FRM II news

CONTENTS

Instrumentation- 2- SPODI- 3- PGAA - 4- NEPOMUC- 5- J-NSE- 6- N-REX+

- 7- Sample Environment

Events- 8- 8th German Neutron Scattering Conference- 9- Open Day 2008- 9- Workshop: Biomolecular Dynamics and

Protein-Water Interactions

-10- DGK Workshop: Neutrons for

Crystallographers

-11- JCNS Workshop 2008: Modern Trends in

Neutron Instrumentation

-12- 12th JCNS Lab Course

Science & Projects-13- FEMaS Kick-off Meeting-14- From Molecular Motions to Pharmaceutical

Products

Inside-16- The Radiation Protection Team-17- Improved Silicon Doping Facility

User Office-18- User Development at FRM II-18- Call for Proposals-19- Reactor Cycles/ Upcoming

No 1

YANL -

Yet Another News Letter ? FRM II (No 9)January 16th, 2009

user.frm2.tum.de

JCNS (No 5)April 6th, 2009

fzj.frm2.tum.de

JA

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Dear colleagues and friends,

About three years ago we started our routine operati-on of the reactor in May 2005, while still strugglingwith the commissioning of the first instruments. Inthe mean time we have passed proposal round 8,but routine does not mean stagnation. Even thoughthe neutron guide hall west is now crowded with in-struments, new projects and ideas still appear near-ly every month. The planning of the instrumentationin new guide hall east is almost settled. Neverthe-less, the major work for the connection of the east-building to the reactor in order to transfer neutronsand positrons remains to be done. Large projects li-ke the ultra cold neutron source or new infrastruc-ture buildings are emerging. A major step next yearwill be the increased participation of the Helmholtzcentres at the FRM II leading to substantial changesin our institute.

News are exiting, but without an appropriate commu-nication they tend to be lost in the daily business.This news letter will try to keep you informed aboutour latest developments concerning the usage of theneutrons in Garching. Furthermore we want to reporton groups doing service and science at the FRM II.The different authors of the contributions presentedhere may remind you that the FRM II is based on thestrong collaboration of scientific groups from all overGermany present here on-site.

Jürgen NeuhausDeputy Director FRM II

www.frm2.tum.de

Deadlines Proposal Rounds

December 2008

Improved Flux, Better Software at SPODI

During the first half of 2008 the performance of thehigh-resolution powder diffractometer SPODI has be-en improved both by a new monochromator focu-sing unit and a new algorithm for the data evaluation.

The new monochromator focusing unit allows conti-nuous change of the focusing distance from 1.4 m to∞. With this device both the flux and the profile ofthe incident neutron beam were improved resultingin higher counting rates of about 50 %.

With respect to data evaluation, a new algorithm hasbeen implemented in the data treatment software toovercome asymmetric broadening effects at lowscattering angles, when using the full detector heightof 300 mm.

Fig. 2: The (012) reflection of corundum, enlarged section of figure 1.Markus Hölzel, Anatoliy Senyshyn

TU Darmstadt

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As a consequence of the vertically divergent beamand the sample height, the Debye-Scherrer rings(figure 1) are smeared out along the vertical direc-tion, resulting in peak broadening and asymmetryespecially at low and high scattering angles (figure2). So far, good peak profiles could only be obtainedby limiting the detector height to about 150 mm (thestraight lines in figure 1). In order to include the fullheight at the less affected intermediate 2θ-range, analgorithm has been developed that uses a variableheight as indicated by the dotted line in figure 1.The line used depends on the sample height andthe required resolution. As seen in figure 3, im-proved peak profiles and higher intensities are ob-tained by this “variable height data” normalized tothe full detector height.

Fig. 1: Two-dimensional data set of a corundum reference sample. The straight white lines define a detector height of 150 mm and 0 denotesthe centre of the detector. The dotted white lines encompass the data used in the “300 mm - variable height” data set.

Fig. 3: Comparison of integrated peak profiles for various dataextraction procedures.

Instrumentation

www.frm2.tum.de/spodi

Unique Inspection in 3D: PGAA Facility

Prompt Gamma Neutron Activation Analysis (PGAA)is a non-destructive radioanalytical technique for thedetermination of elemental composition of differentsamples. The main advantages of this technique arethe shorter irradiaiton times compared to the stan-dard Neutron Activation Analysis (NAA) and the easypreparation of the samples.

The facility uses the cold neutron beam of NL4bwhich has a very high intensity due to the ellipticallytapered design of the beam guide. The neutrons arefocused at the sample position with a maximum ther-mal equivalent flux of 6.3·1010 n/cm² s (1.7·1010

n/cm² s using the measured mean energy of the neu-tron spectrum). Furthermore, two different measuringpositions are available, as the last 1.1 m of the beamguide is removable. The two measuring positions ha-ve different properties: With a useable area of 14mm x 38 mm (width x height) at a distance of 35 cmor with 4 mm x 10 mm at 9 cm.

The detection system consists of two HPGe detec-tors, both with a standard Compton suppression sys-tem. A low measuring background and a carefulcalibration of the efficiency curve ensures a goodquality of analysis.

