Neutroni e Luce di …statistics.roma2.infn.it/~notiziario/2003/pdf/vol8-n2_03.pdf · EDITORIALE 2...

NOTIZIARIONeutroni e Luce di Sincrotrone

Cover photo:Elettra Italian national, synchrotronradiation, laboratory located inBasovizza in the outskirts of Trieste.(foto: Barnabà)

Il è pubblicato a

cura del C.N.R. in collaborazionecon la Facoltà di Scienze M.F.N. e ilDipartimento di Fisica dell’Universitàdegli Studi di Roma “Tor Vergata”.

Vol. 8 n. 2 Luglio 2003Autorizzazione del Tribunale diRoma n. 124/96 del 22-03-96

DIRETTORE RESPONSABILE:

C. Andreani

COMITATO DI DIREZIONE:

M. Apice, P. Bosi

COMITATO DI REDAZIONE:

L. Avaldi, F. Aliotta,F. Carsughi, G. Ruocco.

SEGRETERIA DI REDAZIONE:

D. Catena

HANNO COLLABORATO

A QUESTO NUMERO:

R. Leckey, C. Petrillo, M.A. Ricci, N. Sasanelli, M. Zoppi

GRAFICA E STAMPA:

om graficavia Fabrizio Luscino 7300174 RomaFinito di stamparenel mese di Luglio 2003

PER NUMERI ARRETRATI

E INFORMAZIONI EDITORIALI:

Desy CatenaUniversità degli Studidi Roma “Tor Vergata”,Presidenza Facoltà di Scienze M.F.N.via della Ricerca Scientifica, 100133 RomaTel: +39 6 72594100Fax: +39 6 2023507E-mail: [email protected]

Vol. 8 n. 2 Luglio 2003


SOMMARIO

Rivista delConsiglio Nazionaledelle Ricerche

EDITORIALE ............................................................................................................................................... 2C. Andreani

RASSEGNA SCIENTIFICA

The Elettra Synchrotron RadiationLaboratory ........................................................................................................................... 3G. Paolucci

The Circular Polarization Beamline at Elettra: Status and Perspectives...................................................... 10T. Prosperi, S. Turchini and N. Zema

GEM: a Shining Light in the ISIS Crown ....................................................................................................................... 19P.G. Radaelli, A.C. Hannon and L.C. Chapon

DOVE NEUTRONI

INES - Italian Neutron Experimental StationRealisation of a neutron diffractometer,downstream from the TOSCA spectrometer,at ISIS (UK)....................................................................................................................... 27M. Zoppi

COMMISSIONI SCIENTIFICHE .................................................................................................... 35

ATTIVITA’ ITALIANA ............................................................................................................................ 45

PROGETTO E.S.S.E.S.S.: the discussion continues .............................................................. 47F. Carsughi

SCUOLE E CONVEGNI.................................................................................................................... 49

VARIE ......................................................................................................................................................... 56

CALENDARIO ........................................................................................................................................ 57

SCADENZE ............................................................................................................................................... 58

FACILITIES ............................................................................................................................................... 59


www.cnr.it/neutronielucedisincrotrone

EDITORIALE

2

NOTIZIARIO NEUTRONI E LUCE DI SINCROTRONE • Vol. 8 n. 2 Luglio 2003

From this issue the Notiziario Neutroni e

Luce di Sincrotrone journal is also on web

at the site address

www.cnr.it/neutronielucedisincrotrone.

Our readers will continue to receive the printed

journal with the additional opportunity to read on

the web about present and past articles, synchrotron

and neutron news, meeting reports and much more,

addressed to scientists who have an interest in

neutron scattering research in a wide spectrum of

disciplines.

Good news for the neutron community!

On December the 4th 2002, the Governments of

France, Germany and the United Kingdom agreed to

an extension of the 1971 Inter-governmental

Convention on the international research institute

known as the Institut Max von Laue - Paul Langevin

(ILL) in Grenoble, France for further ten years.

This act extends the duration of the Convention and

related subsequent agreements to the year 2013, thus

guaranteeing continuity in the field of fundamental

and applied research with neutrons at the ILL.

On May the 12th the final permission for the star-up

and following routine operation of FRM-II Reactor in

Garching was released. The estimate is now a period

of 10 to 12 months for taking FRM-II into full

operation, with the first criticality foreseen in August

to September and first neutrons at the instruments

due in early autumn 2003.

On April the 8th the UK government announced a

commitment of about 100M pounds for the

construction of a second target station at the ISIS

Pulsed Neutron and Muon Facility, sited at the

Rutherford Appleton Laboratory.

Meeting reports included in this issue provide timely

coverage of the recent past and near future activity of

the Italian Community in synchrotron and neutron

research. Scientific research is sorted, as tradition,

from a broad array of articles.

This time we welcome an article by G. Paolucci on

the ELETTRA Synchrotron Radiation Laboratory;

T. Prosperi et al. give us a contribution on a well

established synchrotron instrument, the Circular

Polarization Beamline at ELETTRA, while by

P. Radaelli writes on the General Materials Neutron

Diffractometer-GEM at ISIS, both excellent

instruments for materials research.

Last but not least I would like to congratulate Joël

Mesot, new editor of the splendid journal Neutron

News, and thank warmly Jerry Lander, director

emeritus of the journal, for his constant and valuable

contribution and dedication to the neutron

community through Neutron News.

Carla Andreani


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Vol. 8 n. 2 Luglio 2003 • NOTIZIARIO NEUTRONI E LUCE DI SINCROTRONE

1. IntroductionElettra is the Italian third generation synchrotron radia-tion laboratory located on the Triestinian Carso plateau.It is built around a medium energy electron storage ringoperated between 2 and 2.4 GeV. The Elettra beamlinescover a wide energy range, from the far infrared to thehard x-rays, as the photon energy ranges between 2 meVand 40 keV, i.e. wavelengths between 0.6 mm and 0.3 Å.The facility is operated by the Sincrotrone Trieste publicno profit company, which also built the accelerator sys-tem and some of the beamlines. Other beamlines arebuilt in collaboration with external partners from differ-ent scientific institutions, both Italian and from othercountries.In addition to the synchrotron radiation activity, Elettrahosts several support and complementary laboratories,which makes it a multidisciplinary Research and Servicecenter, competitive at the international level by employ-ing advanced micro/nano analytical, photolithographicand radiographic techniques. Researchers at Elettra areactive in fields as diverse as genomics, pharmacology,biomedicine, catalysis and chemical processes, micro-electronics and micromechanics.This wide range of applications makes Elettra an inter-national crossroad where researchers, coming from dif-ferent countries and disciplines and from academic andapplied research, interact and exchange in a competitive,yet friendly, atmosphere, producing new knowledge andtraining junior researchers. Training of younger genera-tions of scientists and engineers for research and indus-try is indeed one of the missions of the Sincrotrone Tri-este public company. Laboratories like Elettra constitutethe backbone of the growing network of European cen-ters of excellence, helping the integration and growth ofEU research and culture. Moreover, Elettra being locatedon the border between the existing and new MemberStates of the EU, is particularly active in the constructionof EU’s rich fabric of cultural and economic exchangewith the Center East.In this paper we will describe the characteristics of thelaboratory as a whole, the access policy and future plans.No details will be given on the specific beamlines: poten-tial users interested in a particular beamline or set ofbeamlines are encouraged to visit our website and con-tact the beamline responsibles listed there.

