onderwater, P.D. Shidling, M. Sohani, O.O.Versolota, L. Willmann, H.W. Wilschut (KVI)

The upgraded tapedrive system uses im-proved tape guides,tension feedback, andaluminum tape.

The study of 12

+ → 12

+ isobaricanalog transitions, such as thepositron decay of 19Ne to 19F, al-lows an independent extraction ofthe parameter Vud. In the 19Nesystem, the lifetime is currentlythe dominant contribution to theuncertainty in Vud. Our goal isto reduce the error in τ (19Ne) bya factor of 3 to the 0.02% level,making its contribution to the un-certainty essentially negligible.

Figure1 : Energy spectra of theclover detector taken during theFebruary 2008 beamtime. Theblue bars indicate the energyrange over which the backgroundsare below our targeted precision.

Our experiment uses the TRIµPseparator to make a beam of 19Nefree of contamination. The beamis implanted into a thick tape,and a tape drive system trans-ports the sample into a shieldedenclosure. Two HPGe clover de-tectors detect the annihilation ra-diation in coincidence. In Febru-ary 2008 we performed an eval-uation of the systematic effectsof our experimental design, aswell as a preliminary measure-ment at the mid 10−3 precisionlevel. We were able to demon-strate that contaminant positron-emitting isotopes will not affectthe lifetime measurement at our

targeted precision, though wecould not place a direct limit on15O. The coincidence backgroundlevels were acceptable over a wideenergy range. We did not as-sess the level of diffusion in thetape, but previous experimentssuggest the effect is very smallin aluminum. We identified twoareas that require improvement:deadtime in the acquisition sys-tem and reliability of tape posi-tioning.A redesign of critical componentsin our setup has drastically im-proved performance. We imple-mented tension feedback in ourtape drive system, allowing forvery fast and smooth motion withsub-millimeter precision in po-sitioning. We also use morepowerful motors, a lower tensiontape guide design, and a simpli-fied, user-friendly pushbutton in-terface. To further limit diffu-sion, we replaced the aluminizedmylar with thick aluminum tapelaminated to a polyester back-ing, so that the 19Ne can be im-planted into the aluminum layerwithout sacrificing tape perfor-mance. We have resolved theissues with our data acqusitionthat lead to high deadtime un-der certain conditions, and haveachieved deadtime-free operationwell above our expected rate.During March 2009, we expect toperform a measurement of τ (19Ne)at our targeted precision. We willcontinue our program of studywith an attempted measurementof τ (21Na). This measurementwill parallel the current study ofaβν , the β-ν angular correlation of21Na, at KVI.

AGOR and RelatedProjects

21

AGOR group activities 22AGOR status report 23Producing spread-out Bragg-peaks for irradiationexperiments 24Irradiation of cell-cultures with 90 MeV/u 12C6+ beams 25A histology-based model for radiation-induced damageto lung tissue 26Numerical simulation of ECRIS 27Extraction of intense ion beams from KVI-AECR 28Commissioning of the KVI 4D emittance meter 29Installation and commissioning of SUPERNANOGAN 30AGOR-FIRM (Facility for IRradiation of Materials)status report 31Enhanced functionality of the AGOR-FIRM beam lineMonte Carlo model 32A digital reference generator for the AGOR RF-system 33

AGOR group activities

22

S. Brandenburg

The beam intensity upgrade forheavy ions again made a fewsteps forward. The 20Ne beam at23.5 MeV per nucleon is now rou-tinely delivered for experimentswith a beam intensity exceeding2.5 µA (200 W). At 15% dutycycle a peak intensity of 13 µA(1020 W peak power) has beenextracted. The prototypes of thebeam loss monitoring and controlsystem were successfully tested.The first stage of the completesystem was installed and is nowroutinely used for monitoring ofthe transmission through the cy-clotron and the high energy beamlines. The remainder of the sys-tem is presently under construc-tion. The construction of thenew electrostatic deflector hasunfortunately been delayed dueto lack of manpower and prob-lems with the manufacturing ofthe insulators by an outside con-tractor. Both issues have beensolved in the meantime and theproject is now progressing satis-factorily. The design of the pre-septum was optimized in consul-tation with the manufacturer toensure its technological feasibil-ity.The performance of the 4D emit-tance meter was validated bycomparing the data obtained withthose of a conventional Allisonscanner at the Phoenix ECR-source at LPSC in Grenoble. Theinstrument is now routinely usedfor emittance measurements. The14 GHz SUPERNANOGAN ECR-source, which was obtained ona long term loan from theHelmholtz Center Berlin, was in-

stalled at KVI and its off-line com-missioning completed. It willinitially be used for experimentson beam formation and extrac-tion and then coupled to the cy-clotron. The existing 14 GHzAECR will then mainly be devotedto metallic ion beams.The capabilities of the in-air ir-radiation setup have again beenextended. A spread-out Braggpeak (SOBP) for 12C at 90 MeVper nucleon was developed forirradiations of cell cultures andbiomolecules and successfullyused in experiments. A first testexperiment for the developmentof a national standard for protontherapy in collaboration with theDutch standards institute (NMi-VSL) was performed using anSOBP for 150 MeV protons. In-stallation of remotely controlledequipment for 2D sample posi-tioning and switching betweencollimators has made the irradi-ations still more efficient. Anagreement was reached with theHelmholtz Center Berlin concern-ing the transfer of an irradiationsetup for heavy ion irradiations toKVI. The removal of the setup andits installation in the experimen-tal hall at KVI are currently beingplanned.The heat recovery system in-stalled on the He compressorshas operated during the wholeyear and exceeded our expecta-tions. Nearly 1500 GJ were de-livered for heating of the KVIpremises, corresponding to 25%of the total heating demand. Thepayback time of the investmentwill be less than two years.

AGOR status report

23

S. Brandenburg, M.A. Hofstee, J. de Jong, A. Kroon and H. Post.

kW of beam

In 2008 the AGOR-facility has op-erated during 29 weeks. Thescheduling statistics is summa-rized in Table I.

Table I: Machine-time usage in hours

2007 2008

Beam delivered 1319 1155Machine tuning 455 471

Machine studies 324 109Non-scheduledstandby 11 82

Scheduled maint. 1013 1051Non-scheduledmaintenance 379 177Scheduled standby 5086 5729

Total 8760 8784

Main technical malfunctionsThe main contribution to the non-scheduled maintenance in thefirst half of 2008 came from a re-curring waterleak in one of the RFresonators, which was repairedduring the summer maintainanceperiod. Repeated breakdowns ofthe MACOR mounting system ofthe inflector was the main causein the second half of the year. Af-ter the summer one of the threecryopumps developed a cryogenicleak and had to be taken out ofoperation. It will be removed forrepairs during the 2009 wintershutdown.

Additions and improvementsThe current-leads of EMC2 weregiving intermittent problems andwill be replaced in the future. Anew design for the electrostaticdeflector (ESD) was finished andconstruction of the new devicehas started. A second ECRsource was obtained from HMIin Berlin. The SUPERNANOGANwas re-assembled at the KVI. Off-line beamtests have been con-cluded succesfully and the sourceis ready to be coupled to the cy-clotron.

Beam developmentFour new beams have been usedfor experiments with the TRIµPfacility: 6Li+ @13.8 MeV/u, 19F5+

@10 MeV/u, 12C5+ @55 MeV/uand 206Pb27+ @8.5 MeV/u. Ofthe latter beam an intensity of8.5×1010 pps was delivered on tar-get.

One kiloWatt of beam achievedOn 4-july-2008 one kilowatt ofpeakpower was reached with the23.5 MeV/u Neon beam used forTRIµP. The beam was acceleratedin pulsemode with a 15% dutycy-cle to protect the extraction ele-ments. An intensity of 4 µA (300W) was extracted in CW mode.

IrradiationsA fully stripped 12C6+ beam at 90MeV/u was delivered for use inradiobiological work with cell cul-tures and DNA material. Irradia-tions are performed for a contin-ually expanding group of clients.Several improvements were madeto the setup, to allow faster oper-ation and the creation of a spreadout bragg peak for the 12C andproton experiments.

Beam Loss monitoring systemThe electrostatic chopper and afirst series of inductive beampick-ups for the beam loss moni-toring and control system neededfor high intensity operation wereinstalled and successfully testedon-line.

Transmission measurementsWe measured the transmissionthrough the cyclotron with sev-eral low intensity, low energyheavy ion beams at a range ofpressures to study the effect of in-teractions with the restgas. Pur-pose of these investigations is tobe able to predict and mediatelosses of the high intensity Neonand Lead beams required for theTRIµP program.

Producing spread-out Bragg-peaks forirradiation experiments

24

M.J. van Goethem1, H.H. Kiewiet, R. Dussel, S. Eggens-Eeltink, W.W.P. OLthuis,L. Slatius, H.A.J. Smit, N.J. de Vries

1 Department of Cell Biology, University Medical Center Groningen

Modulator wheel forproton irradiations

In the course of 2008 KVI hasstarted two projects which inves-tigate the interaction of carbonion beams with biological sam-ples [1,2]. In addition the KVIand NMI (Dutch Standards In-stitute) have started a project inwhich the dose deposited by 150MeV protons is measured usinga calorimeter and then comparedto a Markus chamber measure-ment. For these experimentsone needs a spread-out Bragg-peak (SOBP) to minimize the dosevariation over the target volume.A SOBP is created by modulat-ing the energy of the particles inthe beam thus shifting the posi-tion of the Bragg-peak (BP) (fig-ure 1). To calculate the weightsof each shifted BP a set of ROOT[3] macros has been developed.These macros need as input apristine Bragg-curve and the rel-ative shifted BP-heights. Know-ing the weights of the pristine-and shifted- BPs one can create aModulation Wheel (MW) as shownin the side picture. The wheelconsists of 4 segments whicheach contain the same stack ofmaterial that modulates the beamenergy. These stacks are ro-tated through the beam with afrequency of 10 Hz. The SOBP isthen generated with a frequencyof 80 Hz. The relatively highfrequency reduces possible dose-errors due to fluctuations in thebeam-intensity and due to start-ing and stopping in the middle ofa modulation period to less than0.1%. For the 12C6+ 90MeV/uirradiations we need a relativelyshort modulation length of only1mm with a maximum dose vari-ation of 1%. In this case thestack of range shifting material isproduced using segments which

are cut from overhead-sheets of0.1mm thick (0.13 mm waterequivalent thickness). In figure2 the measured SOBP created bythis MW is shown.

Depth Water (mm)0 5 10 15 20 25 30 35 40

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Figure1 : Creation of a sim-ulated proton spread-out Bragg-peak (blue) by summing the shiftedBragg peaks (red dashed) with thecorrect weighting to the pristineBragg-peak (red solid)

Depth Water (mm)4 6 8 10 12 14

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Figure2 : Measured pristine (redcircles) and SOBP (blue squares)for 12C6+ ions at 90 MeV/u

[1] Plasmid DNA, Hong MingDang, KVI annual report2008.

[2] Irradiation of cell cultureswith 90 MeV/u 12C6+, KVIannual report 2008.

[3] ROOT data analysis frame-work, http://root.cern.ch.

Irradiation of cell-cultures with90 MeV/u 12C6+ beams

25

M. J. van Goethem1, M. Niemantverdriet1, R. P. Coppes1,2, S. Brandenburg, P. vanLuijk1,2.

1Department of Cell Biology, University Medical Center Groningen2Department of Radiation Oncology, University Medical Center Groningen

Irradiation setup

The Relative Biological Effective-ness RBEs is defined as a mea-sure how effective a certain typeof radiation, such as carbon-ions,kills cells compared to a photonirradiation. This is relevant forthe irradiation of tumors whereone wants to kill the tumor cells.For healthy tissue not only cellkilling, but also changes in thefunctioning of cells are relevantoutcomes. Therefore the RBEh,for healthy tissue, should be de-fined using observables that mea-sure tissue function. We wantto investigate if for carbon-ion ir-radiations, RBEs is the same asRBEh. An observable which isrelevant for lung tissue is thePAI-1 enzyme which plays a rolein the formation of fibrosis. Inthis study we investigate the up-regulation of the PAI-1 enzymein cells after exposure to irradi-ation under the assumption thata stronger up-regulation of thePAI-1 enzyme leads to a higherchance of the formation of fibrosisand thereby a loss of lung-tissue-function.The carbon-ion irradiations areperformed at KVI with 90MeV/uusing the irradiation setup in theH-cell (see picture), the photon ir-radiations are performed at theUMCG. We have irradiated cell-cultures using a 30mm diame-ter field leaving 2.5mm marginaround the wells containing thecultures. The field was formedusing a 1.16mm Pb foil and hasa dose-variation less than 3% .In order to maximize RBEs thecell-cultures should be placed inthe Bragg-peak. For Carbon theBragg-peak is very narrow andwe place the cells in the cen-ter of an spread-out Bragg-peakto minimize dose variations due

to small positioning errors. TheSOBP is produced using the mod-ulation wheel described in ref-erence [1]. The dose variationover the SOBP is less than 1%,the total variation of the dose oneach cell in a culture is there-fore less than 4%. We have con-firmed our dose delivery usingKodak EBT radio-dosimetric filmin the cell cultures boxes. TheBeam Intensity Monitor was cal-ibrated for the carbon irradiationusing a protocol provided by theIAEA [2]. Figure 1 shows the ob-tained dose response curves forcell-survival after carbon-ion ir-radiation measured in two seper-ate experiments, illustrating thatthe data is reproducible. Thisnice first partial result is promis-ing and we hope to have a full setof results early 2009.

Figure1 : Preliminary result of thefraction surviving cells as functionof applied carbon-ion dose(filledsymbols), and x-ray’s (open cir-cles), the measured RBE for 10%survival is 2.4

[1] Producing spread-out Bragg-peaks for irradiation exper-iments, KVI Annual Report2008.

[2] IAEA Technical Report Series398.

A histology-based model forradiation-induced damage to lung tissue

26

P. van Luijk1, J.M. Schippers1,2, S. Brandenburg, J.A. Langendijk1, R. P. Coppes1,3

1Department of Radiation Oncology, University Medical Center Groningen2Accelerator department, Paul Scherrer Institut, Villigen, Switzerland3 Department of Cell Biology, University Medical Center Groningen

Irradiated-volume de-pendence of damage tothe lung tissue for twodose levels. Both thedamage inside and out-side the radiation fielddepend on irradiatedvolume, independent ofdose.

Optimal implementation of newradiotherapy techniques requiresaccurate predictive models fornormal tissue damage. Previ-ously we tested the applicabil-ity of the Critical-Volume (CV)model to estimate the risk of lungcomplications [1]. In the CVmodel the relation between localdose and local tissue damage isdescribed with a tissue damagemodel (TDM) and subsequentlythe amount of damaged tissue istranslated into loss of organ func-tion. Conventionally, tissue dam-age is modeled using local doseonly. In the lung, however, dam-age has also been observed out-side the irradiation field. To testwhether there are significant dis-crepancies between the classical,local-dose based model and mea-sured local tissue damage, 59rats were irradiated with gradeddoses to 100%, 88%, 63% and50% of the lung using 150 MeVprotons. Eight weeks after irra-diation lung-tissue samples werecollected inside and outside theirradiated region. The num-ber of inflammatory cells, infil-trates, vascular hypertrophy andalveolar destruction were scored.Clear damage outside the radi-ation field was found (figure 1).In addition, the severity of dam-age depends on irradiated vol-ume, independent of (local) dose(side figure). A fit of the clas-sical, local-dose based model tothese data showed significant(p<0.05) discrepancies. A newTDM was formulated based on di-rect local damage depending onlyon local dose and indirect lo-cal damage depending on the en-tire dose distribution. Tissue isassumed to be damaged if oneor both occur. This TDM does

describe all types and severitiesof local damage observed cor-rectly. The CV model, enhancedwith the new TDM, could de-scribe the functional data. Sub-sequently, the fitted TDM wasincorporated in the CV model.The resulting model was foundto correctly describe previously-published [1] breathing-rate data.In conclusion, using histologi-cal data a novel TDM for therisk of radiation-induced lung tis-sue damage was developed andvalidated in a second dataset.Thus using this new TDM wecan describe consistently the de-pendence of local tissue damageand the consequent loss of or-gan function in a single model.Calculation of the risk of nor-mal tissue damage using the im-proved model is expected to bemore accurate than conventionalconcepts like mean dose to thelungs, allowing further optimiza-tion of radiotherapy.

Figure1 : Dose dependency ofhistological assessment of damageto lung tissue. Damage occurs bothinside and outside the radiationfield.

[1] P. van Luijk et al., Int. J.Radiat. Oncol. Biol. Phys.69,552 (2007).

Numerical simulation of ECRIS

27

V. Mironov

The ion density profileat the plasma electrode

Numerical simulation of theplasma in an Electron CyclotronResonance Ion Source (ECRIS)can improve the understandingof the relative importance of dif-ferent processes that influencethe source performance. We de-veloped a 3-D PIC-MC code tomodel the ion dynamics in theplasma [1]. The code reproducesthe spatial and charge-state dis-tributions of ions in the beamsextracted from the source and in-side the plasma chamber. Thecalculated ion beam profiles areused for simulations of the iontransport in the beam line andinjection into the cyclotron. Thecode can also be used to studythe response of the extracted ionbeams with respect to variationsin the magnetic field profile, gascomposition, electron tempera-ture etc. An important check ofthe model assumptions would bethe reproduction of various ef-fects known in ECR sources.One of these effects, the isotopeanomaly, has been systemati-cally studied at KVI almost twentyyears ago [2]. When the ECRIS isrunning with a mixture of differ-ent isotopes of the same element,ions with high charge states ionsare produced more effectively forthe heavier isotope than for thelighter isotope. Reasons for thismass dependence are still not un-derstood completely.We simulated the ion source pro-cesses when injecting a gas mix-ture of two neon isotopes, 20Neand 22Ne. The gas flow of bothisotopes into the plasma was set

to be equal and the electrontemperature was assumed to be1 keV. The calculated ratio ofthe extracted ion currents for theneon isotopes is shown in Fig-ure 1 as a function of chargestate. The dependence closelyresembles the experimentally ob-served effect.The higher efficiency of produc-ing the high charge states ofthe heavier isotope was foundto be connected to two factors.The heavier isotope stays in theplasma for a longer time becausethe ion confinement time is pro-portional to the ion thermal veloc-ity. Furthermore, the heavy iso-tope is concentrated in the denserparts of the ECR plasma due tothe reduced ion diffusion in theradial direction. Combined to-gether, these effects result in theisotope anomaly.

Figure1 : Ratio of the extractedion currents for 22Ne and 20Ne iso-topes.

[1] V. Mironov and J.P.M. Bei-jers, arXiv:0811.2865.

[2] A.G. Drentje, Rev. Sci. In-strum. 63, 2875 (1992).

Extraction of intense ion beamsfrom KVI-AECR

28

S. Saminathan, V. Mironov, J.P.M. Beijers, and S. Brandenburg

Ion trajectories in theKVI-AECR extractionsystem.

We have started a simulation pro-gramme to improve the ion ex-traction from the ECR ion sourceand transport into the cyclotron.This work is mainly driven bythe demands for TRIµP experi-ments at KVI, i.e. a 1 kW heavy-ion beam on target. In order tobetter understand beam extrac-tion and transport we performdetailed 3D simulations of theseprocesses. First we simulate thespatial distribution of the ionsat the plasma electrode aperturewith a 3D Monte-Carlo PIC-code[1]. Then the ions are extractedby a three-electrode accel-decelextraction system. In this calcu-lation the magnetic fringe fields ofthe hexapole magnet and extrac-tion solenoid are also taken intoaccount.Generally the space charge withinthe extracted ion beam fromthe ECR ion source is not fullycompensated by the secondarycharged particles (electrons) pro-duced by ionization of the resid-

ual gas. This nonzero charge den-sity creates an electric field withinthe extracted beam. For a DCion beam this force is predomi-nantly outward and it will causethe beam to expand in diame-ter and continuously change thebeam divergence due to repulsioneffects. Such space charge effectscan severely alter the beam op-tics.The results of the 3D simulationfor He1+ and He2+ beams at anextraction voltage of 24.7 kV aredisplayed in figure 1. The cal-culated emittance at the end ofthe ground electrode is mainlycaused by the diverging fringefield of the extraction solenoidand space charge effects, whichalso distort the beam. The emit-tance of the extracted ion beamstrongly increases with increas-ing extracted current. Beamhollowing appears for non-zerospace charge.

[1] V. Mironov and J.P.M. Bei-jers, arXiv:0811.2865.

Figure1 : Spatial intensity distribution of He ions at the end of theground electrode for a beam current of (a) 0 mA, (b) 0.6 mA and(c) 1.0 mA. Horizontal emittances at the same position for a beamcurrent of (d) 0 mA, (e) 0.6 mA and (f) 1.0 mA.

Commissioning of the KVI4D emittance meter

29

H.R. Kremers, S. Saminathan, J.P.M. Beijers, and S. Brandenburg

The pepperpot emit-tance meter.

The performance of the KVI 4Demittance meter has been vali-dated by cross check measure-ments with an Allison scanner atthe APHOENIX source at LPSCin Grenoble. The KVI 4D emit-tance meter was installed down-stream of two Allison scanners atthe test bench of the APHOENIXsource. We investigated system-atically the influence of severalparameters such as beam inten-sity, charge state, high voltageon the Multi Channel Plate (MCP)and beam rotation on the per-formance of the KVI 4D instru-ment. With every change of pa-rameter the emittance in horizon-tal as well as vertical plane wasmeasured by the Allison scan-ner and then with the KVI 4Demittance meter. The measure-ments with the Allison scannerand the KVI 4D emittance meterwere found to be in good agree-

ment (see Figure 1).This agreement is independent ofthe charge state and the beam in-tensity. The high voltage on theMCP slightly influences the resultof the measurement. This maybe due to the algorithm used forbackground subtraction. The KVIemittance meter was also capa-ble of dissipating a beam powerof 20 Watt generated by a beamof 550 µA of 35 kV Ne6+ ions.The 4D data of the KVI emittancemeter show significant transversecorrelations that can not be ob-served with the 2D Allison scan-ner, thus illustrating the impor-tance of measuring the full 4Dphase space distribution. In-vestigation of this dataset showslamentation of the beam, see fig-ure 1 (bottom left).

[1] H.R. Kremers et al., KVI An-nual Report 2006.

Figure1 : Measured x-x’ emittance of a Ne6+ beam by an Allisonscanner (top left) and the KVI-4D emittance meter (top right ; Exampleof filamentation in the x-x’ 4D data (down left); Example of selectinga part of the filamentation.

Installation and commissioning ofSUPERNANOGAN

30

J. Mulder, J.P.M. Beijers, M. Bleeker, M.A. Kronenburg, I. Smid, M. Stokroos,A. de Vries, N.J. de Vries

The SUPERNANOGANat its testbench.

In the framework of the KVI-GSIcollaboration we have obtaineda SUPERNANOGAN ion sourcevia a long-term loan agreementfrom the Hahn-Meitner Institutein Berlin, Germany. SUPER-NANOGAN is a compact ECR ionsource operating at 14.5 GHzand with both the longitudi-nal and radial confining mag-netic fields produced with per-manent NdFeB magnets [1]. TheSUPERNANOGAN source will re-place the polarized-ion sourcePOLIS and will be used as asecond multiply-charged ion in-jector for AGOR. Therefore alsoa new beamline with analyzingmagnet has been set up. With theSUPERNANOGAN installed at theAGOR injection line we will havetwo heavy-ion injectors availableand thus more time to develop in-tense ion beams with KVI-AECR.After its arrival at KVI in March2008 SUPERNANOGAN has beenfully assembled off-line in a newlyprepared experimental room.Also a short test beam line hasbeen set up including an einzel-lens, analyzing magnet and Fara-day cup. In addition, we havedesigned and constructed a newdiagnostics box which is shown infigure 1. It is a compact, 450 mmlong, UHV compatible vacuumchamber with a CF 150 pumpflange, motor-controlled horizon-tal and vertical slits, a harp

Figure1 : The diagnostics box forSUPERNANOGAN.

for measuring the beam profileand a Faraday cup. It is also pos-sible to mount a pepperpot emit-tance meter instead of the Fara-day cup.The first plasma was producedin October and the first 20 kVNeon beam has been extracted onDecember 18, 2008. A prelimi-nary charge-state distribution ofthis beam is shown in figure 2.Because of the low RF powerthat was injected (only 40 W) thecharge-state distribution peaks atsingly-charged ions. The entiresetup will be moved and attachedto the AGOR injection line in2009. We will there also installadequate radiation shielding sothat the source can be run athigher RF powers.

Figure2 : Charge-state distribu-tion of first neon beam with SU-PERNANOGAN.

[1] P. Sortais et al., Rev. Sci.Istrum. 69, 656 (1998).

AGOR-FIRM (Facility for IRradiation ofMaterials) status report

31

H.H. Kiewiet , S. Brandenburg, R. Dussel, M.J. van Goethema, E.R. van der Graaf,W.W.P. Olthuis, R.W. Ostendorf, H.A.J. Smita Dept. Cell biology, section Radiation and Stress Cell Biology, University MedicalCenter Groningen, University of Groningen, Groningen, The Netherlands.

XY table and dual colli-mator system on bread-board table

During the last few years, theamount of customers (both in-ternal and external) using theAGOR-FIRM set-up [1] has in-creased significantly. Also thenumber of radiobiological exper-iments increased with the ad-dition of cell culture and DNA-plasmid radiation damage exper-iments using carbon ion beams[2]. Since each experiment de-mands a different arrangementof the components in the beamline, we decided to rebuild thebeam line using a modular sup-port system. In 2008, the sup-ports of both beam line and theirradiation set-up were replacedby breadboard tables. For allbeam line components, universalmounting plates were developed.The mounting plates allow allcomponents to be placed at anyposition in the beam line with anaccuracy of +/-0.25mm withoutany (time consuming) alignment.Components can be moved witha 5 mm stepping interval in andperpendicular to the beam direc-tion. Changing between experi-ment set-ups can now be done ina few minutes rather than hoursin the past.In many experiments, a largeamount of samples needs to be ir-radiated in a relatively short time.This demands fast changes of tar-gets, beam energy and field shap-ing collimators, without the ne-cessity to enter the area. In 2006,a multi leaf degrader was alreadyinstalled. In 2008 we developeda remote controlled XY-table, acollimator switching mechanismand energy modulating wheels [2]

for both protons and carbon ions.The XY-table contains a largemounting rack, that allows us tomove samples through the beamwith a range of 600 mm in hori-zontal and 300 mm in vertical di-rection with a relative accuracy of0.01 mm. The table was usedwith great effectivity during ra-diobiology experiments where upto 18 samples could be irradi-ated with varying doses withouthaving to enter the area betweenthe irradiations. Also changingbetween racks with pre-mountedsamples is now a matter of sec-onds.The collimator changing mecha-nism contains two field shapingcollimators. One of the mainproblems with our previous col-limator support was the possibil-ity of misalignment caused by ro-tation of the collimator mount.Since the collimators have alength of 45 mm in the beamdirection, small rotations of thecollimator immediately cause apenumbra. Since there is a signif-icant number of field shaping col-limators available, the mechani-cal design of the collimators itselfcould not be changed. Therefore,in the new design special effortshave been made to increase thepositioning accuracy of the ex-isting collimators. The mechani-cal position resolution is now +/-0.05 mm in all directions.

[1] H.H. Kiewiet et al. KVI An-nual Report 2006.

[2] M.J. van Goethem et al. KVIAnnual Report 2008.

Enhanced functionality of the AGOR-FIRMbeam line Monte Carlo model

32

E.R. van der Graaf, R.W. Ostendorf, M.A. Hofstee, M.J. van Goethem

beam

Degrader plates

Collimator

Model of the energy de-grader

Planning and design of irradia-tions with the AGOR Facility forIRradiation of Materials (AGOR-FIRM) are aided by simulationswith a Monte Carlo simulationmodel (implemented in MCNPX)of the AGOR-FIRM beam line [1].This model has been restructuredand extended with new function-alities. The restructering con-sisted of setting up the modelanew in such a way that all ma-jor components can now be later-ally moved in and out of the beamand also displaced in the beamdirection. This was achievedby using the MCNPX coordinatetransforms option for the sur-faces of which these units arecomposed. This new functional-ity allows easy rearrangement ofthe set-up of the beam line to as-sess e.g. the resulting proton fluxand energy distribution at the po-sition of the Devices Under Test.Three new components wereadded to the model: an energy de-grader, a range telescope, and awater absorber. The degrader isused to lower the primary protonenergy and consist of nine alu-minium plates of various thick-nesses that can be placed (re-motely controlled) in the beam.In the MC model (side figure) thenine plates can be moved in andout the beam individually andalong the beam line as one unit.The range telescope (Multi-LeaveFaraday Cup, MLFC) is usedto measure proton energies andconsists of a stack of 64 alu-minium sheets that are inter-spersed with Kapton foils. To al-low accurate modelling the massand surface area of each sheetwas precisely determined and

their surface density was calcu-lated and converted into densityby division by the nominal thick-ness of 500 µm. The so obtained64 densities were used in the MC-NPX input file. Figure 1 showsthat the agreement between mea-surements with the MLFC for var-ious degraded energies and modelcalculations for these settings isvery good.To facilitate Bragg peak simula-tions of charged particles in wa-ter, a linear water absorber hasbeen added to the input file. Thewater absorber is divided in threeparts that each can be dividedin finer sections. This allows fore.g. a coarse division for thesection before the Bragg peak, afine division for the section withthe steep rise and fall part of theBragg peak and again a coarse di-vision for the part downstream ofthe Bragg peak. Analysis of mea-sured and simulated Bragg peaksfor 150 MeV protons in water ison-going.

Leaf nr.

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Figure1 : Comparison of mea-surements and simulations for theMLFC.

[1] E.R. van der Graaf, and R.W.Ostendorf, KVI Annual Re-port 2007.

A digital reference generator forthe AGOR RF-system

33

M. Stokroos, S. Brandenburg

Close view of the Ana-log Devices AD9959chip

The existing reference generatorfor the AGOR RF-system pro-duces the correctly phased sig-nals for the three RF-resonatorsand buncher by mixing the out-puts of a variable frequency syn-thesizer (424 to 462 MHz) and afixed 400 MHz oscillator, stabi-lized by the 10 MHz reference out-put of the synthesizer. The sig-nals from the synthesizer and the400 MHz oscillator are amplifiedand split into four signal paths.Three of the 400 MHz signals arethen delayed by an amount de-pending on the harmonic mode.By mixing and low-pass filtering,the required signals with a fre-quency between 24 and 62Mhzand a phase depending on the de-lay of the 400 MHz signals areproduced. Frequent malfunction-ing of several components led tothe decision to develop a new ref-erence generator based on mod-ern DDS Direct Digital Synthesis(DDS) techniques.The new reference generator isbased on the 4-channel AD9959DDS-chip, which contains foursynchronized outputs and oper-ates at 500 mega-samples persecond. All required timing andcontrol logic for channel syn-chronization are on chip. Thissingle chip therefore offers thecomplete solution for the genera-tion of three individual resonatorsignals plus an additional sig-nal output for the buncher. Toshorten the development time itwas decided to use the AnalogDevices AD9959-PCB evaluationboard as the basis for the system.The AD9959 chip is programmedthrough a micro-controller via a3-wire SPI interface. The micro-controller runs a program thatreads a set of control parametersfrom a dual-ported memory andwrites the data through SPI afteran update command is applied.

The dual-ported memory can beaccessed from an FBCORE unit,which is a standard BITBUS mod-ule, used at the KVI for commu-nication between the control sys-tem and peripheral equipment.In this application the AD9959runs in single-tone mode, mak-ing channel independent settingof the output frequency andphase possible. The originalvariable synthesizer now clocksthe AD9959 at the resonator fre-quency. The smooth frequencydetuning function of the syn-thesizer, which is important forcontinuous operation of the res-onators, is thus retained. TheAD9959s internal clock multi-plier is programmed to work atthe highest internal clock-ratepossible to optimize the rejec-tion of alias frequencies above1/2fclock and spurious signals.The independent setting of thefrequency for each output is usedfor beam phase measurements.Slightly changing the buncherfrequency produces a Fouriercomponent in the beam inducedsignal on the phase probes that iscompletely free from interferenceof the RF-system. This greatlyimproves the signal-to-noise ra-tio. Furthermore, this modula-tion technique provides informa-tion on the bunch width, phaseacceptance, bunching efficiencyand the number of turns, fromwhich the acceleration voltagecan be deduced [1].The control of the new digital ref-erence generator has been inte-grated in the control software ofthe RF-system. The device hasproven to be a stable and reliablereplacement of the previous elec-tronics.

[1] T.W. Nijboer, W.K. van Asseltand S. Brandenburg, Proc.ICCA2004, pg. 416.

Nuclear and HadronicPhysics

35

Nuclear and hadron physics activities 37GRID and high-performance computing at KVI 38Physics analysis studies using PandaROOT 39Pattern classification techniques for particle identification 40A shower analysis for the electro-magnetic calorimeter ofPANDA 41Simulations of the EXL detection system for studies withexotic nuclei 42Design studies for the backward endcap EMC of PANDA 43Options for backward endcap electromagnetic calorimeterfor PANDA 44Design of the forward endcap electromagnetic calorimeterfor PANDA 45Characteristics of a cryogenic ion guide 46A cryogenic gas catcher for high-energy radioactive ions:conceptual design 47Design concept for a novel spectrometer at the eA colliderELISE 48Rate dependence of the PANDA ASIC and discretepreamplifiers 49Timing performance of PANDA EMC preamplifiers 50Status of the EPICS implementation for NuSTAR controls 51Status of self-sustained front-end control loops 52Spike rejection and noise-level triggering for scintillatordetectors 53A fast peak-finding algorithm for amplitude histogramanalysis 54Calibration of a position-sensitive photodiode using digitalsignal analysis 55r-process studies with EXL 56Status of the EXL demonstrator 57Analyzing powers 1H(d,pp)n breakup reaction at 130 MeV 58Proton-deuteron breakup studies at 135 MeV 59Deuteron-deuteron breakup at 65 MeV/nucleon 60Four-body studies with polarized beams 61Pionic fusion in light-ion systems 62Study of the Pygmy dipole resonances in 94Mo with the(α, α′γ) method 63

Nuclear and hadron physics activities

36

N. Kalantar-Nayestanaki

The nuclear and hadron physicsgroup has been active on vari-ous fronts in 2008. The bulkof our activities was focussed inthe direction of FAIR within theKVI-GSI program. In addition tothese activities, there are a fewprojects which were initiated inthe interacting-hadron programand which are now nearly com-pleted.In 2008, Myroslav Kavatsyukjoined the group and is partici-pating in the PANDA project inwhich he is coordinating the elec-tronics developments. Within thePANDA project, KVI has a majorcontribution and a coordinationrole in the computation and sim-ulations. In the past year, theKVI participated in the formula-tion of the technical design re-port (TDR) of the ElectroMagneticCalorimeter (EMC) for PANDA.This report is the first TDR ap-proved by FAIR. Work is now be-ing done on various aspects suchas the mechanical design andelectronics developments. Thegroup is involved in the designof low-noise, low-power amplifiersused in the readout of avalanchephoto-diodes and vacuum photo-triodes. The theory group at KVIis active in describing a coupled-channel partial wave frameworkfor anti-proton proton annihila-tions. The results are postedin the chapter discussing all thetheoretical developments at KVI.The NuSTAR group is active onsimulations for the design of theEXL detector as well as its me-chanical design which started atthe end of the year. There hasbeen lots of progress on the slowcontrol system and on evaluat-ing various protocols for exper-imental controls. For this pur-pose, effort has been put into sig-nal analysis techniques such asdeveloping fast peak-finding algo-rithms. In addition, techniquesare being developed for rejection

of spikes in a signal or findingand subtracting the right base-line from the signal in order toobtain the true signal shape. In2008, we had the pleasure of hav-ing Georg Berg from University ofNotre Dame in the United Statesat KVI. He worked on the designof the spectrometer for the ELISeproject at FAIR. His work has re-sulted in the first concept of apossible spectrometer. The workon the design of the cryogenic gascatcher is coming to an end andparts will be ordered in 2009.As with any other large projectwhich is just starting up, ourFAIR activities are presentlymostly concentrated on eithersimulations to come up with thebest design and to prepare fordata analysis, or technical devel-opments such as mechanical andelectronics design. This chapterfollows this logic with the com-putational developments at thebeginning followed by the tech-nical developments towards theend of the chapter.The last six pages of this chapterare allocated to nuclear physicsactivities performed with AGORat KVI. The breakup experimentsin the three-body system havenow been completed at 65 and135 MeV/nucleon. Preliminaryresults of analyzing powers anddifferential cross sections are pre-sented. The data taken for thefour-body system are being ana-lyzed here at KVI as well as atIUCF and preliminary results areemerging showing that all the re-action channels can be well iden-tified and preliminary cross sec-tions and spin observables havebeen unambiguously obtained.The sub-threshold pion produc-tion experiment which was doneat KVI has resulted in very niceresults. The last section reportson a new experiment dealing withpygmy dipole resonance in 94Mo.