Recently, in the frame of the EU project Ancient

Charm, a new setup was added. This new configura-tion allows a new type of analysis, the so calledPrompt Gamma Activation Imaging (PGAI).

With this particular set-up position sensitive PGAAmeasurements reveal the spatial distribution of ele-ments inside the object. This goal is achieved by in-troducing a neutron collimator that reduces the areaof neutrons to a 2 mm wide spot and a gamma col-limator of 3 mm in diameter in front of the HPGe de-tector. The intersection of these two collimatorsdefines the active measurement volume inside thesample.

In addition to standard PGAA and PGAI, a neutronradiography system was installed. This system al-lows one to acquire a tomographic image of thesample and confirms also the correct positioning ofthe sample inside the beam through neutron radio-graphy. The combination of tomographic imagingand 3D elemental analysis presents the new methodfor the analysis of historic objects.

A future development for the standard PGAA instru-ment is the full automation of the measuring processand the data acquisition system. Efforts will be madeto further decrease the peak-to-noise ratio and thebackground count rate. Concerning PGAI and theAncient Charm project, the efficiency of the systemwill be increased in order to be able to acquire morecomplete PGAI measurements on real objects com-ing from different museums. Another aim is to in-crease the spatial resolution of the PGAI system.

Petra KudějováUniversität zu Köln

Tomography of a Proto Corinthianceramic vase, 600-500 bC, foundin Cerveteri, Italy.

Schematic view of the PGAA facility with Gamma detectors on the left andright and CCD-camera for tomography in beam direction.

Instrumentation

www.frm2.tum.de/pgaa3

Multi-Purpose Positrons at NEPOMUC

At the start of 2008, a new in-pile gamma-converterand Pt-moderator was installed at the neutron in-duced positron source NEPOMUC of the FRM II.The unprecedented intensity of the moderatedpositron beam amounts to (9.0 ±0.8)·108 moderatedpositrons per second at an energy of 1 keV. Hence,the beam facility NEPOMUC provides the worldhighest intensity of a monoenergetic positron beamreported so far. Up to now, no degradation of thepositron yield has been observed after severalmonths of operation. Thus, the long-term stability ofthe positron beam enables a wide variety of experi-ments in solid state and surface physics, materialsscience and atomic physics with high reliability.

Presently, four spectrometers are in operation at theNEPOMUC positron beamline, and a fifth experi-ment is currently being installed:

Crystal defects in metals, semiconductors or insulat-ing materials and the free volume of polymers arestudied with the pulsed low-energy positron systemfor positron lifetime measurements (PLEPS). Thisunique spectrometer allows depth dependent meas-urements up to a few µm.

Creative chaos on using po-sitrons at different experi-mental stations.

Christoph HugenschmidtFRM II

The coincident Doppler-broadening (CDB) spectrome-ter allows the investigation of defects near the sur-face and in the bulk up to a few µm with a lateralresolution between 300 µm and 2 mm. Moreover, ele-mental information in the surrounding of defects isgained which plays a major role e.g. for the under-standing of precipitation growth in metallic alloys.

An apparatus for positron annihilation induced Auger-electron spectroscopy (PAES) was set into operationwith a new electron analyser. By this challenging newtechnique the topmost atomic layer of surfaces canbe analysed with improved sensitivity.

A multi-purpose beamport allows various experimen-tal set-ups to be connected to the positron beamline.At present, an apparatus for the production of the ne-gatively charged positronium ion Ps- is in operation inorder to study this fundamental bound state of threeleptons.

An experimental interface is currently installed in or-der to enable the operation of a positron microscope,developed at the Universität der Bundeswehr Mün-chen for positron lifetime studies with an enhanced la-teral resolution of about 1 µm.

Instrumentation

www.frm2.tum.de/nepomuc4

A New Beast in the Guide Hall: J-NSE

The neutron spin-echo spectrometer J-NSE providesvery high energy resolution and is therefore well sui-ted for slow processes of mesoscopic objects. Spinmanipulations of the neutrons are used to convert ti-ny velocity changes of the neutron during the scatte-ring process into changes of the polarization of theneutron beam. Figure 1 shows the main precessioncoil of the second arm of the spectrometer.

Since its restart after the relocation from the Jülich re-actor FRJ-2 to the FRM II at Garching, experimentshave been carried out in different fields of soft matterphysics such as polymer dynamics, confinement ef-fects, microemulsions, micelles and microgels, and al-so first experiments of the dynamics of paramagneticsamples have been conducted. Figure 2 shows an ex-ample of the dynamics of the surfactant layer in a bi-continuous, sponge like microemulsion which allowsthe determination of the bending rigidity of the mem-brane.

The new end position in the neutron guide hall of theFRM II provides a very intense neutron beam with a15 fold gain of intensity at the sample position com-pared to the setup in Jülich at the same wavelength.

Fig. 1: Sample stage and secondarm of the J-NSE spectro-meter with the main preces-sion coil (green).