2. Elettra: presentBeing a third generation synchrotron radiation source,Elettra is characterized by its high brilliance. Brilliance isa physical quantity defined as the number of photonsper second per unit solid angle per unit area in a givenbandwidth. A plot of the brilliance of a selection of pho-ton source presently available or under construction atElettra is shown in figure 1. A high brilliance implies thatbeamlines can be built so that a high photon flux is con-centrated in a small spot at the sample, allowing mi-croscopy, high resolution or high flux measurements.Given this characteristic of the sources, a number ofbeamlines have been designed to make the best possibleuse of Elettra. The beamlines at Elettra have been de-

THE ELETTRA SYNCHROTRON RADIATIONLABORATORYG. PaolucciSincrotrone Trieste S.C.p.A.S.S. 14 Km 163.5, in Area Science Park34012 Basovizza-Trieste, Italy

Articolo ricevuto in redazione nel mese di Giugno 2003

Fig. 1. Plot of the brilliance of some photon source of Elettra: the bendingmagnets, the existing multipole wiggler used for x-ray diffraction andsmall angle x-ray scattering (W14), the superconducting wiggler to beused by the second x-ray diffraction beamline (SCW), the electromagneticwiggler used by the circular polarization beamline (EEW), the 12.5 and 5.6undulators the figure eight undulator (FEU). EUFELE is the storage ringbased FEL. The four expected peak brilliances of the FERMI @ ELETTRAFEL shown on the plot correspond to various phases of the developmentof the project.


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signed and built by the Sincrotrone Trieste no-profitcompany alone or in partnership with a number of Ital-ian and international research institutions. The role ofeach partner in the construction of the beamline is statedby specific formal agreements. For each beamline agroup with researchers and technicians coming from allthe institutions involved is formed to construct, operateand upgrade the beamline. In this way an efficient ex-change of expertise among the different partners can beachieved. The group taking care of the beamline (“Grup-po di Ricerca”, or GdR) has access to typically 30% of theavailable beam time for in house research, maintenanceand instrumentation development. The remaining 70% isallocated through a selection by an international reviewcommittee. In some cases the specific agreements withthe partners require that a fraction of this time be allocat-ed to groups of a given nationality. One of the partners isthe Abdus Salam Center for Theoretical Physics (ICTP)and for that agreement a total of 1500 hours per year areallocated to groups coming from developing countries.Presently, this represents 1.6 % of the total availablebeam time. Apart from these restrictions, no a priori se-lection is operated on the nationality of our users, whichmakes Elettra one of the national research infrastructuresmost open to international use: for example during 2002almost 60% of the users were from outside Italy (seetable 1). The opening towards the users from other coun-tries has allowed starting several research collaborationsamong Elettra scientists, the international user commu-nity and the network of SR research infrastructure, lead-ing, for example, to a number of EU founded projects.

The range of applications of the beamlines spans fromatomic and molecular physics to life sciences and eachbeamline has been built having a specific application in

mind. This means that normally they are provided withall the instrumentation set needed for the class of experi-ments the beamline has been built for. Moreover, sup-port laboratories and workshops are available on site forsample preparation and treatment and for special sam-ple handling and mounting. Presently (June 2003), thereare 16 beamlines in operation and open to external users,1 FEL line under test, 3 beamlines in commissioningphase and 6 under construction (figure 2). A beamlinesummary is reported in table 2, where we have indicatedthe source type, the institution involved and typical ap-

plications. It is worth emphasizing that the applicationsare wider than what is indicated in the table and that po-tential users are encouraged to think of new applicationsof our beamlines, contact beamline responsibles andsubmit proposals in new fields: beamlines open to exter-nal users are continuously upgraded in order to meet theneeds of the most advanced research.A variety of insertion devices are installed on all theavailable “long” (4.5 m) straight sections on the ring: ofthe 11 available straight sections, 4 have planar undula-tors, 1 electromagnetic wiggler/undulator, 1 permanentmagnet wiggler, 3 APPLE (Advanced Planar PolarizedLight Emitter) undulators, 1 figure eight undulator, 1 su-perconducting wiggler. Each insertion device has beenoptimized for the required photon energy range. A re-cent theoretical and experimental study has shown that

Table 1. Nationality of Elettra users in 2002

Italy 347 France 109 Germany 94 United Kingdom 74 Austria 33 India 27 Switzerland 16 Denmark 15 Slovak Republic 15 Czek Republic 14 Finland 14 Hungary 14 Japan 11 Sweden 11

Belgium 8 USA 7 Holland 6 Spain 5 Brazil 4 Portugal 4 Poland 3 Russia 3 Australia 2 Bielorus 2 Canada 2 Rumania 2 Ireland 1

Total 843

Fig. 2. Scheme of Elettra beamlines around the storage ring


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Beamline Source Typical Applications Partner/otherfunding sources

1 TWINMIC Short planar U X-ray imaging for materials and EUlife sciences

2 Nanospectroscopy APPLE U Microscopy of magneticmaterials

3 EUFELE (Free-Electron Laser) FEL Time resolved two color EUexperiments

4 ESCA Microscopy Planar U Spatial evolution of chemical Enitecnologiereactions

5 SuperESCA Planar U Surface science

6 Spectro Microscopy Planar U 2D mapping of the properties FIRBof high Tc superconductors

7 VUV Photoemission Planar U Electronic structure of CNRsemiconductors

8 Circularly Polarized Light Electromagnetic Dichroism EU, CNRW/U

9 SAXS (Small Angle Planar W Polymers and biological systems Austrian Acad. of SciencesX-Ray Scattering)

10 XRD1 (X-ray Diffraction) Planar W Protein crystallography CNR

11 Materials science Bending Surfaces of technologically EU, Czeck Acad. of Sciences, relevant materials Charles Univ.

of Prague

12 SYRMEP (SYnchrotron Bending Phase contrast mammography University of Trieste, INFN,Radiation for MEdical and tomography Fondazione CRTrieste Physics)

13 Gas Phase Planar U Atoms and molecules CNR, INFM, INSTM, Univ Roma 1

14 MCX (Powder Diffraction Bending (short W) Earth and materials science INSTM, Univ. of Trento Beamline)

15 ALOISA (Advanced Line for Planar W/U Surface structures INFM Overlayer, Interface and Surface Analysis)

16 BEAR (Bending magnet for Bending Optical properties INFMEmission Absorption and Reflectivity)

17 LILIT (Lab of Interdisciplinary Bending 2D nanolithography INFM, CNR LIThography)

18 BACH (Beamline for Advanced APPLE U Strongly correlated systems INFMdiCHroism)

19 IRSR (InfraRed Spectroscopy) Bending Life and environmental sciences INFM

20 APE (Advanced Photoelectric- APPLE U Electronic structure INFMeffect Experiments)

21 X-ray microfluorescence Bending Material science, archaeometry, traces Regione FVGmeasurements

22 DXRL (Deep-etch Lithography) Bending High aspect ratio microfabrication

23 IUVS (Inelastic Ultra Violet Figure 8 U Vibrational excitations in disorderedScattering) systems

24 BAD Elph Figure 8 U Very high energy and momentum FIRBresolution low energy photoemission

25 XAFS (X-ray Absorption Fine Bending Non crystalline materials, catalysts ICTPStructure)

26 XRD2 (X-ray Diffraction) Superconducting W Protein crystallography

Table 2. Summary of the beamlines at Elettra. Beamlines shown in italic are under construction (see also figure 2). The applications in the table are justexamples of what a given beamline can offer to the user community: detailed descriptions of the beamlines can be found on the Elettra website(http://www.Elettra.trieste.it) A variety of photon sources are present at Elettra, including linear and circularly polarized insertion devices. Circularlypolarized light is emitted by the Electromagnetic Wiggler/Undulator (8) and by the APPLE (Advanced Planar Polarized Light Emitter) undulators (2, 18,20). The Figure 8 undulator (23, 24) produces linearly horizontal or vertical polarized light.