GRID and high-performance computingat KVI

37

J.G. Messchendorp, M. Babai, and J.C. van der Weele

Towards a supercom-puter?

KVI is involved in various fu-ture experiments which requireimmense computing and stor-age resources. Primarily drivenby the activities for the PANDAproject, KVI is looking into vari-ous technologies which would en-able a high-performance comput-ing (HPC) infrastructure. A fewof these initiatives have been al-ready mentioned in the annualreport of KVI of 2007. Here, wesummarize the highlights of theactivities in 2008.

Figure1 : The contributions ofthe different sites in PandaGRIDfor successful job completion dur-ing the second data challenge in2008. The fraction of jobs accom-plished at KVI is indicated as thedark green and blue areas. Dataare taken from Ref. [1]

In the past year, a HPC clus-ter consisting of six 2 GHz dualquad-core Intel Xeon nodes eachequipped with 8 GBytes of mem-ory and 500 GBytes of hard-disk space, has been bought andbrought to operation at the endof the year. The cluster has beenembedded in the PandaGRID [2]and has successfully participatedin the last data challenge (DC)of the PANDA collaboration. Fig-ure 1 depicts some of the resultsof the last DC. The fraction ofaccomplished jobs is shown forthe different participating sites.Note that the contribution of KVI

is presently about 6%. The aimfor the future is to increase thisnumber significantly by addingcomputing nodes of the comput-ing center at the University ofGroningen to the PandaGRID. Be-sides the PANDA DC, the KVIcluster has already been used ex-tensively for simulations for de-sign studies of the EMC and forphysics benchmark studies forthe physics book of PANDA.HPC on batch farms or GRIDinfrastructures works effectivelyin case the computing-intensiveproject can be divided up in well-separated jobs, each running inparallel on different nodes orcores. Our applications, pre-dominantly simulations and dataanalysis, can in most cases makeuse of this advantage since theyare driven by units of indepen-dent events. The computing ar-chitectures are, however, chang-ing rapidly in time. The trendis that the future computers willcontain tens or even hundredsof cores operating on top of ashared-memory architecture. It isquestionable whether our presentsoftware and HPC strategy will beable to make use of the advan-tages of the upcoming computingarchitectures. KVI is looking intothe new developments, in partic-ular in view of the software de-sign of the simulation and analy-sis framework, PandaRoot. Expe-riences have been obtained in ex-ploring the OpenMP standard [3]in parts of the EMC reconstruc-tion software, which would en-able the code to run more effi-ciently on many-core computers.The investigations are still ongo-ing.

[1] http://panda-wiki.gsi.de

[2] http://mlr2.gla.ac.uk:7001

[3] http://openmp.org/wp/

Physics analysis studies using PandaRoot

38

A. Biegun and J.G. Messchendorp

An overview of thequark antiquark statesas a function of theirmass. The correspond-ing anti-proton beammomenta covered byPANDA are indicatedas well.

The PANDA experiment at the Fa-cility for Antiproton and Ion Re-search in Darmstadt, FAIR, hasa rich experimental program withthe main goal to improve theknowledge of the strong inter-action. In preparation for thatexperiment detailed simulationsand a corresponding analysis ofvarious physics channels are car-ried out.Various physics benchmarkchannels have already been stud-ied using an older computingframework and its results arepresently being documented inthe first PANDA physics book.These results will be verifiedand extended by using a newerand more complete simulationand analysis framework, Panda-Root [1]. A few channels havealready been analyzed with thenew framework. Here we discussan example decay mode of thecharmonium state hc, namely thechannel

p+ p→ hc → ηc + γ →

(π0 + π0 + η) + γ → 7γ. (1)

For this channel, the perfor-mance of the ElectroMagneticCalorimeter (EMC) of PANDA isessential. The EMC allows an ac-curate measurement of the pho-ton energy and scattering anglewithin the energy range between10 MeV and 15 GeV with - in com-bination with the tracking detec-tors - an excellent particle identi-fication [2].To generate reaction (1), the Evt-Gen event generator has beenused [3]. The response of theEMC was studied using varioustransport models together witha realistic digitization includingthe electronic responses and pho-ton statistics. The Rho analysispackage [4] has been applied toreconstruct invariant masses of

the intermediate states, namelythe π0, η, and ηc mesons, fromwhich, finally, the hc mass is re-constructed as shown in Fig. 1.A mass resolution (FWHM) of70 MeV is predicted togetherwith a peak-to-background ratioof 30:1. Note, however, that thebackground only contains contri-butions from combinatorics withmisidentified clusters. A re-construction efficiency of about30% has been determined. Fur-ther studies will be done inthe near future to improve theperformance and include othercompeting background channels.Also, other decay modes includ-ing charged particles will be ana-lyzed.

Figure1 : The reconstructed in-variant mass of the charmoniumstate, hc, with the decay given inEq. (1).

[1] S. Spataro et al., Journal ofPhysics 119 (2008) 032035.

[2] EMC Technical Design Re-port, October 2008arXiv:0810.1216v1.

[3] http://www.slac.stanford.edu/lange/EvtGen.

[4] K. Gotzen et al., Journal ofPhysics 119 (2008) 032020.

Pattern classification techniques forparticle identification

39

V. Suyam Jothi, M. Babai, and J.G. Messchendorp

Figure 2: The electron-detection efficiency as afunction of the pion re-jection efficiency.

The PANDA program at the fu-ture FAIR facility has ambitionsto study the strong interactionvia annihilations of anti protonswith protons or nuclei. PANDAwill cover an extensive physicsprogram, including charmoniumspectroscopy, search for exoticstates such as hybrids and glue-balls, hypernuclei studies, andobservations of weak and electro-magnetic decays. In preparation,various design studies and de-tailed simulations are being pur-sued by the PANDA collabora-tion. For this, a simulation andanalysis framework, carrying thename PandaRoot, is presently un-der construction, which includesa complete model of the proposeddetector, realistic transport mod-els, and advanced tracking andreconstruction algorithms.The broad physics program ofPANDA requires an excellent par-ticle identification. Various de-tectors have been proposed andare evaluated which will makea particle identification possible.This includes an electromagneticcalorimeter (EMC), Cherenkov de-tectors, time-of-flight detectors,and a central tracking device,consisting of a micro vertex detec-tor (MVD) combined with a straw-tube tracker (STT) or a time-projection chamber (TPC).In this work, pattern-recognitionmethods are evaluated to opti-mize the particle identificationof pions, electrons, positrons,kaons, and (anti) protons bya multi-dimensional data anal-ysis exploiting all the informa-tion registered by the detectorsof PANDA. Multi-variate analysistechniques, such as density es-timators, neural networks, learn-ing vector quantization, and deci-sion trees are considered for thistask.In 2008, various multi-variateanalysis tools have been imple-

mented in the PandaRoot frame-work. Figures 1 and 2 showpreliminary results of an exam-ple study. Here, 105 electron andpion events have been generatedrandomly distributed in phasespace and within a momentumrange of 0-5 GeV/c. The responseof the detectors has been simu-lated using the Geant4 transportmodel and digitization. Further-more, a complete track recon-struction was performed usinga conformal mapping algorithmfor track finding and GEANE fortrack matching. Figure 1 de-picts E/p for pions and electronswhere E is the deposited en-ergy in the EMC and p the ab-solute momentum reconstructedfrom the STT. Figure 2 repre-sents the receiver operating char-acteristics (ROC) derived from amulti-dimensional density esti-mator (kNN) based on p and E/p.The ROC curve shows the corre-lation between the detection effi-ciency of electrons and the pion-background rejection. Informa-tion from other detectors will beincluded in the near future aswell. Furthermore, the analy-sis will be carried out for thecomplete momentum range up to15 GeV/c.

Figure1 : A simulated distri-bution of E/p for electrons (blue)and pions (red). Electrons arestopped in the EMC, depositingcomplete energy, whereas pionspunch through the EMC, leavingonly a fraction of their energy.

A shower analysis for the electro-magneticcalorimeter of PANDA

40

C. Geldmann and J.G. Messchendorp

A receiver operatingcharacterics analy-sis using the EMCof PANDA. The curvequantifies the sepa-ration power betweenphotons and neutralpions.

In this project we have stud-ied overlapping electromagneticshowers based on simulateddata from the electromagneticcalorimeter (EMC) of PANDA. Ouraim was to classify events byfinding methods which are ableto distinguish between single-and multi-particle induced elec-tromagnetic showers. For thispurpose, the response of the EMCfor photons and neutral pions hasbeen simulated using the Pan-daRoot framework. In the firststep of the analysis, electromag-netic showers have been investi-gated by visualizing the data fromthe EMC. In this process, we ob-tained insight in the energy dis-tributions and shower shapes of(merged) clusters in the EMC formomenta up to 10 GeV/c. Threedifferent methods have been usedand evaluated to identify the par-ticle type by analyzing the electro-magnetic showers in the EMC. Inthe first approach, the kinematicsof a pion decay were exploited inan algorithm that calculates theinvariant mass of the event andcompares this with the actualpion mass. This method makesuse of so-called “bump recogni-tion” techniques to identify twooverlapping showers in a mergedcluster. For relatively lower mo-menta, this method was useful toidentify two photons of a pion de-cay, albeit a time-consuming al-gorithm. Another powerful ob-servable we have found, was theratio of the energy deposited inthe central crystal of a clus-ter and the total measured clus-ter energy. This parameter hasshown a similar efficiency forlower momenta, but is also appli-cable at higher momenta. Com-parable separation power for theenergy range between 10 MeVand 10 GeV was also obtained

by exploring so-called cluster mo-ment functions [1]. The clus-ter moment functions can beused to quantify the informationabout the shape of electromag-netic showers. For this work,the 2nd lateral cluster momentwas implemented. It uses energy-weighted distances of calorimetercells from the shower axis to esti-mate a lateral shower profile. Fig-ure 1 depicts the 2nd lateral clus-ter moment response for pion-and photon events from the sim-ulated EMC data. The efficiencyof all methods has been stud-ied by means of a ROC-analysis(receiver operating characteristic)[2], which is illustrated in Fig. 2.In addition to this, a combinationof the different techniques hasbeen investigated. A combinationof these parameters is advanta-geous, since the various observ-ables for the pion-photon separa-tion discussed here are partly in-dependent.

Figure1 : The 2nd lateral clustermoment for neutral pions (red) andphotons (blue).

[2] https://twiki.cern.ch/twiki/bin/-view/Atlas/ClusterMoments.

[3] T. Fawcett, Pattern Recogni-tion Letters, 27, 861 (2006).

Simulations of the EXL detection systemfor studies with exotic nuclei

41

H. Moeini and N. Kalantar-Nayestanaki

Fig. A : EXL Recoiland Gamma Array.For the sake of clar-ity, only three rowsof crystals for the for-ward/backward partof the calorimeter areshown here.

The objective of the EXL project isto capitalize on light-ion inducedreactions in inverse kinematicsby using novel storage ring tech-niques and a universal detectorsystem. The overall design for therecoil and γ-ray detector for EXLis divided into two major arrays,namely the EXL Silicon ParticleArray (ESPA) for low energy par-ticles, and the EXL Gamma andParticle Array (EGPA) which actsas a calorimeter. The simulationsfor the EGPA were started by tak-ing over the previous work donefor the ESPA [1]. Based on theongoing R&D for the individualcrystals and because of synergywith R3B, we started to make theEXL calorimeter with the samegeometry for the individual crys-tals (right rectangular prismoids)as in the R3B calorimeter. Forthe EXL, we arranged the crystalsin a clusterized way along η- andψ-direction (Fig. A) and came upwith 12504 and 1758 crystals forthe forward and backward EGPA,respectively.In order to have a comprehen-sive survey on the effect of theUHV shell on the resolutions, the

simulations were done for shellsmade of Aluminum, Kapton, andDuplex Stainless Steel with thick-nesses of 0.1, 0.5, and 1 mm (Fig-ure 1). A comparison of the simu-lations results for the overall res-olution shows that Duplex Stain-less Steel may not be a good can-didate; the resolution consider-ably worsens at low thrown pro-ton energies. Nevertheless, itshould be mentioned that what-ever material is chosen for theultimate UHV shell, one shouldconsider that for the energy re-gion of 10 to 20 MeV after punch-through energy, the shell is themost crucial.The full geometry of the major de-tector elements of EXL was com-pleted by integrating the alreadydesigned magnetic spectrometerelements [2] as well as imple-menting the forward scintillatorarrays (preceded by iron convert-ers) into the main code.

[1] A. Zalite and L. Zalite, privatecommunication.

[2] M. Mahjour-Shafiei, privatecommunication.

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Figure1 : Energy resolution for thrown protons towards region A(placed around 85 in LAB and depicted in red in Fig. A) in the EXLrecoil setup in the absence of shell (plus signs), with a shell of thick-ness 0.1 mm (empty triangles), 0.5 mm (full triangles) and 1 mm (fullsquares) made of Duplex Stainless Steel, Kapton and Aluminum.

Design studies for the backward endcapEMC of PANDA

42

A. Biegun, J.G. Messchendorp, H. Lohner, H. Smit

Two of the proposedgeometries for thebackward endcapEMC of PANDA. Three-dimensional views ofA) straight and B) tiltedcrystal arrangementsare shown.

The KVI is involved in the designof the Electromagnetic Calorime-ter (EMC) of PANDA [1]. The EMCwill consist of a forward endcap(FwEndCap), a backward end-cap (BwEndCap), and a Barrel.With this coverage the completephase space is available whichis mandatory for precision spec-troscopy of charmonium statesand exotic hadrons in the char-monium region.Various geometries for theBwEndCap have been pro-posed [2] and are currently be-ing evaluated to check the effec-tive angular coverage at back-ward directions and to optimizethe energy and spatial resolu-tions, especially at the edges ofthe detector. Three different ge-ometries have been implementedinto the simulation and the anal-ysis computing framework forPANDA, called PandaRoot [3], andtested for the performance. Twoof them make use of straight crys-tals with different sizes, namely20x20 mm2 and 26x26 mm2, andthe third one uses tilted crystalswith a shape and a size identi-cal to that of the FwEndCap. Ineach of the geometries the lengthof crystals is 200 mm.The response for photons withdifferent incident energies dis-tributed homogeneously withinthe angular range of θ=150-174

and φ=0-360 has been simu-lated. The total deposited energysummed over all crystals in theBwEndCap taking into accountthe electronic response of EMCcrystals was compared to the in-cident photon energy. The en-ergy resolution, defined as the fullwidth at half maximum (FWHM)with respect to the mean de-posited photon energy, is de-picted in figure 1 for two geome-tries. The energy resolution of theBwEndCap varies from about 1%

for high energy photons, >3 GeV,up to 7% for low energy photons,<300 MeV.

Figure1 : The energy resolutionas a function of incident photonenergy and angle for A) straightand B) tilted crystals (see also sidepanel).

In general, the simulations pre-dict rather similar resolutions forthe straight and tilted geometriesin the core of the detection area.However, strong differences arefound at the outer edge of the de-tector, θ ≈ 150. In the straightgeometry the number of crystalrings with bad resolution (>10%)doubles. At 150 and for ener-gies above 1 GeV the resolutionincreases from 7% to 10% for thestraight geometry. Here, the tiltedcrystals show clearly a better per-formance in energy resolution.Further studies of the positionresolution and the influence ofthe material placed in front of theBwEndCap detector will be per-formed.

[1] www-panda.gsi.de

[2] H. Lohner, H. Smit, this vol-ume, p. 43.

[3] fairroot.gsi.de

Options for the backward endcapelectromagnetic calorimeter for PANDA

43

H. Lohner, H.A.J. Smit

The components of thePANDA electromagneticcalorimeter: the back-ward endcap, the bar-rel, and the forwardendcap electromagneticcalorimeter, with thebeam going from left toright.

The goal of anti-proton proton an-nihilation studies in the PANDAspectrometer at the new FAIR fa-cility at Darmstadt is to inves-tigate charm-meson states andexotic mesons containig strongglue components. For a uniqueassignment of quantum num-bers to newly identified states apartial-wave analysis is manda-tory, based on measurements ofcomplete angular distributions.This requires an almost completecoverage of the full solid angleby the electromagnetic calorime-ter (EMC). For the TDR of thePANDA EMC [1] the options fora design of the backward end-cap EMC have been investigated.Lead tungstate, PbWO4 (PWO),will be applied as scintillator ma-terial with typical crystal sizes asdefined for the barrel and forwardendcap EMC.

Figure1 : Acceptance of thePANDA backward endcap EMC.

At polar angles above 135 the ex-pected differential rates per crys-tal are about 1 kHz per 20 MeV atenergies of 50 MeV. The maxiumenergy deposition is about 200MeV. The design concept of theforward endcap has been appliedalso for the backward endcapEMC. This approach simplifiesthe mechanical construction ofcrystals and submodules and the

application of photosensors andreadout electronics. The angularacceptance (figure 1) is limited bythe space available inside the tar-get spectrometer. The maximumopening diameter is 920 mm. Theinner hole of 200 mm diameter isdetermined by the beam pipe anda safe distance to prevent distur-bance from beam halo. This de-fines the maximum polar angle of169.7. The tilting of the crys-tals due to the off-pointing projec-tive geometry, oriented towards apoint 200 mm farther than thetarget, determines the minimumpolar angle of 151.4. Therefore,this design leaves a gap of 11.4

to the maxiumum coverage of thebarrel reaching up to 140.Alternative designs have been in-vestigated like the use of straightcrystals. In this case a coveragefrom 169.7 upto 144.6 couldbe achieved which minimizes thecoverage gap to 4.6. However,at the extreme non-perpendicularangle of incidence the photonshower will only partially be col-lected which results in reducedenergy resolution. In a compro-mising approach, the exact geom-etry of the forward endcap EMCcrystals has been studied. In thiscase the angle of incidence re-mains close to perpendicular, butthe coverage will reach only until146. The advantages of the var-ious designs in terms of energyresolution have been studied in aseparate contribution to this re-port [2].

[1] TDR for PANDA EMC,F.-H. Heinsius et al.(H. Lohner) eds., ThePANDA Collaboration, e-Print: arXiv:0810.1216v1[physics.ins-det].

[2] A. Biegun et al. this volume,p. 42.

Design of the forward endcapelectromagnetic calorimeter for PANDA

44

H. Lohner, R. Bergsma, A. Glazenborg-Kluttig, W.W.P. Olthuis, H.A.J. Smit,A. de Vries

The barrel (left, cutto get a better viewto the inside) and theforward endcap part(right) of the electromag-netic calorimeter. Dis-played are the PWOcrystals with the carbonfiber alveole packs, thesupport feet connectingto the support beam,held by the supportrings at front and back.On the right side theforward endcap crys-tals inside the carbonfiber packs are shownalong with the insula-tion (shown transpar-ent) and the eight sup-porting structures onthe outside.

The PANDA collaboration (an-tiProton ANnihilations at DArm-stadt) presently develops a multi-purpose detector for tracking,calorimetry and particle identifi-cation in search for as yet undis-covered charm-meson states andmesons containing a strong gluecomponent. The ElectromagneticCalorimeter (EMC) of PANDAcomprises of the central tar-get calorimeter, read out bylarge-area avalanche photodiodesand the forward endcap EMC,read out by vacuum phototriodes.Lead tungstate, PbWO4 (PWO), avery compact and radiation hardcrystal, has been chosen as thescintillator material.

Figure1 : Alveole test setup.

In the course of 2008 after ap-proval of the Technical DesignReport for the PANDA EMC [1],the major design criteria of theforward endcap EMC were fixedincluding the dimensions of theindividual crystals and the over-all dimensions of the insulatedcontainment. With these criteriaat hand, the collaboration placedthe order for all the 3600 crys-tals foreseen for the forward end-cap EMC. The side figure showsthe integration in front of the tar-get calorimeter. After details ofthe laminated structure of thesolenoid were known, a conceptfor the support structure of theforward endcap EMC inside the

solenoid was developed.The crystals are arranged in sub-modules of 16 crystals each,mounted in thin Carbon fibercontainers (alveoles). A com-plete prototype of four submod-ules including all parts neededfor mounting dummy “crystals”made from brass has been fab-ricated at KVI. This prototypewas used for examining the wrap-ping and loading procedure witha weight of 16 kg of dummy “crys-tals”, practicing the gluing of alu-minum holders to the alveoles,and finally mounting the sub-module to the mounting plate.Particular effort was taken to as-sure the stability of the alveoles.A weight of 450 kg was put on topof a loaded and mounted alveolebefore it started to break. Thisresults in a safety factor of 28.However, the stability was testedin much finer detail as the neigh-boring submodules are attachedto the mounting plate with smalldistances of maximum 1 mmand the submodules should notmove or sag under the weightof the crystals by more than 0.1mm. Long-term stability testswere performed with 5 alveolesover periods of four weeks witha reading accuracy of 0.005 mm(figure 1 shows the arrangementof measurement gauges). Thealveoles sag by 0.03 mm withinfour days and then maintain theirposition within the reading accu-racy during the test period of sev-eral weeks.

[1] Technical Design Reportfor PANDA ElectromagneticCalorimeter, F.-H. Heinsiuset al. (H. Lohner) eds.,The PANDA Collaboration,e-Print: arXiv:0810.1216v1[physics.ins-det].

Characteristics of a cryogenic ion guide

45

M. Ranjan, P. Dendooven, H.A.J. Smit, D.J.M. Tilman, H. Timersma, I. Moore1,H. Penttila1, A. Saastamoinen1, J. Aysto1, W.R. Plass2,3, C. Scheidenberger2,3,A. Popov4; 1University of Jyvaskyla; 2Justus Liebig University, Giessen; 3GSI,Darmstadt; 4Petersburg Nuclear Physics Institute, Russia

The cryogenic ion guideand its on-line installa-tion at the IGISOL facil-ity.

As a precursor to a cryogenicgas catcher for the Super Frag-ment Recoil Separator at FAIR, aliquid-nitrogen-cooled cryogenicion guide (CIG) was developedand characterized. A small ionguide stopping cell (stopping vol-ume about 30 mm long and10 mm diameter, exit-hole di-ameter 0.6 mm) was used tostop 340 MeV 58Ni ions from theJyvaskyla cyclotron. A tuneabledegrader foil thickness in frontof the ion guide allowed the op-timization of the stopping effi-ciency. The ion guide (yellow inthe sidebar figure) is attached tothe cold finger of a liquid nitro-gen dewar. The helium stoppinggas is cooled via a transfer linesubmerged in the liquid nitrogenand running through the middleof the cold finger. The expectedT1/2 temperature scaling of theamount of gas (g/s) flowing outof the ion guide for constant den-sity was confirmed. This scaling

relaxes the differential pumpingrequirements compared to roomtemperature operation or allowsan increased stopping gas den-sity for the same pumping sys-tem. The extracted ion beamintensity vs. mass number (fig-ure 1) shows the disappearanceof many contaminant beams atlow temperature, indicating theeffectiveness of stopping gas pu-rification due to cryogenic oper-ation. The extraction efficiencyof the 58Ni ions at a tempera-ture of 87 K is rather indepen-dent of pressure between 30 and185 mbar and quite constant upto an ionisation rate density ofthe stopping gas of ∼1014 /cm3/s.Final results await the comple-tion of the data analysis. It isclear that the cryogenic ion guideshows no obstacles to the useof high-density cryogenic heliumgas for the stopping and extrac-tion of high-energy ions.

Figure1 : Mass scan at room and low temperature. Many impuritybeams are not present at 87 K; beams of elements not yet frozen atthis temperature (noble gases, oxygen, nitrogen) persist. 4He+

2 is thedominant helium ion at low temperature.

A cryogenic gas catcher for high-energyradioactive ions: conceptual design

46

M. Ranjan, P. Dendooven, F.P. Schreuder, L. Slatius, I. Moore1, H. Penttila1,A. Saastamoinen1, J. Aysto1, W.R. Plass2,3, C. Scheidenberger2,3, H. Geissel2,3,H. Weick3, P. Thirolf4; 1University of Jyvaskyla; 2Justus Liebig University, Giessen;3GSI, Darmstadt; 4Ludwig Maximilians University, Munich

At the low-energy branch of theSuper Fragment Recoil Separa-tor (Super-FRS) facility at FAIR,studies of exotic isotopes using,among others, laser techniquesand ion traps are planned. An ioncatcher device will transform rel-ativistic ions from the Super-FRSinto a high-quality low-energy ionbeam. For this purpose, weare developing a cryogenic gascatcher.A conceptual design of such a gascatcher device is shown in fig-ure 1. The high-energy radioac-tive ions are stopped and ther-malized in helium gas. The de-vice will operate at low temper-ature (down to about 70 K), en-suring the high purity of the he-lium gas. This choice is based onour recent studies of ion trans-port inside a cryogenic gas cell[1,2] showing very good ion trans-port and survival efficiencies dueto the freezing out of the impuri-ties. Cryogenic operation also al-lows a wider choice of materialscompared to an ultra-high vac-uum compatible system.Based on the properties of theSuper-FRS, an areal weight of2 to 20 mg/cm2 of helium gasis required to stop the ions andan area 10 cm high and 25 cmwide should be covered. Follow-ing this, we propose to constructa gas cell of length 1 m with innerdiameter of 0.25 m. The gas flowthrough the small exit-hole (100to 500 cm3/s) is too slow for fastand efficient extraction of the ionsstopped throughout the volume ofthe cell (about 5 × 104 cm3). Wehave opted for a DC field through-out the length of the cell and anRF structure (cone or carpet) withDC field superimposed at the exitside to guide the ions towards theexit-hole without hitting the wall.A full RF wall along the length

could be added later if needed.As we aim for high-density op-eration (up to 1 bar room tem-perature equivalent pressure), weaim to push the limits of DC field(>100 V/cm) and RF force (am-plitude several 100 Vpp and elec-trode spacing 0.25 mm for a car-pet structure).

Figure1 : Conceptual design ofa cryogenic gas catcher for theSuper-FRS. The electrode structureis mounted inside the cryogenic in-ner cylinder which is sitting insidean outer, room temperature cylin-der with a thermal insulation vac-uum in between. The modular de-sign facilitates modifications, es-pecially in the electrode structure.Eventually increasing the lengthwill also be straightforward.

[1] P. Dendooven et al., NIM A558, 580 (2006).

[2] S. Purushothaman et al.,NIM B 266, 4488 (2008).

Design concept for a novel spectrometer atthe eA collider ELISE

47

G.P.A. Berg1, T. Adachi2, M. Couder1, M. Fujiwara2, M.N. Harakeh, N. Kalantar-Nayestanaki, I.A. Koop3, H. Simon4, L. Slatius, H. Wortche1) Dept. of Physics and Joint Inst. for Nucl. Astrophysics, Univ. of Notre Dame,U.S.A.2) RCNP, Osaka University, Japan3) Budker Institute for Nuclear Physics, Novosibirsk , Russian Federation4) GSI Helmholtzzentrum fur Schwerionenforschung, Darmstadt, Germany

Electron scattering is one of themost reliable tools to study nu-clear structure. In a uniqueway this tool will become avail-able for the investigation of ex-otic nuclei at the electron-ion col-lider at FAIR. The main instru-ment of the ELISe detector sys-tems is planned to be an elec-tron spectrometer that acceptsthe full reaction cone of the col-liding beams. Because of theshort lifetimes of the collidingion beams, the ELISe facility isbased on the colliding storagerings EAR and NESR for electronsand ions, respectively. This con-dition poses challenging aspectsto acceptance and the resolutionof the spectrometer. In addi-tion, small momentum transfersof about 0.05 GeV/c are required.This can only be achieved if thespectrometer can be operated atsmall angles which is also favor-able since the Mott cross section

increases at small angles.The present design is based ona concept by Koop and collab-orators who proposed to use apre-deflector dipole magnet. Thefigure shows a 3D rendering ofthe spectrometer. The electronbeam enters the pre-deflector andpasses through the centre beampipe. Electrons that have un-dergone an ion collision are bentby the dipole field and the wedgeshaped vacuum chamber in prin-ciple allow for acceptence of scat-tered electron on both sides of thebeam line. The analysing magnetsystem shown on the left consistsof a quadrupole, a hexapole anda vertical bending dipole magnet.By moving the analysing systemthe full angular range from about10 to 60 can be covered.At present extensive ion-opticalstudies are performed to optimizeand to finalize the spectrometersetup.

Figure1 : Schematic 3D-view of the ELISe spectrometer design.

Rate dependence of the PANDA ASIC anddiscrete preamplifiers

48

E. Guliyev, M. Kavatsyuk, P.J.J. Lemmens, H. Lohner, T.P. Poelman

Experimental setup em-ploying a cooled PWOcrystal, light pulser,Large Area APD, peam-plifier and samplingADC (SADC) readout.

The PANDA ElectromagneticCalorimeter (EMC) will employPbWO4 (PWO) scintillation crys-tals for the detection of high-energy photons, electrons andmesons. The EMC will be placedinside of the solenoid magnet.Since a high-intensity antiprotonbeam will be used on a fixed tar-get, the event-rate distributionin the EMC is not uniform. Av-erage event rates of 10 kHz areexpected in the barrel part of theEMC, increasing up to 100 kHzin the most forward region. Theforward endcap EMC will be ex-posed to event rates up to 500kHz. To provide a stable gain athigh rates and magnetic fields ofup to 2 T, large-area avalanchephoto-diodes (LAAPD) and vac-uum photo-triodes (VPT) will beused as photosensors for the bar-rel and the forward endcap EMC,respectively. For optimum signal-to-noise performance low-powerlow-noise preamplifiers were de-veloped: the discrete componentpreamplifier (LNP)[1] for the VPTand the ASIC APFEL II [2] for theLAAPD readout.The performance of the devel-oped front-end electronics hasbeen studied at different count-ing rates in order to observethe stability of the output pulseheight. To this end the ex-perimental setup (figure on theright side) was developed. Thetests were performed with LNPand ASIC preamplifiers coupledto LAAPD. The LAAPD was trig-gered by light pulses generatedby two LED pulsers. One of theLED pulsers was used as a ref-erence and was kept at a con-stant pulse rate of 1 kHz. Thefrequency of the other one wasvaried in rate up to 700 kHz.In a series of measurements thedetector response to the refer-ence LED pulser was measured,while changing the frequency of

the other pulser. The measuredresponse using both the LNP andthe ASIC preamplifiers is shownin figure 1 (upper panel).

05

10152025

0 100 200 300 400 500 600 700LED pulser frequency (kHz)

-2

0

2

4

Puls

e-he

ight

dev

iatio

n (%

)

Figure1 : Frequency depen-dent amplitude deviations for LNP(red line) and ASIC (black line)preamplifiers. Upper panel: “de-fault” configuration of preampli-fiers; Lower panel: with modifica-tions.

The observed frequency depen-dence of the amplitude is dueto the increased current at highrates which causes a slightchange of the actual bias volt-age and leads to a drop of theLAAPD gain. Another series ofmeasurements was done whenthe high-voltage was adjusted foreach level of counting rate in or-der to keep the LAAPD bias volt-age constant. This procedure al-lows to keep the pulse height con-stant (lower panel of figure 1).The final design of the preampli-fiers needs to include a stabiliza-tion of the actual bias voltage onthe LAAPD or requires accurateon-line monitoring. A simple wayof bias voltage stabilization is toreduce the resistance in the high-voltage filter. However, the impli-cations for stability against pick-up noise need to be studied.

[1] W. Erni, M. Steinacher, Univ.Basel, in PANDA TPR, Feb.2005.

[2] P. Wieczorek, H. Flemming,GSI report (2007) 30.

Timing performance of PANDA EMCpreamplifiers

49

M. Kavatsyuk, E. Guliyev, P.J.J. Lemmens, H. Lohner, T.P. Poelman

0 0.5 1Time (µs)

0

0.2

0.4

0.6

0.8

Sign

al le

vel (

V)

x10

x10

Figure 1 : The pulse-forms measured withLED light pulser afterdiscrete preamplifier(black solid line), ASICAPFEL II high gain (blueline) and low gain (redline) outputs. Signalshape obtained withdiscrete preamplifierand 2 A·GeV 6Li beam(black dashed line).

The PANDA experiment will ex-ploit antiproton-proton annihila-tions to study the spectrum ofcharm-hadron masses, and tosearch for predicted exotic hybridstates and glueballs. To this end,the experiment is designed to runat high luminosities up to 2 · 107

interactions/s in order to providesensitivity to rare decay chan-nels. In order to achieve cleanbackground conditions by ex-cellent event correlations amongthe various sub-detector systems,the time resolution for the elec-tromagnetic calorimeter (EMC)should be around 1 ns. Here,we investigate the achievable timeresolution.The EMC is designed for optimumenergy resolution. It employscooled PbWO4 scintillating crys-tals. The large area avalanchephoto diodes (LAAPD) and phototriodes were chosen as a photosensors for the barrel EMC andfor the forward endcap EMC, re-spectively, because of their abil-ity to operate in high magneticfields. To achieve the requireddynamic range of 104, low-noiselow-power preamplifiers were de-signed, namely the discrete com-ponent LNP [1] and ASIC APFELII [2] which will be employed inthe forward endcap and the bar-rel EMC, respectively. The ASIChas a built-in two-stage shaperand provides two outputs withhigh and low gains. The dis-crete preamplifier is a single-range resistor-reset type with de-cay constant of 25 µs. The deliv-ered signal shapes are comparedin figure 1. To extract energy andtime information, the EMC willemploy a sampling ADC (SADC)with optimized sampling rate andbit-resolution. This approachavoids analogue delays and elim-inates dead time of the read-outsystem as data will be processedon-line by a fast FPGA. The bit-

resolution is fixed by the require-ments of the energy resolutionand is about 12 bit. The samplingrate does not have an impact onthe energy resolution, howeverplays an important role in thetiming of detector signals. Theexact time-stamping algorithmswere developed and tested usinga LED pulser, cosmic rays, and2 A·GeV 6Li beam [3]. The LEDpulser provides two times bettertime resolution since the signalrise time for cosmic rays and ionbeam is ∼ 4 times longer (seefig. 1). This indicates that thetime-stamping method is not thelimiting factor. The signals weredigitized by a 16 bit 100 MHz SAD(Struck SIS3302). During theanalysis data were re-sampled tothe desired lower frequency forcomparison. To find the optimalsampling rate, the measurementswith ion beams were analyzed.For ∼ 180 MeV energy depositionthe time resolution is 1.2 ns forsampling rates of 100, 50 and25 MHz. However, at 25 MHzthe results are not stable againstsmall changes in analysis param-eters. Therefore, the frequency of50 MHz is proposed. The devel-oped algorithms are being imple-mented in FPGA. The present re-sults are based on measurementsusing a prototype PbWO4 crystaland will be repeated with produc-tion crystals. These results willfurther be verified with the proto-type of the EMC digitizer.