Fig. 2: Intermediate scattering function of a bicontinuous microe-mulsion measured at a wavelength of 8 Å

The accessible q range is 0.02 to 1.7 Å-1, corres-ponding to distances of interest from 0.37 to 30 nm.Fourier times between 3 ps and 150 ns can be ac-cessed at the moment due to the possibility of vary-ing the wavelength at the end position of theneutron guide. Ongoing development will improvecorrection coils which will allow the use of higherfield integrals and therefore increasing the dynamicrange of the spectrometer.

Olaf HoldererJCNS, Garching

Instrumentation

www.frm2.tum.de/jnse5

Combining Neutrons and X-rays in Reflectometry: N-REX+

The instrument is located in the neutron guide hallat the cold guide NL1. It is equipped with a focus-sing HOPG monochromator using wavelengths inthe range 2 Å to 6 Å.

Its design enables experiments with polarized neut-rons, including wide angle neutron spin analysisand specular and off-specular reflectivity measure-ments on surfaces and interfaces of solid and liquidsamples. In addition grazing incidence and evanes-cent wave diffraction measurements can be taken.As an option, in-situ X-ray characterization andspin-echo resolved grazing incidence neutron scat-tering (SERGIS) are available.

For horizontal and vertical sample orentation stand-ardised environments including high magneticfields up to 7.5 T, medium temperatures with liquidthermostat for cooling and heating and low temper-atures down to at least 4 K can be used. Low pres-sure gas atmospheres at T < 300 °C and a mediumpressure (p < 10 bar) gas cell with silicon substrateare routinely provided. For special experiments alarge diameter (100 mm) silicon liquid film cell (T <100 °C) and an active anti-vibration device for ex-periments on free liquid surfaces can be used.

The combined neutron and X-ray reflectometer N-REX+ of the Max-Planck-Institut für Metallforschunghas become operational. The project is part of thejoint initiative of several Max Planck institutes at theFRM II for a focused research programme exploitingthe unique properties of neutrons for the investiga-tion of advanced materials and condensed matterphenomena.

Adrian RühmMPI für Metallforschung, Stuttgart

The Great Escape of Neu-tronosaurus Rex from thebox, frightened by polari-zed neutrons.

Neutron reflectivity results obtained on a nickel / titanium multi-layer after different heat treatments.

Instrumentation

www.frm2.tum.de/nrex6

Sub-Kelvin Temperature Routinely Available

For scientific experiments at the FRM II changingtemperature is the most requested and in terms ofmilli Kelvin measurements one of the most deman-ding parameter. The sample environment group incollaboration with an external company have develo-ped cryo-liquid free cryostats that are now in operati-on at nearly all instruments. These top loadingcryostats achieve a lowest temperature of about 3 Ksolely by pushing a single button. This ease of ope-ration has been the paradigm of the new 3He samplestick insert which extends the lowest temperaturedown to around 400 mK.

The low temperatures, however, need special carefor mounting the assembly prior to the experimentwhich takes normally half a day. For measuring ti-mes of about one day using the single shot mode ofthe 3He filling, lowest temperatures down to 380 mKhave been achieved while in continuous operation450 mK over several weeks are possible.

The strong cooling power of 1 mW, even at 500 mK,permits one to cool down most of the samples inves-tigated from 3 K down to the lowest temperature wi-thin 10 min. This has been advantageous during arecent experiment at the single crystal diffractome-ter RESI where frequent temperature changes from0.5 K to 8 K were requested.

The 3He-insert in operation at the instrumentPANDA. No limitation of the insert is given con-cerning the tilt of the cryostat as frequently usedat the three-axis spectrometers. In addition tothe He compressor (left) the gas handling system(rack of 60 cm by 80 cm and 220 cm height) withpumps and compressors for the 3He can be seenbehind.

Jürgen NeuhausFRM II

All together two 3He low temperature inserts areavailable for routine operation, one further is underconstruction. The design of the cooling stage allowseasy modification in order to meet special require-ments for user experiments like gas adsorption onthe sample or in-situ pressure variation.

Full remote control of the 3He-system is allowed bythe gas handling equipment. This concerns not onlythe integration of the temperature control into the in-strument software but as well remote trouble shoot-ing for the members of the sample environmentgroup if requested out of working hours.

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“A stable and reliableoperation for the lowtemperature inserts hasbeen our main ambitionfor this development”,says Jürgen Peters,head of the sample en-vironment group.

Instrumentation

www.frm2.tum.de/en/services/sample-environment

The 8th German Neutron Scattering Conference was held on the 14-17 September 2008, organised by FRM II atGarching near Munich. It was a joint event of the German and Austrian Committees for Research with Neutrons,gathering 261 participants. Plenary talks and two parallel sessions dealing with the broad range of topics inherentto neutron scattering made up the programme, including 2 poster sessions on Monday and Tuesday, presenting251 contributions. Special mini-symposia had been organised to highlight current topics in solid-state physics:“Function from Frustration in Modern Multiferroics”, “Dynamics, Kinetics, Complex Materials in the Light of SANSand Reflectometry” and “Materials Science” with the focus on applied science.