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it is possible to install IDs also the “short”(1.5 m) straightsections (which were not considered as possible photonsources originally) on the ring without affecting the per-formance of the ring. Short undulators, for example (fig-ure 1) can provide a gain in brilliance of about a factor 10with respect to bending magnets. The first beamline tomake use of a short undulator will be TWINMIC.The spread in types of insertion devices reflects both thevariety of applications and the advances in insertion de-vice technology and of the theory of the accelerator. Forexample APPLE undulators are devices which can pro-vide linearly and circularly polarized radiation: in thelinear regime they behave exactly like a planar undula-

tor, while as circularly polarized sources they are ex-tremely valuable for the study of dichroic systems, suchas magnetic systems. They allow changing the polariza-tion in a few seconds. One of the beamlines fed by AP-PLE undulators is the APE project built by INFM andcomposed of two branches one for low energy (10-100eV) and one for high energy (140-1500) photoemission(see also http://ape.tasc.infm.it). The two branches canbe used simultaneously and independently due to a di-pole electromagnet (figure 3), which bends the electronbeam by 2 mrad. Horizontally deflecting mirrors furtherdeviate the two photon beams so that the experimentalstations are about 4 m apart (figure 4) and a preparationchamber could be built between them. The figure 8 un-dulator, (figure 5) provides only linearly polarized light(horizontal or vertical), but has the characteristic of alow high harmonic content on the axis, thus allowing togo low energies (figure 1) with very high on-axis intensi-

ty and low heat load problems; for this reasons it is usedfor the inelastic UV scattering beamline which requiresextremely high resolution (∆E/E~10-6) and flux(http://www.elettra.trieste.it/experiments/ beam-lines/iuvs/index.html). A second branch is being builtfor very high-resolution low energy photoemission.We mentioned already that access to the Elettra laborato-ry is not restricted to particular countries or institutions:potential new users should contact the Elettra staff togather as much information as possible on the possibili-ties offered by the research infrastructure for their prob-lem. After that they should write a proposal through ourVirtual User Office link (http://users. elettra.trieste.it/)following the instructions, contained there in. There aretwo deadlines for proposal submission per year, one onFebruary 28th and one on August 31st for beam time allo-cation in the second semester of the year and the first se-mester of the following year respectively.Recent measurements and technical developments per-formed on Elettra beamlines are described in 389 paperson international refereed journals in the years 2000 to2002. This number is comparable to what is produced inother similar facilities and shows the presence of Elettrain the international research. Table 3 shows a breakdownof these publications in terms of research areas. The visi-bility of the research performed in our laboratory is fur-ther confirmed by over 100 oral and invited conferencecontributions, PhD and graduation theses. For detailsand consultation of the Elettra publication database,please refer to: http://users.elettra.trieste.it/root/plsql/publi_mgr.startup. Since 1997 Elettra publishes eachyear a selection of experimental and technical achieve-ments, the Elettra Highlights, which are available at thelink http://www.elettra.trieste.it/science/highlights/index.html.

3. Future plansA laboratory such as Elettra must remain at the forefrontof international research. For this reason the acceleratorsystem is continuously upgraded. Several upgrades arebeing carried out to provide users with a stable and reli-able beam. The most demanding of these upgrades is thenew injector. Presently injection is performed with a 900MeV linac. The electron energy is subsequently rampedto 2 or 2.4 GeV. A new full energy injector based on abooster synchrotron is being built. This will allow pop-up injection, i.e. the electron current in the ring will beconstant as new electrons are injected as soon as the cur-rent decreases below a certain threshold. This operationmode is implemented on newer sources, such as theSwiss Light Source. This virtually constant intensitymode has several advantages, most notably the completeabsence of thermal drifts on both the storage ring andthe optical elements and the possibility of installing low

Fig. 3. Detail of the insertion devices on section 9 of the ring, feeding theAPE set of beamlines. The dipole magnet between the two undulatorsdeviates the beam by 2 mrad, thus allowing independent operation of thetwo beamlines. The structure of the APPLE undulators is also apparentfrom the picture: each of the undulators is composed of four sets ofmagnets, two above and two below the electron orbit. Horizontal slidingof the “left” magnets with respect to the “right” magnets changes thehorizontal component of the magnetic field and therefore the polarizatonof the emitted radiation.


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gap ID which is presently not possible as they drasticallyreduce the lifetime. In addition to the advantages for the storage ring users,the construction of the booster synchrotron will com-pletely free the LINAC from its role as injector and weplan to use our present LINAC as the starting element ofa new advanced (or 4th generation) source: theFERMI @ ELETTRA (Free Electron laser Radiation forMultidisciplinary Investigations at Elettra) FEL. Thecharacteristics in terms of brilliance of this source withrespect to the existing sources at Elettra are shown in fig-ure 1: we expect a gain of over 10 orders of magnitude in

brilliance. Such an increase is due to the interaction ofthe electron beam with the photon beam it is producing.In order to obtain this interaction it is necessary to beable to produce compressed electron bunches as thephase delay between the beams has to be controlled bet-ter than a few fs. There are two possible schemes to startthe emission process:i) the shot noise of the electron beam is amplified -the

so called SASE (Self Amplification of SpontaneousEmission),

ii) the oscillation is started by an external conventionallaser.

Research field Number of papersAtoms molecules and Plasmas 39Catalitic Materials-Surface Science 111Hard Condensed Matter:Electronic and Magnetic Structure 42Hard Condensed Matter: Structure 35Instrumentation and Technol. Materials 31Life and Medical Sciences 39(excluding Crystallography) Polymers and Soft Matter 19Protein and Macromolec. Crystallography 73Total 389

Table 3. Papers on refereed international journals published from 2000 to2002 with data measured at the Elettra beamlines or description of in-strumentation development on the beamlines.

Fig. 5. One of the two sections of the figure eight undulator installed onthe storage ring.

Fig. 4 (below). The APE set of beamlines, showing the low- (right hand side) and high-energy branches. The two experimental stations are connected tothe same sample preparation chamber.


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Although the second scheme (seeded source) is less effi-cient and more technically demanding, because of syn-chronization problems, it has the great advantage for theusers that the time structure and the wavelength of theemitted photons is predictable and reproducible. As mentioned above, Elettra has already a FEL source(EUFELE), supported by the European Union, which sofar has reached the shortest wavelength for a storage-ring based FEL (190 nm) and is normally operated atabout 250 nm (figure 1). The limit of these sources is thatthey need optical cavities, like a conventional laser, andthe reflectivity of the mirrors drops below those wave-lengths. This problem is absent in a linac based FEL. Given the existing LINAC, and the expertise in settingup accelerator based user facilities, beamlines and asso-ciated advanced instrumentation, Elettra is planning todevelop a 4th generation light source. In order to definethe characteristics of the new source, we consulted sev-eral possible Italian users groups, as well as the promi-nent members of the foreign Elettra users community, invarious fields of research. From their statements of inter-

est, from specific proposals from potential users andfrom scientists involved in the design of experimentaland characterization instruments for laser pulses, agroup of scientific institutions led by the Elettra labora-tory formulated the FERMI @ ELETTRA project. It iscentered on the clear indications for three spectral bandsof highest interest: one band around 40 nm wavelength,one around 10 nm and one in the soft x-ray regionaround 1.5 – 1.2 nm. Potential users are strongly interest-ed in the availability of light with tunable polarization,in very short pulses of order 100 fs, with sufficient relia-bility and reproducibility, in time and intensity, to per-form time resolved experiments on such time scales.The two bands centered around 40 and 10 nm will re-quire the upgrade of our linac with a new gun, somebunch compressors and some additional minor modifi-cations, and will be based on the seeding principle, giv-en the demand of potential users for a predictable andreproducible photon beam. For the 40 nm line, a conven-tional 200 nm wavelength laser will be fed into an undu-lator with the first harmonic tuned to the same wave-

Fig. 6. Schematic future appearance of the Elettra site, showing the new booster injector, and the FERMI @ ELETTRA 4th generation source built startingfrom the existing LINAC and with its experimental hall.