[1] W. Erni, M. Steinacher, Univ.Basel, in PANDA TechnicalProgress Report, Feb. 2005.

[2] P. Wieczorek, H. Flemming,GSI report (2007) 30.

[3] We thank the HypHI groupat GSI for the opportunity totest PbWO4 crystals with ionbeam.

Status of the EPICS implementation forNuSTAR controls

50

V.I. Stoica, M. Babai, N. Kalantar-Nayestanaki, C. Rigollet, P. Schakel, H.J. Wortche

In the framework of theFAIR/NUSTAR collaboration KVItook responsibility for experi-ment controls. Candidate sys-tem for the NuSTAR experimen-tal controls is the ExperimentalPhysics and Industrial ControlSystem (EPICS) [1]. EPICS is aset of Open Source software col-laboratively developed and usedworldwide to create distributedsoft real-time control systems forlarge scientific instruments suchas particle accelerators. Dis-tributed control systems typicallycomprise tens or even hundredsof computers, networked togetherto allow communication betweenthem and to provide control andfeedback of the various parts ofthe device from a central controlroom, or even remotely over theinternet.Despite the fact that EPICS isbroadly used it has its disad-vantages such as complexity anda rather steep learning curve.The requirements before having aworking EPICS system can chal-lenge even expert hardware pro-grammers. To be able to start,you will need to know how to in-stall the system properly, chooseand learn which client tools touse and to be able to create de-

vice support which mainly con-sists of an EPICS database andprotocols file, and all the inter-connections that need to be madebetween EPICS tools.To overcome those setbacks weorganised a three-days EPICStraining course in collaborationwith Rok Sabjan (Cosylab), aim-ing to learn how to set up anEPICS environment.To test our ability of EPICS han-dling, a driver and device sup-port was developed for an ISEGhigh voltage unit to allow controlof the device and enable the userwith several options needed in theconcept of self adjusting controlloops. The comunication betweenthe ISEG high voltage unit andcomputer is realised with the helpof a CAN to RS232 converter ora CAN to USB conector, thereforeit can be conected using both theserial or the USB port of the com-puter. A user interface was alsocreated which allows the user tocontrol the device in an easy andintuitive way (see figure 1).The software package was sub-mitted to the EPICS colaborationand added on the EPICS website[1].

[1] http://www.epics.org/

Figure1 : User interface for the ISEG High Voltage unit.

Status of self-sustained front-endcontrol loops

51

V.I. Stoica, M. Babai, N. Kalantar-Nayestanaki, C. Rigollet, P. Schakel, H.J. Wortche

The NuSTAR collaboration atFAIR comprises experiments em-ploying low-energy beams (HiS-pec, DeSpec, LaSpec, MATS),high-energy beams (R3B), as wellas experiments in the ring branch(EXL, ELISe, AIC). This implies ahuge number of active detectorchannels in which the user takesinterest. Not only the amountof channels sets the standards,but also stringent requirementsin terms of precision and dynam-ics. In order to achieve thesegoals we will need to implementspecific controls. At KVI we arefocusing on studying the feasibil-ity and the development of self-sustained control loops.The control chain starts with adetector read by an ADC whichis linked to a FPGA. The signalis digitized and several algorithmsare applied in order to obtain theparameters that we can changeautomatically in the supplies. Weare starting from a system formedby a TR board [1], a high volt-age unit and a detector. The goalis to be able to bring and keepthe detector in its optimal work-ing range. To achieve this we areimplementing several algorithms

that will compute incoming dataand react by modifying the con-trolled supplies of the loop (e.g.high voltage unit), based on thechanges in the signal parametersthat we have defined.One of the algorithms mentionedabove is a spectral auto calibra-tion routine that automaticallyidentifies the quality factor of aspectrum and submits changesto the software that controls thehigh voltage, raising or loweringthe voltage to obtain the best res-olution [2].We investigated EPICS as a tool inimplementing our control loops,however we observed that duringthe analysis steps, EPICS has totransmit large amounts of datathrough the IP-network and thatEPICS data transmission takesplace only if the value of a certainvariable is changed, this affectingstatistics. Therefore, we decidedto use DIM protocol and do theanalysis on a front-end processor.

[1] P. Schakel et al., this volume,p. 52.

[2] M. Babai et al., this volume,p. 53.

Figure1 : Schematic representation of a control loop

Spike rejection and noise-level triggeringfor scintillator detectors

52

P. Schakel, M. Babai, C. Rigollet, V.I. Stoica, H.J. Wortche

Scheme of the modularanalysis and data flow.

The front-end electronics for thenext generation of nuclear de-tectors will commonly feature apreamplifier, a high-speed sam-pling ADC, an FPGA and a micro-processor. Presently KVI is focus-ing on FPGA applications. Build-ing blocks of VHDL code havebeen developed for the real-timeanalysis of digitized signals gen-erated by nuclear detectors. Cen-tral to this is a baseline followerwhich corrects baseline fluctu-ations [1]. It consists of anIIR-filter which reconstructs thebaseline in the absence of a pulseand freezes otherwise.The baseline is subtracted fromthe signal and the resulting am-plitudes are tested to see whetherthey exceed an adjustable thresh-old. The resulting triggers indi-cate presence of a pulse and de-fine the timing of the sequence ofsubsequent analysis steps: pulseamplitude determination, timestamping, pulse/trigger ratio, thebaseline noise level and the ringbuffer for transferring the digi-tized waveform. Data transfer to

the microprocessor is handled onan internal bus and via an inter-face block. Control parametersare available for manual or auto-mated tuning by the microproces-sor.The trigger level of the pulse de-tector can be set to a fixed valueor can be dynamically correlatedto the actual noise level of thebaseline in units of the standarddeviation (kσ trigger). In addition,a minimum duration time for ex-ceeding the trigger level can bedefined to reject spikes. This isillustrated in Fig. 1.The VHDL code is tested witha setup consisting of a Gen-eral Purpose Trigger and Read-out Board (TRB) [2], A QuadADCboard (14 bits, 100 MHz, devel-oped by KVI) and various photo-multiplier detectors and radiationsources.

[1] J.H. Jungmann et al., KVIAnn. Rep. 2007, p. 54.

[2] W. Krzemien et al., GSI,http://arxiv.org/abs/0810.4723v1

Figure1 : Amplitude spectrum of a 137Cs source measured with NaIscintillator. The inlay shows the effect of the spike rejection for verysmall amplitudes.

A fast peak-finding algorithm foramplitude histogram analysis

53

M. Babai, P. Schakel, V. Stoica, C. Rigollet, H. Wortche

Figure 3: Preliminaryresults of the applica-tion of our peak find-ing algorithm on experi-mental data. Top: Fullwidth as a function ofvoltage. Bottom: FWHMas a function of voltage.Each color represents adifferent data set.

In this project we are focusingon the development of a fast,light weight algorithm for findingpeaks in amplitude histograms.The method is developed underthe assumption that the ampli-tude spectrum is due to the irra-diation of a detector with a cal-ibration source or a calibrationpulser, i.e. the sequence of rel-evant peaks is a priori known.Final goal is to embed the al-gorithm in a front-end runningself-calibration process. For thispurpose we are using system-atic data sets containing ampli-tude histograms for different highvoltage values and two differentsources, namely 137Cs and 60Co.A typical dataset for both sourcesis shown in figure 1.

Figure1 : Amplitude histogramfor Cs and Co measured at 800volt. y-axis: amplitude counts. x-axis: positions

Using this method we are inter-ested to select the relevant peaksof each histogram, in this casepeaks around 1100 and 600 keVfor 137Cs and 60Co respectively.Because the method can be verytime consuming and will be im-plemented on a local embeddedCPU, solutions including fittingprocedures and sliding windowbased methods have been ex-cluded. Rather, we have chosenan approach where the originaldata set is smoothed by using apseudo-Gaussian filter, which isdefined as a three times recur-sive application of a box filter to

original data with identical pa-rameters. Subsequently, the firstderivative (DS) is computed andsmoothed by a median filter oflength three. The resulting DSis used for locating the peak po-sitions by the zero-crossing. Asone can observe in figure 2, DScan contain a large number ofzero-crossings indicating the po-sition of all peaks. Because wewant to isolate the peaks with thehighest amplitude value, the sig-nal is scanned from left to rightand the first position exceed-ing a certain pre-defined thresh-old, is marked as the startingpoint. Starting from this chan-nel index the subsequent [(2 ∗(number of expected peaks)) + 1]zero-crossings are marked andlater on used to identify the po-sitions of the optima. An exam-ple of the results of these steps isshown in figure 2.

Figure2 : Ppos: the start and theend of the important region. Mpos:positions of the calibration peak.Qpos: positions used to computethe full width at half maximum(FWHM).

Preliminary results are shown infigure 3. One can observe thatin the case of the green line theFWHM goes through its optimum,which can indicate the optimaloperational voltage for the useddetector.

Calibration of a position-sensitivephotodiode using digital signal analysis

54

P. Lubberdink, M. Babai, C. Rigollet, P. Schakel, V.I. Stoica, H.J. Wortche

Ratio of summed frontamplitudes and backamplitude.

We have investigated the feasibil-ity of calibrating a position sen-sitive photo diode (PSP) [1]. ThePSP under investigation was aHamamatsu S5378-02, 300 µmthick. The basic material washighly resisting, high purity n-type silicon with an active areaof 45 mm × 45 mm. The frontof the PSP (anode, p-type) wasread out via 4 contacts arrangedin the corners, the back (cathode,n-type) by one contact. Pream-plifiers used in the experimentwere of the CSTA2 type, pro-vided by the Institute of NuclearPhysics, TU Darmstadt, standardinstrumentation for PSD readoutat GSI. The signals were fed intoa TRB board extended with a 100MHz, 14 bit QuadADC (for de-tails see [2]). For baseline cor-rection and for signal triggeringwe applied the baseline followerrunning on the on-board FPGA[3]. The difference of charges ex-tracted by the front contacts nor-malized by the total charge ex-tracted by the back contact yielda measure of the charge realize lo-cation, i.e. the penetration pointof a charged particle.The behavior of the diode hasbeen investigated with the ob-jective to develop an automaticcalibration procedure. Calibra-tion data have been taken byirradiating the PSP with sec-ondary beams generated by a 600MeV/nucleon 12C beam imping-ing on a 1 g/cm2 Pb target, withbeam intensities ranging from 1kHz to 50 kHz particles on tar-get. These measurements havebeen performed with the PSP lo-

cated downstream the ToF wall ofthe ALADIN setup at GSI. Alter-natively the PSP has been irra-diated by means of a mechanicalsupport which allowed controlledpositioning of a light fiber in frontof the PSP. This way, a well de-fined irradiation of the PSP hasbeen achieved on the which theautomatic gain matching and op-timal bias voltage setting rely.A strong correlation has been ob-served between front and backmeasured charge amplitudes, thecorrelation was found to be posi-tion dependent. Because both thefront and back signals are posi-tion dependent, no linear relationwith energy is available whichexcludes this specific choice ofelectronics for ∆E − E detec-tion. Among the problems ob-served were strong pulse shapevariations, a dependence of de-cay times on the amplitude andundershoot, possibly indicatingcross talk between the PSP andthe preamplifiers. Therefore, thereplacement of the preamplifiersshould be considered.However, the position depen-dence of the signal amplitudes issymmetric when the sum of thefront amplitudes is used for nor-malization, yielding a sensitivityfor central positioning monitor-ing.

[1] P. Lubberdink, Master The-sis, October 2008, Univer-sity of Groningen.

[2] P. Schakel et al., this volume,p. 52.

[3] J.H. Jungmann et al., KVIAnn. Rep. 2007, p. 54.

r-process studies with EXL

55

C. Rigollet

Chandra X-ray Imagesof supernova remnantCassiopeia A taken inDecember 2007. Credit:NASA/CXC/SAO/D.Patnaude et al.

Since the B2FH paper publishedin 1957 [1], in which the authorsoutlined the basic processes ofelement formation in stars, weknow that about half of the heavyelements, i.e. heavier than Iron,are formed by slow neutron cap-tures (s-process) along the val-ley of stability, while the otherhalf is produced by rapid neutroncaptures (r-process) towards theneutron dripline, and a tiny frac-tion by neutron and alpha pho-todisintegration (p-process) at theproton dripline.In the r-process, the nucleus isfaced with a high neutron fluxleading to rapid neutron cap-tures. The high temperatureassociated with the high neu-tron density environment pro-duces large numbers of high en-ergy γ-rays that instigate nu-clear photodesintegration. Thetime scale for both reactions ismuch shorter than the β-decaylifetime and the reactions cometo an equilibrium balance. Themaximum abundance along anisotopic chain occurs at a spe-cific neutron separation energySn. The r-process path connectsnuclei with the same Sn for differ-ent atomic numbers.At the so-called waiting point,(γ, n) reactions win over the neu-tron captures and the r-processstops temporarily waiting to β-decay to the next isotopic chain,where the equilibrium is restored.With temperatures and neutrondensities decreasing, the neutronto seed ratio drops and soon be-comes so small that the equilib-rium starts to fail and β-decay be-comes faster than neutron cap-tures (freeze-out). At this pointthe (n, γ) rates become signifi-cant and influence the shape ofthe abundance peaks and canwiden them. The key elements

of the r-process in terms of nu-clear physics quantities, are β-decay half-life, β-delayed neutronemission and (n, γ) cross sectionat freeze-out conditions.With the intense radioactive ionbeams delivered by the upcom-ing FAIR facility some unexploredareas of the r-process path willbecome accessible for the firsttime, notably around the closedneutron shells N=82 and 126.Whereas the mass and β-decayhalf-lives of the fragments (ions)can be readily measured in theactual ESR ring, neutron cap-ture cross sections (at freeze outconditions) are usually impracti-cal to measure directly. Moreover,knowledge of excited states andspectroscopic factors are impor-tant as input parameters in nu-cleosynthesis models. The latterquantities can be extracted fromthe one neutron transfer (d, p) re-action, whose cross section is re-lated to the (n, γ) one. In inversekinematics, this type of studiesrequires a high energy resolu-tion and high Z selectivity. Oneideal instrument for such mea-surements is the EXL target recoildetector, at present under devel-opment.To answer the questions posedby the r-process, it is not neces-sary nor possible to perform mea-surements for all unstable nu-clei involved in astrophysical sce-narios. The main goal is to es-tablish the general nuclear struc-ture trend evolving far from sta-bility. This knowledge will allowus to better understand one as-pect of the synthesis of heavy el-ements in the universe and pro-vide stronger constraints on themodels.

[1] Burbidge, Burbidge, Fowlerand Hoyle, Rev. Mod. Phys.29 (1957).

Status of the EXL demonstrator

56

C. Rigollet, H. Kiewiet, E.R. van der Graaf, N. Kalantar, M.F. Lindemulder,H. Timersma, A. de Vries

Vacuum chamber andmulti-port flange

In 2008 a proposal was acceptedby the KVI PAC requesting 2shifts to test the EXL demonstra-tor with a proton beam. Thedemonstrator comprises 2 dou-ble sided silicon strip detectors(DSSD) followed by 2 Lithiumdrifted Silicon (Si(Li)) enclosed invacuum (10−6 mbar). This stackof ∆E-E detectors represents akey element of the EXL SiliconParticle Array (ESPA) and theplanned in-beam tests a first steptowards the realisation of the fullrecoil detector at the NESR.The detectors are placed in avacuum chamber closed at theback by a flange, which holdsall necessary (UHV) feedthroughsto instrument the DSSDs (64x16and 64x64 strips) as well asboth Si(Li)s (8 pads each). Themulti-port flange (DN250CF) de-signed at KVI carries six smallerDN63CF flanges fitted with Sub-D 50 pin feedthroughs andsix DN16CF flanges for coaxialfeedthroughs and/or cooling ones(water Swagelock feedthroughs).This flange will be later on fittedonto the new ESR chamber on theexisting ring at GSI for further ex-periments.For the tests at the AGOR cy-clotron, the optimum beam en-ergy was determined with MCNPXsimulations. Proton energies of45, 50 and 55 MeV were sim-ulated through the AGORFIRMbeamline, from the aramica exitfoil of the accelerator to the en-trance foil of the vacuum cham-ber, with 60 cm of air between thetwo foils. The most important fac-tor of energy loss for the protonsis their passage through air. Theinitial proton energy is chosen sothat all protons are stopped in thelast Si(Li), allowing the full energy

reconstruction. At the same timeone would like to measure the en-ergy resolution of the DSSDs andtherefore the energy distributionafter the protons travel throughthe air should be as small as pos-sible. Choosing 50 MeV as theinitial beam energy gives an en-ergy spread (FWHM) of 185 keVat the first DSSD, a mean energyof 48.9 MeV, 48.2 MeV and 47.5MeV at the first DSSD, the sec-ond one and the first Si(Li), re-spectively.For this first test run, the DSSDsare instrumented by the Edin-burgh group’s electronics withtheir preamplifiers fixed insidethe chamber. The preamplifierswill be cooled using an ethanol re-circulating chiller. The Si(Li)s areoperated under a bias voltage of+800V in vacuum and will also becooled to improve the energy res-olution of the pads.For the run test, the chamber canbe placed at 55 cm of the exit foilof the accelerator (Figure 1). Dur-ing beam tuning, a thin scintil-lator paddle will be placed at thedownstream end of the harp, fol-lowed by a photo film to recordthe beam spot size and finally bya stopper.

Figure1 : AGORFIRM beamline,the demonstrator will be placed af-ter the harp.

Analyzing powers of the 1H(d,pp)n breakupreaction at 130 MeV

57

R. Sworst1), A. Biegun2), K. Bodek1), I. Ciepał1), N. Kalantar-Nayestanaki, M. Kis,St. Kistryn1), B. Kłos2), A. Kozela3), M. Mahjour-Shafiei, E. Stephan2), J. Zejma1),W. Zipper2); 1Jagiellonian Univ., Cracow, Poland; 2Univ. of Silesia, Katowice,Poland; 3Institute of Nuclear Physics Polish Academy of Sciences Cracow, Poland

Map of χ2/d.o.f. valuesfor Axy data comparedto N2LO (upper panel)and N3LO (lower panel)calculations; each smallsquare represents theresult for one kinemati-cal configuration.

Systematic comparison of the an-alyzing power data, measured forthe 1H(~d,pp)n breakup reaction at130 MeV, with the modern theo-retical calculations has been per-formed. High precision vectorAx, Ay and tensor Axx, Axy, Ayyanalyzing powers were evaluatedfor 81 kinematical configurations,in total over 800 data points foreach observable. These data areconfronted with results of rig-orous Faddeev-type calculationsperformed with the use of modernrealistic nucleon-nucleon poten-tials alone (2N) or combined withthe Tucsone-Melbourne three nu-cleon force model (2N+TM99), forthe potential generated within thechiral perturbation theory (ChPTN2LO and ChPT N3LO) as well asby the coupled-channel approachwith the explicit treatment of asingle ∆ isobar (CDB+∆) and withthe Coulomb interaction included(CDB+∆+C).In order to have a measure ofthe quality of the data descrip-tion provided by the models, χ2

values were calculated for eachobservable. The comparison wasperformed globally, for the wholeset of data points, and also forits various subsets. In the lattercase, the χ2 values were calcu-lated individually for each kine-matical configuration of the twoprotons, defined by the protonemission angles, or for bins in en-ergy of the relative motion of thetwo protons (see Fig. 1).For a majority of the studiedconfigurations results of all the-oretical predictions are consis-tent with each other and de-scribe experimental results quitewell. This means, in particular,that pure NN potentials are suffi-

cient to reproduce the analyzingpower data in a certain part ofthe phase space. In some regionsdiscrepancies have been observedfor tensor analyzing powers (c.f.Fig. 1) which, in contrast to thecross section data [1], are oftennot removed by inclusion of threenucleon force. This situation re-sembles the results obtained fortensor analyzing powers of theelastic dp scattering process [2]and indicates incompleteness ofthe present-day treatment of thethree nucleon system dynamics.

Figure1 : Quality of descriptionof two analyzing powers providedby various calculations, expressedin terms of χ2/d.o.f; for details seetext.

[1] St. Kistryn et al., Phys. Rev.C 72, 044006 (2005).

[2] E. Stephan et al., Phys. Rev.C 76, 057001 (2007).

Proton-deuteron break-up at 135 MeV

58

M. Eslami-Kalantari, N. Kalantar-Nayestanaki, H. Mardanpour, and J.G. Messchen-dorp for the KVI, Crakow and Katowice collaboration

-0.4

-0.2

0.0

0.2

0.4

NNNN+TM’CDB+Prelim. results

(25 ,25 ,180 )

30 60 90 120 150

-0.4

-0.2

0.0

0.2

0.4

30 60 90 120 150

(25 ,25 ,40 )

(25 ,20 ,180 )

30 60 90 120 15030 60 90 120 150

(25 ,20 ,40 )

Ay

S[MeV]

Figure 2: Preliminaryanalyzing power datafor the same configura-tion as in Figure 1.

In the last few decades sev-eral semi-phenomenological two-nucleon models have becomeavailable, which describe two-nucleon scattering observablesvery accurately. Cross sectiondata for elastic proton-deuteronscattering show large disagree-ments between data and theo-retical predictions based on rig-orous Faddeev calculations, es-pecially in the angular rangewhere the cross section is atits minimum. Calculations withNN forces combined with 2π-exchange type 3NFs remove partof this discrepancy and lead toa better description of the mea-sured cross sections specially forenergies below 100 MeV/nucleon.However, the description of spinobservables is still not satisfac-tory [1].The break-up reaction allows asystematic study of 3NFs, therebyproviding a detailed insight in theabove-mentioned discrepancies.Predictions show that large 3NFeffects can be expected at specifickinematical regions in the break-up reaction. A systematic studyof the break-up reaction hasbeen started at KVI using SALADand the 4π detection systemBINA. Break-up cross sectionsand analyzing powers at ener-gies of 65 and 190 MeV/nucleonhave been published [2,3]. Herewe present measurements of thebreak-up cross sections and vec-tor analyzing powers for a pro-ton beam energy of 135 MeV. Pre-liminary results have been com-pared with state-of-the-art Fad-deev calculations. Figure 1 de-picts a fraction of the cross sec-tion data as a function of S,i.e. the energy correlation be-tween the two final-state pro-tons. The lines show the calcula-tions of the Bochum-Crakow andHanover theory groups, where the

blue lines represent calculationsusing a CD-Bonn two-nucleonpotential and the red lines showthe results based on the CD-BonnNN potential together with theTM’ 3NF. The green lines repre-sent the CD-Bonn NN potentialextended with the ∆ isobar. Forthis configuration and observablethe effect of a 3NF is predicted tobe small and the data are reason-ably well described by the calcu-lations. On the contrary, for thevector analyzing power, depictedin Figure 2, large discrepancieswith theory are observed at smallrelative energies between the twooutgoing protons.

89

10

2

3

456

89

10

2

3

456

NNNN+TM’CDB+Prelim.results

(25 ,25 ,180 )

30 60 90 120 150

2

3

456789

30 60 90 120 150

2

3

456789

(25 ,25 ,40 )

(25 ,20 ,180 )

30 60 90 120 15030 60 90 120 150

(25 ,20 ,40 )

d5/d

12d

S[b/

(sr2 M

eV)]

S[MeV]

Figure1 : Preliminary cross sec-tion data for the break-up reactionin comparison with predictions byrigorous Faddeev calculations.

[1] H. Mardanpour et al., Eur.Phys. J. A 31, 383 (2007).

[2] St. Kistryn et al., Phys. Rev.C 72, 044006 (2005).

[3] H. Mardanpour, PhD the-sis, University of Groningen(2008).

Deuteron-deuteron break-up at65 MeV/nucleon

59

A. Ramazani-Moghaddam-Arani, N. Kalantar-Nayestanaki, H. Mardanpour, andJ.G. Messchendorp, for the KVI, Cracow, Katowice, and IUCF collaboration onBINA

Energy [MeV]

En

erg

y [M

eV]

30405060708090

100110120

1020304050607080

All channels

30405060708090

100110120

1020304050607080

d + d "p + d" + n

30405060708090

100110120

1020304050607080

d + d "d + p" + n

20 40 60 80 100 1202030405060708090

100110120

01020304050607080

d + d p + n + p + n

Co

un

ts

Figure 2: The corre-lation between the en-ergy of two coincidencehits for the same con-figuration as presentedin Fig. 1. The TOFinformation was usedto uniquely identify thethree-body (middle-twopanels) and four-body(bottom panel) break-upchannels.

An experimental observation ofthe deuteron-deuteron scatteringprocess provides a rich databaseto study three-nucleon force ef-fects. These data will provide rig-orous tests of upcoming ab-initiocalculations for the four-nucleonsystems and, thereby, yield newinsights in three-nucleon force ef-fects.A deuteron-deuteron scatteringexperiment was performed atKVI in which a 65 MeV/nucleonpolarized deuteron beam ofdeuteron impinged on a liquid-deuterium target. Some of thefinal-state channels, namely theelastic, neutron- transfer, andbreak-up channels, have beenidentified. The break-up reactionhas a much larger phase spacethan reactions with two particlesin the final state and is thereforeattractive to study three-nucleonforce effects. The deuteron-deuteron scattering reaction hasa three-body, d+d→ p+d+n, anda four-body, d+ d→ p+ p+ n+ n,break-up final state. The BINAdetector system provides an ex-cellent particle identification (PID)via a measurement of the de-posited energies and the time-of-flight (TOF) of some of the final-state particles. With this, thevarious final-state channels havebeen identified uniquely.Figure 1 depicts the calibratedTOF difference between two coin-cident particles which were reg-istered in the forward scintil-lators of BINA. The spectrumwas obtained for a limited en-ergy and angular range of thetwo final-state particles. Threeclear peaks can be recognizedwhich correspond to proton-proton and proton-deuteron co-incidences. The identification ofthe peaks was confirmed usingthe ∆E-E response. Note that

the three-body break-up chan-nel, corresponding to proton-deuteron coincidences, can beseparated from the four-bodybreak-up reaction, correspond-ing to the proton-proton coinci-dences.

TDC_1 - TDC_2 [Channel]-30 -20 -10 0 10 20 30

Co

un

ts

0

20

40

60

80

100

pd

pp

dp

Figure1 : The TOF differencebetween two hits in the forwardscintillators of BINA. The spectrumwas obtained for a limited energyrange of a certain configuration(θp = θd = 25, |φp − φd| = 180).

Figure 2 represents the correla-tion between the deposited ener-gies of two particles which weredetected in coincidence in theforward BINA detectors with thesame kinematical configurationas for the events shown in Fig. 1.For the top panel, no TOF con-dition has been applied, result-ing in a mixture of three- andfour-body break-up events. ThePID information from the TOFdifferences was used to sepa-rate these two channels. Theresults are shown in the otherpanels of Fig. 2, respectively.The solid curve in the secondpanel represents the relativisticenergy correlation between pro-ton and deuteron for the three-body break-up channel. By mak-ing use of the PID and by an-alyzing the energy correlationsas presented in Fig. 2, exclu-sive cross sections and analyz-ing powers have been obtainedfor the three-body break-up reac-tion.

Four-body studies with polarized beam

60

C.D. Bailey1, E.J. Stephenson1, A.D. Bacher1, A.M. Micherdzinska2, J.G. Messchen-dorp, A. Biegun, M. Eslami-Kalantari, L. Jouleizadeh, N. Kalantar-Nayestanaki,H. Mardanpour, H. Moeini, A. Ramazani-Moghaddam-Arani, S.V. Schende,H. Wortche, E. Stephan3, St. Kistryn4, K. Sekiguchi5, A. Deltuva6, A. Fonseca6;1IUCF, USA; 2George Washington U., USA; 3University of Silesia, Poland;4Jagellonian University, Poland; 5RIKEN, Japan; 6University of Lisbon, Portugal

20 40 60 80 100 120 140-0.4

0.0

0.4

0.8

-0.5

-0.3

-0.1

0.1

0.3

0.5

0.03

0.05

0.07

0.10

θ c.m. (deg)

Ay

Ayy

σ(θ)

(m

b/sr

)

The cross section andanalyzing powers ford+d→p+t at 180 MeV.Errors shown are pointto point errors. System-atic error for the crosssection is 5.03%. Thesystematic error for Ayis 1.78%, and for Ayy is2.05%.

We are reporting final resultsfor measurements of d+d elasticscattering at 130 and 180 MeVand for measurements of thed+d→p+t reaction at 180 MeV.Both experiments used the po-larized deuteron beam from theAGOR cyclotron and the BBS forparticle detection. These data willbe used to evaluate new 4-bodytheoretical calculations. Mea-surements of d+p elastic scatter-ing made at the same time weredescribed in the previous AnnualReport.Beam polarization was deter-mined from d+p elastic scatteringat the In-Beam Polarimeter. Anal-ysis of events at the BBS involvedtrack reconstruction to determinethe scattering angle and the sub-traction of background from thecarbon portion of the CD2 tar-gets. Corrections were made fordead time and wire chamber in-efficiency. The data were dividedinto 1 bins. Peak sums for thevarious polarization states wereused to determine the differentialcross section and the vector (Ay)and tensor (Ayy) analyzing powerangular distributions. These dataare shown in the figures.At the smaller angles, the crosssection follows the trend of lowerenergy measurements [1] and isonly a function of the momentumtransfer. The vector analyzingpower is positive in response tothe NN spin-orbit potential. Someof the measurements show signif-

icant energy dependence that canbe used to test theory. Further-more, the d+d→p+t cross sectiondata demonstrates the expectedsymmetry about θc.m.=90 due tothe indistinguishability of the en-trance channel deuterons whenthey are unpolarized.

θ c.m. (deg)

Ay

Ayy

σ(θ)

(m

b/sr

)20 40 60 80 100 120

-0.6

-0.2

0.2

-0.2

0.0

0.2

0.4

0.1

1.0

10.

Figure1 : The cross section andanalyzing powers (Ay and Ayy) ford+d elastic scattering. Black di-amonds are 130 MeV, open trian-gles are 180 MeV. Errors shownon plot are point to point errors.Systematic errors for the cross sec-tions are 5% at both energies. Sys-tematic errors for Ay and Ayy are(1.3%, 1.8%) and (2.1%, 2.0%) for130 and 180 MeV, respectively.

[1] C. Alderliesten et al., Phy.Rev. 18, 2001 (1978).

Pionic fusion in light-ion systems

61

L. Joulaeizadeh, J.C.S. Bacelar, R. Caplar1, P. Dendooven, I. Gasparic1, H. Kiewiet,H. Lohner, H. Timersma; 1Ruder Boskovic Institute, Zagreb, Croatia

-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0

cos( c.m.

0

)

10-1

2

5

1

2

5

10

2

5

102

d/d

[nb/

sr]

6Li(

4He,

0)10

B*, KVI-data

4He(

3He,

0)7Be, KVI-data

4He(

3He,

0)7Be, cluster-model

Angular distributionof pionic fusion reac-tion cross section atsub-threshold ener-gies. Full and emptycircles are the resultsof the KVI experimentsfor the 6Li(4He,π0)10B∗

and 4He(3He,π0)7Bereactions, respectively.The solid blue curve isthe calculated resultobtained using thecluster model wavefunction of 7Be for the4He(3He,π0)7Be reaction[3]. The dashed greencurve is the result ofthe polynomial fit tothe 4He(3He,π0)7Beexperimental result.The solid black curveis the fitted result tothe 6Li(4He,π0)10B∗

experimental data.

In order to study the role ofpions in the nuclear interac-tion, two pionic fusion experi-ments have been performed us-ing the AGOR accelerator facilityat KVI [1,2]. Pionic fusion is ahighly coherent process in whichtwo nuclei fuse to a united nu-cleus and the available centre-of-mass energy is emitted in thepion channel. The examined re-actions were 4He(3He,π0)7Be and6Li(4He,π0)10B∗ and both reac-tions were performed at beam en-ergies about 10 MeV above thecoherent pion production thresh-old. We identified the reactionby measuring the fused systemin the magnetic spectrometer andthe produced neutral pions in thePlastic Ball detection system withlarge acceptance.In case of the 6Li(4He,π0)10B∗ re-action, the reconstructed invari-ant mass of photon pairs from π0

decay is shown in figure 1. Thesolid and dashed curves are theresults of the measurement andthe Monte-Carlo simulation, re-spectively. A very good agreementis observed giving a high confi-dence in the data reconstruction.In order to provide sensitivity tothe full dynamics and relevantprocesses involved in the pionicfusion reaction, almost the fullangular distributions of neutralpions have been measured (fulland empty circles in figure 2). Aphenomenological description ofthe angular distribution

(dσ

dΩ)c.m =

i∑n=0

anPn(cosθc.m), (1)

where Pn(cosθc.m) and θc.m arethe Legendre Polynomials and thecentre-of-mass angle of π0, re-spectively, has been fitted to theexperimental results. The polyno-

mial fit with i=3 to the experimen-tal results reproduces the samebehaviour of the angular distri-bution predicted by the clustermodel for the 4He(3He,π0)7Be re-action [3]. This result confirmsthe importance of the cluster-ing correlations for both reac-tions. By integration of the fit-ted curves the total cross sec-tion of 11.84 ± 1.18 nb and 61.25 ±2.31 nb for the 6Li(4He,π0)10B∗ and4He(3He,π0)7Be reactions, respec-tively, were obtained. The massdependence of the total cross sec-tion is in agreement with the ex-trapolated results of the existingmodels for these reaction [3,4].

0

5

10

0 50 100 150 200

Cou

nts

M [MeV]γγ

γo

50 < θ <160,lab

o

Figure1 : The measured (solidcurve) and simulated (dashedcurve) two photon invariant massdistribution.

[1] L. Joulaeizadeh et al., AIPconf. proc., 475 (2008);ISBN: 978-0-7354-0490-8.

[2] L. Joulaeizadeh et al., Int. J.Mod. Phys. A, (2008) (sub-mitted).

[3] T. Kajino et al., Phys. Rev. C,35, 1370 (1987).

[4] A. Volya et al., Phys. Rev. C,52, 305 (1999).

Study of the pygmy dipole resonance in94Mo with the (α, α′γ) method

62

J. Endres1), D. Savran2), P. Butler3), M.N. Harakeh, N. Pietralla2), M. Scheck3),V.I. Stoica, H.J. Wortche, and A. Zilges1)

1Institut fur Kernphysik, Universitat zu Koln, Germany2Institut fur Kernphysik, TU Darmstadt, Germany3Department of Physics, University of Liverpool, United KingdomSupported by the DFG (ZI 510/4.1 and SFB 634) and EURONS

In the last years we have starteda systematic study of the PygmyDipole Resonance (PDR) in semi-magic nuclei at the BBS using the(α, α′γ) reaction. At an incidentenergy of 136 MeV the scatteredα-particles and γ-decays are de-tected in coincidence using theBBS and an array of High Pu-rity Germanium (HPGe) detec-tors. This high resolution coin-cidence method has been turnedout to be a powerful tool tostudy the PDR below the neu-tron threshold even in nuclei withrather high level density [1].With 138Ba, 140Ce and 124Sn twoN = 82 isotones and one Z =50 isotope have been investigatedwith the (α, α′γ) reaction and con-fronted to results from NuclearResonance Fluorescence (NRF)experiments [2]. The compari-son revealed a remarkable differ-ence. Up to about 6 MeV nearlyall 1− states known from NRF ex-periments are also observed inthe (α, α′γ) reaction. In contrastthe higher lying states in the en-ergy region 6-8 MeV are com-pletely missing or are stronglysuppressed in the α-scatteringexperiments. This abrupt changeof response is a clear sign for astructural difference between thetwo groups of 1− states. There-fore, the PDR seems to be split-ted up into two parts with differ-ent structures which is not obvi-ous in recent microscopic calcu-lations.In December 2008 we investi-gated for the first time a non-magic nucleus and performeda (α, α′γ) experiment on 94Mo.