8th German Neutron Scattering ConferenceSeptember 15-17, 2008 - Garching

Obviously, the event’s interest focused strongly onthe development of new methods and instrumentsusing neutrons. A special session was dedicated tothe new spallation sources SNS, ISIS’s second tar-get station and the developments related to the ea-gerly anticipated European Spallation Source.Topical sessions covered magnetism, soft matter,materials and dynamics.

All participants enjoyed the dinner in the Hofbräukel-

ler and Richard Wagner, director of the ILL, provideda memorable speech about the world of soccer quo-ting sentences from prominent players.

At the conference dinner, Götz Eckold, UniversitätGöttingen, the new head of the Committee for Rese-arch with Neutrons, thanked Helmut Schober, ILL,for his excellent work and engagement during thepast three years.

Since 2002 the Wolfram-Prandl prizehas been awarded to young scien-tists who have done outstandingwork in the fields of neutron scatte-ring, method development or funda-mental physics with neutrons.Presented at the bi-annual Germanneutron scattering conference, theprize money of 2,500 Euro is equallyfunded by the neutron centresGKSS, HMI, FRM II, JCNS and ILL.The 2008 Wolfram-Prandl prize wasawarded to Michael Marek Koza ofthe ILL for his outstanding work onthe structure and dynamics of cry-stalline and amorphous ice. In hisprize lecture he gave an overview ofthe temperature-pressure phase dia-gram of the still fascinating substan-ce water and shed more light on themiracle of high- and low-densityamorphous phases of ice.

Presentation of the Wolfram-Prandl prize to Michael Marek Koza (second from left) by thehead of the German Committee for Neutron Research Helmut Schober (right) in the pre-sence of Winfried Petry (scientific director of the FRM II) and Ina Lommatzsch (FRM II UserOffice).

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Ralf Gilles, FRM II explaining the use of the future small anglescattering machine SANS-1 to potential users.

Jürgen NeuhausFRM II

Wolfram-Prandl-Prize 2008

Events

Open Day 2008October 18, 2008 - Research Campus Garching

Queuing up for two hours, handing in their passportsand coming back at a certain time - hundreds of peo-ple gladly did so at the open doors of the neutronsource FRM II. From 10:00 to 19:00 on Saturday, 18th

October, in total 488 visitors had a look inside the re-actor, the experimental and the neutron guide hall.

In 32 groups of 15 people and in 15-minute cyclesthey got to know more about the research at the neu-tron source. The interest in visiting the reactor wasso huge, that three hours after the start of registrati-on the visitor groups were fully booked. When thelists were full, some visitors even waited for hours,just in case somebody would not show up, to get achance to visit the reactor.

A lot of attention was attracted by the presentations of the FRM II-radiation protection group. Three staff membersconstantly explained the safety concept of the neutron source and how measurement of radiation takes place.

Public talks given by the scientific director, Winfried Petry, the deputy director, Jürgen Neuhaus, and the formertechnical director, Klaus Schreckenbach, were well received. The audience came to know the newest scientifichighlights of FRM II, the use of positrons in materials science and atomic physics and general aspects of the ap-plication of neutrons.

Workshop

Biomolecular Dynamics and Protein-Water InteractionsSeptember 24-26, 2008 - Feldafing

More than 60 scientists from Europe, USA, Australiaand Japan attended the international workshop onBiomolecular Dynamics and Protein-Water Interac-

tions on September 24-26, 2008 in the beautiful sur-rounding of the InWent Education Center close toLake Starnberg south of Munich.

The workshop was jointly organized by WolfgangDoster of Physics Department of Technische Uni-versität München, and Thomas Gutberlet of JülichCentre for Neutron Science. Forschungs-Neutronen-quelle Heinz Maier-Leibnitz (FRM II) and Forschung-szentrum Jülich GmbH gave generous financialsupport.

The focus of the workshop was the discussion of themechanism of the protein dynamical transition, pro-tein hydration and protein dynamics studied by neut-ron scattering and other methods.

The highlights of the workshop were intense discus-sion between the participants, an evening poster ses-sion and a visit of the Roseninsel in Lake Starnbergafter the end of the workshop.

Most participants appreciated the open and infor-mal way to discuss current competing dynamicmodels and experimental approaches to study pro-tein dynamics.

A clear demand for more sophisticated neutron ex-periments to study dynamical phenomena in prote-ins and biological systems was expressed.Regarding the use of neutron spectroscopy in thefield of water dynamics the participants were verydelighted with recent developments to use of newinstruments such as the time-of-flight spectrome-ter TOFTOF or the backscattering instrumentSPHERES. Combining these techniques with dedi-cated simulation efforts and complementary NMRstudies to gain more insight into protein and waterdynamics is clearly going to be a strong topic forthe future.

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Andrea VoitFRM II

Long lines for the registration at FRM II. By noon, all tours at theneutron source were fully booked.