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length (the modulator). In the modulator, the laser pulseand the electron bunch are carefully superposed, pro-ducing a modulation of the electron bunch density withperiods corresponding to the harmonics of 200 nm, andwhen the modulated bunch is transferred to an undula-tor (the amplifier), with the fundamental tuned to 40 nm,exponential growth of the emitted power and laser ac-tion set in. The time structure of the 40 nm laser pulseswill reproduce the time structure of the conventionalseed laser. For the 10 nm line two seeding schemes areenvisaged, one based on a conventional non-linear opti-cal system to produce the 5th harmonic of the seed laser,which is then fed into a 40 nm modulator and then into a10 nm amplifier; alternatively and a cascade-systemwhereby modulators at 200 nm and 40 nm in sequencemodulate the bunch at 10 nm wavelength, before thebunch is fed into the amplifier. Simulations of the twoschemes are under way. On the other hand, for the pro-duction of 1.5 to 1.2 nm radiation, the best course of ac-tion appears to be an upgrade of the linac energy to 3GeV. This can be done on the existing site (see figure 6)by pushing backwards the gun and the starting sectionof the LINAC by some 200 m, and inserting all the neces-sary accelerating and bunch compression sections, asneeded. The seeding scheme for these shorter wave-lengths has not been finalized. Some of the most exciting perspectives for experimentsusing the new sources are in the time structure. Theavailability of ultrashort (100 fs) pulses will allow manyinteresting time-dependent and pump-probe experi-ments covering the valence band (40 nm) and the core-level spectroscopies (10-1.2 nm). However, for these pos-sibilities to become realities, we started a substantialR&D program in instrumentation, especially concerningsynchronization and timing between short pulses (theelectron gun laser, the seed laser, the storage ring master

clock for the pump-probe experiments using synchro-tron radiation) and detection schemes. The fact that Elet-tra and the FEL will be close will make this kind of ex-periment possible (figure 7). The development programhas already started at Elettra in co-operation with INFM,where all the necessary expertise can be found.Microscopy and imaging can take advantage of the fullspatial coherence of the new sources to implement holo-graphic schemes based on the possibility to invert coher-ent diffraction data of non periodic objects, for whichoversampling is possible.Following the user requests, the undulators on the FER-MI @ ELETTRA source will allow operation in both lin-ear and circular polarization regime: Presently, we en-visage to use APPLE type undulators, but are also opento accept possible advances in undulator technology.Following a specific call for proposals, in 2002, the FER-MI @ ELETTRA project has been submitted to the ItalianMinistry for Education, University and Research.

4. ConclusionsElettra is a lively synchrotron radiation laboratory, of-fering high level instrumentation and expertise to itsusers. We carry on continuous development in terms ofmachine stability, new beamlines and upgrade of exist-ing beamlines. A new 4th generation source has beenproposed to complement (and not to replace!) the exist-ing one.

Fig. 7. Constructing a 4th generation source close to a 3rd generation storage ring allows two color experiments as depicted above. Radiation from abending magnet or from an ID of Elettra can be focused onto a sample.


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AbstractThe Circular Polarization Beamline at ELETTRA is devoted tothe study of dichroic phenomena. Its source, the EllipticalElectromagnetic Wiggler, is designed for providing circularlypolarized radiation both in undulator mode and under wigglercondition. The beamline covers a very broad photon energyrange (5-1000 eV) by using the combination of a Normal Inci-dence Monochromator together with a Spherical Grazing Inci-dence Monochromator (Padmore-like configuration). Resolu-tion and fluxes available at the beamline correspond to the de-sign specification. The wide fan of possible experiments whichmay take advantage of using the radiation available at thisbeamline cannot be performed with a single specific end-sta-tion, but user owned experimental set-ups are welcome at theCircular Polarization Beamline.

IntroductionThe development of insertion devices able to producecircularly polarized radiation in the vacuum ultravioletand soft-X ray regions opens the possibility of a large va-riety of experiments, since both the absorption and thephotoemission spectra may depend on the polarizationstate of the incident light. Classical experiments havebeen performed on magnetic materials but new resultsmay involve also non-chiral and non-magnetic com-pounds. The panorama of the possible experiments al-lowed with circularly polarized soft-x ray radiation in-clude magnetic and natural dichroism as well as mag-netic extended X-ray absorption fine structure, spin-re-solved photoemission and vacuum ultraviolet ellipsom-etry. As in the case of other third generation synchrotron radi-ation sources, also at ELETTRA a project for the produc-tion and use of circularly polarized radiation was devel-oped. The Circular Polarization Beamline is a joint pro-ject between the Istituto di Struttura della Materia (ISM)and Istituto di Chimica dei Materiali (ICMAT), nowjoined into the ISM, of the Consiglio Nazionale delleRicerche (CNR), which took care of the design and con-struction of the beamline [1], and Sincrotrone Triestewhich was in charge for providing the insertion deviceand the beamline front-end. The insertion device - a nov-el design of an Electromagnetic Elliptical Wiggler (EEW)- was developed in the frame of a RTD project of the Eu-ropean Commission, involving Sincrotrone Trieste (coor-

dinator), BESSY and MAX-lab. The EEW [3] allows towork with variable polarization state either using thefirst harmonic emission in the energy range from 5 eV toabout 150 eV, or exploiting the continuum smooth emis-sion of the wiggler mode from 40 eV up to 1000 eV.The beamline has been designed with the priority of pre-serving as much as possible the degree of circular polar-ization of the radiation emitted by the EEW, although forseveral photon energy ranges it has meant a reductionon the performances in terms of flux or photon energyresolution.Taking into account the large variety of experiments,from solid state physics to gas-phase spectroscopy,which would need circularly polarized radiation in con-junction with the very wide spectral range covered atthis beamline, the beamline policy for what concerningthe experimental setup, tend to encourage the users tobring their own experimental apparatus. The beamlinestaff give the maximum support for the installation onthe beamline. This ensure a very high rate of success ofthe proposed experiments. An experimental setup forsoft X-ray absorption and magnetic dichroism on filmand solid sample is, at present, available for the users.

Circular Polarization Beamline Electromagnetic Elliptical Wiggler The EEW was designed to provide linearly and circular-ly polarized radiation over a wide range of photon ener-gies, 5-1500 eV, using both undulator and wiggler modes

THE CIRCULAR POLARIZATION BEAMLINE AT ELETTRA: STATUS AND PERSPECTIVEST. Prosperi, S. Turchini, N. ZemaIstituto di Struttura della Materia-CNR, Roma, I-00133 Roma, Italy

Articolo ricevuto in redazione nel mese di Aprile 2003

Fig. 1. Photograph of the EEW in position on the storage ring.


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of operation [3,4]. The request for helicity switching ledto a fully electromagnetic design which combines thehorizontal and vertical periodic magnets into one open-sided structure, as shown in fig. 1. In table I the mainconstruction parameters of the device and the maximumallowed electrical parameters are reported.