Seven large volume germaniumdetectors were placed as close aspossible to the scattering cham-ber in front of the BBS at differentangles with respect to the beamaxis. The different positions al-low a determination of the α-γ an-gular correlation and by this anassignment of the multipole char-acter of the observed transitions.Due to the coincident measure-ment the excitation energy andthe γ-decay energy the selectionof the decay channels is possible.

0

10

20

coun

ts2000 3000 4000 5000 6000 7000

Energy [keV]

0

10

20

30

coun

ts

= 102

= 229

Figure1 : Ground state decayspectra observed in (α, α′γ) for agermanium detector at 102o (upperpart) and 229o(lower part).Because the 1− states of inter-est decay predominantly to theground state a selection of thedecays into the ground state isa very effective filter to separatethe PDR from other excitations inthe same energy region. Figure 1shows the spectra of two germa-nium detectors where the decaysinto the ground state are selected.The analysis of the 94Mo(α, α′γ)experiment is still in progress.

[1] http://www.bnl.gov/edm/.

[2] F.J.M. Farley et al., Phys.Rev. Lett. 93, 052001(2004).

Astro Particle Physics

63

The KVI astroparticle physics program 66Ultra-high cosmic rays and neutrino observations with WSRT 67Detection of ultra-high energy cosmic rays with LOFAR 68Coherent bremsstrahlung radiation for cosmic ray inducedair showers 69Simulation of a realistic air shower detector 70Radio waves emitted from ultra-high energy cosmic raysimpinging on the Moon 71Photosensors for KM3NeT optical module 72Development of the MAXIMA stations 73Multi-station trigger for MAXIMA 74Smart trigger for radio detection of cosmic rays 75

The KVI astroparticle physics program

64

A.M. van den Berg, M.H.H. Broekroelofs, E.D. Fraenkel, S. Harmsma, F. Haverkort,N. Kalantar-Nayestanaki, O. Kavatsyuk, H. Lohner, R. Meyhandan, F. Poortenga,O. Scholten, K. Singh, G. van der Steenhoven, S. ter Veen, A.R. van Vliet, K.D. deVries

Artist impression ofGamma-Ray Burster070714B which is apossible source forextermely high-energyparticles. Credit:NASA/Dana Berry

We focus on the detection ofthe highest energy particles inthe cosmos, using the ANTARESunder-water neutrino telescopein the Mediterranean Sea, theWesterbork Synthesis Radio Tele-scope in the Netherlands, andthe Pierre Auger Observatory inArgentina. At the same time,we contribute to developments fornew observatories: LOFAR in theNetherlands, and KM3NeT alsoin the Mediterranean Sea. Thisresearch has been organized inthe Netherlands at a nationallevel and we work closely togetherwith groups in Amsterdam (FOMinstitute Nikhef), and Nijmegen(IMAPP of the Radboud Univer-sity).

ANTARES and KM3NeT

On 29 May 2008 the last ofthe fully instrumented detectorlines of the ANTARES deep-seaneutrino telescope was connectedto its data-acquisition station onshore at La Seyne-sur-Mer inFrance. Since then ANTAREScovers an effective volume of 5·107

m3 and it is the largest neutrinotelescope in the northern hemi-sphere. The telescope is usedto hunt for high-energy neutri-nos from galactic or extra-galacticsources produced in cosmic ac-celeration processes or by cos-mic rays, accelerated beyond theGZK threshold. In addition, thedetection of neutrinos originatingfrom the annihilation of possibleweakly-interaction massive parti-cles will be studied. Our contri-bution has focused on the R&Dfor the optical sensor for the suc-cessor of ANTARES, the KM3NeTfor which substantial funding atthe national level has been allo-cated at the end of 2008.

Pierre Auger Observatory

The last surface detector stationof this observatory was deployedon 13 June 2008, completing itsbaseline detectors. The collabo-ration is producing many results,ranging from the flux spectrumof observed cosmic particles, andlimits on the τ-neutrino and theγ-ray fluxes. For the secondyear in a row the results of thePierre Auger Collaboration havebeen marked by the IAP and theAPS as one of the top ten physicsstories of the year. At the KVI wecontribute through the theoreti-cal and experimental R&D pro-gram initiated for the construc-tion of a large radio antenna ar-ray suited for the observation ofcosmic rays by detecting elec-tromagnetic pulses in the radio-frequency band.

WSRT and LOFAR

The Westerbork Synthesis RadioTelescope (WSRT) and the LO-FAR are two observatories in theNetherlands operated for radio-astronomical surveys. With theNuMoon project initiated by KVIthese observatories are and willbe used as well for the hunt ofcosmic particles which hit thesurface of the moon. The im-pact and the subsequent parti-cle shower which develops in thelunar regolith causes the emis-sion of weak signals in the radio-frequency band. For high enoughenergies these signals can be de-tected with both types of tele-scopes. At the KVI we perform thesensitivity calculations, processdata obtained with the WSRT andmake simulations for the LOFARobservatory.

Ultra-high energy cosmic rays andneutrino observations with WSRT

65

K. Singh 1, S. Buitink 2, O. Scholten 1, H. Falcke 2, B. Stappers 3, R. G. Storm 4,1 RUG; 2 RU; 3 UvM, 4 ASTRON

Neutrino flux limit es-tablished by WSRTwith 20 hours of data

Askaryan predicted that the par-ticle showers in dense mediasuch as lunar regolith producecoherent pulses of microwaveCherenkov radiation. At wave-lengths comparable to the sizeof the shower, the emission be-comes nearly isotropic whichmakes the detection of the pulseefficient [1].

Currently, observations with theWesterbork Synthesis Radio Tele-scope (WSRT) are taking place.We use two beams of 4 bandseach of 20 MHz to cover one thirdof the visible lunar surface. Re-moval of RFI and ionospheric de-dispersion is performed as an in-tial step of the data processing.

Triggering is performed on powerintegrated over 5 consecutivetime samples (P5) normalised tothe average power for each po-larisation. The peak search isperformed in all 4 bands. In ad-

dition, width cuts are applied tocut pulses that are wider than 12,10 or 8 bins. The detection effi-ciency for pulses in the data anal-ysis is found by adding pulsesat random location with randomphases to a real data sample. Thedetection threshold is defined asthe sum over the P5 values in 4bands. It is clear from Fig. 1 thatthe detection efficiency saturatesat higher signal strength.

The highest value of the thresholdfor which no pulses are seen in a20 hrs observation is 60 in unitsof system noise. The neutrinoflux limit is obtained based onthis detection threshold, which isan order of magnitude lower thanthe current FORTE limit [2].

[1] O. Scholten et al., Astropart.Phys. 26, 219 (2006).

[2] O. Scholten et al., ARENAproceedings, (2008).

Figure1 : Detection efficiency against pulse strength

Detection of ultra-high energy cosmic rayswith LOFAR

66

K. Singh 1, O. Scholten 1, S. Buitink 2, H. Falcke 2, A. Horneffer 2, L. Bahren 2

1 RUG; 2 RU

The low flux of Ultra High En-ergy (1021eV) Cosmic Rays (UHE-CRs) calls for detectors of largedetection area with high duty cy-cle and our strategy is to use theMoon. Our strategy here is tosearch for short radio pulses thatare emitted when a UHE cosmicray impacts on the lunar surface.The induced particle shower inthe lunar regolith emits a coher-ent electromagnetic pulse that ispowerful enough to be detectedat Earth. Sensitive radio tele-scopes such as LOFAR (Low Fre-quency Array) and WSRT (West-erbork Radio Telescope) are ob-serving at lower frequencies andhave sufficient sensitivity to de-tect UHECRs [1].

Currently, LOFAR (Low Fre-quency Array) is planned for 36antenna fields (stations) in theNetherlands in which 18 stationsare in the central core within thearea of 2 km diameter. In ad-dition to these, 8 stations areplanned in other European coun-

tries. Simulations for flux lim-its are performed to find the op-timal operation made of the LO-FAR antenna system. The extrap-olation of flux spectra observedat higher energies by the PierreAuger Observatory (PAO) shouldbe measurable [2]. The sensitiv-ity of LOFAR observations is plot-ted in color in Fig. 1 when an-tennas of all core stations will bephased towards the Moon coher-ently. However, sensitivity will in-crease and hence lower down theenergy threshold if remote sta-tions and European stations (E-LOFAR) will also be configuredcoherently, which is plotted inblue colour. The steepest fittedcurve to PAO data in high ener-gies corresponds to spectral index4.4, and it is evident from Fig. 1that it should indeed measurablewithin observing time of 1 year.

[1] O. Scholten et al., Astropart.Phys. 26, 219 (2006).

[2] K. Singh et al., ECRS Pro-ceedings (2008).

Figure1 : Detection limits on cosmic rays with LOFAR for differentobserving times and configurations.

Coherent bremsstrahlung radiation forcosmic ray induced air showers

67

K.D. de Vries, O. Scholten

5 10 2 5 102

2

(MHz)

10-1

2

5

1

2

5

10

2

5

102

Ey(

V/m

/Mhz

)

Egeo

Efull

Emd

EDip

ECx

EBr

Br

Cx

The frequency spectrafor the y componentfor the different sub-leading contributions tothe electric field. Themain, geomagnetic,contribution is polar-ized in the y directionand is also given, to-gether with the full fieldgiven by adding up alldifferent contributions.

When a cosmic ray (CR) entersthe Earth’s atmosphere, an Ex-tensive Air Shower (EAS) is in-duced. A cascade of particlescomes toward the Earth with ap-proximately the speed of light.Due to the high velocity of the pri-mary particle, all secundaries willmove close to each other. Thiscan be visualized as a pancake ofparticles flying toward the Earth.The deflection of electrons andpositrons due to the Earth’s mag-netic field can macroscopically bedescribed by a net current trav-eling toward the Earth’s surface.Since the total amount of par-ticles within the shower front isnot constant over time, the totalcurrent changes. This time vari-ation, in combination with retar-dation effects, causes an electricpulse to be emitted in the radiofrequency range.Since the total number of parti-cles is not constant over time, wehave to take into account the ra-diation emitted during the accel-eration and deceleration of theseparticles. The bremsstrahlungcontribution from the dipolecharge distribution is calculatedto be small. However, as shownby Askaryan [1], there will be

a net charge excess due to theknock out of electrons from heav-ier elements of about 20%. Thenet variation of this co-movingcharge excess current is shown togive a significant bremsstrahlungcontribution.Calculations have been per-formed in the far field Fraunhoferlimit, r ∼= R − ~eR · ~ξ, assumingthat the distance from the centerof the air shower to the observer,R, pointing in the ~eR direction,is large compared to the aver-age distance between the electronand positron ξ. A sudden deceler-ation is considered. The calcula-tion shows a similar contributionfor the co-moving charge excessas for the bremsstrahlung chargeexcess of about 30% with respectto the leading component due tocoherent geomagnetic radiation.The xy-polarization for the chargeexcess components and the geo-magnetic radiation is given in fig-ure [1]. With this correction thepolarization of the electric fielddepends on the observer position.

[1] G. A. Askaryan, Zh. Eksp.Teor. Fiz. 41, 616(1961)[Soviet Physics JETP 14,441 (1962)].

Figure1 : Polarization of the electric field for the charge excess con-tribution and the geomagnetic contribution in the xy direction for dif-ferent observer positions, a distance d from the impact point.

Simulation of a realisticair shower detector

68

E.D. Fraenkel, S. Harmsma, K.D. de Vries

A simple parametriza-tion can be made to de-scribe an inclined airshower. With zenith an-gle θ, for an observerplaced a distance dfrom the impact point.

The detection of cosmic rays hasbeen widely explored in recentyears at the Pierre Auger observa-tory. Several events have alreadybeen measured with the use ofradio antennas. A macroscopicmodel has been developed to de-scribe the electric pulse from anair shower [1]. To obtain realis-tic simulations for the observedpulse, this model has been ex-tended for a realistic geometry. Aparametrization has been madeto obtain pulses for an arbitraryshower in an arbitrary magneticfield for different observer posi-tion, see side figure.To compare simulations with themeasured signal, antenna char-acteristics and noise have to beadded into the simulated pulse.With the use of RDAS [2], afirst comparison has been madebetween a measured signal andsimulations. This is done for areal event measured at the ob-servatory, where the geometry isknown from detection by sur-face detectors. The RDAS sim-ulation program is used to addnoise to the simulated pulse toobtain a comparison with themeasured data. A different ap-proach has been made by includ-ing the phase shifts of the severalcomponents of the antenna setupwith the use of a circuit simula-tor. This gives a good comparisonfor the envelope of the measuredpulse and the simulated pulse,see figure [1].

Figure1 : A simulated radio pulseafter including phase shifts. At thetop the simulated field is given, inthe center the field is given after in-cluding phase shifts, at the bottomthe measured pulse is given.

In the future simulations will beextended to obtain more realis-tic comparison between measure-ment and theory.

[1] Olaf Scholten, Klaus Werner,and Febdian Rusydi, As-tropart. Phys. 29, 2008, 94.

[2] Stefan Fliescher, forthe Auger Collaboration,arXiv:0811.1893 [astro-ph],Nov 2008.

Radio waves emitted from ultra-highenergy cosmic rays impinging on the Moon

69

Sander ter Veen, Stijn Buitink1, Olaf Scholten, Kalpana Singh.1 Radboud University, Nijmegen

10-1

1 10 102

103

104

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WSRT 40.8 hours

LOFAR 1 month

SKA 1 week

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eV]

E3

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NM-h-limitSat Feb 07 200923:55:22

Flux limit for for Ultra-high energy cosmicrays as determinedfrom the recent obser-vations with the WSRTand flux limits thatcan be observed withLOFAR and SKA. Thedata are from the PierreAuger Observatory [1].

When ultra-high energy cosmicrays impinge on the moon theycreate a particle shower in the re-golith close to the surface. Be-cause of the large interactioncross section, cosmic ray inducedshowers develop at the surfaceand their average depth is thusof the order of their length orless. For the NuMoon observa-tions we are interested in radiowaves with a wave length of thesame size as the shower length.It thus needs to be investigated iffor these shallow showers there isa critical depth for which the pic-ture of Cherenkov emission andbreaking of waves at the lunarsurface applies.To be able to estimate the effectof shower depth on the emittedradio waves we have investigatedthe emission from a showers atvarying depth below the surface.We have used a geometry wherethe shower is taken parallel to thesurface. For this simplified geom-etry we have calculated the emis-sion of radio waves through a re-fracting surface. We find that atlarge distances from the moon theintensity does not depend on thedepth of the shower. In a future

paper we will report on the detailsof this work and give an interpre-tation of this, at first sight, sur-prising result.On the basis of the above the re-sults of the recent observationsat the Westerbork Synthesis Ra-dio Telescope (WSRT) can alsobe interpreted in terms of a fluxlimit on Cosmic rays. The analy-sis of 40 hours gives rise to thelimit indicated by the thick redcurve in the figure. For com-parison the data measured at thePierre Auger Observatory [1] aregiven. The presently determinedflux limit is thus well above whatcould be expected. The grey bandindicates an E−3 extrapolation ofthe present data. Future obser-vations at LOFAR will be sensitiveto much lower fluxes and lowerenergies. With the Square Kilo-meter Array (SKA) we will be ableto see cosmic ray impacts on themoon. The sensitivity limits areindicated for observations in twofrequency bands.

[1] J. Abraham et al. [PierreAuger Collaboration], Phys.Rev. Lett. 101, 061101(2008).

Photosensors for the KM3NeToptical module

70

O. Kavatsyuk, H. Kiewiet, H. Lohner

Concept of a KM3NeToptical module with 303-inch photomultipliertubes.

The ANTARES underwater neu-trino telescope, fully operationalsince May 2008, covers a sensi-tive surface of ≈0.05 km2. Al-though being the largest neu-trino detector viewing the Galac-tic Center, an efficient searchfor high-energy neutrinos origi-nating from galactic and extra-galactic sources requires a de-tector of km3 size which is cur-rently being developed [1]. In or-der to improve the rejection of en-vironmental background and toincrease the sensitivity to ultra-high energy neutrinos, a new op-tical module [2] with an arrange-ment of several small photo mul-tiplier tubes (PMT’s) is a promis-ing alternative to a single 10-inchPMT. The advantages of smallPMT’s are the directional sensitiv-ity (see figure on the right), higherquantum efficiency (QE) >30%,smaller transit time spread andbetter two-photon separation ca-pability [3].The Photonis 3-inch PMT XP53X2was selected and further devel-oped in gain performance. Theproperties of single PMT sam-ples have been investigated at KVIwith emphasis on high QE at lowdark noise. Due to thermionicand secondary emission a typ-ical decrease in dark noise bya factor of 2 for about 4.5 de-crease in temperature was ob-served. The use of a voltage dis-tribution (PMT-base) with a built-in preamplifier (Nikhef design) al-lowed to reduce heat dissipa-tion and electronic noise. Figure1 shows the charge distributionspectrum measured with an LEDpulser (black histogram) in a fastsampling ADC (Acqiris). The po-sition of the single-photoelectron(SPE) peak was determined andthe PMT gain was derived. FittingGaussian curves to the measuredcharge-distribution results in thegreen curve containing contribu-

tions from 1, 2 and 3 photo elec-trons (red curves). Operation oftubes at a gain of 106 provides agood peak-to-valley ratio of 2.7 to3 for different PMT samples.In order to determine the dark-noise rate above the 0.3 SPEthreshold (indicated by a verticalmagenta line in figure 1), a con-stant fraction discriminator (CFD)was used. In order to avoidcounting after-pulses, the widthof the CFD gate was set to 100ns. The results were confirmed bymeasuring the charge distribu-tion with a 10 kHz random trig-ger and determining the integralabove 0.3 SPE normalized to theAcqiris live time.

charge (pC)10 20 30 40 50 60

cou

nts

0

50

100

150

200

250 0.3SPE

P

V

Figure1 : Measured charge distri-bution.The observed dark-noise rates be-tween 5 and 25 kHz (at 20C ) fordifferent tested PMT samples cor-respond to dark currents of 0.8 to4.0 nA which are lower than spec-ified in the factory test sheets.Currently, a setup for measure-ments of the photo-cathode ho-mogeneity is being calibrated. Itwill allow precise 2D scanningof the photo-cathode sensitivityfor PMT’s with a newly developedcurved window matched to thecurvature of the OM glass sphere.

[1] KM3NeT Conceptual DesignReport, www.km3net.org/CDR/CDR-KM3NeT.pdf.

[2] P. Kooijman, NIM A 567, 508(2006).

[3] H. Lohner, A. Mjøs, NIM A49222, 10.1016/j.nima.2008.12.037.

Development of the MAXIMA stations

71

J. Coppensa), H. Falckea), E.D. Fraenkel, S. Harmsma, J. Horandela) S.J.de Jonga), P.J.J. Lemmens, R. Meyhandan, I. Smid, H. Schoorlemmera), F.P.Schreuder, R. Terol, C.W.J. Timmermansb), A.M. van den Berg, J. Vorenholt, forthe Pierre Auger Collaborationa) IMAPP, Radboud University, Nijmegen, The Netherlands.b) NIKHEF, Amsterdam, The Netherlands.

Working on MAXIMA

For the detection of radio sig-nals induced by ultra-high energycosmic-rays (i.e. E > 1017 eV),we are developing solitary sta-tions which are being deployedand commissioned at the south-ern site of the Pierre Auger Obser-vatory, located in Argentina. Afterthe very successful measurementcampaign last year [1], where weused stations connected directlyto a central data-acquisition sys-tem and a power system, we de-cided to construct solitary sta-tions which can be deployedwithin a range of 5 km from acentral DAQ system. In 2008,we deployed the first 4 stations,which are the stepping stonesfor the Multi-Antenna eXperimentIn Malargue Argentina (MAXIMA).They run on solar power, have awireless communication system,and a first-level trigger based ona streaming signal analysis pro-cedure. KVI has contributed tothe mechanics of the station, thepower harvesting and distribu-tion systems (48 V, 0.9 A, and180 Ah), the analog electronics(in particular the low-noise pre-and main amplifiers with a totalgain of 40 dB), the communica-tion system (based on commer-cial 5.6 GHz WiFi), and the event-building software [2]. Our part-ners in Nijmegen and Amsterdamcontributed through the fast digi-tal scope (200 megasamples s−1),the GPS timing (accuracy 3 ns),and the in-station software for lo-cal DAQ.After the assembly of the sta-tions in the pampas in Argentina,the commissioning phase started,

where we were faced with tech-nical problems, which have beenand are being solved. As thestations electronics is very closeto the sensor (i.e. the loga-rithmic periodic dipole antenna),any short pulses produced in ourelectronics lead to false triggersin the DAQ process. Sourcesfor such short pulses are mainlydigital electronics (i.e. in sta-tion CPU’s for the DAQ and wire-less communication), and DC-DCconverters. Measurements havebeen performed to identify thesesources and measures are beingtaken to reduce these spikes. Thewireless communication systemruns flawlessly with a very highstation to station throughput of22 Mbps in a meshed networkconfiguration.In the next measurement cam-paign starting in the spring of2009, we expect the whole sys-tem to be quiet enough (-70dBm/MHz in the frequency bandbetween 30 and 80 MHz), suchthat the dominant noise contribu-tion is the noise from the galacticcenter.In the meantime, we have initi-ated the formation of a consor-tium between industrial partners(SME’s) and research institutesto design and construct a nextgeneration wireless sensor, wherepower reduction and further sys-tem integration are the drivingforces.

[1] KVI Annual Report 2007,p. 61.

[2] S. Harmsma and A.M. vanden Berg, this volume, p. 72.

Multi-station trigger for MAXIMA

72

S. Harmsma and A.M. van den Berg, for the Pierre Auger Collaboration

The MAXIMA sta-tions in Argentinaare equipped withan outdoor wireless-communication device

One of KVI’s contributions to theMAXIMA detector array [1] is thedevelopment of a multi-stationtriggering system and the event-building software.

Due to the limitations of wire-less communication systems, itwill not be possible to transmitall triggered events to the centraldata-acquisition system when thenumber of stations in the ar-ray is large. Although we cur-rently have deployed only fourstations and the available band-width is large (54 Mbps nominal),we have already developed anintelligent system to reduce therequired bandwidth. This sys-tem is the multi-station trigger,which makes sure that data areonly transmitted when multiplestations have (coincident) data.This multi-station trigger makesthe detector system scalable to alarge array with many stations,and also allows for low-powerwireless communication with asmaller nominal bandwidth.

Figure1 : Solitary stations runsoftware that connects to the DAQserver over the wireless TCP/IPnetwork

The multi-station trigger hasbeen implemented by installing aserver at the central DAQ loca-tion. This server only acts pas-sively: it listens to the wirelessTCP/IP network for stations toconnect. Stations function asclients and connect to the serverby their own initiative. Afterall, the server doesn’t know howmany stations are operational ata certain time, as stations may

become unavailable due to emptybatteries or other problems. Thecentral philosophy of the arrayis that single stations may go’up’ or ’down’, while the rest ofthe stations and the central DAQserver remain functioning nor-mally. Stations will try to restorethe connection to the DAQ serverwhenever that is necessary.

Figure2 : Communication schemeof the multi-station trigger

To reduce the required band-width, we use the following stra-tegy. Whenever a local stationhas triggered and has some dataavailable, these data are writtento a buffer in its memory. It thenproceeds to send the GPS time-stamp belonging to the data tothe central DAQ server, indicatingthat is has data available at thespecified time. The server thenproceeds to compare the time-stamps from all stations for co-incidences in space and time. Ifsuch a coincidence is found, itwill contact the stations involvedand request the full data for theevent. If the station receives sucha data-request within 120 sec-onds, the full event is sent forstorage to disk. Otherwise, it willassume the central DAQ serverwas not interested and removethe data from the buffer to makespace for new events.

[1] J. Coppens et al., this vol-ume, p. 71.

Smart trigger for radio detectionof cosmic rays

73

E.D. Fraenkel, A.M. van den Berg for the Pierre Auger Collaboration, L.R.B.Schomakera)

a) AI Institute, Groningen University.

When a radio signal from a cos-mic air-shower reaches one of theMAXIMA antennas (see p. 71)this produces a signal (see Fig-ure 1) which is sent to a digitizingscope. Each antenna is equippedwith a Wi-Fi link to a centralhub where the digitized pulsesare stored (see p. 72). Since thesignal is digitized at a high rateof 200 to 400 MHz a continuousstream of samples to the centraldata acquisition (DAQ) system isimpossible.The scopes are thereforeequipped with a trigger mech-anism that responds to var-ious properties of the signal(such as threshold- and baseline-crossings). Whenever the condi-tions that could indicate a cosmicair-shower are satisfied, the timesamples of that moment are se-lected and sent to the DAQ.There is however some room forimprovement in the hardware aswell as in the software. The newscopes provided by NIKHEF havean ethernet connection and anon-board CPU which opens upopportunities for implementing aSmart Trigger.Research is being done on select-ing and classifying pulses fromthe data that have been gathereduntil now. A trigger based ontechniques from machine learn-ing and pattern classification iscurrently being developed.A non-linear predictor, a MultiLayer Perceptron [1], is trainedto predict the background noiseof the system. By comparingthe predicted value with the ac-tual value an error can be deter-mined. Any pulse, from a cos-mic ray but also man-made or at-mospheric, will cause a peak inthis error. Furthermore, one can

exploit the overall asymmetry ofthese pulses. A prediction is doneforward as well as backward intime. Then the product of thesetwo errors is taken (see Figure 2).

Figure1 : A cosmic ray inducedasymmetric pulse as measured byone of the MAXIMA antennas.

To lay the groundwork, an off-line analysis of the data usingthis method is prepared. Byusing the aforementioned predic-tor, time windows containing thepulses will be selected from thedata and then classified with aKohonen classifier [1]. An on-line trigger will be implemented,using the results from these tech-niques.

Figure2 : The product of the for-ward and backward error as afunction of time with the measuredsignal as a background.

[1] R.O. Duda, P.E. Hart, D.G.Stork (2001). Pattern Clas-sification. 2nd ed. Canada:Wiley-Interscience. p282-335, p576-579.

Life Inspired Physics

75

The life-inspired physics program 78Precise determination of 2-deoxy-D-ribose internal energiesafter keV proton collisions 79Plasmid DNA damage induced by carbon ions at Bragg-peakenergies 80Ionization and fragmentation of anthracene by interactionwith keV H+ and He2+ ions 81Ion-induced ionization and fragmentation of amino acids 82Optimizing timing resolution of TOF PET detectors basedon monolithic scintillators 83First experiments with LaBr3:Ce crystals coupled directly toSiPM sensors 84

The life-inspired physics program

76

Thomas Schlatholter

The program aims at a generalimprovement of the knowledge onthe interaction of ionizing radia-tion with biological systems. Theapplied goal of the program in col-laboration with UMCG is the im-provement of the therapeutic in-dex of cancer patients who havebeen treated using ionizing radi-ation. The KVI research com-bines complementary activities.On one hand, in radiobiologicalstudies and related fundamentalresearch on a molecular level, ex-periments utilize the wide rangeof ion energies available at theinstitute for studies on the bio-logical action of fast ions, slow

ions and X-rays. On the otherhand the KVI expertise in ac-celerator and ion-beam technol-ogy, detector physics and com-putational physics is applied totackle issues such as dose de-livery verification, fast scanningtechniques and improvement oftreatment planning on the basisof imaging data.Some results obtained in 2008are highlighted in the following.In an attempt to bridge the gapbetween studies on biomolecularradiation action and radiobiology,we have begun to investigate theinteraction of C ions at Braggpeak energies with plasmid DNA.

Figure1 : Alignment of the new reaction microscope.

Precise determination of 2-deoxy-D-riboseinternal energies after keV proton

collisions

77

F. Alvarado, J. Bernard1, L. Bin1, R. Bredy1, L. Chen1, R. Hoekstra, S. Martin1, andT. Schlatholter1Universite Lyon 1; CNRS; LASIM UMR 5579, 43 Boulevard du 11 Novembre 1918,F-69622 Villeurbannne, France

350 400 450 500 550 600

TOF 2

X Axis Title

TO

F 1

3 keV p+

The interaction of keV protonswith building blocks of DNA isof particular biological relevancein view of the increasing numberof facilities employing MeV pro-ton irradiation for tumor treat-ment. When the ions traverse tis-sue and are decelerated to MeVand sub-MeV energies, the so-called Bragg-peak is reached. Atthe ion energies in the Bragg-peak region the induced damageis highest due to maximum lin-ear energy transfer and relativebiological effectiveness. The vol-ume selectivity given by the ex-istence of such a well localizedBragg peak region renders pro-ton therapy such a promising toolfor cancer treatment. Further-more, biological consequences ofirradiation with energetic protonsfrom galactic cosmic rays and so-lar particle events are a limit-ing factor for human space explo-ration. This issue is of particu-lar importance for future mannedmissions outside low earth orbit,e.g. lunar or Mars missions.We have recently shown that ion-ization and fragmentation of 2-deoxy-D-ribose (dR) - a moleculefrom the DNA backbone - uponimpact of keV and sub-keV ionsmay be the dominant direct pro-cess in fast ion induced DNAdamage [1]. In these studies, themass spectrum of the fragmentions was found to largely follow apower-law distribution indicatinga statistical fragmentation pro-cess.In Lyon, we were able to study the

energetics of double electron cap-ture processes in keV proton col-lisions with dR: H+ + dR → H−

+ dR2+∗. By coincident measure-ment of the fragment times-of-flight and the proton energy loss,the excitation energy of the inter-mediate dR2+∗ complex could beassigned to the various dissocia-tion channels, e.g. for 3 keV pro-tons:C5H10O2

4++6.3 eV−→ CH+

3 + C2H3O++C2H4O3

C5H10O24++5.2 eV

−→ H3O+ + C2H3O++C3H4O2

C5H10O24++7.0 eV

−→ CH3O+ + C2H3O++C2H4O2

In line with the expectationsfrom the statistical fragmentationmodel, we observed a rather weakdependence of this excitation en-ergy on the fragment mass but astrong dependence on the kineticenergy of the incoming proton.The applied experimental tech-nique is expected to become anexcellent tool for future nanodosi-metric studies in the contextof biomolecular radiation dam-age. The limitation to projec-tile ions where the outgoing pro-jectile state is well defined willbecome less crucial for the in-vestigation of larger biomolecularclusters, e.g. water-solvated DNAoligomers, where the amount ofdeposited energy will be muchlarger.

[1] F. Alvarado et al., Chem.Phys. 8, 1922 (2006).

[2] F. Alvarado et al., Chem.Phys. 9, 1254 (2008).

Plasmid DNA damage induced by carbonions at Bragg-peak energies

78

H.M. Dang, M.J. van Goethem, R. Hoekstra, T. Schlatholter

Contrast enhanced im-age of a typical elec-trophoresis gel. (1): con-trol solution, (2-8) ir-radiated samples withdifferent dose (20 Gy,30 Gy, 45 Gy, 60Gy, and 90 Gy, re-spectively) and markedmolecular (M).

Proton and heavy ion therapy oftumors is becoming an estab-lished form of cancer treatmentwith facilities operational or un-der construction all over Europeand world-wide. Molecular mech-anisms underlying proton/heavyion induced radiation damage arethought to be of fundamentallydifferent quality than those ac-tive in conventional irradiation ofbiological tissue. One possibilityof studying ion induced radiationdamage on the molecular level isthe quantification of single anddouble strand breaks of plasmidDNA upon irradiation with car-bon ions at Bragg peak energies.pBR322, the first artificial plas-mid created in 1977, is a closedloop of double stranded DNA thatis natively supercoiled. Singlestrand breakage leads to DNA re-laxation to circular form whereasone or multiple double strandbreaks lead to formation of linearDNA or short linear fragments,respectively. The most straight-forward technique for quantifi-cation of the DNA damage isthus the separation of the dif-ferent conformations. A reli-able separation technique is gel-electrophoresis where the po-lar DNA molecules travel underthe influence of an electric fieldthrough a cross-linked polymer.The polymer porosity is chosensuch that the different DNA con-formations will travel with maxi-mum velocity spread. A fluores-cent marker tagged to the DNA al-lows identification of the differentconformations and quantificationof their relative yields.We have investigated the dam-age in water solvated plasmidDNA induced by 90 MeV/u C6+

ions slowed down to Bragg peakenergies as a function of dose(20 Gy to 120 Gy). The forma-tion of relaxed DNA (single strandbreak-ssb), linear fragments (lin-ear DNA-double strand break-dsb) and multiple double strandbreaks is obvious from the figureon the side, which displays firstresults from the gel electrophore-sis analysis. As can be seenfrom the figure, the supercoiledplasmid moves furthest, followedby linear molecules and finallynicked (open) circular molecules[1]. It is apparent that irradiationcauses marked changes to occurin the samples (fig. 1). The su-percoiled conformation decreaseswith dose whereas relaxed andlinear conformations stronlgy in-crease. The results representa proof of principle study. Atpresent it is difficult to give anaccurate description of the dam-age process. In the near future,we will study the damage pro-cess much more thoroughly byvariation of DNA concentration,dose rate, presence of solvationmedium and radical scavengers.

0 20 40 60 80 100

SSB DSB Super coiled

Frac

tion

DN

A (a

rb u

nits

)

Dose (Gy)

Figure1 : The changes in plasmidconformation due to Bragg peak C ir-radiation.

[1] C. Bailly et al., Methods Enzy-mol. 340, 610 (2001).

Ionization and fragmentation ofanthracene by interaction with

keV H+ and He2+ ions

79

J. Postma, S. Bari, H. Dost, P. Sobocinski, R. Hoekstra, I. Smid, and T. Schlatholter

0.0

0.2

0.4

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0.4

0.6

0.0

0.2

0.4

0.6

0 1 2 3 40.0

0.2

0.4

0.6

0 1 2 3 4

C5Hn

30 keV 40 keV

C1Hn

8 keV 20 keV

C2Hn

C3Hn

Rel

ativ

e yi

eld

C4Hn

C6Hn

C7Hn

C8Hn

n

CmH+n fragment yields

upon He2+ interactionswith Anthracene.

Many interstellar objects suchas HII regions, the interstel-lar medium and galaxies arefound to have strong IR emis-sions. Currently, so-calledPolycyclic Aromatic Hydrocarbon(PAHs) molecules, identified asthe carriers of these IR emissions,are the largest molecules knownto exist in interstellar space.Large numbers of PAHs are ob-served to be ejected from star richregions and galaxies, driven bydust winds and keV ionic shock-waves. They are very stable andtheir IR features serve as trackersfor many (kpc) interstellar phe-nomena. It is of great interestto astronomers to have a quan-tification of the dynamics, cross-sections and the subsequent ion-chemistry of PAHs upon keV ionicirradiation.