Thomas GutberletJCNS, Garching

Events

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DGK (AK7) Workshop

Neutrons for CrystallographersSeptember 17-18, 2008 - Garching

The working group Neutron Scattering (AK7) of theGerman Society for Crystallography (Deutsche Ge-sellschaft für Kristallographie, DGK) held the work-shop Neutrons for Crystallographers following the 8th

German Neutron Scattering Conference at Garchingat Technische Universität München from 17th to 18th

September 2008.

The workshop was aimed at students and scientistsof the different disciplines in natural and materialssciences. A general introduction to the use of neu-trons was given, followed by the application of neu-trons for the research in different scientific topics.

On the first day the analysis of atomic and magneticstructures using neutron diffraction was explained.During four lectures, two on powder methods andtwo on single crystal diffraction, subdivided intostructure determination and magnetism (R. Gilles,A. Schneidewind, M. Meven, M. Braden). On the se-cond day four lectures were held on phonons andmagnons, diffuse scattering, material science andsoft matter (M. Braden, F. Frey, W. Brokmeier, V. Ha-ramus).

Details were given about the instruments for the dif-ferent applications during a guided tour of the neut-ron source Heinz Maier-Leibnitz (FRM II) after thelectures.

The workshop was very well attended. Beside thenumerous participants from all over Germany andbeyond (Aachen, Augsburg, Braunschweig,Dresden, Freiberg, Köln, München, Regensburg,Göttingen, Innsbruck) attendees of the neutron scat-tering conference joined the workshop. Thus, morethan 50 participants filled the lecture hall. Therewere many questions after the lectures and livelydiscussions between the audience and the speak-ers in the breaks between the lectures. This under-lines the large interest in the methods presented aswell as the successful mixture of lectures, discus-sions and guided tour of a research facility.

With the support of FRM II and DGK this workshopcould be realised without any participation fee.

Martin MevenFRM II

The well attended lecturehall at the Physics Depart-ment of Technische Universi-tät München at Garching

Events

JCNS Workshop 2008

Modern Trends in Neutron InstrumentationOctober 15-17, 2008 - Bernried

New developments and concepts in neutron scatter-ing instrumentation was the topic of a well receivedrecent workshop organized by the Jülich Centre forNeutron Science. More than 60 scientists from neut-ron facilities across the world joined the event in theconference hotel Seeblick at Bernried at Lake Starn-berg.

The workshop covered concepts and challenges inneutron instrumentation for spallation neutronsources as well as reactor sources. New projectsand developments in small angle neutron scattering,neutron diffraction, neutron spin echo spectroscopy,backscattering and time-of-flight spectroscopy, neu-

tron reflectometry, neutron polarization and Larmortechniques and simulation techniques were presen-ted. Lively discussions accompanied the presentati-ons and intense poster session.

Several instruments and projects at the FRM II werepresented within the workshop: the diffuse polarisedspectrometer DNS (JCNS), the polarized diffractome-ter HEIDI (RWTH Aachen), the POWTEX diffractome-ter project (RWTH Aachen, Universität Göttingen),the TRISP spectrometer (MPG), MIRA (TUM), the re-launched Jülich NSE instrument, KWS-2 SANS in-struments of JCNS, TOFTOF (TUM), the future ther-mal time-of-flight spectrometer TOPAS (JCNS), thenew backscattering instrument SPHERES (JCNS),the new reflectometer MARIA (JCNS) and the reflec-tometer N-REX+ (MPG).

On the second day the workshop visited the FRM IIfacility at Garching where the participants joined thelocal instrument responsibles for intense discussionson site. Afterwards the participants relaxed at theworkshop dinner where an introduction to the historyof Bavarian beer brewing was given.

The workshop participants agreed to collect the pre-sentations given during the workshop and to makethem available at the workshop webside

www.jcns.info/Workshop

to allow the general neutron community to follow thediscussions.

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Thomas GutberletJCNS, Garching

Lively discussions at the poster session at Bernried

Events

12th JCNS Laboratory Course Neutron ScatteringSeptember 1-12, 2008

The 12th Laboratory Course on Neutron Scatteringwas held by the Jülich Centre for Neutron ScienceSeptember 1–12. The lectures took place atForschungszentrum Jülich and the experimentswere carried out at the FRM II. 50 young studentsand scientists from a variety of disciplines such asphysics, chemistry etc. from all around the worldtook the chance to learn theory and hands-on neut-ron scattering on selected instruemnts at FRM II.The course was supported by the Integrated Infra-structure Initiative for Neutron Scattering and MuonSpectroscopy (NMI3) and SoftComp, the EuropeanNetwork of Excellence for Soft Matter Composites.

The lectures gave a comprehensive introduction toneutron sources, into scattering theory and instru-mentation. Furthermore, selected topics of con-densed matter research were presented. At FRM IIthe students performed experiments at the backscat-tering instrument SPHERES, the neutron reflectomet-er TREFF, the Jülich neutron spin-echo spectrometerJ-NSE, small angle scattering at KWS-2, single crys-tal and powder diffraction at HEIDI and SPODI, polar-isation analysis at DNS, zero field spin echospectroscopy at RESEDA, three-axis spectroscopyat PUMA and time-of-flight spectroscopy at TOFTOF.