Period length 212 mmTotal yoke length 3.322 mPole gap 18 mm

Vertical field Horizontal fieldMaximum field amplitude 0.50 T 0.10 TNumber of poles 32 31Maximum current 160 A 275 A

Table I. Main EEW parameters

Further details of the design, construction and perfor-mance of the device are given in Ref. [4,5]. The electrical parameters reported in table I correspondto the wiggler mode of operation of the insertion device.Under these conditions the EEW operates for differentvalues of the vertical and horizontal magnetic field pro-viding an elliptically polarized radiation and a continu-um soft x-ray emission spectrum extending from 40 eVto more than 1000 eV. In addition to the continuum, theEEW emits a spectrum of harmonics in the low photonenergy side (<40eV), whose fundamental energy is at 4.5eV when ELETTRA operates at 2.0 GeV. At high harmon-ic numbers (n>>10), the series of harmonics merge thecontinuum emission of the EEW. The degree of circularpolarization changes with photon energy in the rangefrom 40% at 8.5 eV to 80% at 575 eV. Full circular polar-ization condition (~90%) should be achieved when theEEW works as a pure circular undulator i.e. when thehorizontal and vertical magnetic fields are equal and lessthan 0.1T (Bx=By<0.1T). Under these conditions the avail-able first harmonic lies in the photon energy range be-tween 50 eV and 150 eV. Undulator mode of operation ofthe EEW allows to produce, in addition to the circularlypolarized radiation and in the same photon energyrange, also linearly polarized radiation with the polar-ization vector parallel or perpendicular to the orbitplane. In fact switching off the horizontal magnetic field,linearly polarized radiation parallel to the orbit plane isproduced, while switching off the vertical coils, the re-maining field drive the stored electrons to oscillate in thedirection perpendicular to the orbit plane emitting verti-cal linearly polarized radiation.In plane linear polarization of the emitted radiation is al-so available in wiggler mode of operation (Bx=0;By=0.5T)of the EEW.Following the commissioning of the EEW and associated

power supplies [5], the a.c. mode of operation have beentested in order to provide a rapid switching of the polar-ization state between left- and right-handed for betterdetection of the dichroic signals. The switching of polar-ization state of the emitted radiation is easily achievedby reversing the horizontal magnetic field, i.e. invertingthe current into the horizontal coils. At present modula-tion of the circular polarization between left and right-hand state is available for wiggler mode of operation, byusing a trapezoidal waveform which change the polar-ization state at 0.1Hz . The net defined polarization stateduration available for measurement is about 4s. Duringthe switching time (about 1s) dynamic correction are ap-plied to the electron beam stored in order to reduce dis-turbances to the other users. The correction are appliedby means of two independent coils placed at the en-trance and exit side of the EEW straight section that aredriven following a “fast feed forward” scheme using apre-built experimental look-up table.

The beamlineIn order to make the characteristic radiation emission ofthe EEW available to the users, a wide photon energyrange (5-1000 eV) beamline has been designed and con-structed [1]. The beamline takes into account several re-quirements: a) small influence on the degree of polariza-tion of the radiation emitted by the EEW, b) high pho-ton flux, c) high resolving power. The beamline is con-stituted of two different monochromators which sharethe entrance and exit slits as well as the pre- and post-fo-cusing optics [2] as sketched in fig 2.One of the monochromators is at normal incidence(NIM) covering the photon energy range 5-35 eV usingtwo, type IV, spherical gratings. The second one, thatcovers the energy range 30-1200 eV, is a grazing inci-dence monochromator (SGM), working in Padmore-type

Fig. 2. A) General layout of the beamline (side view); B) Grazing incidenceconfiguration; C) Normal incidence configuration. Angles and distancesare not in scale for graphical reasons. G’is the normal incidence gratingwhile G represents the grazing incidence one.


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configuration, equipped with a variable angle plane mir-ror and four spherical gratings. Switching between thetwo monochromators is obtained by simply inserting orremoving one mirror (M’2). The beamline accepts a maxi-mum emission angle of (2 hor. x 1 vert.)mrad2 of theEEW radiation that is focused in the vertical plane bymeans of plane (M0) and toroidal (M1) mirrors onto theentrance slit (S1). Both mirrors of the focusing opticshave 2.5 deg. grazing incidence and return the radiationparallel to the orbit plane. After the exit slit (S2) the radi-ation is focussed at the sample position with a toroidalmirror (M3).

Grating # Gas Transitions Resolving power

calculated measured

G1 Ne 1s -> np 3300 ª3400(850 eV)

G1 O2 1s -> π∗and Rydberg

states 6500 --(530 eV)

G2 N2 1s -> π∗ 6000 ≈7600vibrational

states (401 eV)

G3 Ar L2,3

2p -> (ns,nd) 6000 ≈4400(244 eV)

G4 He Rydberg statesof the

N=2 series 8500 ≈81001s2 ->(2snp+2pns)

65 eV)G4 Ne 2s -> np 11000 ≈11000

(48 eV)

Table II. Summary of the available resolving power for the beamline at severalphoton energies.

The resolution and photon flux values obtained duringthe commissioning of the beamline are reported in TableII and Table III respectively. The acceptance solid angleof the beamline was (1x0.3)mrad2.Resolution data for the SGM have been determined fromdeconvolution of absorption spectra of noble gases taken by means of a double ion chamber as described in [6]. Infig. 3 we show the Ne and N2 absorption spectra as anexample of the procedure used to determine the resolv-ing power values. The photon flux transmitted through the beamline as afunction of photon energy with a slit aperture of 20 µmis summarized in fig. 4. The data reported have been col-lected with a calibrated silicon diode while the EEW wasoperating in wiggler mode. The strong intensity modula-

tion reported for the low energy gratings (G4 and G3) isdue to the incomplete wiggler behavior of the EEW inthis energy range which put in evidence that the emittedelectromagnetic spectrum results as the summation ofthe discrete emission of harmonic instead of a continu-um. The signature of the presence of carbon and oxygenon the optics is visible in the curves relative to G3, G2,and G1 gratings.

Photon energy (eV) Grating Photon flux (phot/s/0.1 % bw/mA)

45.6 G4 1.2 x 109

65.1 G4 1.0 x 1010

401 G2 4.0 x 107

531 G2 3.2 x 107

531 G1 1.0 x 108

867 G1 6.0 x 107

Table III. Measured values of the photon fluxes at selected photon energies

The photon flux avaiable on the sample, as well as thephoton energy resolution, is crucial for the proper evalu-ation of the feasibility of a given experiment. In fig. 5 thephoton energy bandwidth togheter with the correspond-ing value of the photon flux is plotted as a function ofthe entrance and exit slits width. The data reported havebeen measured at 245 eV (Ar L2,3 absorption threshold)and 867 eV (Ne K absorption threshold) were resolutionhas been determined from the Gaussian brodening ob-tained with a fitting procedure performed using Voigtfunctions while the photon flux was determined by us-ing the double ion chamber [6].

Fig. 3. Upper panel- The vibrational states of the N2 1s -> p* transition.The experimental spectrum (dots) was fitted with seven Voigt functions(dashed line). Lower panel- The Ne 2s-1 np Rydberg series. The full line isthe result of a fit using Fano profiles convoluted with a Gaussian. Theenergy distance of the two last distinguishable lines (n=18 and 19)corresponds well to the Gaussian width.