0 20 40 60 80 100 120 140 160 1800.0

0.8

1.6

2.4

33

34

84 86 88 90 92 94 96 98 100102

36 38 40 42 44 46 48 50 52 54

60 62 64 66 68 70 72 74 76 78

12 14 16 18 20 22 24 26 28 30

100 120 140 160

a)

e)d)

c)

C14H+10

H+

C+4

C+3

yiel

d (a

rbitr

ary

units

)

C+2

b)

+3H+2H

+H

+H+2H

C+8

C+7

+4H

+3H+2H+H

+4H

C+3

+H+2H

+3H

+4H C+4

+H+2H

+3H

+H

+4H

+3H+2H+H

C+6

+4H

+3H+2H

C+5

+4H

+3H+2H

+H

C+2

C+

+H +2H+3H

+H+2H

+3H

C12H+6

C10H+n

C8H+n

C9H+n

Figure1 : 30 keV He2+ on An-thracene

Figure 1 shows a general overviewof the dominant features of He2+

interactions with anthracene, arelatively small PAH.

Something we investigated inmore detail was the yield of frag-ments of the type CmH+

n .It is known that even numberedcarbon clusters C4, C6 and C8

form a polyyne structure withalternating bonds (·C≡C–C≡C–C≡C·) [1]. H atom addition toboth highly reactive ends of sucha chain leads to CmH2 forma-tion. Odd numbered clustershave a cumulenic bonding struc-ture (:C=C=C=C=C:) which is lessreactive and for which a smallerdegree of hydrogenation is ob-served.The figure on the side shows therelative yields of the CmH+

n frag-ments in collisions of anthracenewith He2+ ions of different kineticenergies.If the collision induced excita-tion of the anthracene moleculeis sufficiently high, the influenceof the initial molecular structureon the fragmentation dynamicsweakens.The measurements indicate thata picture of anthracene as ahot system upon interaction withkeV ions seems valid. Namelya polyyne structure seems pre-ferred in the CmH+

n fragmentsfor even m and for CmH+

n frag-ments with m odd, having a cu-mulenic bonding structure, in-deed a lesser degree hydrogena-tion is found.Currently we are attempting toextend the measurements to sub-keV energies to access an un-explored domain of astrophysicalphenomena in this area of re-search.

[1] H.W. Kroto, J.R. Heath,S.C. O’Brien, R.F. Curl, andR.E. Smalley. AstrophysicalJournal 314, 352 (1988).

Ion-induced ionization and fragmentationof amino acids

80

S. Bari, F. Alvarado, H. Dost, S. Eggens-Eeltink, R. Hoekstra, J. Postma, I. Smid,P. Sobocinski, and T. Schlatholter

Mass spectrum of prod-uct ions from 50 keVO5+ with glycine (top),alanine (middle) andvaline (bottom). Thedotted line indicatesthe respective parentcation.

In human cells, DNA is woundaround protein spools. Theseproteins are known to protect theDNA against indirect and to someextent even direct radiation dam-age. Research of radiation ac-tion upon amino acids, the build-ing blocks of proteins, is thus oneof the fundamental steps in un-derstanding biological radiationdamage.We investigate the interaction ofslow singly and multiply chargedions, like H+, Heq+ and O5+

with the amino acids glycine, ala-nine and valine. The ions ex-tracted from the ECRIS at KVIare pulsed and collide with thegaseous target evaporated froman oven. The collision prod-ucts are extracted by means ofa static electric field into a re-flectron time-of-flight spectrome-ter. The experiment can run insingles and coincidence mode.The main figure shows massspectra of positively chargedmass products from collisionswith 50 keV O5+ with all threeamino acids. It is obvious thatfor all three molecules extensivefragmentation is observed. Theparent peak, indicated with thedotted line, is small or almostnot visible. For all molecules, thedominant fragmentation processfor the single ionization chan-nel is found to be formation ofH+ fragment and loss of the car-boxyl group (COOH+). Forma-tion of H3

+ requires substantialrearrangement of the moleculeand seems to be a more generalphenomenon in fragmentation ofamino acids. Qualitatively, themass spectra resemble those ob-tained by electron and VUV pho-ton impact.

If the molecule is at least dou-bly ionized, two or more fragmentcations stemming from the samemolecular fragmentation eventcan be detected in coincidenceand more in depth information onthe fragmentation dynamics canbe obtained. From the resultingcorrelation plot (see Fig. 1) kineticenergies of fragment ions H+, C+,N+ and O+ are determined.

Figure1 : Correlation plot forH+C+, H+N+ and H+O+ ion pairsfrom 20 keV He2+ collisions withglycine. On the right, kinetic en-ergies are given for each fragmention in eV.

The observed energies are high-est for H+ (most probable kineticenergy: 5 eV) and O+ (maxi-mum kinetic energy: 7-8eV) andare very similar for the threemolecules under study. Theseenergies imply that ion induceddamage of proteins might pro-duce sufficiently energetic sec-ondary ions to induce furtherdamage to neighboring DNA.

Optimizing timing resolution of TOF PETdetectors based on monolithic scintillators

81

R. Vinke, F.J. Beekman1, H.T. van Dam1, P. Dendooven, H. Lohner, D.R. Schaart1,S. Seifert1; 1Technical University Delft, The Netherlands

Monte Carlo simula-tion of scintillationlight transport after a511 keV gamma photoninteraction inside amonolithic scintillationcrystal.

In the SciSiLiA project, a newPositron Emission Tomography(PET) detector concept is beingdeveloped: fast and bright mono-lithic scintillators (see side fig-ure) read out by novel, high-speed, semiconductor light sen-sors. The structure of these de-tectors promises improved spatialresolution whereas adding time-of-flight (TOF) capability signifi-cantly improves the image signal-to-noise ratio. The technology be-ing developed aims at enabling 5-minute PET scans and the detec-tion of lesions smaller than 5 mm,potentially opening up new PETapplications in e.g. brain imag-ing, cancer screening and radia-tion therapy planning.An advanced detector scanningsetup was constructed (figure 1).Using a highly collimated 511keV gamma beam, the detectorresponse as function of beamposition was recorded employ-ing computer-controlled trans-lation stages. Additionally,high-resolution TOF measure-ments were performed usinga high-speed waveform digitizerand specialized time-pickoff al-

gorithms. A statistics-basedMaximum Likelihood Estimation(MLE) algorithm was set up toreconstruct the 3D gamma pho-toconversion position inside thescintillation crystal. The ob-tained spatial resolution (FWHM)across the face of the crystalwas ∼2.7 mm; the depth-of-interaction resolution is ∼2.5 mmnear the photosensor and de-grades to ∼4 mm for events closeto the front surface of the crys-tal. Observed edge effects requirefurther investigation. A variablepropagation delay (time walk) ofthe scintillation light inside thecrystal was shown to depend ina rather complicated way on thegamma photoconversion positioninside the crystal. Calculationsshow that for large LaBr3:Ce3+

scintillation crystals, a significantimprovement in timing resolutioncan be expected when correctingfor this time walk effect.Details of this work are reportedin [1].

[1] R. Vinke et al., IEEE Nucl. Sci.Symp. Med. Imag. Conf.Record M06-207, Dresden(2008).

Figure1 : Experimental setup.

First experiments with LaBr3:Ce crystalscoupled directly to SiPM sensors

82

R. Vinke, F.J. Beekman1, H.T. van Dam1, P. Dendooven, H. Lohner, D.R. Schaart1,S. Seifert1; 1Technical University Delft, The Netherlands

Parts of the detector as-sembly.

LaBr3:Ce has high potential fortime-of-flight positron emissiontomography (TOF PET) becauseof its fast response (∼16 ns de-cay time) and high light yield(∼70,000 photons/MeV). To ben-efit optimally from these proper-ties, the scintillation light shouldbe read out with a fast and effi-cient photosensor. Silicon pho-tomultipliers (SiPM’s) are a verypromising candidate: they showhigh photon detection efficiency,high gain, very good pulse heightresolution and a fast responsewith small timing jitter. Fur-thermore, these devices operateat low bias voltage, their smalldimensions allow a compact me-chanical design, and their insen-sitivity to magnetic fields allowsoperation in a Magnetic Reso-nance Imaging environment.We have for the first time di-rectly coupled LaBr3:Ce scintilla-tion crystals to SiPM photosen-sors (see figure on the right).Two detectors consisting of a3×3×5 mm3 LaBr3:Ce crystalcoupled to a SiPM using a di-electric gel were constructed.The SiPM’s (Hamamatsu MPPCS10362-33-025C) had an activearea of 3×3 mm2 with 14400Geiger-mode avalanche photodi-odes (microcells) each having asize of 25×25 µm2. The crys-tal surfaces not coupled to theSiPM were covered with highly re-flective Spectralon material. Thedetectors were assembled in adry box to avoid deteriorationof the crystals due to humidity.The charge pulses of each SiPMwere converted by a shunt resis-tor into voltage pulses and sentthrough a high-bandwidth ampli-fier stage. A 22Na point sourcewas placed in between the twodetectors to provide coincidences

between 511 keV positron annihi-lation photons.The measurements were focusedon the timing performance. Withthis goal, the detector signalswere digitized at 8 GS/s and 10bit ADC resolution. Coincidencetiming spectra were constructedfrom the digitized pulses usingseveral timing algorithms. Thebest timing performance was ob-tained by applying constant frac-tion (CF) timing on a cubic splinesmoothed version of the pulses.The amount of smoothing as wellas the fraction of the ampli-tude used in the CF time pick-off were optimization parametersthat were varied to obtain thebest timing resolution. A coin-cidence timing resolution of 228ps FWHM (see figure 1) and anenergy resolution of 6.5% FWHMwere obtained. More details canbe found in [1].The results presented here showthe high potential for use inTOF-PET of detectors based onLaBr3:Ce and SiPM’s. In a nextstep we will combine a fast SiPMsensor array with a monolithicLaBr3:Ce crystal for simultane-ous optimization of spatial andtiming resolution.

Figure1 : Coincidence timingspectrum

[1] D.R. Schaart et al., IEEE Nucl.Sci. Symp. Med. Imag.Conf.Record M06-229, Dres-den (2008).

Theory

83

The KVI theory group 86Atomic parity violation in a single Radium ion 87Light shifts in Ba+ and Ra+ 88Ab-initio calculation of polarizabilities in Lithium 89Neutron radiative β-decay 90Coupled-channels description of φ-meson production 91Photoproduction of η mesons within a coupled-channelsK-matrix approach 92

The KVI theory group

84

Rob Timmermans

We are happy to report that inDecember of last year, Laura To-los joined our group on a Ros-alind Franklin fellowship. Shewill work on the physics ofstrangeness and charm relevant,for instance, for the PANDA ex-periments at the future FAIR fa-cility.In May, our postdoc Bijaya Sahoowas granted an NWO Veni fellow-ship. His research focuses on thecalculation of atomic propertiesusing relativistic coupled-clustertheory, an advanced many-bodymethod, and in particular on thestructure of the radium ion forthe atomic parity violation effortsat KVI.In 2008 two Ph.D. studentsjoined the theory group. In Au-gust, Daren Zhou started hiswork on strangeness produc-tion in antiproton-proton inter-actions. Jordy de Vries, whostarted in October, works on(time-reversal violating) electric-dipole moments in effective fieldtheory, in the framework of thenational FOM program.The proposal in the framework ofthe FOM projectruimte, entitled

”Lorentz invariance on trial in β-decay,” submitted by Gerco On-derwater and Rob Timmermanswas granted in November. Fund-ing was obtained for a Ph.D. stu-dent and a postdoc.As always, the theory group re-mains a popular place for stu-dents to do their bachelor or mas-ter project. Last year, five stu-dents graduated. Jordy de Vriesfinished his thesis on radiativeβ-decay. Krijn de Vries, whostayed on at KVI as a Ph.D.-student in cosmic-ray physics,wrote a thesis on extensive air-showers. Kaspar Schlebusch didresearch on the feasibility of pro-ducing polarized antiprotons andJan Smit on the seesaw mecha-nism for neutrinos. Wim Ottjesworked on the breaking of Lorentzinvariance in the muon g−2 ex-periment.Currently, Maarten Broekroelofs,Frank Haverkort, Martijn Re-icher, Auke Sijtema, and Ar-jen van Vliet are working ontheir master theses in the theorygroup.We are looking forward to excitingresults in 2009!

Figure1 : Portraits of Hendrik Antoon Lorentz (1916) by MensoKamerlingh Onnes, the brother of Heike, and of Albert Einstein(1920) by Harm Kamerlingh Onnes, his son. In the framework ofthe FOM projectruimte we will test Lorentz invariance, which is atthe basis of special relativity.

Atomic parity violation in asingle Radium ion

85

L. W. Wansbeek, B. K. Sahoo, K. Jungmann, R.G.E. Timmermans

The exchange of a Z0

boson between nuclearquarks and electrons.This exchange causesatomic parity violation.

The goal of the recently startedradium ion experiment at theKVI is to measure a low-energyvalue of the electroweak mixing orWeinberg angle (θW ), in order totest the Standard Model of parti-cle physics. The SM predicts that,due to radiative corrections, θWangle does not stay constant as afunction of the energy at which itis probed, the so-called runningof the Weinberg angle. A valueof θW will be found by measuringthe splitting between the two Zee-man m-levels of the ground stateof a single trapped and cooled ra-dium ion.Due to the exchange of Z0 bosonsbetween the quarks in the radiumnucleus and the electrons (seeFigure), all states acquire smalladmixtures of states of oppositeparity. In particular, the 7S1/2

ground state acquires a smallnP1/2 admixture. This effect iscalled atomic parity violation, orparity nonconservation (PNC). Asa consequence, the 7S1/2 → 6D3/2

transition in radium is no longerE1-forbidden, because there isnow a tiny E1PNC amplitude be-tween the P1/2 states admixedin the 7S1/2 and 6D3/2. Theinterference between the E1PNC

amplitude and the allowed E2quadrupole amplitude causes asmall m-level dependent lightshift of the ground state. By mea-suring this P -odd observable, in-formation about the size of weakcharge of the radium nucleus canbe extracted. From this, theWeinberg angle can be calculated[1].In order to find a reliable value forthe Weinberg angle, it is impor-tant to have a very accurate (sub-1% level) theoretical value for the

parity non-conserving amplitudeE1PNC in radium. At the mo-ment, this value is not availablein the literature. In fact, manyother properties of the radium ionwhich will be important for theexperiment, such as polarizabili-ties and the hyperfine interactionconstants, are unknown or notknown to any sufficient accuracy.We carried out a calculation ofE1PNC using relativistic couple-cluster theory. We found [2]

E1PNC = 46.4(1.4)×10−11iea0(−QW /N) .

By comparing the hyperfine in-teraction constants calculated byus and experimental values fromthe ISOLDE collaboration, we es-timate the current accuarcy ofour result to be about 3%. Inorder to achieve sub-1% accu-racy, we have to make several re-finements to our methods. Cur-rently, we are studying the ef-fect of the neutron skin on ourcalculation. Also, we are work-ing to incorporate the Breit in-teraction. Future projects in-clude vacuum polarization andother QED effects, and the im-provement of the coupled-clustermethod. Finally, since the AGORfacility can produce different ra-dium isotopes, we will look at thereduction of uncertainty causedby atomic theory that the study ofthese different isotopes can pro-vide.

[1] N. Fortson, Phys. Rev. Lett.70, 2383 (1993).

[2] L.W.Wansbeek, B. K. Sahoo,R. G. E. Timmermans, K.Jungmann et al., Phys. Rev.A 78, 050501(R) (2007).

Light shifts in Ba+ and Ra+

86

L.W. Wansbeek, B.K. Sahoo, K. Jungmann, R.G.E. Timmermans

500 1000 1500 2000−0.1

−0.05

0

0.05

0.1

λ [nm]

Ligh

tshi

ft [k

Hz/

mW

]

The light shift of the7S1/2 (blue) and 6D3/2

(thick red) levels of Ra+.We assumed a laser fo-cused on a spot size ofradius 50 µm.

Recently, both singly ionized bar-ium (Ba+) and radium (Ra+) havebeen proposed as candidates forparity non-conservation (PNC) ex-periments. These ions are alsosuitable for atomic clock exper-iments. Accurate determinationof the electric dipole (E1) matrixelements is essential in achiev-ing sub-one percent PNC ampli-tudes in the above ions. For Ba+

many experimental values for thematrix elements are available forcomparison to calculations, al-though they are not very accu-rate. For Ra+ no measurementsare available.As shown in [1], by far the largestcontribution to the PNC ampli-tude in Ra+ comes from theintermediate 7P1/2 state. Thisstate contributes around 111 %,while the second largest con-tribution, from the core orbital5P3/2, contributes less than 15%. This means that beingable to accurately calculate the〈7P1/2|D|6D3/2〉 in Ra+ (and thecorresponding 6P1/2 matrix ele-ment is Ba+) is especially desir-able. However, this matrix ele-ment is notoriously hard to cal-culate.It was suggested that a measure-ment of the ratio of the light shiftsof the 7S1/2 and 6D3/2 states ata well chosen wavelength couldhelp to increase the accuracy ofmany important matrix elements.A picture of these light shifts ofthe 7S1/2 and 6D3/2 states of Ra+

in shown in Figure 1. Last year,such a measurement was com-pleted for Ba+, at two differentwavelengths [2]. The authorsused the outcome of the measure-

ments to find

〈5D3/2|D|6P1/2〉 = 3.14(3),〈5D3/2|D|4F5/2〉 = 4.36(36),

where it is not clear what theytook for the initial values anduncertainties of the matrix ele-ments. Also, They did not elab-orate on how to extract the ma-trix elements and their uncertain-ties from the measurements. Wepropose to use the properties ofthe conditional normal distribu-tion for the interpretation. Usingthis method, we find

〈5D3/2|D|6P1/2〉 = 3.01(5)[2.97(6)],〈5D3/2|D|4F5/2〉 = 4.07(33)[4.0(5)],

with between the square brack-ets the initial values. Forthe important matrix element〈5D3/2|D|6P1/2〉, there is a 5% dif-ference between our result andthat of [2].Using our method, we can alsopredict what is the most informa-tive wavelength to perform a mea-surement of the lightshift ratiofor Ra+. A measurement at λ ≈500nm, could reduced the currentuncertainty of the 〈5D3/2|D|6P1/2〉element by about 25 %.

[1] L.W.Wansbeek, B. K. Sahoo,R. G. E. Timmermans, K.Jungmann et al., Phys. Rev.A 78, 050501(R) (2007).

[2] J.A. Sherman et al., Phys.Rev. A 78, 052514 (2008).

[3] B.K. Sahoo, L.W. Wansbeek,K. Jungmann, R.G.E. Tim-mermans, in preparation.

Ab-initio calculation of polarizabilitiesin Lithium

87

L. W. Wansbeek, B. K. Sahoo, R. G. E. Timmermans

Diagram used in thecoupled-cluster calcula-tion.

The scattering between ultracoldatoms is dominated by the long-range van der Waals interaction.Lithium (Li) is an interesting can-didate for ultracold atomic exper-iments since it possesses bothfermionic (6Li) and bosonic (7Li)isotopes.For the theoretical description ofsuch systems, a knowledge ofthe interatomic potential is nec-essary. The electrostatic partV (R) of this potential is given by

V (R) = −C6

R6− C8

R8+ · · · , (1)

where C6 and C8 are known asdispersion or van der Waals co-efficients. The van der Waals co-efficients can be calculated fromthe imaginary parts of the dy-namic dipole and quadrupole po-larizabilities.An often-used method to cal-culate the polarizabilities isthe sum-over-intermediate-states approach, which employsdipole/quadrupole matrix ele-ments and excitation energies ofimportant states. This method,however, is limited in its accu-racy because of the exclusion ofthe high lying states for compu-tational reasons. We have useda novel, ab initio, method to de-termine the static and dynamicpolarizabilities of atoms, withinthe framework of the relativisticcoupled-cluster (RCC) method.

Figure1 : The imaginary partof the dipole polarizability of theground state of Li as a function ofthe angular frequency.

We have applied this method tocalculate the polarizabilities andconsequently the van der Waalscoefficients of Li.We have calculated the aboveproperties for both the ground-states and the important excitedstates. The Figures show the re-sults for the imaginary part of thedynamic dipole and quadrupolepolarizability of the ground stateof Li. By putting ω = 0,the static polarizabilities can befound. The van der Waals coeffi-cients are obtained by integratingthese curves. We find

C6 = 1.396(6)× 103,

C8 = 0.8360× 105.

These results compare nicely tothose obtained by other groups.We hope to use this method in thefuture to perform ab initio calcu-lations of polarizabilities for heav-ier atoms. We also plan to extendthe method to other properties.

Figure2 : The imaginary part ofthe quadrupole polarizability of theground state of Li as a function ofthe angular frequency.

[1]L. W. Wansbeek, B. K. Sahoo,R. G. E. Timmermans, B.P. Das, and D. Mukherjee,Phys. Rev. A 78, 012515(2008).

Neutron radiative β-decay

88

J. de Vries, R.G.E. Timmermans

Figure 1: The photonpolarization as a func-tion of its energy.

Neutron and nuclear beta decayhave played an important role inthe understanding of weak inter-actions. It is an intuitively sim-ple process and if one ignoresany structure effects of the nu-cleons, the process is very sim-ilar to muon decay. This sim-ilarity is one of the reasons forthe universal (V−A)-theory. Inrecent years many experimentswere performed to test this the-ory and as the experiments be-come more precise, further testsbecome possible.To make precise predictions weneed to take both nucleon struc-ture and radiative correctionsinto account. In Ref. [1] theseeffects were investigated in radia-tive neutron beta decay, which isthe process where the outgoingcharged particles emit a photondue to bremsstrahlung,

n→ p+ e− + νe + γ.

They found that structure effectsonly play a role at the O(0.5%)-level, so these effects can safelybe ignored. This makes radia-tive neutron beta decay a suit-able candidate for studying theelectroweak part of the StandardModel (SM).In our project we calculated, ina relativistically covariant andgauge invariant way, the branch-ing ratio and photon polarizationof neutron and tritium radiativebeta decay. We can extend thecalculation to heavier elementsbut the results are less reliablesince structure effects start play-ing a role. The branching ra-tio we found for neutron radiativedecay fits with recent experimen-tal data. However, more accurateexperiments are needed since thecurrent experimental errors arebig. Up to now there is no data

on radiative tritium decay. Forthe calculation of the outgoingphoton polarization we used amethod that involves Stokes pa-rameters. We found that thephoton becomes completely left-handed only at maximum pho-ton energy which follows froma completely right-handed anti-neutrino and the absence of anyscalar and tensor interaction.We also investigated two founda-tions of the SM, i.e., maximumparity violation, and the vectoraxial vector structure of the weakinteraction. We inserted scalarand tensor interactions and cal-culated their effects. The new in-teractions change the branchingratios and polarization (Figure 1)of the photon. We also introduced(V+A)-interactions but found thatat the current experimental limitsthese effects are negligible. Newexperiments are needed to testthese predictions.On the theoretical side progresscan be made on several parts.For accuracy it is necessary toinclude Coulomb interactions be-tween the final state particles.This has already been done forlifetime calculations but is diffi-cult for branching ratio and po-larization predictions. Instead oflooking at beta decay it wouldbe interesting to look at electroncapture processes since these ex-periments can be performed withmore accuracy.

[1] V. Bernard, S. Gardner, U.Meissner, and C. Zhang,Phys. Lett. B 593, 105(2004); 599, 348(E) (2004).

[2] J. de Vries, Master The-sis, University of Groningen,July 2008.

Coupled-channels description ofφ-meson production

89

Sho Ozaki1, Atsushi Hosaka1, and Olaf Scholten.1 RCNP, Osaka University, Japan

2000 3000 40000.0

0.5

1.0

1.5

2.0

p( , )p

treeCC+R

E lab [MeV]

d/d

t[b/

GeV

2 ]

Different calculationsof the forward anglecross section for Pho-toinduced Φ-mesonproduction are com-pared to data [3].

We are analyzing data on photo-induced kaon production, usinga channel-coupled effective La-grangian model. The coupled-channels aspect is implementedthrough a K-matrix formulation,allowing for the possibility of afull coupled channels formulationin a rather large model space.Calculations are performed in apartial-wave basis including par-tial waves up to J=20. Themodel Lagrangian is gauge invari-ant and obeys crossing symme-try. A detailed description of ourmodel can be found in Refs. [1,2].In the forward angle cross sectionof photo-induced Φ-meson pro-duction off the nucleon intriguingstructures have been observed inrecent experiments. The energywhere the structure in the crosssection occurs lies very close thethe threshold of Λ∗(1520) produc-tion. Since this is a resonancewith a rather narrow width, chan-nel coupling to the Λ∗(1520) couldthus be responsible for structuresin the Φ-meson photo-productioncross section. For this reason wehave extended the Groningen K-matrix model to include the K +Λ∗ reaction channel where theΛ∗(1520) state has an intrinsicspin of 3/2. An interesting aspectof the K + Λ∗ → N + Φ interactionkernel is that in a certain energywindow and for certain scatteringangles the intermediate kaon in

the t-channel exchange diagramobeys on-shell kinematics. Thiswould give rise to delta-functionlike contribution to the kernel.We have been able to effectivelyinclude this pole contribution bytaking into account the width ofthe Λ∗(1520)-baryon that of theΦ-meson. The drawn curve inthe figure shows the tree level re-sults where the effect of the cou-pled channels is displayed by thedashed red curve. This indicatesthat while the coupled channelseffects are large they cannot ex-plain the structure seen in thedata.In the calculation given by theblue dashed-dotted line a reso-nance has been included which isregarded as a K−K−N resonantstate which couples strongly tothe K+Λ∗ channel and also to theN + Φ and not to any other. Forcertain coupling strength this hasthe effect of depleting the forwardangle cross section and thus thestructure seen in the SPRING8data [3] can be explained.

[1] A. Usov and O. Scholten,Phys. Rev. C 72, 025205(2005).

[2] A. Usov and O. Scholten,Phys. Rev. C 74, 015205(2006).

[3] T. Mibe et al. [LEPS Collabo-ration], Phys. Rev. Lett. 95,182001 (2005).

Photoproduction of η-mesons within acoupled-channels K-matrix approach

90

Radhey Shyam1, and Olaf Scholten.1 Saha Institute of Nuclear Physics, Kolkata, India

1.4 1.6 1.8 2.0 2.2 2.4 2.6W (GeV)

10-2

10-1

100

101

102

103

σ tot (

µb)

TotalS11 (1535)S11 (1650)D13 (1520)D13 (1700)P13 (1720)P11 (1710)Background

1H (γ,η)

1H

Figure 2: Contributionof various resonancesin the Photoproductionof η mesons.

We investigate photoproduc-tion of η-mesons off protonsand neutrons within a coupled-channels effective-Lagrangianmethod which is based on theK-matrix approach [1,2]. Thetwo-body final channels includedare πN , ηN , φN , ρN , γN , KΛ,and KΣ. Non-resonant meson-baryon interactions are includedin the model via nucleon inter-mediate states in the s- and u-channels and meson exchangesin the t-channel amplitude andthe u-channel resonances. Thenucleon resonances S11(1535),S11(1650), S31(1620), P11(1440),P11(1710), P13(1720), P33(1232),P33(1600), D13(1520), D13(1700),and D33(1700) are included ex-plicitly in calculations. Ourmodel describes simultaneouslythe available data as well on totaland differential cross sections ason beam and target asymmetries.This holds for the γp → ηp re-action for photon energies rang-ing from very close to thresholdto up to 3 GeV (see, eg. Fig. 2for the fits to the cross sectiondata). The polarization observ-ables show strong sensitivity toresonances that otherwise con-tribute only weakly to the totalcross section. It is found that thepronounced bump-like structureseen in the excitation function ofthe γn → ηn cross section at γenergies around 1 GeV, can be

explained by the interference ef-fects of S11, P11 and P13 resonancecontributions (see Fig.2 of [3]).

0.0

5.0

10.0

15.0

σ tot (

µb)

1H (γ,η)

1H

1n(γ,η)

1n

0.8 1.2 1.6 2 2.4Eγ (GeV)

0.5

1.0

1.5

R

Figure1 : (Upper Panel) Totalcross sections (σtot) for γp → ηp(dashed line) and γn → ηn (fullline) reactions as a function of inci-dent photon energy. The ratio R oftotal cross sections of the γn → ηnand γp → ηp reactions as a func-tion of photon energy.

[1] A. Usov and O. Scholten,Phys. Rev. C 72, 025205(2005).

[2] A. Usov and O. Scholten,Phys. Rev. C 74, 015205(2006).

[3] R. Shyam and O. Scholten,Phys. Rev. C 78, 065201(2008).

Atomic Physics

91

Overview of atomic physics 94State-selective electron capture in He2+-Na(3p) interactionsstudied with the MOTRIMS technique 95Atomic electron energy spectra of slow He2+ ions impinging onmetallic surfaces 96Temperatures of even and odd isotopes of Ca trapped in amagneto-optical trap 97The initial oscillatory behaviour of ion guiding throughnanocapillaries 98

Overview of atomic physics

92

Thomas Schlatholter and Ronnie Hoekstra.

Throughout the year the grouphas been active in three ofthe research programs at KVI,namely: GSI, TRIµP, and Life--inspired Physics. In the follow-ing some selected achievementswithin the specific programs willbe mentioned.”GSI:” In close collaboration withthe Atomic Physics group at GSIequipment for the GSI-HITRAP fa-cility was designed and built inthe KVI workshops. In particular,two UHV-compatible ion beam di-agnostics boxes were constructedand delivered. The UHV cham-ber (IISIS) containing a multipleelectrostatic lens system to decel-erate the very-highly charged ionbeams extracted from the coolertrap has been taken into oper-ation. Ion optics and trans-port tests commenced success-fully. The electron statistics de-tector supplied by Aumayr et al(TU Vienna) has been mounted onto the setup. Extensive tests willstart in 2009. In addition, a firstprototype for the electrostatic de-flectors for the beam line servingfuture low-energy experiments atGSI-HITRAP is approaching com-pletion.”TRIµP:” For many applicationsusing laser cooled and trappedatoms it is of key importanceto have long-term frequency sta-bilization of the laser. To doso a new spectroscopy methodwhich was developed by uslast year (Light-Pressure inducedSpectroscopy: LiPS) was success-fully applied to study the trap dy-namics of even and odd isotopesof Ca in a magneto-optical trap(MOT). No difference in the tem-peratures of even and odd iso-

topes of calcium is observed, incontrast to earlier experiments onSr.”Life-inspired Physics:” Manysuccessful experiments on heavy-particle induced fragmentation ofsmall bio-molecules have beenperformed. For example, ex-periments on α and β alanineshowed that the actual conforma-tion of the molecules strongly af-fects the stability of the moleculesunder ion impact. First experi-ments on the creation of strandbreaks in plasmid DNA by meansof MeV carbon beams from theKVI cyclotron AGOR have beenperformed. Last but certainlynot least we took our combinedelectrospray, tandem mass spec-trometer, Paul trap set up intooperation, which will allow forthe first fragmentation studies(embedded) trapped biomolecuarions.”ITSLEIF” Our low-energy highly-charged ion facility (ZERNIKE-LEIF) which is one of the dis-tributed host facilities of theEuropean Infrastructure Initia-tive (ITSLEIF) received guests re-searchers from Berlin, Debrecen,Lyon, Caen and Freiburg. Theyperformed a wide variety of exper-iments ranging from ion guidingthrough nanocapillaries, molecu-lar fragmentation to charge trans-fer in collisions on a laser-cooledNa target.Two PhD students defended theirtheses successfully:Gabriel Hasan - MOTRIMS inves-tigations of electron removal fromNa by highly charged ions,Albert Mollema - Laser cooling,trapping and spectroscopy of cal-cium isotopes.

State-selective electron capture in He2+ -Na(3p) interactions studied by the

MOTRIMS technique

93

V.G. Hasan and R. Hoekstra

0 2 4 6 8 10 12 140.0

0.5

1.0

1.5

2.0

2.5

3.0

(Na*

)/(N

a)

E (keV/amu)

Ratio of one-electroncapture by He2+ ions incollisions on Na(3p) andNa(3s).

At low collision energies, elec-tron capture dominates the in-teraction dynamics between mul-tiply charged ions and neutrals,and therefore plays a significantrole in man-made and astro-physical plasmas. The photonemission following charge trans-fer reactions is an important di-agnostics tool to access proper-ties of for example fusion plas-mas or the solar wind. One-electron capture proceeds mainlyby transfer of the most looselybound atomic electron, therefore(quasi) one-electron models canbe used to describe electron pro-cesses at low energies, i.e. ve-locities well below the classicalorbiting velocity (vorb) of the ac-tive electron. In particular thereal or pseudo one-electron sys-tems of fully stripped ions inter-acting with either atomic hydro-gen or alkali atoms are used tobenchmark calculations.In large tokamaks charge ex-change recombination spec-troscopy (CXRS) based on visiblelight emission following electroncapture from the neutral heatingbeams is a key diagnostic tool tomeasure fusion-plasma parame-ters. Neutral beams of specieswith low-Z (hydrogen, deuteriumand helium) are used for suchdiagnostics. A small fraction ofthe neutral beam is collisionallyexcited (H(2s), He(1s2s 1S) andHe(1s2s 3S) metastables). Cap-ture from these excited neutralscan resonantly populate the high-lying states which give rise tothe light emission in the visiblespectral range that is used forCXRS. Therefore, a small frac-tion of metastables can strongly

influence the CXRS signals. Ex-periments with metastable H orHe targets are basically impos-sible. However, capture fromground state sodium Na(3s) andexcited sodium Na(3p) can beused to estimate cross sectionsfor metastable H and He. Thebasis for this estimate is thesimilarity in binding energies ofthe metastables and Na(3s) andNa(3p).Following our systematic study ofstate selective one-electron cap-ture in He2+ - Na(3s) [1] wehave now performed a similarstudy on He2+ - Na(3p) collisionsat energies of 2-13 keV/amu.This energy range encompassesthe regime in which the inter-actions change from being dom-inated by resonant state selectivecapture to having many possiblechannels, including ionization.The transition occurs around 5.5keV/amu which corresponds to avelocity equal to the classical or-biting velocity of the Na(3p) elec-tron.To study the interaction of theHe2+ ions with the laser-excitedNa(3p) the MOTRIMS (MagnetoOptical Trapping Recoil Ion Mo-mentum Spectroscopy) techniqueis used, which is basically aCOLTRIMS method in which thecold target is provided by meansof laser cooling and trapping. Thecooling and trapping interactionswith the laser imply that partof the Na atoms is in the ex-cited state. By appropriate laserswitching schemes it is possibleto disentangle collisions on Na(3s)and Na(3p).

[1] S. Knoop et al., J. Phys. B:38, 1987 (2005).