Thomas GutberletJCNS, Garching

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Interested students keeping an eye on TOFTOF's sampleenvironment (above), enjoying data treatment at DNS (left) andlooking SPHERES over (bottom).

The response was overwhelmingly positive. Thesplitting of the locations was surprisingly not seenas a burden although it implied a daylong bus tripfrom Jülich to Munich. Rather the students appreci-ated the possibility to get to know two major re-search centres in Germany.

The next Laboratory Course will be held again atJülich and Garching on September 7-18, 2009.

Events

www.fz-juelich.de/iff/wns_lab_now

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FEMaS: Neutrons and Positrons for Fusion EnergyOctober 8, 2008 - Garching

In a Coordination Action, the Euratom seventh fra-mework programme for nuclear research and trai-ning has launched the FEMaS-CA on October 1,2008. The development of fusion energy is stronglycorrelated to the development of new materials forthe fusion chamber of the reactor. The main con-cerns are structural materials to resist the neutron ir-radiation and maintain mechanical stability up tohigh temperatures in addition to a low activation pro-perty. In addition plasma-facing materials have to beengineered in order to remove the high heat fluxes.Coatings have to be developed for electrical insula-tion and corrosion resistance under irradiation andin contact to liquid cooling metals.

The FEMaS coordination action wants to improvethe use of advanced materials characterisation me-thods such as neutron and synchrotron radiation aswell as high resolution TEM and the use of positronsfor defect characterisation. The consortium as awhole is divided into 5 work packages dealing withradiation damage, synchrotron based methods, neu-tron source based methods including positrons,TEM based methods and advanced mechanical tes-ting and characterisation.

Lively discussions already during the registration of the kick-off meeting in Garching.

Jürgen Neuhaus FRM II

A first kick-off meeting was held on the 8th October 2008 at the Max-Planck-Institut for Plasma Physics at Garching. Besides plenary sessions dealing with general aspects concerning the organisation and presentations from EU officers, the work package groups met for a first exchange of envisaged pro-jects from the fusion energy community and large scale facilities offering the advanced characterisa-tion methods.

The neutrons and positrons offered by FRM II are coordinated by Christoph Morkel

contact: christoph.morkel@frm2.tum.de

A first workshop to present and discuss upcoming developments and possible collaborations will take place in Lisbon on January 12-14th, 2009.

Science & Projects

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From Molecular Motions to Pharmaceutical Products:

TOFTOF in motion

The TOFTOF team in frontof the instrument.

With the beginning of routine operation of theTOFTOF spectrometer in 2005 the first efforts havebeen made to establish a small research group at thespectrometer. The research is focussed on studies ofmolecular motions and the spatial arrangement of or-ganic molecules in dispersions used in pharmacy ascarrier systems for drug delivery but also in the foodindustry and other applications.

The first studies included experiments on the dynam-ics of liquid (bulk and dispersed) phases of simplemolecules like oils and fats but also on the motionsof stabilizer molecules or other additives such asdrug molecules in pharmaceutical formulations. Fromthese studies a better insight to the transport mech-anism of the molecules in simple molecular liquidsbut also in phospholipid mono- and bilayers could beachieved. The understanding of the microscopicstructure and dynamics should help to optimize mac-roscopic physico-chemical properties of, e.g., phar-maceutical products such as drug release rate ordispersion stability.

Due to the fact that dispersions are metastable sys-tems it is essential to have the possibility to prepareand characterize the samples on-site. For that purpo-

se besides the basic laboratory equipmentprovided by FRM II some special apparatuseswere granted by the “Bund der Freunde der Tech-nischen Universität München eV” which also fin-anced the first Ph.D. student in that project over aone year period.

Using a neutron time-of-flight spectrometer forstudies on the molecular dynamics of native phar-maceutical systems for intravenous administrationwas a novel idea. It had to be demonstrated firstthat quasi-elastic neutron spectroscopy (QENS) iswell suited to reveal properties of systems relevantfor pharmaceutical science. Already with the firstquasi-elastic time-of-flight neutron scattering (TOF-QENS) experiments it could be demonstrated for aco-enzyme Q10 nano-emulsion stabilized by phos-pholipids in an aqueous phase that it is possible tomeasure in detail the molecular motions inside thenano-sized droplets of dispersions. It turned outthat the observed results are not only relevant forthe pharmaceutical applications but also of generalinterest from physical point of view. Therefore, asystematic study on the picosecond dynamics asprobed by TOF-QENS of medium-chain n-alkaneswas initiated.

Science & Projects

Intermediate scattering function of the n-alkane C32H66 at 90ºC measured with the TOFTOF spectrometer using the labeled instrumen-tal resolutions (FWHM of the elastic line). Representative trajectories of a single molecule as extracted from MD simulations of the sameliquid alkane are plotted for time ranges between 0 ps and 1 ps, 20 ps, 400 ps and 8 ns, respectively. The time evolution is indicated foreach picture by colour intensification. For each picture 20 snapshots of the molecule equidistant in time are overlayed.