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Measurements of the polarization were made using amultilayer polarimeter, developed in the framework ofthe RTD project of the European Commission for the EEW[7], at several photon energies between 92 and 573 eV.Fig. 6 shows the measured linear and circular polariza-tion rates as a function of the horizontal deflection para-meter (i.e. EEW horizontal current Ih) for wiggler mode.At 92.5 eV a comparison between undulator and wig-gler mode of operation is reported. In the undulator casea maximum circular polarization rate close to unit can beobtained with equal vertical and horizontal deflectionparameters (Kx=Ky), whereas in the wiggler case smallervalues of the circular polarization rate are obtained dueto the ratio Kx/Ky always less than unit. In both cases re-versing the horizontal magnetic field direction results ina change of the helicity of the radiation as expected.The photon energy range below 40 eV is available withthe characteristic discrete line spectrum emitted by an un-dulator. In fact even in the case of operation in wigglermode the spectral distribution from the EEW results inthe emission of discrete lines whose separation is 4.5 eV.The emitted radiation is analyzed passing through aNIM monochromator equipped with two 2400 l/mmgratings, the first gold coated and the second coatedwith Al+MgF2, for high (35-10 eV) and low (10-4 eV)photon energies, respectively. A simplified scanningmechanism for photon energy selection have been cho-sen. It consists of a simple rotation around the gratingaxes instead of the traditional rotation plus translationthat guarantee the Rowland condition of focussing [8].The lack of Rowland circle condition strongly reduce themaximum obtainable resolving power, due to the severeeffect of defocus aberration introduced. Holographicallycorrected gratings are able to minimize, in a specific

spectral region, the effect of defocusing on the resolu-tion, making resolving power comparable with that ofRowland circle mounting. In fig. 7 the absorption spec-trum of He and Ne gases at the fundamental transitionare reported.The photon energy resolution at relevant energies of fun-damental absorption line of He (21.2 eV) and Neon (16.7eV) gases shows a FWHM of about ∆EHe=4meV at Heline and ∆ENe=2meV at Ne absorption structure with 20µm slit apertures. The FWHM is influenced by the pho-ton bandpass and the contribution from the gas, which ismade of the natural linewidth plus the experimental pa-rameters such as gas pressure, effective light-path etc.. Areasonable value for the gas contribution to the FWHMcould be considered of the order of 2 meV for the He lineand of about 1 meV in the case of Ne. Using these con-sideration, from the spectra shown in fig. 7, the availableresolving power is of about 6000 at 21.2 eV and 10000 at16.7 eV. In order to verify the estimated value of the re-solving power at 21 eV, the threshold photoelectronspectrum relative to the ionization transition from theNe 2p3/2 at 21.5 eV was measured (fig.8). The appliedtechnique uses a very narrow bandpass photoelectron

Fig. 4. Spectral dependence of the transmitted photons through thebeamline using the grazing incidence monochromator. The photon fluxesare measured at sample position with calibrated silicon photodiode.

Fig. 5. Measured fluxes and bandwidths as a function of the entrance andexit slit width taken at 245 eV and 867 eV photon energy.


14


analyzer (∆Ek<1 meV, courtesy dr. S.Stranges, GAPHBeamline) and allows the selection of very low kineticenergy emitted electrons (hundreds meV), i.e. edge elec-trons at ionization transition. The observed features inthe threshold photoelectron spectra then are not verymuch influenced, in their width, by the detector band-pass but are mostly defined by the photon resolution. In fig. 8 the threshold photoelectron spectra at ionizationtransition energy of Ne 2p3/2, at 21.5 eV, shows that theFWHM is of about 3 meV with 20 µm slits and about 2meV with 10 µm slits. These values, neglecting the ana-lyzer contribution, give a resolving power of about 7000and 10000 respectively.In the NIM range of photon energy the polarization char-acteristic of the beamline has been evaluated and mea-sured at 8.4 eV by means of a MgF2 quarter wave plate.The results shows a degree of circular polarization of theorder of 30-40% depending on the mode of operation.

Recent AchievementsBecause of the specificity of the beamline to measure thedichroic behavior of materials, it was very important toprovide a mode of operation that allows to minimize un-

certainty introduced in the dichroic spectra by the ran-dom errors of monochromator repositioning. This is es-pecially required at the absorption edges of materials,where rapid change in the signal intensity may intro-duce false dichroic signal when scanning sequential ab-sorption spectra alternating the right- and left–hand cir-cular polarization of the photon beam. Handness switch-ing of circular polarization is often important in the caseof MCD measurements in magnetic materials where thereversing of the magnetic field in not always repro-ducible, but it is crucial in the case of Natural CircularDichroism whose properties cannot be reversed byswitching any external field. The EEW could produce alternatively a right- and left-handed circularly polarized radiation at a frequency of0.1 Hz operating in wiggler mode. A trapezoidal wave-form is generated to drive the horizontal current powersupply allowing to switch between +270A and –270Aproducing the change of the polarization handness. Af-ter a 1s switching time, a definite polarization state re-main for about 4s, during this period the measurementoccurs. Due to the need of derive small dichroic signals,several measurements may be averaged in the steady

Fig. 6. Degree of circular (S3) and linear (S1) polarization available at sample position measured as a function of wiggler horizontal deflection para-meter at 574 eV, 270 eV and 92.5 eV photon energies. At 92.5 eV a comparison between wiggler and undulator for the EEW mode of operation isshown. The Stokes coefficients were measured by means of a multilayer polarimeter equipped with a suitable set of multilayers for each of the ana-lyzed photon energies.


15


state period before changing to the new handness, start-ing a new set of measurements. The sequence may be re-peated for several times until the desired signal to noiseratio is reached. The timing of the measured signals tothe polarization state is controlled by a suitable referencestatus voltage level from the EEW power supply. Themeasured signal from the sample is normalized to theincident photon flux detected through the photocurrentemitted by the last mirror gold surface. Examples of theresults obtained using the switching mode of acquisitionis reported in fig. 9. The Oxygen K-edge in PropyleneOxide in vapor phase is reported, no evidence ofdichroic behavior is expected. The detection limit is de-termined by the noise and depend on the statistics of thedata set. The spectrum shown in fig. 9A has been ob-tained averaging two readings of the signals and thenoise level results in a few over thousands in the differ-ence spectrum. Fig. 9B reports the absorption and MCDspectrum at Fe L2,3 edge measured on Fe79B19Si5. The datahave been obtained in residual magnetization measuringthe total drain current from the sample. Single acquisi-tion has been used for the measurement.

Experimental ResultsThe quality of the performances of the beamline allowsto exploit a large variety of experiments. From the fieldof magnetic material results were obtained in thin filmsystems relevant for applications in magnetoelectronics,such as FeNi film on sputtered NiO films. They were in-vestigated by means of photoemission electron mi-croscopy (PEEM) to determine the magnetic microstruc-ture and the magnetic coupling phenomena. The ele-ment-selective magnetic information is exploitedthrough the magnetic circular dichroism at element spe-cific absorption edges in the soft X-rays. The obtained re-sults [9] suggest that the domain shape and sizes foundat the surface of antiferromagnetically coupled metallicmultilayers has a ferromagnetic coupling contribution,presumably caused by a build-up of roughness duringthe growth process. The magnetic domain patterns (fig.10) in FeNi microstructures on sputtered NiO films re-flect the presence of a local exchange anisotropy, causingthe phenomenon of exchange biasing or pinning of theferromagnetic layer. The studies on the structural andmagnetic properties of new magnetic materials broughtthe interest of the scientific community in the field ofmagnetic thin films such as manganites, ferrite an gener-ally oxides with perovskite structure. The characteristicsof Colossal Magneto-Resistance (CMR) and the strongenhancement of the magnetic moments induced by thereduced geometry together with the possibility of con-trolling the magnetic properties through the induceddistortion of crystal lattice by suitable doping, makethese materials of interest for technological application.