Atomic electron energy spectra of slowHe2+ ions impinging on metallic surfaces

94

E. Bodewits, H.M. Dang, A.J. de Nijs, F. Rengers, L. Slatius and R. Hoekstra.

0

15

30

45

607590105

120

135

150

165

180

Angular distribution ofemitted KLL electrons

The multiple electron capturespectroscopy (MECS) method [1]is based on the electron emis-sion from the doubly-excited He∗∗

atoms formed upon the inter-action of the slow ions with asolid surface. The He∗∗ atomscan decay by auto-ionization, giv-ing rise to characteristic KLLAuger spectra. The relevantstates in doubly excited He∗∗ fromwhich the auto-ionization elec-trons stem are 2s2 1S, 2s2p 3P,2p2 1D, and 2s2p 1P. The Auger de-cay of those He(2`2`′) states leadsto the emission of electrons withkinetic energies of 33.3, 33.7,35.3 and 35.5 eV, respectively.Because the pairs of states 2s2 1Sand 2s2p 3P, and 2p2 1D and2s2p 1P are very close in energy,only two lines are resolved. Oneline corresponds to the pair 2s2 1S- 2s2p 3P, the so-called triplet line,while the second one correspondsto the pair 2p2 1D - 2s2p 1P whichwill be referred to as the singletline.The probability for capturing thetwo electrons into either tripletor singlet states depends on thespin ordering of the surface elec-trons. When the surface hasa high degree of spin polariza-tion, capture into triplet states islikely to dominate, while for lowdegrees of surface spin polariza-tion, capture into singlet stateswill be favored. The polarizationdependence of the state popula-tion is then expected to be re-flected in the intensity ratio ofthe KLL Auger lines correspond-ing to the decay of triplet or sin-glet states. When the spin polar-ization of a surface changes (e.g.by changing the temperature ofa ferromagnet), the intensity ra-tio of the spectral lines will alsochange. For the ferromagneticexample the observed changes inthe intensity ratio as a functionof the temperature can be used to

extract the local spin polarization.Recently, it has been shown [2]that small work function changesinduced by percents of oxygen ad-sorption may influence the spec-tra due to the (not-)exact match-ing of the binding energies of thedoubly-excited He∗∗ levels andthe work function. This match-ing aspect is a condition not in-corporated in the over-the-barrierdescription which assumes thatan electron is captured as soonas the potential energy barrierbetween the surface and the in-coming ion drops below the workfunction. In our earlier work onNi, the derived degrees of sur-face spin polarization appeared todepend somewhat on the scat-tering conditions (angle of inci-dence and energy), while for Feno clear effect was observed. Tofurther address the question towhat extent the agreement be-tween MECS and earlier datamight be fortuitous, investiga-tions of the influence of scatter-ing geometries have been made[3]. For comparison, different tar-gets have been used, namely Fe,Ni, Al, Gd, and W. In addition an-gular distributions of the emittedKLL Auger electrons have beenmeasured for W as a target toverify the model assumption ofstatistical population of the or-bital angular momentum states.As can be seen from the figurethe angular emission pattern isfar from isotropic indicating thatthe assumption of statistical statepopulations might need to be re-visited.

[1] M. Unipan et al., PRL 96(2006) 177601.

[2] S. Wethekam et al., Surf. Sci.603 (2009) 209.

[3] E. Bodewits et al., NIM B(2009) in press.

Temperatures of even and odd isotopes ofCa trapped in a magneto-optical trap

95

A.K. Mollema and R. Hoekstra

−50 −45 −40 −35 −30 −25 −200.5

1

1.5

2

2.5

3

3.5

Detuning [MHz]

Tem

pera

ture

[mK

]

Comparison of 42Ca(closed circles) and43Ca (closed squares)MOT temperatures. Thelaser intensity s0 was0.08.

The trap dynamics of even andodd isotopes of Ca in a magneto-optical trap (MOT) has been in-vestigated. Light alkaline-earthisotopes like 40Ca and 88Sr canbe laser cooled and trapped us-ing the optical 1S0−1P1 resonancetransition. Since these transi-tions are almost closed, both iso-topes resemble an almost per-fect two-level system. Remark-ably enough, measurements yieldtemperatures that are systemati-cally well above the Doppler tem-perature limit.However, measurements of thetemperature of 87Sr yield temper-atures below the Doppler limit [1],which is ascribed to the hyper-fine structure of 87Sr. In con-trast to the even isotopes the oddalkaline-earth isotopes do have a(non-zero) nuclear spin. There-fore, such a sub-Doppler coolingeffect might also be expected inthe case of 43Ca, which has anuclear spin of 7/2. We there-fore measured the temperature of43Ca in the MOT of our AlCaTrazsetup [2] using the release andrecapture method and comparedthis to a similar measurement of42Ca.The results of the measurementsare shown in the figure. Fromthe figure it is obvious that thetemperatures exceed the Dopplerlimit (dashed line) by about a fac-tor of two. The recent 3D densitymatrix approach by Choi et al. [3]for (1+3)-level atoms (for exam-

ple 42Ca) which includes multi-photon processes (solid line) isseen to describe the temperatureof the atoms well as function oflaser detuning.Comparing the data for 42Ca and43Ca, it turns out that no appre-ciable sub-Doppler cooling effectis observable in these measure-ments. It is not yet clear whatcauses the difference in trappingbehavior between 43Ca and 87Sr.As the exact hyperfine structuredetails (sequence and spacings) of43Ca and 87Sr are clearly differ-ent, it is likely that the sequenceand larger spacing in 43Ca (seefigure 1) inhibit the sub-Dopplercooling in 43Ca at least at the red-detunings and low laser intensi-ties used in our investigations.

4s 1S0

4p 1P1

F = 7/2

F’ = 9/2

F’ = 7/2

F’ = 5/250.0 MHz

73.3 MHz

43Ca

5s 1S0

5p 1P1

F = 9/2

F’ = 9/2

F’ = 11/2

F’ = 7/2

43 MHz

17 MHz

87Sr

Figure1 : Comparison of the hy-perfine structures of 43Ca and 87Sr.

[1]X. Y. Xu et al., Phys. Rev.Lett. 90, 193002 (2003).

[2] A.K. Mollema et al., Phys.Rev. A. 77, 043409 (2008).

[3] S.K. Choi et al., Phys. Rev. A.77, 015405 (2008).

The initial oscillatory behaviour of ionguiding through nanocapillaries

96

N. Stolterfoht1, B. Sulik2, Z. Juhasz2, E. Bodewits, A.J. de Nijs, H.M.Dang, R.Hoekstra1Helmholtz-Zentrum fur Materialien und Energie, D-14109 Berlin, Germany2Institute of Nuclear Research (ATOMKI), H-4001 Debrecen, Hungary

Oscillatory behaviorin the initial phase ofion guiding throughnanocapillaries.

The dynamics of guiding highlycharged ions through nanocapil-laries is far from being fully un-derstood. Here we report aboutthe initial phases of ion guidingthrough such capillaries.The capillaries are produced in athin foil of insulating material us-ing a high energy beam. Afterproducing the capillaries, a thingold film is evaporated on the foilin order to avoid charge up of thesurface which would prevent theions to enter the capillary at all.The guiding of ions through cap-illaries is based on charging up ofthe capillary walls. When ions en-ter a capillary, a positive chargeis build up on the wall. Whensubsequently other ions then en-ter the capillary, they experiencethis deposited charge and get de-flected. When there is enoughcharge on the walls, ions areguided through the capillary andcome out on the other side of thefoil. The ions are deflected intothe same direction as the tilt an-gle of the capillaries.There are many parameters thatinfluence the overall guiding effi-ciency. One of the largest effectsis the density of the capillaries,which is rather straightforward tounderstand. A factor that playsa key role is the deposited chargein particular the charge depositednear the entrance of the capillary.We investigated the guiding char-acteristics as a function of thedeposited charge on the capillar-ies to find out how the guiding isevolving. Two different samples

of 12µm thickness were investi-gated, namely one with capillariesof 200nm diameter and one with400nm diameter capillaries. Inboth cases the density of the cap-illaries was 106 capillaries/cm2.In all the experiments a beam ofNe7+ was used. Typically, thecurrent on the target was on theorder of tens of pA. In order todetermine the guiding power thenumber of ions going through thecapillaries was measured as afunction of the tilt angle (0 to10). While the capillaries werestarting to guide, the mean valueof the exit angle oscillated be-tween specific values as can beseen in figure on the right. A pos-sible explanation is illustrated infigure 1, which shows the tem-poral sequence of charge patchesbeing created and dissolved [1].

Figure1 : Top to bottom time se-quence of charge patches beingcreated and dissolved in line withobserved transmission profiles.

[1] N. Stolterfoht et al., Phys.Rev. A. 79, 022901 (2008).

Personnel

97

Personnel Overview 100

98

1director IPN Orsay; extraordinary professor at Groningen University

2fellow of the KNAW (Royal Dutch Academy of Sciences

3senior research scientist at NIKHEF; professor by special appointment at Groningen University

Scientific Staff

Senior Research Scientists

Dr. ir. J.P.M. BeijersDr. A.M. van den BergProf. Dr. S. BrandenburgDr. P.G. DendoovenProf. Dr. S. Gales1 (until 1 December)Dr. E.R. van der GraafProf. dr. M.N. Harakeh (director)Prof. dr. ir. R.A. HoekstraDr. M.A. HofsteeProf. dr. K.P. JungmannProf. dr. N. Kalantar-NayestanakiProf. dr. H. Lohner

Dr. J.G. MesschendorpDr. ir. C.J.G. OnderwaterDr. R.W. OstendorfDr. C.E. RigolletDr. T.A. Schlatholter2Dr. O. ScholtenProf. dr. G. van der Steenhoven3 (until 15November)Prof. dr. R.G.E. TimmermansDr. L. WillmannProf. dr. H.W.E.M. WilschutDr. H.J. Wortche

Post-docs and Graduate Students

Drs. F. Alvarado Chacon (until 16January)Drs. S. BariDr. A.K. BiegunDrs. E. BodewitsDr. A.M. Bubak (until 8 November)Drs. H.M. DangDrs. S. De (until 1 November)Drs. M. EslamikalantariE.D. Fraenkel Msc (from 18 August)Drs. G.S. GiriDrs. E. GuliyevIr. S. HarmsmaDrs. V.G. Hasan (until 1 November)Drs. D.J. van der HoekDrs. L. JoulaeizadehDr. M. Kavatsyuk (from 6 February)Dr. O. Kavatsyuk (from 1 May)Drs. W.L. KruithofDrs. H. Mardanpour Mollalar (until 1February)Dr. R. Meyhandan (until 1 July)Dr. V. MironovDrs. H. MoeiniDrs. A.J. Mol (until 1 March)Drs. A.K. Mollema (until 1 November)

Drs. J.J.U. PostmaDrs. S. Purushothaman (until 1 October)Drs. A. Ramezani Moghadem AraniDrs. M. RanjanDr. B.K. Sahoo (from 1 March)Drs. S. SaminathanDrs. B. Santra (from 1 August)Drs. A. Sen (from 1 September)Dr. P. Shidling (from 1 May)Drs. M. da Silva e SilvaDr. K. Singh (from 1 May)Dr. P.A. Sobocinskihfill (until 1 April)Dr. M. SohaniDrs. S. StoicaDrs. V.I. StoicaDrs. V. Suyam JothiDr. L. Tolos Rigueiro (from 1 December)Drs. O.O. VersolatoIr. R. VinkeJ. de Vries Msc (from 1 October)K.D. de Vries Msc (from 1 October)Drs. L.W. WansbeekDrs. D. Zhou (from 1 August)

Undergraduate Students

J.M.P. AzpiazuO. BartenG.M. BeardaS. BoonstraR. BorgerN.P.M. BrantjesR. BremerM. BroekroelofsH. BuistJ. van DijkM. DoorF. DuvouxD. GossetA. GrootF. HaverkortM. InklaarJ.H. JungmannH. KuipersP. Lenel

P. LubberdinkC. MalloryR. van der MeerS. NiphuisA. de NijsW. OttjesS. OzakiM. ReicherG. ReitsmaC. SchlebuschA. SijtemaJ. SmitS. ter VeenA. van VlietM. VonkJ. de VriesK. de VriesU. Wegner

99

4for 50%; works also in the Mechanical department and vacuum techniques group

5for 50%; works also in the Electronics and electrotechnical group

6for 50%; works also in the Research Technicians group

7for 50%; works also in the Cyclotron operation, cryogenics and cooling-techniques group

Emeritus Guests

Ir. O.C. DermoisDr. A.E.L. DieperinkDr. A.G. DrentjeDr. J. van KlinkenProf. dr. R.J. de Meijer

Prof. dr. R. MorgensternProf. dr. R.H. SiemssenDr. S.Y. van der WerfProf. dr. A. van der Woude

Visiting Scientists and Engineers (for longer than one month)

Dr. M.J. van Goethem, University Medical Center Groningen, Groningen, The Nether-landsProf. dr. U.L. van Kolck, University of Arizona, Tucson, USAProf. dr. C.L. Korpa, Janus Pannonius University, Pecs, HungaryIng. F. Poortenga, Dockinga College, Dokkum, The NetherlandsDr. S. Shimizu, Osaka University, Osaka, JapanProf. dr. R. Shyam, Saha Institute of Nuclear Physics, Calcutta, IndiaProf. dr. A.R. Young, North Carolina State University, Raleigh, USA

Technical and Administrative Staff

Cyclotron operation, cryogenic and cooling techniques

D.W. BakkerIng. J.E. de Jong (from 1 September)Ing. A. Kroon (until 1 June)Ing. J. Mekkering5

H. PostF. Rengers

J.G. Siebring5

R. Terol5R. Tjoelker5

J.N. de Vries6

Ing. N.J. van WiefferenIng. R.H.L. van Wooning5

Information Technology

Drs. M. BabaiIng. F. Barzangy (until 1 August)Dr. P.A. KroonIng. R.F. Pelster (from 7 July)

F. Sporrel (until 1 September)Ing. J.C. van der WeeleDr. F. Zwarts

Research Technicians

H. FraiquinIng. L. HuismanIng. H.H. KiewietA.W. Kluttig Msc (from 22 May)Ing. H.R. KremersIng. J. Mulder

F. RengersH.J. Timersma4

J.N. de Vries7

Ing. R.H.L. van Wooning

Electronics and Electrotechnics

M.O. Bleeker (until 1 November)D. DamstraIng. H.A.P. van der DuinA. FelzelIng. M.A. HevingaH. KooiIng. M. Kronenburg (from 18 August)Ing. P.J.J. Lemmens (from 1 August)Ing. J. Mekkering7

Ing. T.W. Nijboer (until 1 May)Ing. T.P. Poelman

F. Rengers7

Ing. P. SchakelIng. F.P. Schreuder (from 1 September)J.G. Siebring7

Ing. M. StokroosB.D. Taenzer (until 1 August)R. Terol7R. Tjoelker7Ing. J. Vorenholt (until 1 February)P. Wieringa

100

Mechanical Design and Construction

Ing. R. BergsmaH. DostR.J. DusselA. Eggens (from 1 March)H.F. GorterE. LatumaleaIng. M.F. Lindemulder (from 1 November)W.W.P. OlthuisL. Slatius

I. SmidIng. H.A.J. SmitD.J.M. TilmanH.J. TimersmaA. de Vries (from 1 March)J.N. de VriesJ.H.J. Wieringa

Apprentices (for at least three months)

O. BollC. GeldmannI. Ishibori

S. RikhofG.J.M. Schutten

Administration and Personnel

Drs. C. van Beilen (from 6 October)M. Groendijk (from 13 October)S.A. Jops (from 15 December)Dr. M. KoopmansH.E. van der MeerS.M. de MeijerA.D. Petitiaux

R.E. SpringerR.J. Steeman-PoelmanG. van der Tuin-VenemaM.W. RuiterA.M. van der Woude

Facility Management

M.J. Booi (from 11 February)H.K. EleniusR. ten HaveP. Mekkes (until 1 December)H. MerkP. Mossel

T. KeimpemaF. RengersG.G. Timersma (from 22 October)E. van der Werf-de Vries (from 1 March)

Scientific Output

101

List of publications 104List of collaborations 120Theses 124Contributions to conferences, workshops, etc. 125Organized conferences, workshops, etc. 130Seminars at KVI 131Seminars and colloquia given outside KVI 133

List of publications

102

J. Abraham et al. (The Pierre Auger Collaboration, S. Harmsma,R. Meyhandan, O. Scholten, A.M. van den Berg)Upper limit on the diffuse flux of ultrahigh energy tau neutrinos fromthe Pierre Auger ObservatoryPhys. Rev. Lett. 100, 211101 (2008)

J. Abraham et al. (The Pierre Auger Collaboration, S. Harmsma,R. Meyhandan, O. Scholten, A.M. van den Berg)Observation of the suppression of the flux of cosmic rays above 4 · 1019

eVPhys. Rev. Lett. 101, 061101 (2008)

J. Abraham et al. (The Pierre Auger Collaboration, S. Harmsma,R. Meyhandan, O. Scholten, A.M. van den Berg)Upper limit on the cosmic-ray photon flux above 1019 eV using thesurface detector of the Pierre Auger Observatory Observation of thesuppression of the flux of cosmic rays above 4 · 1019 eVAstropart. Phys. 29, 243-256 (2008)

J. Abraham et al. (The Pierre Auger Collaboration, S. Harmsma,R. Meyhandan, O. Scholten, A.M. van den Berg)Correlation of the highest-energy cosmic rays with the positions ofnearby active galactic nucleiAstropart. Phys. 29, 188-204 (2008)

M.M. Aggarwal et al. (the WA98 Collaboration, T.K. Ghosh, H. Lohner,K. Reygers)Source radii at target rapidity from two-proton and two-deuteron corre-lations in central Pb + Pb collisions at 158-A-GeVe-Print: arXiv:0709.2477 [nucl-ex] (2008)

M.M. Aggarwal et al. (the WA98 Collaboration, T.K. Ghosh, H. Lohner,K. Reygers)Suppression of High-pT Neutral Pion Production in Central Pb + PbCollisions at

√sN = 17.3 GeV Relative to p + C and p + Pb Collisions

Phys. Rev. Lett. 100, 242301 (2008)

F. Alvarado, J. Bernard, B. Li, R. Bredy, L. Chen, R. Hoekstra,S. Martin, T. SchlatholterPrecise determination of 2-deoxy-D-ribose internal energies after keVproton collisionsChem. Phys. 9, 1254-1258 (2008)

J. Alvarez-Muniz, for the Pierre Auger Collaboration (S. Harmsma,R. Meyhandan, O. Scholten, A.M. van den Berg)The sensitivity of the surface detector of the Pierre Auger Observatoryto UHE Earth-skimming and down-going neutrinosProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages389-392 (2008)

103

L. Anchordoqui, for the Pierre Auger Collaboration (S. Harmsma,R. Meyhandan, O. Scholten, A.M. van den Berg)Search for Coincidences in Time and Arrival Direction of Auger Datawith Astrophysical TransientsProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages437-440 (2008)

S. Andringa, for the Pierre Auger Collaboration (S. Harmsma,R. Meyhandan, O. Scholten, A.M. van den Berg)3D Reconstruction of Extensive Air Showers from Fluorescence DataProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 5, pages913-916 (2008)

T. Arion, R. Flesch, T. Schlatholter, F. Alvarado, R. Hoekstra,R. Morgenstern, E. RuhlCollision Induced Fragmentation of Free Sulfur ClustersInt. J. Mass. Spectr. 277, 197 (2008)

E. Armengaud, for the Pierre Auger Collaboration (S. Harmsma,R. Meyhandan, O. Scholten, A.M. van den Berg)Search for large-scale anisotropies with the Auger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages175-178 (2008)

M. Ave, for the Pierre Auger Collaboration (S. Harmsma, R. Mey-handan, O. Scholten, A.M. van den Berg)Reconstruction accuracy of the surface detector array of the PierreAuger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages307-310 (2008)

S. Bari, P. Sobocinski, J. Postma, F. Alvarado, R. Hoekstra, V. Berni-gaud, B. Manil, J. Rangama, B. Huber, T. SchlatholterFragmentation of α- and β-alanine molecules by ions at Bragg-peakenergiesJ. Chem. Phys. 128, 074306 (2008)

J.P.M. Beijers, H.R. Kremers, V. Mironov, J. Mulder, S. Sami-nathan, S. BrandenburgIon source development at KVIRev. Sci. Instr. 79, 02A320 (2008)

S. Ben Zvi, for the Pierre Auger CollaborationMeasurements of aerosols at the Pierre Auger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages355-358 (2008)

104

G.W. Bennett, B. Bousquet, H.N. Brown, G. Bunce, R.M. Carey,P. Cushman, G.T. Danby, P.T. Debevec, M. Deile, H. Deng,W. Deninger, S.K. Dhawan, V.P. Druzhinin, L. Duong, E. Efstathiadis,F.J.M. Farley, G.V. Fedotovich, S. Giron, F.E. Gray, D. Grigoriev,M. Grosse-Perdekamp, A. Grossmann, M.F. Hare, D.W. Hertzog,X. Huang, V.W. Hughes, M. Iwasaki, K. Jungmann, D. Kawall,B.I. Khazin, J. Kindem, F. Krienen, I. Kronkvist, A. Lam, R. Larsen,Y.Y. Lee, I. Logashenko, R. McNabb, W. Meng, J. Mi, J.P. Miller,W.M. Morse, D. Nikas, C.J.G. Onderwater, Y. Orlov, C.S. Ozben,J.M. Paley, Q. Peng, C.C. Polly, J. Pretz, R. Prigl, G. zu Putlitz,T. Qian, S.I. Redin, O. Rind, B.L. Roberts, N. Ryskulov, P. Shagin,Y.K. Semertzidis, Yu.M. Shatunov, E.P. Sichtermann, E. Solodov,M. Sossong, A. Steinmetz, L.R. Sulak, A. Trofimov, D. Urner, P. vonWalter, D. Warburton, A. YamamotoSearch for Lorentz and CPT violation effects in muon spin precessionPhys. Rev. Lett. 100, 091602 (2008)

A.M. van den Berg, for the Pierre Auger Collaboration (S. Harmsma,R. Meyhandan, O. Scholten, A.M. van den Berg)Radio detection of high-energy cosmic rays at the Pierre Auger Obser-vatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 5, pages885-888 (2008)

X. Bertou, for the Pierre Auger Collaboration (S. Harmsma, R. Mey-handan, O. Scholten, A.M. van den Berg)Search for Gamma Ray Bursts using the single particle technique at thePierre Auger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages441-444 (2008)

O. Blanch Bigas, for the Pierre Auger Collaboration (S. Harmsma,R. Meyhandan, O. Scholten, A.M. van den Berg)Limits to the diffuse flux of UHE tau neutrinos at EeV energies from thePierre Auger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 5, pages1369-1372 (2008)

C. Bleve, for the Pierre Auger Collaboration (S. Harmsma, R. Meyhan-dan, O. Scholten, A.M. van den Berg)Weather induced effects on extensive air showers observed with thesurface detector of the Pierre Auger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages319-322 (2008)

S. Brandenburg , J.P.M. Beijers, H.R. Kremers, V. Mironov, J. Mulder,S. SaminathanIon source development at the AGOR facilityProc. XVIIIth Int. Conf. on Cyclotrons and their Applications, Catania(Italy) 2007, eds. D. Riffugiato and L.A.C. Piazza, 303 (2008)

105

S. Brandenburg, J.P.M. Beijers, M.A. Hofstee, H.R. Kremers,V. Mironov, T.W. Nijboer, J. VorenholtHigh intensity operation of the AGOR-cyclotron for RIB-productionProc. XVIIIth Int. Conf. on Cyclotrons and their Applications, Catania(Italy) 2007, eds. D. Riffugiato and L.A.C. Piazza, 493 (2008)

S. Brandenburg, M.A. Hofstee, T.W. NijboerInfluence of the RF magnetic field on the beam phase in cyclotronsProc. XVIIIth Int. Conf. on Cyclotrons and their Applications, Catania(Italy) 2007, eds. D. Riffugiato and L.A.C. Piazza, 373 (2008)

R. Castelijns et al. (the CB-ELSA/TAPS Collaboration, R. Castelijns,H. Lohner, J. Messchendorp)Nucleon resonance decay by the K0 Σ+ channelEur. Phys. J. A 35, 39 - 45 (2008)

G. Ciavola, S. Gammino, S. Barbarino, L. Celona, F. Consoli,G. Gallo, F. Maimone, D. Mascali, S. Passarello, A. Galata, K. Tin-schert, P. Spaedtke, R. Lang, J. Maeder, J. Rossbach, H. Koivisto,M. Savonen, T. Koponen, P. Suominen, T. Ropponen, C. Barue,M. Lechartier, J.P.M. Beijers, S. Brandenburg, H.R. Kremers, D. Van-rooyen, D. Kuchler, R. Scrivens, L. Schachter, S. Dobrescu, K. StiebingA status report of the multipurpose superconducting electron cyclotronresonance ion sourceRev. Sci. Instr. 79, 02A326 (2008)

B. Dawson, for the Pierre Auger Collaboration (S. Harmsma, R. Mey-handan, O. Scholten, A.M. van den Berg)Hybrid Performance of the Pierre Auger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages425-428 (2008)

P. Degroote, D. Bodewits, M. ReyniersFolding ion rays in comet C/2004 Q2 (Machholz) and the connectionwith the solar windAstron. Astrophys. 477, L41-L44 (2008)

B.D. DePaola, R. Morgenstern, N. AndersenMOTRIMS: Magneto-Optical Trap Recoil Ion Momentum SpectroscopyAdv. At. Mol. Opt. Phys. 55, 139 (2008)

G. Dixit, H.S. Nateraj, B.K. Sahoo, R.K. Chaudhuri, S. MajumderAb inito relativistic many-body calculation of hyperfine splitting of113Cd+

Phys. Rev. A 77, 012718 (2008)

H. Dohmann, C. Baumer, D. Frekers, E.-W. Grewe, M.N. Harakeh,S. Hollstein, H. Johansson, L. Popescu, S. Rakers, D. Savran, H. Si-mon, J.H. Thies, A.M. van den Berg, H.J. Wortche, A. ZilgesThe (d,2He) reaction on 96Mo and the double-decay matrix elements for96ZrPhys. Rev. C 78, 041602 (R) (2008)

106

A.G. Drentje, A. Kitagawa, M. MuramatsuExperiments with fundamental aspects performed in a small ECR ionsource for a new carbon therapy facilityIEEE Transactions on Plasma Science 36 No 4, 1502 (2008)

D. Elsner et al. (the CB-ELSA/TAPS Collaboration, R. Castelijns,H. Lohner, J. Messchendorp)Linearly polarized photon beams at ELSA and measurement of thebeam asymmetry in π0-photoproduction off the protone-Print: arXiv:0810.1849 (nucl-ex) (2008)

J. Endres, A. Zilges, N. Pietralla, D. Savran, K. Sonnabend,M.N. Harakeh, V. Stoica, H. Wortche, P. Butler, R.D. Herzberg,M. Scheck, R. Krucken, L. Popescu, S. Harissopulos, A. LagoyannisStudy of the Pygmy Dipole Resonance in 124Sn by means of the (α, α′γ)reactionProc. of the 13th International Conference on Capture Gamma-RaySpectroscopy and Related Topics (CGS13), Cologne, Germany; August25-29 (2008)

R. Engel, for the Pierre Auger Collaboration (S. Harmsma, R. Meyhan-dan, O. Scholten, A.M. van den Berg)Test of hadronic interaction models with data from the Pierre AugerObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages385-388 (2008)

A. Etchegoyen, for the Pierre Auger Collaboration (S. Harmsma,R. Meyhandan, O. Scholten, A.M. van den Berg)AMIGA, Auger Muons and Infill for the Ground ArrayProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 5, pages1191-1194 (2008)

P. Facal San Luis, for the Pierre Auger Collaboration (S. Harmsma,R. Meyhandan, O. Scholten, A.M. van den Berg)Measurement of the UHECR spectrum above 1019 eV at the Pierre AugerObservatory using showers with zenith angles greater than 60

Proc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages339-342 (2008)

H.O.U. Fynbo, C.A. Diget, S. Hyldegaard, H.B. Jeppesen, H.H. Knud-sen, O. Kirsebom, K. Riisager, M. Alcorta, R. Boutami, M.J.G. Borge,M. Madurga, O. Tengblad, S. Brandenburg, P. Dendooven, K. Jung-mann, G.J.G. Onderwater, A. Rogachevsky, M. Sohani, E. Traykov,H.W. Wilschut, J. Buscher, P.V. Duppen, M. Huyse, R. Raabe, T. Ero-nen, J. Huikary, A. Jokinen, A. Kankainen, K. Perajarvi, I. Moore,A. Nieminen, H. Penttila, S. Rinta-Antila, A. Saastamoinen, Y. Wang,J. Aysto, B. Jonson, T. Nilsson, G. Nyman, K. Wilhelmsen, B. Fulton,S. Fox, F.C. BarkerThe beta-decay approach for studying 12CJournal of Physics: Conference Series 111, 012003 (2008)

107

P. Ghia, for the Pierre Auger Collaboration (S. Harmsma, R. Meyhan-dan, O. Scholten, A.M. van den Berg)Testing the surface detector simulation for the Pierre Auger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages315-318 (2008)

E.-W. Grewe, C. Baumer, H. Dohmann, D. Frekers, M.N. Harakeh,S. Hollstein, H. Johansson, L. Popescu, S. Rakers, D. Savran, H. Si-mon, J.H. Thies, A.M. van den Berg, H.J. Wortche, A. ZilgesThe (d,2He) reaction on 76Se and the double-β-decay matrix elementsfor A = 76Phys. Rev. C 78, 044301 (2008)

E.-W. Grewe, C. Baumer, H. Dohmann, D. Frekers, M.N. Harakeh,S. Hollstein, H. Johansson, K. Langanke, G. Martnez-Pinedo,F. Nowacki, I. Petermann, L. Popescu, S. Rakers, D. Savran, K. Sieja,H. Simon, J.H. Thies, A.M. van den Berg, H.J. Wortche, A. ZilgesStudies on the double-β decay nucleus 64Zn using the (d,2He)-reactionPhys. Rev. C 77, 064303 (2008)

E. Gutz et al. (the CB-ELSA/TAPS Collaboration, R. Castelijns,H. Lohner, J. Messchendorp)Measurement of the beam asymmetry Σ in π η: Production off the protonwith the CB-ELSA/TAPS experimentEur. Phys. J. A 35, 291-293 (2008)

D. Harari, for the Pierre Auger Collaboration (S. Harmsma, R. Mey-handan, O. Scholten, A.M. van den Berg)Search for correlation of UHECRs and BL Lacs in Pierre Auger Observa-tory dataProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages283-286 (2008)

M. Healy, for the Pierre Auger Collaboration (S. Harmsma, R. Mey-handan, O. Scholten, A.M. van den Berg)Composition-sensitive parameters measured with the surface detectorof the Pierre Auger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages377-380 (2008)

M. Healy, for the Pierre Auger Collaboration (S. Harmsma, R. Mey-handan, O. Scholten, A.M. van den Berg)Search for Ultra-High Energy Photons with the Pierre Auger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages381-384 (2008)

F.-H. Heinsius, B. Kopf, B. Lewandowski, H. Lohner, R. Novotny,K. Peters, P. Rosier, L. Schmitt, A. Vasiliev (eds.), the PANDA Collabo-rationTechnical design report for PANDA Electromagnetic Calorimeter (EMC)e-Print: arXiv:0810.1216v1 [physics.ins-det] (2008)

108

R. Higa, W.-W. Hammer, U. van Kolckαα scattering in halo effective field theoryNucl. Phys. A 809, 171-188 (2008)

I. Horn et al. (the CB-ELSA Collaboration, R. Castelijns, H. Lohner,J. Messchendorp)Evidence for a Parity Doublet ∆(1920)P33 and ∆(1940)D33 fromγ p→ p π0 ηPhys. Rev. Lett. 101, 202002 (2008)

I. Horn et al. (the CB-ELSA/TAPS Collaboration, R. Castelijns,H. Lohner, J. Messchendorp)Study of the reaction γ p→ p π0 ηEur. Phys. J. A 38, 173 - 186 (2008)

B.A. Huber, L. Adoui, V. Bernigaud, B. Manil, L. Manoury,J. Rangama, P. Rousseau, N. Haag, H. Johansson, H.T. Schmidt,H. Cederquist, S. Brondsted-Nielsen, B. Liu, H. Zettergren,P. Hvelplund, F. Alvarado, S. Bari, R. Hoekstra, J. Postma,T. SchlatholterFragmentation of isolated and nanosolvated biomolecular systemsAIP Conf. Proc. 1080, 21 (2008)

M. Hunyadi, M.N. HarakehGiant resonance overtones: Compression modes of the nucleusNuclear Physics News International 18, 10-16 (2008)

S. Hyldegaard, H.O.U. Fynbo, K. Riisager, S. Brandenburg, P. Den-dooven, K. Jungmann, C.J.G. Onderwater, A. Rogachevskiy, M. So-hani, E. Traykov, H.W. Wilschut, J. Buscher, M. Huyse, R. Raabe,M. Alcorta, M.J.G. Borge, M. Madurga, O. Tengblad, C.A.A. Diget,B.R. Fulton, A.S. Jokinen, K. Perajarvi, A. Saastamoinen, J. Aysto,B. Jonson, G. NymanStudies of C-12 using beta-decaysInt. J. Mod. Phys. E-Nucl. Phys. 17, 2182 (2008)

I. Jaegle et al. (the CB-ELSA/TAPS Collaboration, R. Castelijns,H. Lohner, J. Messchendorp)Quasi-free photoproduction of η-mesons of the neutronPhys. Rev. Lett. 100, 252002 (2008)

L. Joulaeizadeh, J. Bacelar, I. Gasparic, H. LohnerPionic fusion experiments at subthreshold energiesAIP Conf. Proceedings 972, 475 - 479 (2008)

N. Kalantar-NayestanakiWhat have we learned about three-nucleon systems at intermediateenergies?AIP Conf. Proc. 1011, 33 (2008)

N. Kalantar-NayestanakiStudy of three-body systems at KVIFew-Body Systems 43, 109 (2008)

109

N. Kalantar-Nayestanaki, H. Moeini, F. Aksouh, K. Beckert, P. Beller,K. Boretzky, A. Chatillon, A. Corsi, P. Egelhof, H. Emling, G. Ickert,S. Ilieva, C. Kozhuharov, T. Le Bleis, X.C. Le Xuang, Y. Litvinov,K. Mahata, J.P. Meier, F. Nolden, U. Popp, H. Simon, M. Steck,T. Stohlker, H. Weick, A. Zalite, O. Kiselev, J. Jourdan, D. Rohe,D. Werthmuller, S. PaschalisResults for the first feasibility study for the EXL project at the experi-mental storage ring at GSIProc. of the Int. Symp. on Physics of Unstable Nuclei ISPUN07,July 2007, Eds. D.T. Khoa, P. Egelhof, S. Gales, N. Van Giai and T.Motobayashi, World Scientific, p. 139 (2008)

St. Kistryn, E. Sthephan, N. Kalantar-Nayestanaki, A. Biegun,K. Bodek, I. Ciepal, A. Deltuva, E. Epelbaum, A.C. Fonseca,W. Glockle, J. Golak, A. Kamada, M. Kis, A. Kozela, M. Mahjour-Shafiei, A. Micherdzinska, A. Nogga, P.U. Sauer, R. Skibinski,H. Witala, J. Zejma, W. ZipperCross sections of the deuteron-proton breakup as a probe of three-nucleon system dynamicsAIP Conf. Proc. 1011, 69 (2008)

St. Kistryn, E. Sthephan, N. Kalantar-Nayestanaki, A. Biegun,K. Bodek, I. Ciepal, A. Deltuva, E. Epelbaum, A.C. Fonseca,W. Glockle, J. Golak, A. Kamada, M. Kis, B. Klos, A. Kozela,M. Mahjour-Shafiei, A. Micherdzinska, P.U. Sauer, R. Skibinski,R. Sworst, H. Witala, J. Zejma, W. ZipperStudies of the three-nucleon system dynamics: Cross sections of thedeuteron-proton breakup at 130 MeVFew-Body Systems 44, 11 (2008)

A. Kitagawa, M. Muramatsu, N. Sasaki, W. Takasugi, S. Wakaisami,S. Biri, A.G. DrentjeMultiply charged carbon-ion production for medical applicationRev. Sci. Instrum. 79, 02C303 (2008)

H. Klages, for the Pierre Auger Collaboration (S. Harmsma, R. Mey-handan, O. Scholten, A.M. van den Berg)HEAT - Enhancement Telescopes for the Pierre Auger Southern Obser-vatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 5, pages849-852 (2008)