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Tobias UnruhFRM II

Including additional molecular dynamics (MD) simula-tions different diffusive motions could be disen-tangled in such liquids ranging from fast tumbling ofCH2 to the long range molecular diffusion. Despitethe rod like shape of the molecules the centre-of-mass diffusion was found to be essentially isotropic.

TOF-QENS studies are also helpful for the under-standing of the molecular transport properties in bio-logical membranes and stabilizer layers indispersions. Evidence was found that the long rangemotion on a picosecond time scale has a flow-likecharacter. This result confirms recent MD simulationsexperimentally and adds another piece of knowledgeto the understanding of lateral diffusion of moleculesin membranes.

The interpretation of the dynamics of phospholipidmolecules in the stabilizing layer of emulsions is,however, difficult without the knowledge of the struc-tural arrangement of the molecules. For this purposea special evaluation method of small angle X-ray scat-tering (SAXS) experiments (X-ray powder pattern sim-ulation analysis, XPPSA) has been developed andfirst results of phospholipid layers surrounding solid

triglyceride nano-particles have been achieved. Thecontinuation of this project is now supported by theDFG for three years and a collaboration with the De-partment of Pharmaceutical Technology of the Tech-nische Universität Braunschweig has beenestablished in order to correlate our results withpharmaceutical parameters of relevant systems.

Today, the small TOFTOF research group consistsof two PhD students, one diploma student, thegroup leader and several working students. It hasstrengthened the in-house research at the TOFTOFspectrometer and already within the first three yearsa lot of valuable insights in the molecular dynamicsof colloidal dispersions have been gained. A list ofrecent publications can be found under

www.e13.physik.tu-muenchen.de/unruh

Science & Projects

The Radiation Protection TeamNew head and new structure

Birgit Wierczinski was born in Freiburg im Breisgau.She studied chemistry at her home town’s universityand at ETH Zürich. After her Ph.D. in Mainz in 1994Birgit Wierczinski accepted post-doc positions in theUSA, Sweden and became a staff member at TUDelft in the Netherlands. Since 2003 she worked atthe Institute for Radiochemistry at Technische Univer-sität München and became staff member of FRM IIin 2007.

The radiation protection division at FRM II was re-structured. The staff members now are divided intofour subdivisions: • applied radiation protection, • in-house chemistry, • radiation protection services and• dosimetry of persons.

Scientists usually get involved with radiation protecti-on for either personal dosimetry or contaminationcontrol. Personal dosimetry at the FRM II is doneusing a combination of daily read-out electronic dosi-meters and the monthly analysis of film badges. Con-tamination control includes regular testing ofinstruments inside the experimental areas as well asclearance measurements of all equipment leavingthese areas. Samples that have been in the neutronbeam are more carefully analysed by gamma-spec-trometric methods.

Of course, the function of reactor supervision is notonly radiation protection. The 23 staff members ex-ercise many duties. For instance, waste water,which is produced within the control area of theFRM II is chemically monitored by the in-housechemistry. Radiation protection services organizesthe disposal of radioactive waste and cleans sensit-ive areas. Two members of the team take care ofthe laundry of overshoes and lab coats. The ap-plied radiation protection team monitors the envir-onment of the neutron source. Probes of water, soiland plants are taken to control the intake of radio-activity in the surrounding of FRM II. Also, radiationprotection ensures, that no radioactive particlesare incorporated by users or staff in FRM II. Radi-ation at workplaces is surveyed daily by measur-ing of the dose rates as well as wipe testing forcontamination control. Regularly, all measuring in-struments, such as whole body and contaminationmonitors, dose rate meters, spectrometers, analyt-ical equipment etc., have to be tested and calib-rated for correct operation.

Access to the neutron source for users has and will become smoother with the new regulations in radiationprotection. This is one of Birgit Wierczinski’s aims. Recently the radio chemist became the new head of reactorsupervision and radiation protection officer. Her predecessor Helmut Zeising retired.

16

FRM II's radiation protection team. Rightmost: The new head Birgit Wierczinski

Andrea VoitFRM II

Inside

www.frm2.tum.de/en/services/radiation-protection

Improved Silicon Doping FacilityMore security and higher output with semiautomatic system

Recently the doping of silicon at FRM II uses a newsemiautomatic system. It replaces a mechanicaldevice for charging the irradiation position with Si-in-gots.

The new system moves the single crystalline Si in-gots between the irradiation channel located in athimble within the D2O moderator tank and the stor-age rack within the pool following predefined tracks.“The handling of the silicon crystals has becomeeasier than before”, says Heiko Gerstenberg, head ofthe irradiation group at FRM II. Another advantage ofthe semi-automatic system, which had total costs ofabout one million Euros: The output of doped siliconhas gone up by several tons compared to the slowermechanical system. This year, Heiko Gerstenberghopes to reach the mark of 10 tons of doped silicon.

In two shifts six irradiation technicians overlook theproduction of doped silicon weekdays from 5:30 to22:30. The products serve the semiconductor in-dustry in Europe and Japan as raw material.