Fig. 7. Left panel - The He 1s –> 2p absorption line, around 21.2 eV takenwith different slit apertures. Right panel- The Ne 2p –> 3s absorptionline, around 16.7 eV taken with different slit apertures.

Fig. 8. Measured photon bandwidth with 20 and 10 µm of slit aperturesat 21.5 eV using threshold photoelectron spectroscopy on Ne.


16


In this frame the properties of nanocrystalline MnxFe3-

xO4 (x=0, 1.18, 1.56 and x=1.9) spinel ferrite thin filmswere investigated by means of the X-ray AbsorptionSpectroscopy (XAS) and X-ray Magnetic CircularDichroism (XMCD) at the Mn and Fe L2,3 edges. By usinga theoretical model based on atomic multiplets and crys-tal field calculations, the structural formulae of thesethin films was determined from the XAS and XMCD da-ta and the results compared with the structural formulaeof fine powders [10].One of the most interesting recent discovery in this areaof activity is an ordered double perovskite Sr2FeMoO6,with alternating Fe3+ (3d5, S = 5/2) and Mo5+ (4d1, S =1/2) ferrimagnetically coupled ions, exhibiting substan-tial CMR even at room temperature. In the proposedmagnetic structure, the system is expected to have a mo-

Fig. 10. Top: 25µm sized square-shaped Permalloy (Ni81Fe19) frames onNiO. Dark and bright areas correspond to oppositely magnetized do-mains (arrows give direction of local magnetization). The encircled re-gions show a breakup in block-like domains. Bottom: Graphical recon-struction of the domain patterns in the top panel. Images has beenrecorded at the Ni L3 edge.

Fig. 11. The XMCD measured at Fe 2p-edge at 77K for ordered and disor-dered Sr2FeMoO6. The corresponding XMCD for Sr2FeMo0.3W0.7O6 is alsoshown.

Fig. 9. A) - Oxygen K-edge measured, in vapor phase, on Propylene Ox-ide. The data was taken in switching mode of polarization collecting thetotal ion yield signal in a gas cell. B) – Fe L2,3 –edge measured onFe79B19Si5 metallic glass under residual magnetization.


17


ment of 4 µB per formula unit (f.u.) due to the ferrimag-netic coupling between Fe3+ 3d5 and Mo5+ 4d1 configura-tions. However, the observed saturation moment in thissystem from bulk magnetization experiments is most of-ten found to be about 3 µB/f.u. With the help of circular-ly polarized light and XMCD spectroscopy we have un-ambiguously shown [11] that the Mo contribution tothe total magnetic moment is negligible and the reducedmoment observed from magnetization measurements isdriven by the presence of mis-site disorder between Feand Mo sites. In fig 11 a comparison of the XMCD re-sults at Fe 2p edges for the disordered Sr2FeMoO6 (melt-quenched Sr2FeMoO6), ordered (normally preparedSr2FeMoO6) and fully ordered (Sr2FeMo0.3W0.7O6) sam-ples is shown. It is evident from the spectra that the

magnetic moment on individual Fe ions decreases re-markably with decreasing ordering.The exchange interactions at the interface formed be-tween ferromagnetic (FM) and antiferromagnetic (AFM)layers result in characteristic properties that find today awide application in the construction of new magneto-electronic devices. The technological interest is mostlydue to the large magnetic coercivities and the exchangebias effect observed in these systems. On a microscopic

scale, however, the interface coupling between AFM andFM films gives rise to various magnetic configurations,encompassing frustrated and non-collinear spin struc-tures due to the competition between exchange cou-plings of opposite sign [12]. First results on Fe(001)/NiO(001) coupled layers investi-gated by means of magnetic circular (MXCD) and linear(MXLD) dichroism in X-ray absorption have been ob-tained. An extensive preliminary characterization ofstructure, morphology and composition, indicated thatthe Fe/NiO bilayers grow uniform on Ag(001) with agood epitaxial quality [13]. The investigation by meansof combined XMCD and XMLD techniques turns out tobe very suitable for the study of the magnetic propertiesTM/NiO (TM= transition metal) structures. In XMCD in

fact the intensities of the TM-L3 and L2 white lines rela-tive to parallel and anti-parallel excitation are quantita-tively linked to the size and direction of the spin and or-bital magnetic moments[14]. On the other hand, XMLDis sensitive to the orientation of the magnetization ax-is[15] and is best suited for the case of AFM like NiO,since for an AFM the XMCD would vanish. It is foundthat different magnetic configurations can be obtainedby varying either the Fe or the NiO layer thicknesses. Aselected example is shown in figg. 12 and 13. In fig. 12 it is reported the polarization dependence ofthe Ni L2 edge for a NiO wedge after the deposition of 8ML Fe (θ is the angle between the surface normal andthe electric vector of the linear polarized light). The in-sets on the left side show the θ dependence of thebranching ratio of P3 and P2 peaks while the insets onthe right side show the azimuthal angle dependence forθ=0° (normal incidence). As a general trend, the Fe layerlowers the Ni XMLD effect. The XMCD measurements at

Fig. 12. XMLD of the Ni L2-XAS for a NiO wedge after deposition of8ML of Fe.

Fig. 13. XMCD at the Fe L2,3 edge for 8ML Fe as a function of the LNiOthickness.


18


the Fe L2,3 edge reported in fig. 13 show a sudden dropof the magnetic moment of Fe. For ∆Fe equal to 8ML thedrop takes places between ∆NiO =6÷8. From angle-depen-dent measurements (not shown here) we can rule out apossible rotation of the Fe magnetic moment. These re-sults point to a complex interplay between Fe and NiOthat has no direct correspondence on the results reportedin the literature for Fe films on bulk NiO up to now. The availability of low energy photons together with thesoft X-ray beam at the same position opens new oppor-tunities for the experiments to be performed at CircularPolarization Beamline. The same sample could be inves-tigated comparing the information obtained from va-lence excitation with the chemical and site specificity of-fered by the core level studies investigated both in pho-toemission and with absorption spectroscopy. The availability of the low photon energy range at Circu-lar Polarization Beamline also faces the requirements forexperimental activity in gas phase spectroscopy. Thesmall dimension of the focal spot, the high flux and thenarrow photon energy bandwidth has been recently ex-ploited by using angular resolved photoelectron spec-troscopy and Constant-Ionic-State (CIS) measurementson atomic Oxygen [16] in comparison with previous dataobtained at Daresbury 3.2 Beamline. The improvement inresolution is reported in fig. 13 by comparing CIS spectrarecorded in a limited spectral region (15.15 – 15.45 eV).The bandwidth in fig.13(a) is 2.5mV whereas the one infig. 13(b) is 20 mV making clearly evident the net im-

provement in the details of the CIS spectrum, openingnew inside into the excitations of Oxygen atom whichneeds further theoretical and experimental studies.

ConclusionThe Circular Polarization Beamline at Elettra is now ful-ly operating for a wide variety of experiments as demon-strated by the proposal submitted by external users,ranging from the magnetic properties of materials andartificial structures to the chiral properties of moleculesand organic compounds including low energy excitationof atoms, small molecules and radicals. The commissionof the beamline has shown that the performances match-es the specifications, especially for what concerning theresolution and the degree of circular polarization all overthe energy range available.