F. Klein et al. (the CB-ELSA/TAPS Collaboration, R. Castelijns,H. Lohner, J. Messchendorp)Beam asymmetry in near threshold omega photoproduction off theprotonPhys. Rev. D 78, 117101 (2008)

R. Knapik, for the Pierre Auger Collaboration (S. Harmsma, R. Mey-handan, O. Scholten, A.M. van den Berg)The absolute, relative, and multi-wavelength calibration of the PierreAuger Observatory fluorescence detectorsProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages343-346 (2008)

110

S. Knoop, D. Fischer, Y. Xue, M. Zapukhlyak, C.J. Osborne, Th. Er-gler, T. Ferger, J. Braun, G. Brenner, H. Bruhns, C. Dimopoulou,S.W. Epp, A.J. Gonzales Martnez, G. Sikler, R. Soria Orts, H. Tawara,T. Kirchner, J.R. Crespo Lopez-Urrutia, R. Moshammer, J. Ullrich,R. HoekstraSingle-electron capture in keV Ar15+...18+ + He collisionsJ. Phys. B: At. Mol. Opt. Phys. 41, 195203 (2008)

H. Koivisto, T. Ropponen, J. Ropponen, T. Koponen, M. Savonen,V. Toivanen, P. Heikkinen, G. Machicoane, J. Stetson, P. Zavodszky,X. Wu, M. Doleans, S. Chouhan, P. Spadtke, H. Beijers, S. Branden-burgProgram to improve the ion beam transmission at JYFLProc. XVIIIth Int. Conf. on Cyclotrons and their Applications, Catania(Italy) 2007, eds. D. Riffugiato and L.A.C. Piazza, 337 (2008)

M. Kotulla et al. (the CB-ELSA/TAPS Collaboration, R. Castelijns,H. Lohner, J. Messchendorp)Modification of the ω-Meson lifetime in nuclear matterPhys. Rev. Lett. 100, 192302 (2008)

H.R. Kremers, J.P.M. Beijers, S. BrandenburgA versatile emittance meter and profile monitorProc. of the 8th European DIPAC07, Venice, Italy 2007 (2008)

G. Lhersonneau, T. Malkiewicz, D. Vakhtin, V. Plokhoi, O. Alyakrin-skiy, M. Barbui, S. Brandenburg, P. Dendooven, M. Cinausero,Y. Kandiev, H. Kettunen, S. Khlebnikov, V. Lyapin, H. Penttila,G. Prete, V. Rizzi, S. Samarin, L.B. Tecchio, W.H. Trzaska, G. TyurinNeutron production by a 13C thick target irradiated by 20-90 MeVprotonsNucl. Instr. Meth. Phys. Res. B 266, 4330 (2008)

Yi Li, M.K. Liou, W.M. Schreiber, B.F. Gibson, R.G.E. Timmer-mansMeson-exchange currents in neutron-proton bremsstrahlungPhys. Rev. C 77, 044001 (2008)

B. Long, U. van KolckRenormalization of singular potentials and power countingAnnals of Physics 323, 1304-1323 (2008)

H. Mardanpour, H.R. Amir-Ahmadi, R. Benard, A. Biegun, M. Eslami-Kalantari, N. Kalantar-Nayestanaki, M. Kis, St. Kistryn, A. Kozela,H. Kuboki, Y. Maeda, M. Mahjour-Shafiei, J.G. Messchendorp,K. Miki, S. Noji, A. Ramazani-Moghaddam-Arani, H. Sakai, M. Sasano,K. Sekiguchi, E. Stephan, R. Sworst, Y. Takahashi, K. YakoA systematic study of 3NF effects in + d break-up with BINA at 190MeVFew-Body Systems 44, 49 (2008)

111

G. Medina Tanco, for the Pierre Auger Collaboration (S. Harmsma,R. Meyhandan, O. Scholten, A.M. van den Berg)Astrophysics Motivation behind the Pierre Auger Southern ObservatoryEnhancementsProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 5, pages1101-1104 (2008)

T. Mertens et al. (the CB-ELSA/TAPS Collaboration, R. Castelijns,H. Lohner, J. Messchendorp)Photoproduction of eta-mesons off nuclei for E(γ) < 2.2 GeVEur. Phys. J. A 38, 195-207 (2008)

T. Mishra, B.K. Sahoo, R.V. PaiPhase separated charge density wave phase in the two species ex-tended Bose-Hubbard modelPhys. Rev. A 78, 013632 (2008)

A.K. Mollema, L.W. Wansbeek, K. Jungmann, R.G.E. Timmer-mans, R. HoekstraLaser-frequency locking using light-pressure-induced spectroscopy in acalcium beamPhys. Rev. A 77, 043409 (2008)

S. Mollerach, for the Pierre Auger Collaboration (S. Harmsma,R. Meyhandan, O. Scholten, A.M. van den Berg)Studies of clustering in the arrival directions of cosmic rays detected atthe Pierre Auger Observatory above 10 EeVProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages279-282 (2008)

V.S. Morozov, A.W. Chao, A.D. Krisch, M.A. Leonova, R.S. Ray-mond, D.W. Sivers, V.K. Wong, A. Garishvili, R. Gebel, A. Lehrach,B. Lorentz, R. Maier, D. Prasuhn, H. Stockhorst, D. Welsch, F. Hin-terberger, K. Ulbrich, A. Schnase, E.J. Stephenson, N.P.M. Brantjes,C.J.G. Onderwater, M. da SilvaExperimental Verification of Predicted Beam-Polarization Oscillationsnear a Spin ResonancePhys. Rev. Lett. 100, 054801 (2008)

M. Muramatsu, A. Kitagawa, Y. Iwata, H. Ogawa, S. Hojo, T. Kubo,Y. Kato, S. Biri, E. Fekete, Y. Yoshida, A.G. DrentjeApplication of compact ECR ion sourceRev. Sci. Instrum. 79, 02A328 (2008)

M. Nanova et al. (the CB-ELSA/TAPS Collaboration, R. Castelijns,H. Lohner, J. Messchendorp)K0 π0 Σ+ and K∗0 Σ+ photoproduction off the protonEur. Phys. J. A 35, 333 - 342 (2008)

H.S. Nataraj, B.K. Sahoo, B.P. Das, D. MukherjeeIntrinsic electric dipole moments of paramagnetic atoms: rubidium andcesiumPhys. Rev. Lett. 101, 033002 (2008)

112

D. Newton, for the Pierre Auger Collaboration (S. Harmsma, R. Mey-handan, O. Scholten, A.M. van den Berg)Selection and reconstruction of very inclined air showers with theSurface Detector of the Pierre Auger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages323-326 (2008)

D. Nitz, for the Pierre Auger Collaboration (S. Harmsma, R. Mey-handan, O. Scholten, A.M. van den Berg)The Northern Site of the Pierre Auger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 5, pages889-892 (2008)

L. Perrone, for the Pierre Auger Collaboration (S. Harmsma, R. Mey-handan, O. Scholten, A.M. van den Berg)Measurement of the UHECR energy spectrum from hybrid data of thePierre Auger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages331-334 (2008)

M. Prouza, for the Pierre Auger Collaboration (S. Harmsma, R. Mey-handan, O. Scholten, A.M. van den Berg)Systematic study of atmosphere-induced influences and uncertaintieson shower reconstruction at the Pierre Auger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages351-354 (2008)

S. Purushothaman, P. Dendooven, I. Moore, H. Penttila, J. Ronkainen,A. Saastamoinen, J. Aysto, K. Perajarvi, N. Takahashi, K. GloosCryogenic helium as stopping medium for high-energy ionsNucl. Instr. and Methods in Phys. Res. B: Beam Interactions withMaterials and Atoms 266, 4488 (2008)

M. Raidal, A. van der Schaaf, I. Bigi, M.L. Mangano, Y. Semertzidis,S. Abel, S. Albino, S. Antusch, E. Arganda, B. Bajc, S. Banerjee,C. Biggio, M. Blanke, W. Bonivento, G.C. Branco, D. Bryman,A.J. Buras, L. Calibbi, A. Ceccucci, P.H. Chankowski, S. David-son, A. Deandrea, D.P. DeMille, F. Deppisch, M.A. Diaz, B. Duling,M. Felcini, W. Fetscher, F. Forti, D.K. Ghosh, M. Giffels, M.A. Giorgi,G. Giudice, E. Goudzovskij, T. Han, P.G. Harris, M.J. Herrero,J. Hisano, R.J. Holt, K. Huitu, A. Ibarra, O. Igonkina, A. Ilakovac,J. Imazato, G. Isidori, F.R. Joaquim, M. Kadastik, Y. Kajiyama,S.F. King, K. Kirch, M.G. Kozlov, M. Krawczyk, T. Kress, O. Lebedev,A. Lusiani, E. Ma, G. Marchiori, A. Masiero, I. Masina, G. Moreau,T. Mori, M. Muntel, N. Neri, F. Nesti, C.J.G. Onderwater, P. Paradisi,S.T. Petcov, M. Picariello, V. Porretti, A. Poschenrieder, M. Pospelov,L. Rebane, M.N. Rebelo, A. Ritz, L. Roberts, A. Romanino, J.M. Roney,A. Rossi, R. Ruckl, G. Senjanovic, N. Serra, T. Shindou, Y. Takan-ishi, C. Tarantino, A.M. Teixeira, E. Torrente-Lujan, K.J. Turzynski,T.E.J. Underwood, S.K. Vempati, O. VivesFlavor physics of leptons and dipole momentsEur. Phys. J. C 57:13-182 (2008)

113

A. Ramazani-Moghaddam-Arani, H.R. Amir-Ahmadi, A.D. Bacher,C.D. Bailey, A. Biegun, M. Eslami-Kalantari, I. Gasparic,L. Joulaeizadeh, N. Kalantar-Nayestanaki, St. Kistryn, A. Kozela,H. Mardanpour, J.G. Messchendorp, A.M. Micherdzinska, H. Moeini,S.V. Shende, E. Stephan, E.J. Stephenson, R. SworstElastic proton-deuteron scattering at intermediate energiesPhys. Rev. C 78, 014006 (2008)

A. Ramazani-Moghaddam-Arani, H.R. Amir-Ahmadi, A. Biegun,M. Eslami-Kalantari, I. Gasparic, L. Joulaeizadeh, N. Kalantar-Nayestanaki, St. Kistryn, A. Kozela, H. Mardanpour, J.G. Messchen-dorp, H. Moeini, S.V. Shende, E. Stephan, R. SworstProton-deuteron elastic scattering at 135 MeV with BINAFew-Body Systems 44, 27 (2008)

M. Roth, for the Pierre Auger Collaboration (S. Harmsma, R. Meyhan-dan, O. Scholten, A.M. van den Berg)Measurement of the UHECR energy spectrum using data from theSurface Detector of the Pierre Auger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages327-330 (2008)

J. Rautenberg, for the Pierre Auger Collaboration (S. Harmsma,R. Meyhandan, O. Scholten, A.M. van den Berg)Online Monitoring of the Pierre Auger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 5, pages993-996 (2008)

B.K. Sahoo, B.P. DasRelativistic coupled-cluster study of dipole polarizabilities in closed-shell atomsPhys. Rev. A 77, 062516 (2008)

B.K. Sahoo, B.P. Das, R.K. Chaudhuri, D. Mukherjee, E.P. Venu-gopalAtomic electric dipole moments from Higgs boson mediated interactionsPhys. Rev. A 78, 010501 (R) (2008)

T.R. Saito, N. Saito, K. Starosta, J. Beller, N. Pietralla, H.J. Woller-sheim, D.L. Balabanski, A. Banu, R.A. Bark, T. Beck, F. Becker,P. Bednarczyk, K.-H. Behr, G. Benzoni, P.G. Bizzeti, C. Boiano,A. Bracco, S. Brambilla, A. Brunle, A. Burger, L. Caceres, F. Camera,F.C.L. Crespi, P. Doornenbal, A.B. Garnsworthy, H. Geissel, J. Gerl,M. Gorska, J. Grebosz, G. Hagemann, J. Jolie, M. Kavatsyuk, O. Ka-vatsyuk, T. Koike, I. Kojouharov, N. Kurz, J. Leske, G. Lo Bianco,A. Maj, S. Mallion, S. Mandal, M. Maliage, T. Otsuka, C.M. Petrache,Zs. Podolyak, W. Prokopowicz, G. Rainovski, P. Reiter, A. Richard,H. Schaffner, S. Schielke, G. Sletten, N.J. Thompson, D. Tonev,J. Walker, N. Warr, O. Wieland, Q. ZhongYrast and non-yrast 2+ states of 134Ce and 136Nd populated in relativis-tic Coulomb excitationPhys. Lett. B 669, 19 (2008)

114

M. Sanchez-Vega, H. Mach, R. Taylor, B. Fogelberg, A. Lindroth,A. Aas, P. Dendooven, A. Honkanen, M. Huhta, G. Lhersonneau,M. Oinonen, J. Parmonen, H. Penttila, J. Aysto, J. Persson, J. KurpetaStudies of quadrupole collectivity in the gamma-soft 106RuThe Eur. Phys. J. A - Hadrons and Nuclei 35, 159 (2008)

E. Santos, for the Pierre Auger Collaboration (S. Harmsma, R. Mey-handan, O. Scholten, A.M. van den Berg)A search for possible anisotropies of cosmic rays with 0.1 < E < 10 EeVin the region of the Galactic CentreProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages171-174 (2008)

A.V. Sarantsev et al. (the CB-ELSA Collaboration, R. Castelijns,H. Lohner, J. Messchendorp)New results on the Roper resonance and the P(11) partial wavePhys. Lett. B 659, 94 - 100 (2008)

D.R. Schaart, H.T. van Dam, S. Seifert, R. Vinke, P. Dendooven,H. Lohner, F.J. BeekmanSiPM-Array Based PET Detectors with Depth-of-Interaction Correction2008 IEEE Nuclear Science Symposium Conference Record, M02-2(2008)

D.R. Schaart, S. Seifert, H.T. van Dam, M.R. de Boer, R. Vinke,P. Dendooven, H. Lohner, F.J. BeekmanFirst Experiments with LaBr3:Ce Crystals Coupled Directly to SiliconPhotomultipliers for PET Applications2008 IEEE Nuclear Science Symposium Conference Record, M06-229(2008)

O. Scholten, K. Werner, F. RusydiA macroscopic description of coherent geomagnetic radiation fromcosmic ray air showersAstropart. Phys. 29, 94 (2008)

O. Scholten, A. van VlietDetermining neutrino absorption spectra at Ultra-High EnergiesJCAP 0806, 015; arXiv:0801.3342v2 [astro-ph], (2008)

O. Scholten, A. UsovCoupled-channels partial-wave analysis of kaon photoproductionMod. Phys. Lett. A Z23, 2305-2308 (2008)

S. Seifert, D.R. Schaart, H.T. van Dam, J. Huizenga, R. Vinke,P. Dendooven, H. Lohner, F.J. BeekmanA High Bandwidth Preamplifier for SiPM-Based TOF PET ScintillationDetectors2008 IEEE Nuclear Science Symposium Conference Record, NM1-2(2008)

115

D. Semikoz, for the Pierre Auger Collaboration (S. Harmsma, R. Mey-handan, O. Scholten, A.M. van den Berg)Constraints on top-down models for the origin of UHECRs from thePierre Auger Observatory dataProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages433-436 (2008)

G. Snow, for the Pierre Auger Collaboration (S. Harmsma, R. Meyhan-dan, O. Scholten, A.M. van den Berg)Education and Outreach for the Pierre Auger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages295-298 (2008)

P. Sobocinski, S. Bari, J. Postma, F. Alvarado, R. Hoekstra, B. Manil,J. Rangama, V. Bernigaud, B.A. Huber, T. SchlatholterIsomeric effects in ion-induced fragmentation of α- and β-alanineJ. Phys.: Conf. Ser. 101, 012006 (2008)

E. Stephan, St. Kistryn, N. Kalantar-Nayestanaki, A. Biegun,K. Bodek, I. Ciepal, A. Deltuva, E. Epelbaum, A.C. Fonseca,W. Glockle, J. Golak, A. Kamada, M. Kis, B. Klos, A. Kozela,M. Mahjour-Shafiei, A. Micherdzinnska, A. Nogga, P.U. Sauer,R. Skibinski, R. Sworst, H. Witala, J. Zejma, W. ZipperA large, precise set of polarization observables for deuteron-protonbreakup at 130 MeVAIP Conf. Proc. 1011, 75 (2008)

I. Stetcu, B.R. Barrett, U. van Kolck, J.P. VaryEffective Theory for Trapped Few-Fermion SystemsPhys. Rev. A 76, 063613 (2007)

T. Suomijarvi, for the Pierre Auger Collaboration (S. Harmsma,R. Meyhandan, O. Scholten, A.M. van den Berg)Performance of the Pierre Auger Observatory Surface DetectorProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages311-314 (2008)

R.G.E. TimmermansLow-energy precision tests of electroweak theoryLecture Notes in Physics 749, 1 (2008)

E. Traykov, U. Dammalapati, S. De, O.C. Dermois, L. Huisman,K. Jungmann, W. Kruithof, A.J. Mol, C.J.G. Onderwater, A. Ro-gachevskiy, M. da Silva e Silva, M. Sohani, O. Versolato, L. Willmann,H.W. WilschutProduction and trapping of radioactive atoms at the TRIµP facilityNucl. Instrum. Meth. B 266, 4532 (2008)

116

P. Travnicek, for the Pierre Auger Collaboration (S. Harmsma, R. Mey-handan, O. Scholten, A.M. van den Berg)New method for atmospheric calibration at the Pierre Auger Observatoryusing FRAM, a robotic astronomical telescopeProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages347-350 (2008)

E. Traykov, U. Dammalapati, S. De, O.C. Dermois, L. Huisman,K. Jungmann, W. Kruithof, A.J. Mol, C.J.G. Onderwater, A. Ro-gachevskiy, M. da Silva e Silva, M. Sohani, O. Versolato, L. Willmann,H.W. WilschutDevelopment of a thermal ionizer as ion catcherNucl. Instrum. Meth. B 266, 4478 (2008)

M. Unger, for the Pierre Auger Collaboration (S. Harmsma, R. Mey-handan, O. Scholten, A.M. van den Berg)Study of the Cosmic Ray Composition above 0.4 EeV using the Longitu-dinal Profiles of Showers observed at the Pierre Auger ObservatoryProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages373-376 (2008)

R. Vinke, H. Lohner, D.R. Schaart, H.T. van Dam, S. Seifert,F.J. Beekman, P. DendoovenOptimizing timing resolution for TOF PET detectors based on monolithicscintillation crystals using fast photosensor arrays2008 IEEE Nuclear Science Symposium Conference Record, M06-207(2008)

L.W. Wansbeek, B.K. Sahoo, R.G.E. Timmermans, K. Jungmann,B.P. Das, D. MuhkerjeeAtomic parity nonconservation in Ra+

Phys. Rev. A 78, 050501 (2008)

L.W. Wansbeek, B.K. Sahoo, B.P. Das, D. Mukherjee, R.G.E. Timmer-mansAb initio determination of polarizabilities and van der Waals coefficientsof Li atoms using the relativistic coupled-cluster methodPhys. Rev. A 78, 012515 (2008)

S.Y. van der WerfComment on ”Improved ray tracing air mass numbers model”Appl. Opt. 47, No. 2, 153-156 (2008)

K. Werner, O. ScholtenMacroscopic treatment of radio emission from cosmic ray air showersbased on shower simulationsAstropart. Phys. 29, 393-411 (2008)

117

T. Yamamoto, for the Pierre Auger Collaboration (S. Harmsma, R. Mey-handan, O. Scholten, A.M. van den Berg)The UHECR spectrum measured at the Pierre Auger Observatory andits astrophysical implicationsProc. of the 30th International Cosmic Ray Conference, UniversidadNacional Autonoma de Mexico, Mexico City, Mexico, Vol. 4, pages335-338 (2008)

R.G.T. Zegers, E.F. Brown, H. Akimune, S.M. Austin, A.M. vanden Berg, B.A. Brown, D.A. Chamulak, Y. Fujita, M. Fujiwara,S. Gales, C.J. Guess, M.N. Harakeh, H. Hashimoto, R. Hayami,G.W. Hitt, M. Itoh, T. Kawabata, K. Kawase, M. Kinoshita, K. Nakan-ishi, S. Nakayama, S. Okumura, Y. Shimbara, M. Uchida, H. Ueno,T. Yamagata, M. YosoiGamow-Teller strength for the analog transitions to the firstT = 1/2, Jπ = 3/2− states in 13C and 13N and the implications fortype Ia supernovaePhys. Rev. C 77, 024307 (2008)

List of collaborations

118

The CB-ELSA Collaboration

A.V. Sarantsev, M. Fuchs, M. Kotulla, U. Thoma, J. Ahrens, J.R.M. Annand,

A.V. Anisovich, G. Anton, R. Bantes, O. Bartholomy, R. Beck, Yu. Beloglazov,

R. Castelijns, V. Crede, A. Ehmanns, J. Ernst, I. Fabry, H. Flemming, A. Fosel,

Chr. Funke, R. Gothe, A. Gridnev, E. Gutz, St. Hoffgen, I. Horn, J. Hossl, D.Hornidge,

S. Janssen, J. Junkersfeld, H. Kalinowsky, F. Klein, E. Klempt, H. Koch, M. Konrad,

B. Kopf, B. Krusche, J. Langheinrich, H. Lohner, I. Lopatin, J. Lotz, J.C. McGeorge,

I.J.D. MacGregor, H. Matthay, D. Menze, J.G.Messchendorp, V. Metag, V.A. Nikonov,

D. Novinski, R. Novotny, M. Ostrick, H. van Pee, M. Pfeiffer, A. Radkov, G. Rosner,

M. Rost, C. Schmidt, B. Schoch, G. Suft, V. Sumachev, T. Szczepanek, D. Walther,

D.P.Watts , Chr. Weinheimer

The CB-ELSA/TAPS Collaboration

R. Castelijns, A.V. Anisovich, G. Anton, J.C.S. Bacelar, B. Bantes, O. Bartholomy,

D. Bayadilov, Y.A. Beloglazov, R. Bogendorfer, V. Crede, H. Dutz, A. Ehmanns,

D. Elsner, K. Essig, R. Ewald, I. Fabry, H. Flemming, K. Fornet-Ponse, M. Fuchs,

C. Funke, R. Gothe, R. Gregor, A.B. Gridnev, E. Gutz, S. Hoffgen, P. Hoffmeister,

I. Horn, J. Hossl, I. Jaegle, J. Junkersfeld, H. Kalinowsky, S. Kammer, Frank Klein,

Friedrich Klein, E. Klempt, H. Koch, M. Konrad, B. Kopf, M. Kotulla, B. Krusche,

J. Langheinrich, H. Lohner, I.V. Lopatin, J. Lotz, S. Lugert, H. Matthay, D. Menze,

T. Mertens, J.G. Messchendorp, V. Metag, C. Morales, M. Nanova, V.A. Nikonov,

D. Novinski, R. Novotny, M. Ostrick, L.M. Pant, H. van Pee, M. Pfeiffer, A. Roy,

A. Radkov, A.V. Sarantsev, S. Schadmand, C. Schmidt, H. Schmieden, B. Schoch,

S. Shende, A. Sule, G. Suft, V.V. Sumachev, T. Szczepanek, U. Thoma, D. Trnka,

R. Varma, D. Walther, C. Weinheimer, and C. Wendel

119

The PANDA Collaboration

W. Erni, I. Keshelashvili, B. Krusche, M. Steinacher, Y. Heng, Z. Liu, H. Liu, X. Shen, O. Wang, H. Xu, F.-

H. Heinsius, T. Held, H. Koch, B. Kopf, M. Pelizaus, M. Steinke, U. Wiedner, J. Zhong, A. Bianconi, M. Bragadireanu,

P. Dan, T. Preda, A. Tudorache, M. De Napoli, F. Giacoppo, G. Raciti, E. Rapisarda, E. Bialkowski, A. Budzanowski,

B. Czech, S. Kliczewski, A. Kozela, P. Kulessa, K. Malgorzata, K. Pysz, W. Schafer, R. Siudak, A. Szczurek, W. Bardan,

P. Brandys, T. Czyzewski, W. Czyzewski, M. Domagala, G. Filo, D. Gil, P. Hawranek, B. Kamys, P. Kazmierczak,

St. Kistryn, K. Korcyl, M. Krawczyk, W. Krzemien, E. Lisowski, A. Magiera, P. Moskal, J. Pietraszek, Z. Rudy,

P. Salabura, J. Smyrski, L. Wojnar, A. Wronska M. Al-Turany, I. Augustin, H. Deppe, H. Flemming, J. Gerl,

K. Gotzen, G. Hohler, D. Lehmann, B. Lewandowski, J. Luhning, F. Maas, D. Mishra, H. Orth, K. Peters, T. Saito,

G. Schepers, L. Schmitt, C. Schwarz, C. Sfienti, P. Wieczorek, A. Wilms, K.-T. Brinkmann, H. Freiesleben, R. Jakel,

R. Kliemt, T. Wurschig, H.-G. Zaunick, V.M. Abazov, G. Alexeev, A. Arefiev, V.I. Astakhov, M.Yu. Barabanov,

B.V. Batyunya, Yu.I. Davydov, V.Kh. Dodokhov, A.A. Efremov, A.G. Fedunov, A.A. Feshchenko, A.S. Galoyan,

S. Grigoryan, A. Karmokov, E.K. Koshurnikov, V.Ch. Kudaev, V.I. Lobanov, Yu.Yu. Lobanov, A.F. Makarov, L.V. Ma-

linina, V.L. Malyshev, G.A. Mustafaev, A. Olshevski, M.A. Pasyuk, E.A. Perevalova, A.A. Piskun, T.A. Pocheptsov,

G. Pontecorvo, V.K. Rodionov, Yu.N. Rogov, R.A. Salmin, A.G. Samartsev, M.G. Sapozhnikov, A. Shabratova,

G.S. Shabratova, A.N. Skachkova, N.B. Skachkov, E.A. Strokovsky, M.K. Suleimanov, R.Sh. Teshev, V.V. Tokmenin,

V.V. Uzhinsky A.S. Vodopianov, S.A. Zaporozhets, N.I. Zhuravlev, A.G. Zorin, D. Branford, K. Fohl, D. Glazier,

D. Watts, P. Woods, W. Eyrich, A. Lehmann, A. Teufel, S. Dobbs, Z. Metreveli, K. Seth, B. Tann, A. Tomaradze,

D. Bettoni, V. Carassiti, A. Cecchi, P. Dalpiaz, E. Fioravanti, M. Negrini, M. Savrie, G. Stancari, B. Dulach,

P. Gianotti, C. Guaraldo, V. Lucherini, E. Pace, A. Bersani, M. Macri, M. Marinelli, R.F. Parodi, W. Doring, P. Drexler,

M. Duren, Z. Gagyi-Palffy, A. Hayrapetyan, M. Kotulla, W. Kuhn, S. Lange, M. Liu, V. Metag, M. Nanova, R. Novotny,

C. Salz, J. Schneider, P. Schonmeier, R. Schubert, S. Spataro, H. Stenzel, C. Strackbein, M. Thiel, U. Thoring,

S. Yang, T. Clarkson, E. Downie, M. Hoek, D. Ireland, R. Kaiser, J. Kellie, I. Lehmann, K. Livingston, S. Lumsden,

D. MacGregor, B. McKinnon, M. Murray, D. Protopopescu, G. Rosner, B. Seitz, G. Yang, M. Babai, A.K. Biegun,

A. Bubak, E. Guliyev, V.S. Jothi, M. Kavatsyuk, H. Lohner, J. Messchendorp, H. Smit, J.C. van der Weele, F. Garcia,

D.-O. Riska, M. Buscher, R. Dosdall, A. Gillitzer, F. Goldenbaum, F. Hugging, M. Mertens, T. Randriamalala,

J. Ritman, S. Schadmand, A. Sokolov, T. Stockmanns, P. Wintz, J. Kisiel, S. Li, Z. Li, Z. Sun, H. Xu, S. Fissum,

K. Hansen, L. Isaksson, M. Lundin, B. Schroder, P. Achenbach, M.C. Mora Espi, J. Pochodzalla, S. Sanchez,

A. Sanchez-Lorente, V.I. Dormenev, A.A. Fedorov, M.V. Korzhik, O.V. Missevitch, V. Balanutsa, V. Chernetsky,

A. Demekhin, A. Dolgolenko, P. Fedorets, A. Gerasimov, V. Goryachev, A. Boukharov, O. Malyshev, I. Marishev,

A. Semenov, C. Hoppner, B. Ketzer, I. Konorov, A. Mann, S. Neubert, S. Paul, Q. Weitzel, A. Khoukaz, T. Rausmann,

A. Taschner, J. Wessels, R. Varma, E. Baldin, K. Kotov, S. Peleganchuk, Yu. Tikhonov, J. Boucher, T. Hennino,

R. Kunne, S. Ong, J. Pouthas, B. Ramstein, P. Rosier, M. Sudol, J. Van de Wiele, T. Zerguerras, K. Dmowski,

R. Korzeniewski, D. Przemyslaw, B. Slowinski, G. Boca, A. Braghieri, S. Costanza, A. Fontana, P. Genova, L. Lavezzi,

P. Montagna, A. Rotondi, N.I. Belikov, A.M. Davidenko, A.A. Derevschikov, Y.M. Goncharenko, V.N. Grishin,

V.A. Kachanov, D.A. Konstantinov, V.A. Kormilitsin, V.I. Kravtsov, Y.A. Matulenko, Y.M. Melnik A.P. Meschanin,

N.G. Minaev, V.V. Mochalov, D.A. Morozov, L.V. Nogach, S.B. Nurushev, A.V. Ryazantsev, P.A. Semenov, L.F. Soloviev,

A.V. Uzunian, A.N. Vasiliev, A.E. Yakutin, T. Back, B. Cederwall, C. Bargholtz, L. Geren, P.E. Tegner, S. Belostotski,

G. Gavrilov, A. Itzotov, A. Kisselev, P. Kravchenko, S. Manaenkov, O. Miklukho, Y. Naryshkin, D. Veretennikov,

V. Vikhrov, A. Zhadanov, L. Fava, D. Panzieri, D. Alberto, A. Amoroso, M. Anselmino, E. Botta, T. Bressani,

M.P. Bussa, L. Busso, F. De Mori, L. Ferrero, A. Grasso, M. Greco, T. Kugathasan, M. Maggiora, S. Marcello,

C. Mulatera, G.C. Serbanut, S. Sosio, R. Bertini, D. Calvo, S. Coli, P. De Remigis, A. Feliciello, A. Filippi, G. Giraudo,

G. Mazza, A. Rivetti, K. Szymanska, F. Tosello, R. Wheadon, O. Morra, M. Agnello, F. Iazzi, K. Szymanska, R. Birsa,

F. Bradamante, A. Bressan, A. Martin, H. Clement, C. Ekstrom, H. Calen, S. Grape, B. Hoistad, T. Johansson,

A. Kupsc, P. Marciniewski, E. Thome, J. Zlomanczuk, J. Dıaz, A. Ortiz, S. Borsuk, A. Chlopik, Z. Guzik, J. Kopec,

T. Kozlowski, D. Melnychuk, M. Plominski, J. Szewinski, K. Traczyk, B. Zwieglinski, P. Buhler, A. Gruber, P. Kienle,

J. Marton, E. Widmann, J. Zmeskal

120

The Pierre Auger CollaborationJ. Abraham, P. Abreu, M. Aglietta, C. Aguirre, E.J. Ahn, D. Allard, I. Allekotte, J. Allen, P. Allison, J. Alvarez-Muniz,

M. Ambrosio, L. Anchordoqui, S. Andringa, A. Anzalone, C. Aramo, S. Argiro, K. Arisaka, F. Arneodo, F. Arqueros,

T. Asch, H. Asorey, P. Assis, B.S. Atulugama, J. Aublin, M. Ave, G. Avila, T. Backer, D. Badagnani, K.B. Barber,

A.F. Barbosa, S.L.C. Barroso, B. Baughman, P. Bauleo, J.J. Beatty, T. Beau, B.R. Becker, K.H. Becker, A. Belletoile,

J.A. Bellido, S. BenZvi, C. Berat, T. Bergmann, P. Bernardini, X. Bertou, P.L. Biermann, P. Billoir, O. Blanch-Bigas,

F. Blanco, P. Blasi, C. Bleve, H. Blumer M. Bohavcova, C. Bonifazi, R. Bonino, J. Brack, P. Brogueira, W.C. Brown,

R. Bruijn, P. Buchholz, A. Bueno, R.E. Burton, N.G. Busca, K.S. Caballero Mora, L. Caramete, R. Caruso, W. Car-

valho, A. Castellina, O. Catalano, L. Cazon, R. Cester, J. Chauvin, A. Chiavassa, J.A. Chinellato, A. Chou, J. Chu-

doba, J. Chye, R.W. Clay, E. Colombo, R. Conceiccao, B. Connolly, F. Contreras, J. Coppens, A. Cordier, U. Cotti,

S. Coutu, C.E. Covault, A. Creusot A. Criss, J. Cronin, A. Curutiu, S. Dagoret-Campagne, K. Daumiller, B.R. Daw-

son, R.M. de Almeida, M. De Domenico, C. De Donato, S.J. de Jong, G. De La Vega, W.J.M. de Mello Junior,

J.R.T. de Mello Neto, I. De Mitri, V. de Souza, G. Decerprit, L. del Peral, O. Deligny, A. Della Selva, C. Delle Fratte,

H. Dembinski, C. Di Giulio, J.C. Diaz, P.N. Diep, C. Dobrigkeit, J.C.D. Olivo, P.N. Dong, D. Dornic, A. Dorofeev,

J.C. dos Anjos, M.T. Dova, D.D. Urso, I. Dutan, M.A. DuVernois, R. Engel, M. Erdmann, C.O. Escobar, A. Etchegoyen,

P. Facal San Luis, H. Falcke, G. Farrar, A.C. Fauth, N. Fazzini, F. Ferrer, A. Ferrero, B. Fick, A. Filevich, A. Filipcic,

I. Fleck, C.E. Fracchiolla, W. Fulgione, B. Garcıa, D. Garcıa Gamez, D. Garcia-Pinto, X. Garrido, G. Gelmini, H. Gem-

meke, P.L. Ghia, M. Giller, H. Glass, L.M. Goggin, M.S. Gold, G. Golup, F. Gomez Albarracin, M. Gomez Berisso,

P. Goncalves, M. Goncalves do Amaral, D. Gonzalez, J.G. Gonzalez, D. Gora, A. Gorgi, P. Gouffon, M. Grigat,

A.F. Grillo, Y. Guardincerri, F. Guarino, G.P. Guedes, J. Gutierrez, J.D. Hague, V. Halenka, P. Hansen, D. Harari,

S. Harmsma, J.L. Harton, A. Haungs, M.D. Healy, T. Hebbeker, G. Hebrero, D. Heck, C. Hojvat, V.C. Holmes, P. Ho-

mola, J.R. Horandel, A. Horneffer, M. Hrabovsky, T. Huege, M. Hussain, M. Iarlori, A. Insolia, F. Ionita, A. Italiano,