The semiautomatic device transports the silicon in-gots to defined spots in the reactor pool. An irradi-ation technician has to manually trigger the step bystep transportation towards the storage rack or theirradiation channel. The human control ensures thata collision with unforeseen obstacles in the water,which the machine does not recognize, is avoided.The irradiation technician stands on a bridge span-ning over the reactor pool to control the movementsof the system.

Andrea VoitFRM II

17

The semiautomatic system is controlled by the supervisingtechnican.

The ingots move from their irradiation position within the modera-tor tank to the storage rack within the reactor pool.

A silicon crystalafter the doping.

Inside

www.frm2.tum.de/en/industry/irridiations

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User Development at FRM II

Since the start of the operation of FRM II in May2005 request for beam time at FRM II instruments,the number of submitted proposals and visits ofusers for experiments have been increasing conti-nuously. In 2008 external users submitted 501 propo-sals to FRM II and JCNS. Summing up the scientificusers more than 1000 researchers will have been atFRM II in 2008. Most users are from German universi-ties and research centres, but about 40 % of the pro-posals of every round are from Europe or overseasas Japan, USA or India.

To organize this amount of proposals and user vi-sits a joint User Office of FRM II and JCNS wasestablished in 2008. The user office handles all ad-ministrative aspects of submission and reviewingof the proposals. It provides help and informationfor users for their stay at FRM II and organizes tra-vel reimbursement and NMI3 support for Europeanusers. All information for FRM II and JCNS users isregularly updated at the user office web pages:

user.frm2.tum.de

fzj.frm2.tum.de

The next User Meeting will take place on May 25,2009 at Garching. Users are invited to present theirrecent results. This will be a good possibility to dis-cuss new projects with the local contacts. Detailson new opportunities and ongoing developmentswill be given by the large number of groups opera-ting the instruments at FRM II:

January 16, 2009 is the next deadline to submit pro-posals for beam time at instruments at FRM II. Pro-posals can be submitted for the following instru-ments:

Diffraction: HEIDI, RESI, SPODI, STRESS-SPEC

Reflectometry: MIRA, N-REX+, REFSANSSpectroscopy: TRISP, PUMA, PANDA,

TOFTOF, RESEDAImaging: ANTARES, NECTAR, PGAAPositrons: NEPOMUCParticle physics: MEPHISTO

Details of the instruments and sample environmentavailable can be obtained from our website

www.frm2.tum.de

Submitted proposals 2005-2008 (FRM II and JCNS).

Call for Proposals

The review of the proposals will take place on March 6, 2009. Results of the referees will be online about two weeks later. The experiments of the ac-cepted proposals will start from the 20th cycle, i.e. from June 2009 on.

The beam time on the instruments of the JCNS faci-lity hosted at FRM II neutron source at Garching are distributed through the JCNS proposal system

fzj.frm2.tum.de

(next deadline is April 6, 2009) for the instruments KWS-2, J-NSE, DNS and SPHERES.

Thomas GutberletJCNS, Garching

User Office

Groups and institutions at FRM II.

FRM II (No 9)

January 16th, 2009

user.frm2.tum.de

JCNS (No 5)

April 6th, 2009

fzj.frm2.tum.de

19

IMPRINT

EditorsThomas GutberletIna LommatzschRichard MoleJürgen NeuhausAndrea Voit

Picture CreditsWenzel Schürmann (Technische Universität

München)Joachim Dorner (Max-Planck-Institut für

Plasmaphysik, Garching)Bjørn Pedersen (FRM II)and editors

ContactTechnische Universität MünchenForschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II)User OfficeLichtenbergstraße 1D-85747 GarchingPhone: +49-(0)89-289 10794Phone: +49-(0)89-289 10703Fax: +49-(0)89-289 10799e-mail: userinfo@frm2.tum.dewww.frm2.tum.de

Upcoming

February 10-13, 2009

9th International Conference on Quasielastic Neutron Scat-tering QENS 2009 (Villigen/ Switzerland)qens2009.web.psi.ch/

February 25-27, 2009

Workshop on Neutrons and X-rays meet biology (Berlin/ Germany)www.helmholtz-berlin.de/events/biology/

March 9-20, 2009

40th IFF Spring School: Spintronics - From GMR toQuantum Information (Jülich/ Germany)www.fz-juelich.de/iff/fs2009

March 26- Apr. 3, 2009

50th Berlin School on Neutron Scattering (Berlin/ Germany)www.helmholtz-berlin.de/events/nschool2009/

May 3-7, 2009

International Conference on Neutron Scattering ICNS(Knoxville/ USA)neutrons.ornl.gov/conf/icns2009/

May 25, 2009

FRM II User Meeting (Garching/ Germany)user.frm2.tum.de

September 7-18, 2009

13th JCNS Laboratory Course - Neutron Scattering (Jülich and Garching/ Germany)www.fz-juelich.de/iff/wns_lab_now/

Merry Christmas &A Happy New Year!

Deadlines Proposal Rounds

User Office

Reactor Cycles FRM II 2009

Cycle Period

18b January 5 – 29 19 March 10 – May 8 20 May 26 – July 2421 August 18 – October 16 22a November 17 – December 23

Crystal ball gazing in wintertime