M. Kaducak, K.H. Kampert, T. Karova, P. Kasper, B. Kegl, B. Keilhauer, E. Kemp, R.M. Kieckhafer, H.O. Klages,

M. Kleifges, J. Kleinfeller, R. Knapik, J. Knapp, D.-H. Koang, A. Krieger, O. Kromer, D. Kuempel, N. Kunka,

A. Kusenko, G. La Rosa, C. Lachaud, B.L. Lago, M.S.A.B. Leao, D. Lebrun, P. Lebrun, J. Lee, M.A. Leigui de Oliveira,

A. Lemiere, A. Letessier-Selvon, M. Leuthold, I. Lhenry-Yvon, R. Lopez, A. Lopez Aguera, J. Lozano Bahilo, A. Lucero,

R. Luna Garca, M.C. Maccarone, C. Macolino, S. Maldera, D. Mandat, P. Mantsch, A.G. Mariazzi, I.C. Maris,

H.R. Marquez Falcon, D. Martello, J. Martınez, O. Martınez Bravo, H.J. Mathes, J. Matthews, J.A.J. Matthews,

G. Matthiae, D. Maurizio, P.O. Mazur,M. McEwen, R.R. McNeil, G. Medina-Tanco, D. Melo, E. Menichetti, A. Men-

shikov, Chr. Meurer, R. Meyhandan, M.I. Micheletti, G. Miele, W. Miller, L. Miramonti, S. Mollerach, M. Mona-

sor, D. Monnier Ragaigne, F. Montanet, B. Morales, C. Morello, J.C. Moreno, C. Morris, M. Mostafa, M.A. Muller,

R. Mussa, G. Navarra, J.L. Navarro, S. Navas, P. Necesal, L. Nellen, C. Newman-Holmes, D. Newton, P.T. Nhung,

N. Nierstenhoefer, D. Nitz, D. Nosek, L. Nozka, J. Oehlschlager, A. Olinto, V.M. Olmos-Gilbaja, M. Ortiz, F. Ortolani,

N. Pacheco, D. Pakk Selmi-Dei, M. Palatka, J. Pallotta, G. Parente, E. Parizot, S. Parlati, S. Pastor, M. Patel, T. Paul,

V. Pavlidou, K. Payet, M. Pech, J. Pekala, R. Pelayo, I.M. Pepe, L. Perrone, R. Pesce, E. Petermann, S. Petrera,

P. Petrinca, A. Petrolini, Y. Petrov, J. Petrovic, C. Pfendner, A. Pichel, R. Piegaia, T. Pierog, M. Pimenta, T. Pinto,

V. Pirronello, O. Pisanti, M. Platino, J. Pochon, V.H. Ponce, P. Privitera, M. Prouza, E.J. Quel, J. Rautenberg, D. Ravi-

gnani, A. Redondo, S. Reucroft, B. Revenu, F.A.S. Rezende, J. Ridky, S. Riggi, M. Risse, C. Riviere, V. Rizi, C. Robledo,

G. Rodriguez, J. Rodriguez Martino, J. Rodriguez Rojo, I. Rodriguez-Cabo, M.D. Rodrıguez-Frıas, G. Ros, J. Rosado,

M. Roth, B. Rouille-d’Orfeuil, E. Roulet, A.C. Rovero, F. Salamida, H. Salazar, G. Salina, F. Sanchez, M. San-

tander, C.E. Santo, E.M. Santos, F. Sarazin, S. Sarkar, R. Sato, N. Scharf, V. Scherini, H. Schieler, P. Schiffer,

A. Schmidt, F. Schmidt, T. Schmidt, O. Scholten, H. Schoorlemmer, J. Schovancova, P. Schovanek, F. Schroeder,

S. Schulte, F. Schussler, D. Schuster, S.J. Sciutto, M. Scuderi, A. Segreto, D. Semikoz, M. Settimo, R.C. Shellard,

I. Sidelnik, B.B. Siffert, N. Smetniansky De Grande, A. Smialkowski, R. Smıda, B.E. Smith, G.R. Snow, P. Sommers,

J. Sorokin, H. Spinka, R. Squartini, E. Strazzeri, A. Stutz, T. Suomijarvi, A.D. Supanitsky, M.S. Sutherland, J. Swain,

Z. Szadkowski, A. Tamashiro, A. Tamburro, T. Tarutina, O. Tascau, R. Tcaciuc, D. Tcherniakhovski, N.T. Thao,

D. Thomas, R. Ticona, J. Tiffenberg, C. Timmermans, W. Tkaczyk, C.J. Todero Peixoto, B. Tome, A. Tonachini,

I. Torres, P. Travnicek, D.B. Tridapalli, G. Tristram, E. Trovato, V. Tuci, M. Tueros, R. Ulrich, M. Unger, M. Urban,

J.F. ValdesGalicia, I. Valino, L. Valore, A.M. van den Berg, R.A. Vazquez, D. Veberic, A. Velarde, T. Venters, V. Verzi,

M. Videla, L. Villasenor, S. Vorobiov, L. Voyvodic, H. Wahlberg, P. Wahrlich, O. Wainberg, D. Warner, A.A. Watson,

S. Westerhoff, B.J. Whelan, G. Wieczorek, L. Wiencke, B. Wilczynska, H. Wilczynski, C. Wileman, M.G. Winnick,

H. Wu, B. Wundheiler, P. Younk, G. Yuan, E. Zas, D. Zavrtanik, M. Zavrtanik, I. Zaw, A. Zepeda, M. Ziolkowski

121

The WA98 Collaboration

P.V.K.S. Baba, S.K. Badyal, S. Bathe, B. Batiounia, T. Bernier, K.B. Bhalla, V.S. Bhatia, C. Blume, D. Bucher,

H. Busching, L. Carlen, S. Chattopadhyay, M.P. Decowski, H. Delagrange, P. Donni, M.R. Dutta Majumdar,

K. El Chenawi, A.K. Dubey, K. Enosawa, S. Fokin, V. Frolov, M.S. Ganti, S. Garpman, O. Gavrishchuk,

F.J.M. Geurts, T.K. Ghosh, R. Glasow, B. Guskov, H.A. Gustafsson, H.H. Gutbrod, I. Hrivnacova, M. Ippolitov,

H. Kalechofsky, R. Kamermans, K. Karadjev, K. Karpio, B. W. Kolb, I. Kosarev, I. Koutcheryaev, A. Kugler, P. Kulinich,

M. Kurata, A. Lebedev, H. Liu, H. Lohner, L. Luquin, D.P. Mahapatra, V. Manko, M. Martin, G. Martınez, A. Maximov,

Y. Miake, G.C. Mishra, B. Mohanty, M.-J. Mora, D. Morrison, T. Moukhanova, D.S. Mukhopadhyay, H. Naef,

B.K. Nandi, S.K. Nayak, T.K. Nayak, A. Nianine, V. Nikitine, S. Nikolaev, P. Nilsson, S. Nishimura, P. Nomokonov,

J. Nystrand, A. Oskarsson, I. Otterlund, S. Pavliouk, T. Peitzmann, D. Peressounko, V. Petracek, V. Petracek,

W. Pinanaud, F. Plasil, M.L. Purschke, J. Rak, R. Raniwala, S. Raniwala, N.K. Rao, F. Retiere, K. Reygers, G. Roland,

L. Rosselet, I. Roufanov, C. Roy, J.M. Rubio, S.S. Sambyal, R. Santo, S. Sato, H. Schlagheck, H.-R. Schmidt,

Y. Schutz, G. Shabratova, T.H. Shah, I. Sibiriak, T. Siemiarczuk, D. Silvermyr, B.C. Sinha, N. Slavine, K. Soderstrom,

G. Sood, S.P. Sorensen, P. Stankus, G. Stefanek, P. Steinberg, E. Stenlund, M. Sumbera, T. Svensson, A. Tsvetkov,

L. Tykarski, E.C.v.d. Pijll, N. v. Eijndhoven, G.J. v. Nieuwenhuizen, A. Vinogradov, Y.P. Viyogi, A. Vodopianov,

S. Voros, B. Wyslouch, G.R. Young

Theses

122

Ph.D.

H. van EsThermoluminescence dating of sediments using mineral zirconUniversity of Groningen, 18 April 2008

H. Mardanpour-MollalarInvestigation of nuclear forces in ~d + p elastic and ~p + d break-upreactions at intermediate energiesUniversity of Groningen, 16 May 2008

S. DeLaser cooling and trapping of bariumUniversity of Groningen, 12 September 2008

M. SohaniSetup for precise measurements of β-decay in optically trapped radioac-tive NaUniversity of Groningen, 13 October 2008

V.G. HasanMOTRIMS investigations of electron removal from Na by highly chargedionsUniversity of Groningen, 20 October 2008

A.K. MollemaLaser-cooling, trapping and spectroscopy of calcium isotopesUniversity of Groningen, 14 November 2008

S. PurushothamanSuperfluid helium and cryogenic noble gases as stopping media for ioncatchers University of Groningen, 28 November 2008

Contributions to conferences,workshops, etc.

123

ASPERA R&D meeting, Lisbon, Portu-gal, 8 January 2008A.M. van den BergRadio detectioninvited talk

EURISOL User Group, Florence, Italy14 - 18 January 2008K. JungmannFundamental Interactions, Exotic Beamsand Physics beyond the Standard Model -Commisioning of TRIµPinvited talk

Physics @ FOM, Veldhoven, the Nether-lands 22 - 23 January 2008K. JungmannTrapped Radioactive Isotopes -µicrolaboratories for fundamental Physicsinvited talk

S. DeCooling of Heavy Alkaline-earth elementstalk

S. Bari, M. Inklaar, D. Gosset, F. van Sei-jen, R. Hoekstra, T. SchlatholterRadiation damage on water-embeddedbiomoleculesposter

E. Bodewits, H. Dang, R. Morgenstern,T. Schlatholter, and R. HoekstraAtomic-scale probing of spin polarization atsurfacesposter

DRSTP AIO/OIO School TheoreticalParticle Physics, Driebergen, 28 Jan-uary - 1 February 2008R.G.E. TimmermansPrecision tests of the Standard Model10 invited lectures

Heraeus-Seminar ”High-Energy CosmicRays - multi messenger astrophysicsin theory and experiment”, Physikzen-trum Bad Honeff, Germany, 11 - 13February 2008A.M. van den BergRadio detection of cosmic raysinvited lecture

DPG Spring Meeting, Darmstadt, Ge-many, 10 - 14 March 2008S. De, J. van den Berg, A.J. Mol, K. Jung-mann, L. WillmannLaser Cooling and Trapping of a LeakySystem: Bariumtalk

O.O Versolato, L.W. Wansbeek, L. Will-mann, R.G. Timmermans, K. JungmannOne single trapped and laser cooled ra-dium ion: Towards an all-optical atomicclockposter

L.W. Wansbeek, O. Versolato, L. Will-mann, R.G. Timmermans, K. JungmannAtomic parity violation in one singletrapped radium ion as a probe of elec-troweak runningposter

A.J. Mol, S. De, K. Jungmann,H.W. Wilschut, L. WillmannSpectroscopy of neutral Radiumtalk

S. Bari, M. Inklaar, D. Gosset, F. van Sei-jen, J. Postma, F. Alvarado, R. Hoekstra,T. SchlatholterRadiation damage on water-embeddedbiomoleculesposter

W.L. Kruithof, D.J. van der Hoek, M.Sohani, L. Willmann, H.W. Wilschut, K.JungmannTrapping of polarized 21Natalk

E. Traykov, O.C. Dermois, D.J. vander Hoek, K. Jungmann, W.L. Kruithof,A.J. Mol, C.J.G. Onderwater, M. da Silva,M. Sohani, O.O. Versolato, L. Willmann,H.W. WilschutDevelopment of a thermal ionizer as ioncatcherposter

Workshop ”Nuclear Physics Researchat the MYRRHA Accelerator”, SCK-CENMol Belgium, 7 - 9 April 2008Hans WilschutTRIµP: atomic traps for the study of funda-mental interactions and symmetriesinvited talk

Nikhef SAC meeting, Nikhef, Amster-dam, The Netherlands, 17 April 2008A.M. van den BergUsing the Pierre Auger Observatory for As-troparticle and High-Energy Physicsinvited talk

The joint R3B/EXL/ELISe collabora-tion meeting on technical issues, GSI,Germany, 21 - 24 April 2008C. RigolletThe R3B and EXL demonstratorstalk

C. RigolletDesign and technical realisation of the fastejectile detector system of EXLtalk

International Workshop on a Very LargeVolume Neutrino Telescope for theMediterranean Sea, VLVnT08, Toulon,France, 22 - 24 April 2008H. Lohner, A. Mjos, for the KM3NeT Col-laborationSensitivity of a multi-photomultiplier opti-cal module for KM3NeTinvited talk

The XXth rencontres de Blois, pre-sented by S. Buitink for the NuMoonCollaboration, Blois, France, 19 - 23May 2008O. ScholtenThe NuMoon experiment: 1rst resultsinvited talk

124

3rd Annual Meeting ITS LEIF, DaBalaıa, Portugal, 19 - 24 May 2008S. Bari, M. Inklaar, D. Gosset, F. van Sei-jen, J. Postma, F. Alvarado, R. Hoekstra,T. SchlatholterRadiation damage on water-embeddedbiomoleculesposter

J. Postma, S. Bari, P. Sobocinski, A. Tie-lens, R. Hoekstra, T. SchlatholterFragmentation and ionization of PolycyclicAromatic Hydrocarbons and Diffuse Inter-stellar Bandsposter

N. Stolterfoht, R. Hellhammer, B. Sulik,Z. Juhasz, E. Bodewits, H. Dang, R. Hoek-stra Ion guiding through nanocapillaries inPET polymers with variable diameterposterE. Bodewits, H. Dang, M. Unipan,A. Robin, R. Morgenstern, R. HoekstraSurface magnetism measured by MECSposter

Symposium on ”Trends in heavy ionphsyics research”, Dubna, Russian Fed-eration, 21 - 25 May 2008M.N. HarakehNuclear Physics at KVI: achievements andperspectivesinvited talk

Atomic cluster collisions: structureand dynamics from the nuclear to thebiological scale (ISACC 2008), St. Pe-tersburg, Russia, 2 - 7 June 2008T. SchlatholterIon collisions with amino acids, clusters ofamino acids and peptidesinvited talk

10th International Workshop on MesonProduction, Properties and Interaction,Krakow, Poland, 6 - 10 June 2008L. JoulaeizadehPionic fusion experiments at subthresholdenergiestalk

Symposium Internationales Wis-senschaftsforum Heidelberg ”P and Tviolation at Low Energies and RelatedPhenomena”, Germany, 9 - 11 June2008R.G.E. TimmermansParity violation in a single radium ioninvited talk

L. WillmannRadium Atom: Electron and Nuclear EDM’sinvited talk

Conference EURORIB08, Giens, France,9 - 13 June 2008M.N. HarakehNuPECC evolving roadmap for RIB largescale facilitiesinvited talk

H.W. WilschutThe role of atomic trapping in beta de-cay and searches for a permanent electricdipole momentinvited talk

M. RanjanCharacterisation of ion beams from a cryo-

genic ion guideposter

T. Faestermann for the S330 and RISINGcollaborationSpectroscopy in the neighbourhood of100Sntalk

C. RigolletFrom ESR to NESR: the EXL experiment atFAIRposter

Radiation Damage in Biomolecular Sys-tems (RADAM 2008), Debrecen, Hun-gary, 13 - 15 June 2008S. BariIon induced ionization and fragmentationof DNA related biomoleculesinvited talk

5th International Conference on NewDevelopments in Photodetection 2008,Aix-les-Bains, France, 15 - 20 June2008R. VinkeOptimizing timing resolution of SiPM sen-sors for use in TOF-PET detectorstalk

The ARENA conference Rome, Italy, 24- 27 June 2008O. ScholtenCoherent radiation from extensive airshowerstalk

O. ScholtenUltra-high energy cosmic ray and neutrinophysics using the mooninvited talk

25th International Conference on LowTemperature Physics, Amsterdam, theNetherlands, 6 - 13 August 2008S. PurushothamanSecond-sound Pulses and Ions in Super-fluid Heliumposter

20th International Conference on theApplication of Accelerators in Researchand Industry (CAARI 2008), Ft. Worth,Texas, 10 - 15 August 2008T. SchlatholterIonization and fragmentation ofbiomolecules and biomolecular clustersupon keV ion impactinvited talk

APFB08, The 4th Asia-Pacific Confer-ence on Few-Body Problems in Physics,Depok, Indonesia, 19 - 23 August 2008J.G. MessendorpFew-nucleon studies at intermediate ener-giesinvited plenary talk

A. Ramazani Moghaddam AraniStudy of all reaction channels in deuteron-deuteron scatteringtalk

M. Eslami-KalantariProton-deuteron break-up measurementswith BINA at 135 MeVtalk

125

14th International Conference on ThePhysics of Highly Charged Ions, HCI-14,Chofu, Japan, 1 - 5 September 2008N. Stolterfoht, R. Hellhammer, B. Sulik,Z. Juhasz, E. Bodewits, H. Dang, R. Hoek-straIon guiding through nanocapillaries in PETpolymers with variable diameterposter

I. Blank, G. Hasan, S. Gotz, T. Mullins,W. Salzmann, R. Morgenstern, M. Wei-demuller, R. HoekstraInvestigation of multiple electron transferin ion - atom collisionsposter

The ENAM 08 conference, Ryn, Poland,7 - 13 September 2008T. Faestermann for the S330 and RISINGcollaborationSpectroscopy in the neighbourhood of100Sntalk

PANDA Collaboration Meeting, Ferrara,Italy, 8 - 12 September 2008R.G.E. TimmermansThe challenge of QCDinvited plenary talk

ESTRO 27 Goteborg, Sweden, 14 - 18September 2008G. Ghobadi, H. Faber, J.M. Schip-pers, S. Brandenburg, J.A. Langendijk,R.P. Coppes, P. van LuijkQuantification of radiation-induced localdamage in rat lung from computed tomog-raphyposter

H. Faber, P. van Luijk, C.T. Muijs,J.M. Schippers, S. Brandenburg,J.A. Langendijk, R.P. CoppesEnhanced expression of early injury withincreased irradiated rat lung volumesposter

P. van Luijk, H. Faber, J.M. Schippers,S. Brandenburg, H. Meertens, J.A. Lan-gendijk, R.P. CoppesThe effect of a sub-tolerance dose to a largevolume on rat parotid gland function afterirradiation of small sub-volumetalk

Klausurtagung des Graduiertenkol-legs ”Eichtheorien experimentelle Testund theoretische Grundlagen”, Bul-lay/Mainz, Germany, 15 - 17 Septem-ber 2008K. JungmannSymmetries in Particle Physics - High-lighted with Examples of Precision Mea-surements at Low Energiesinvited lecture series

18th International Workshop on ECRIon Sources ECRIS08, Chicago, USA,15 - 18 September 2008A. Kitagawa, M. Muramatsu, T. Fujita,W. Takasugi, S. Wakaisami, S. Biri,A.G. DrentjeProduction of Multi-Charged Ions for Exper-imental Use at HIMACposter

G.S. Taki, R. Bhandari, D. Chakraborty,

P. Sarma, P. Ray, A.G. Drentje, T. Naka-gawaStudy of the dependence of ECR ion cur-rent on periodic plasma disturbancetalk

H.R. Kremers, S. Brandenburg J.P.M. Bei-jers, V. Mironov, S. SaminathanSystematic comparison between a pepper-pot and an ALLISON emittance metertalk

H.R. Kremers, J.P.M. Beijers, S. Branden-burg, S. Saminathan, V. MironovComparison between an ALLISON scannerand the KVI-4D emittance metertalk

V. Mironov, J.P.M. Beijers, S. SaminathanThree-dimensional simulations of ion dy-namics in plasma of electron cyclotron res-onance ion sourcetalk, not presented because of refusal ofUS authorities to grant an entrance visa

A. Kitagawa, M. Muramatsu, T. Fujita,W. Takasugi, S. Wakaisami, S. Biri,A.G. DrentjeProduction of Multi-Charged Ions for Exper-imental Use at HIMACposter

G.S. Taki, R. Bhandari, D. Chakraborty,P. Sarma, P. Ray, A.G. Drentje, T. Naka-gawaStudy of the dependence of ECR ion cur-rent on periodic plasma disturbancetalk

The 7th International Conferenceon Nuclear Physics at Storage Rings(STORI’08), Lanzhou, China, 15 - 18September 2008N. Kalantar-NayestanakiFirst feasibility study for EXL with pro-totype detectors at the ESR and detectorsimulationstalk

14th International Symposium onSmall Particles and Inorganic Clusters,Valladolid, Spain, 15 - 19 September2008J. PostmaIonization and fragmentation of isolatedbiomolecules and clusters: An overview ofenvironment effects and structure depen-dencetalk

6th Balkan school on Nuclear Physics,Troyan, Bulgaria, 17 - 24 September2008H.W. WilschutThe radioactive nucleus as a laboratory forfundamental interaction studiesinvited lecture

17th International Conference on In-elastic Ion Surface Interactions, IISC-17, Porquerolles, France, 21 - 26September 2008E. Bodewits, A. de Nijs, H.M. Dang,T. Schlatholter, R. HoekstraInteraction of low-energy He2+ ions withsurfacesposter

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International workshop on ”Low En-ergy Precision Electroweak Physics inthe LHC Era”, Seattle, USA, 22 Septem-ber - 5 December 2008C.J.G. OnderwaterMagnetometry for Muon g − 2invited talk

ECT* Workshop on Bound States andResonances in Effective Field Theories,Trento, Italy, 29 September - 3 October2008R.G.E. TimmermansChiral effective field theory for the two-nucleon system: Pining for the fjords?invited talk

Auger radio Workshop, RWTH Aachen,Germany, 30 September - 1 October2008E.D. FraenkelSetup of MAXIMA stationstalk

K. de VriesRealistic shower simulations for geomag-netic radiationtalk

Spin 2008: 18th International Sympo-sium on Spin Physics, Charlottesville,University of Virginia, USA, 6 - 11 Oc-tober 2008C.J.G. OnderwaterStorage Rings for EDM Searchesinvited talk

M. da SilvaTowards High-Precision Deuteron Po-larimetry talk

N. Kalantar-NayestanakiWhat have we learned about three-nucleonsystems at intermediate energies?invited talk

3rd LASPEC-MATS Workshop, Matalas-canas (Huelva), Spain, 9 - 10 October2008P.DendoovenTowards a cryogenic gas catcher for theSuper-FRSinvited talk

Joint R3B/EXL/ELISe collaborationmeeting, Goteborg, Sweden, 13 - 17October 2008C. RigolletR3B and EXL demonstrators: Status andperspectivestalk

C. RigolletMechanical design of the R3B and EXLdemonstratorstalk

C. RigolletIn-beam tests of the R3B and EXL demon-stratorstalk

European Cyclotron Progress Meeting,Berlin, Germany, 16 - 18 October 2008

S. Brandenburg, J.P.M. Beijers, M.A. Hof-stee, H.R. Kremers, V. Mironov, J. Mulder,H. PostThe AGOR-facility towards 1 kW heavy ionbeamstalk

M.A. Hofstee, S. BrandenburgVacuum effects in the AGOR cyclotron forhigh power heavy ion beamstalk

R. Ostendorf, M.A. Hofstee, S. Branden-burg, M. van Goethem, E. van der Graaf,H. KiewietThe AGORFIRM Facility for Irradiation ofMaterialsposter

S. Brandenburg for the AGOR-designteamStability of superconducting cyclotron mag-netsposter

2008 IEEE Nuclear Science Symposiumand Medical Imaging Conference, Dres-den, Germany, 19 - 25 October 2008R. VinkeOptimizing timing resolution for TOF PETdetectors based on monolithic scintillationcrystals using fast photosensor arraysposter

ASPERA R&D Meeting, Nikhef, Amster-dam, the Netherlands, 28 October 2008A.M. van den BergScience meets SME’s, lessons learned fromSWITSinvited talk

A.M. van den BergRadio detection of cosmic particlesinvited talk

32nd Annual National Meeting of theSection Atomic, Molecular and Opti-cal Physics, Lunteren, 28 - 29 October2008T. SchlatholterMolecular mechanisms underlying heavyion therapyinvited talk

S. Bari, G. Reitsma, F. Duvoux, M. Vonk,J. Postma, F. Alvarado, R. Hoekstra,T. SchlatholterIon-induced ionization and fragmentationof DNA related biomoleculesposter

J. Postma, S. Bari, P. Sobocinski, A. Tie-lens, R. Hoekstra, T. SchlatholterFragmentation and ionization of PolycyclicAromatic Hydrocarbons and InterstellarPhenomenaposter

H. M. Dang, E. Bodewits, R. Hoekstra,T. SchlatholterMultiply charged ion induced modificationof uracil thin filmsposter

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NNV Najaarsvergadering Secties Kern-fysica en Hoge-energiefysica, Lunteren,the Netherlands, 7 November 2008M. RanjanA cryogenic gas catcher for high energy ra-dioactive ionstalk

K. de VriesA macroscopic model for Extensive AirShower simulationstalk

M. da Silva e SilvaTowards high precision deuteron polarime-trytalk

A.M. van den BergThe Pierre Auger Observatory, a telescopeto observe the high-energy universeinvited talk

A. BiegunSimulations for the future experiment -PANDAtalk

M. Eslami-KalantariStudy of three-nucleon force effects inproton-deuteron break-up at 135 MeVtalk

H. MoeiniFirst feasibility experiment and simula-tions for EXLtalk

K. SinghUltra-high energy cosmic ray and neutrinophysics using the Moontalk

A. Ramazani Moghaddam AraniA study of all reaction channels indeuteron-deuteron scattering at 65MeV/nucleontalk

P. ShidlingProduction of short-lived radium nuclidesat the TRIµP facilitytalk

S. StoicaDynamic generation of resonances in nu-cleon antinucleon scatteringtalk

Contribution to the InternationalConference on Particles And Nuclei,PANIC08, Eilat, Israel, 9 - 14 November2008H. Lohner, for the ANTARES CollaborationHigh Energy Neutrino Detection in theANTARES Underwater Neutrino Telescopeinvited talk

Workshop Japan-Netherlands on En-ergy Transition, Groningen, the Nether-lands, 17 November 2008M.N. HarakehNuclear Energy: Transition and Sustain-abilityinvited talk

Annual Coastal Ecology Workshop,Haamstede, the Netherlands, 24 - 27November 2008A.V. de Groot, J.P. BakkerSand in the salt marshtalk

Organized conferences, workshops, etc.

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The 4th Computing workshop on tracking, pattern recogni-tion and particle identification with the FAIR-Root frame-workKVI Groningen, the Netherlands, 21 - 25 January 2008A. Biegun, A. Bubak, J.G. Messchendorp

PANDA Electromagnetic Calorimeter / FE Electronics Meet-ingKVI Groningen, the Netherlands, 31 January - 1 February 2008H. Lohner

Highlights in Nuclear StructureEcole national superieure de chimie de Paris, France, 12 - 13 May2008A. Korichi, C. Rigollet, J.N. Wilson, H. Savajols, D. Dassie

FANTOM study week ”The Early Universe”Munster, Germany, 15 - 16 May 2008D. Frekers, F. Hammache, R. Hoekstra, M. Koopmans, N. Severi-jns, R. Timmermans, D. Van Neck, Chr. Weinheimer

Symposium ”P and T violation at low energies and relatedPhenomena”Heidelberg, Germany, 9 - 11 June 2008M. DeKiewiet, T. Gasenzo, K. Jungmann, O. Nachtmann, T.Stohlker

FANTOM study week ”Nuclear Astrophysics”Paris, France, 3 - 6 November 2008D. Frekers, F. Hammache, R. Hoekstra, M. Koopmans, N. Severi-jns, R. Timmermans, D. Van Neck, Chr. Weinheimer

Seminars at KVI

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21 January 2008S. Knoop, Innsbruck, SwitserlandEfimov physics in ultra cold atomic andmolecular quantum Cs gases

4 March 2008N. Stolterfoht, HMI Berlin, GermanyGuided transmission of highly chargedions through nanocapillaries in an insu-lating polymer

18 March 2008J. Engelen, CERN, SwitzerlandProton-proton collisions at 14 TeV: all ornothing

25 March 2008M. de Huu, Physicist, R&D DepartmentContrinex AG, SwitzerlandA sensor’s life

8 April 2008S. Scherer, Univ. Mainz, GermanyChiral perturbation theory – success andchallenge

15 April 2008S. Shimizu, Osaka University, JapanSearch for T -violating transverse muon po-larization in K+ → π0 µ+ ν at J-PARC

22 April 2008P. Havinga, Univ. Twente, Enschede, TheNetherlandsEnvironmental Wireless Sensor Networkson Coral Reefs: Scientific Needs and Tech-nological Challenges

6 May 2008T. Saito, GSI Darmstadt, GermanyHypernuclei

15 May 2008H. Mardanpour AMSL/KVI Groningen,The NetherlandsInvestigation of nuclear forces in d+p elas-tic and p+ d break-up reactions

16 May 2008P. Sauer, University of Hannover, Ger-manyFew-nucleon scattering – The inclusion ofCoulomb in the description

20 May 2008S. Lange, University Giessen, GermanyNew Charmonium States at Belle

27 May 2008G. Palasantzas, Zernike Institute for Ad-vanced Materials, University of Gronin-gen, The NetherlandsCasimir effect. From surface science to lab-oratory cosmology

3 June 2008R. Shyam, Saha Institute of NuclearPhysics, Kolkata, IndiaOpen and hidden strangeness productionwith hadronic and electromagnetic probes

24 June 2008E. Hedlund, Uppsala, SwedenStudies of heavy ion induced desorption inthe energy range 5− 100 MeV/u

1 July 2008U. Thoma, University Bonn, GermanyBaryon Spectroscopy: Recent Results fromthe Crystal Barrel/TAPS Experiment atELSA

1 August 2008S. Rahaman, University of Jyvaskyla, Fin-landIon traps and their applications in preci-sion experiments

12 Aug 2008B. van Kolck, Arizona University, Tucson,USAFrom nuclei to cold atoms and back

14 August 2008A. Sedrakian, ITP, Univ. Frankfurt amMain, GermanySelected problems in few and many bodyphysics of compact stars

1 September 2008A. Arima, Japan Science Foundation,Tokyo, Japan0+ dominance and related topics

2 September 2008S. De, KVI Groningen, The NetherlandsLaser cooling and trapping of barium

9 September 2008A. Mollema, KVI Groningen, The Nether-landsAspects of laser cooling, trapping and spec-troscopy of calcium isotopes

12 September 2008E. Riis, Strathclyde University, Glasgow,ScotlandBose Einstein Condensates in rings andcold Calcium

23 September 2008C. Roos, Inst. for Quantum Optics andQuantum Information, Austrian Academyof Sciences, Innsbruck, AustriaPrecision measurements with one and twotrapped calcium ions

30 September 2008T.H.J.J. van der Hagen, Reactor InstituteDelft, The NetherlandsFrom fossil technologies towards an En-ergy Revolution

3 October 2008T. Kishimoto, director RCNP, JapanStudy of 48Ca Double Beta Decay and Can-dles

7 October 2008P. Wieczorek, GSI Darmstadt, GermanyASIC development for PANDA

9 October 2008T. Kessler, Univ. Jyvaskyla, FinlandDevelopment and application of laser tech-nologies at radioactive ion beam facilities

13 October 2008M. Sohani, KVI Groningen, The Nether-landsSetup for precise measurements of beta-decay in optically trapped radioactive Na

130

14 October 2008F. Maas, GSI Darmstadt, GermanyThe structure of the nucleon, from parityviolation to antiproton annihilation

15 October 2008G. Hasan, KVI Groningen, The Nether-landsMotrims investigations of electron removalfrom Na by highly charged ions

20 November 2008P. Maris, Dept. of Physics and Astronomy,Iowa State University, USAAb initio calculations of light nuclei

27 NovemberS. Purushothaman, KVI Groningen, TheNetherlandsSuperfluid helium and cryogenic noblegases as stopping media for ion catchers

Seminars and colloquia givenoutside KVI

131

O. ScholtenMacroscopic Geo-Magnetic RadiationModelSeminar, Subatech, Nantes, France14 January 2008

A. MollemaLaser cooling, trapping, spectroscopy andtrace analysis of calcium isotopesSeminar, University of Strathclyde, De-partment of Physics, Glasgow, Scotland,United Kingdom25 January 2008

A.G. DrentjeExperiments with a small ECR Ion sourcefor Carbon TherapyColloquium, iThemba LABS, Stellen-bosch, South Africa28 January 2008

O. ScholtenA coupled-channels partial-wave analysisof kaon photoproduction dataSeminar, Giessen, Germany7 February 2008

R. HoekstraIon induced radiation on the molecularlevelColloquium, Max Planck Institute Heidel-berg, Heidelberg, Germany13 February 2008

H.M. DangProduction and analysis of biomolecularthin films for ion irradiation studiesPresentation, 1st ITS LEIF Winter School,Obergurgl, Austria21 February 2008

R.G.E. TimmermansUnificatie van natuurkrachtenLecture at the ”Open dag op locatie”, Fac-ulty of Sciences, University of Groningen,TheNetherlands7 March 2008

L. WillmannSearches for violations of fundamentalsymmetries: How laser cooling of leakyatomic systems can ContributeColloquium, Strathclyde University, Glas-gow, United Kingdom19 March 2008

O. ScholtenUltra-high energy cosmic ray and neutrinophysics using the moonSeminar, MPI, Munchen, Germany10 April 2008

P. DendoovenDetector technology for time-of-flightpositron emission tomographySeminar, University of Jyvaskyla, Finland24 April 2008

T. SchlatholterIonization and fragmentation ofbiomolecules and biomolecular clustersupon keV ion impactSeminar, Open University, Milton Keynes,UK29 May 2008

S. BariIon-induced ionization and fragmentationof DNA related biomoleculesSeminar, Stockholm University, Stock-holm, Sweden18 September 2008

H.W. WilschutFundamental symmetries and interactionsstudied with radioactive isotopesColloquium, European Graduate SchoolGiessen, Giessen, Germany23 October 2008

R.G.E. TimmermansContactPublic lecture at the KVI ”Open Dag”, KVIGroningen, The Netherlands26 October 2008

S. BrandenburgKernenergie: bijdrage aan de energietran-sitie?Rotary Groningen, The Netherlands29 October 2009

M.N. HarakehStudy of spin-isospin modes and their in-fluence on astrophysical processesSeminar, Institute of Nuclear Physics,Polish Academy of Sciences (IFJ PAN),Krakow, Poland20 October 2008

M.N. HarakehNuclear physics programs at KVI: achieve-ments and perspectivesSeminar, Hadron Physics Research Cen-ter, Krakow, Poland21 October 2008

L. WillmannSpiegelsPublic lecture at the KVI ”Open Dag”, KVIGroningen, The Netherlands26 October 2008

R.G.E. TimmermansDe val van pariteitLecture at the ”Philosophy-meets-physics”evening, organized by STUFF (”StudentenFaculteit Filosofie”), University of Gronin-gen, The Netherlands11 November 2008

T. SchlatholterMolecular mechanisms underlying heavyion therapySeminar, Universitat Giessen, Giessen,Germany13 November 2008

S. BrandenburgKernenergie: bijdrage aan de energietran-sitie?Probus Club, Veendam, The Netherlands19 November 2008

M.N. HarakehNuclear Energy: Transition and Sustain-abilityLecture, Social Systems Analysis of Tech-nological Innovation, Faculty of Eco-nomics and Business, University ofGroningen, Groningen, The Netherlands5 December 2008

132

A.G. DrentjeExperiments with fundamental aspectsperformed in a small ECR Ion source forCarbon TherapyInternational Seminar on ECR Ion Sourceand Nanotechnology, Toyo University,Kawagoe, Japan6 December 2008

S. BrandenburgRadiotherapy with ionsSymposium Medische Fysica TFV Profes-

sor Francken, Groningen, The Nether-lands10 December 2008

R.G.E. TimmermansThe Nobel Prize in Physics 2008Physics Colloquium, Faculty of Mathe-matics and Natural Sciences, Universityof Groningen, The Netherlands18 December 2008