Acknowledgments The construction of the Circular Polarization Beamlinewould not have been possible without the effort of alarge number of people. We would like to thank all thecollaborators from ELETTRA staff, colleagues fromISM/ICMAT for their support and technical assistance.In particular we want to thank A.Derossi, B.Diviacco,F.Lama, M.Piacentini, S.Rinaldi, L.Stichauer, S.Zennarowhose participation to this project was fundamental forthe development of the beamline, M. Veronese andC.Grazioli and C.Carbone whose recent collaboration isnow fundamental for the activity of the group.

References1. A. Derossi, F.Lama, M.Piacentini, T.Prosperi, N.Zema, Rev. Sci. In-

strum. 66, 1718 (1995)2. D. Desiderio et al., Synchrotron Radiation News 12, 34 (1999) 3. R.P. Walker and B. Diviacco, Rev. Sci. Instrum. 63, 332 (1992).4. R.P. Walker et al., Design of an Electromagnetic Elliptical Wiggler

for ELETTRA, Proc. Particle Accelerator Conference, Vancouver,May 1997, p.3527

5. R.P. Walker et al., Construction and Testing of an ElectromagneticElliptical Wiggler for ELETTRA, Proc. 1998 European Particle Accel-erator Conference, Stockholm, Jun. ’98. p. 2255.

6. J.A.R. Samson, J. Opt. Soc. Am. 54, 1, (1964).7. H.-Ch. Mertins et al., Synchrotron Radiation News 11, 42 (1998).8. J.A.R.Samson, Techniques of VUV Spectroscopy (Wiley, NewYork 1967).9. C.M.Schneider,O.de Haas, U.Muschiol, N.Cramer, A.Oelsner,

M.Klais, O.Schmidt, G.H.Fecher, W.Jark, G.Schonhense, J. of Magn.Magn. Mater. 233, 14 (2001).

10. L.Stichauer, A.Mirone, S.Turchini, T.Prosperi, S.Zennaro, N.Zema,F.Lama, R.Pontin, Z.Simsa, Ph.Tailhades, C.Bonningue, J. Appl. Phys.90, 2511 (2001).

11. S.Ray, A.Kumar, D.D.Sarma, R.Cimino, S.Turchini, S.Zennaro, N.Ze-ma Phys. Rev. Lett. 87, 097204 (2001).

12. C. Leighton, M.R. Fitzsimmons, A. Hoffmann, J. Dura, C.F. Ma-jkrzak, M.S. Lund, I.K. Schuller, Phys. Rev. B 65, 64403 (2002)

13. P. Luches, M. Liberati, S. Valeri, submitted to Surf. Sci. (2002)14. G. Schultz, W. Wagner, W. Wilhelm, P. Kienle, R. Zeller, R. Frahm,

and G. Materlik, Phys. Rev. Lett. 58, 737 (1987).15. B. T. Thole, G. van der Laan, and G. A. Sawatzky, Phys. Rev. Lett. 55,

2086 (1985); G. van der Laan, B. T. Thole, G. A. Sawatzky, J. B. Goed-koop, J. C. Fuggle, J.-M. Esteva, R. Karnatak, J. P. Remeika, and H.A. Dabkowska, Phys. Rev. B 34, 6529 (1986).

16. L.J. Beeching, A.A. Dias, J.M. Dyke, A. Morris, S. Stranges, J.B. West,N. Zema, L. Zuin, Molecular Physics 101, 575 (2003).

Fig. 14. Constant-ionic-state (CIS) spectra of atomic oxygen recorded atθ= 0∞, at Circular Polarization Beamline fig. 14(a), and at Daresbury onBL3.2, fig. 14(b) in the 15.1- 15.5 eV photon energy region to show a com-parison of resolution in CIS spectra recorded with the Daresbury andElettra synchrotron radiation sources.


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IntroductionPowder diffraction and non-crystalline materials scatter-ing have undoubtedly been two of the best success sto-ries of neutron scattering at pulsed sources. Time-of-flight (TOF) neutron powder diffractometers are clearlyvery competitive with their constant-wavelength (CW)counterparts in a variety of applications, and there is anumber of areas where the two types of machines aredistinctly complementary. Similarly, TOF non-crys-talline materials diffractometers have proven to be com-plementary to their CW counterparts, with clear pointsof strength in the study of hydrogenous materials,among others. Medium-resolution powder diffractionand scattering from liquids and amorphous solids (L&A)have broadly similar instrument requirements, and cangreatly benefit from a common platform, especially inaddressing “boundary” areas, such as the study of disor-der in crystalline materials. In recognition of this fact, aconsortium of UK universities, headed by Prof. PeterDay1,2 (The Royal Institution of Great Britain) wasformed in 1997 with the aim of developing, in partner-ship with ISIS, the scientific and technical case for astate-of-the-art “General Materials Neutron Diffractome-ter”, for the study of crystalline and non-crystalline ma-terials at high neutron flux 3. Jointly funded by the UKEngineering and Physics Research Council and by theJapanese Institute of Chemical and Physical Research,RIKEN, the GEM proposal was rapidly put through itspaces, and developed into a very ambitious project.GEM was to replace the Liquid and Amorphous Diffrac-tometer, LAD, on the same beamline, directly looking ata poisoned liquid methane (L-CH4) moderator, but witha primary flightpath increased to 17m for better resolu-tion. Particularly impressive was to be the detector de-sign (Fig. 1), based on an array of over 6500 scintillatorelements, for a total solid angle coverage exceeding 4sterad. Also noteworthy is the out-of-plane detector cov-erage of ±45 degrees at most angles. The light emitted bythe scintillators is detected by a series of photo-multipli-er tubes, conferring to the instrument its characteristic“hedgehog” shape. Although the GEM detectors andelectronics were designed and prototyped “in house”,the mass production requirements of the GEM detectorsfar exceeded the capacity of the ISIS detector lab. There-fore, for the first time at ISIS, the GEM detectors were to

be built by external contractors. The LAD beamline wasdismantled in the early months of 1999, and the GEMbeamline was quickly constructed in its place during thefollowing summer. The GEM shutter was first opened onOctober 12, 1999, and some of the neutrons scattered byan Yttrium Aluminium Garnet (YAG) powder samplewere detected at 90 degrees by a then sparsely populat-ed array. More and more detector modules were in-stalled in the following 31/2 years, and the collimation,an essential part of an instrument for which low back-

grounds are required, was progressively built. At thesame time, sample environment kit specifically designedfor GEM was being developed and commissioned. Nowthat GEM is essentially completed, it seems to be a goodtime to review what has been accomplished thus far, andto outline some of the future challenges and opportuni-ties awaiting us on GEM and other diffraction beam-lines, presently been proposed for the second target sta-tion (TS-II) at ISIS.

Instrument concept*In general, for a given maximum resolution, CW diffrac-tometers have a higher neutron flux on the sample and a

GEM: A SHINING LIGHT IN THE ISISCROWNPaolo G. Radaelli, Alex C. Hannonand Laurent C. ChaponISIS Facility, Rutherford Appleton Laboratory

Articolo ricevuto in redazione nel mese di Maggio 2003

* See Appendix I for the full set of instrument parameters

Fig. 1. An early engineering design of the GEM detector and vacuumsample tank. The beam enters the instrument from the left of the picture.


20


more sharply peaked resolution function near the “take-off” angle, while TOF diffractometers have larger detec-tor solid angles and flatter resolution curves. The latter isachieved by exploiting the polychromatic nature of thepulsed beam at a fixed scattering angle. Angles nearbackscattering are a natural choice, because they pro-vides the best resolution at the intrinsic focusing condi-tion for TOF diffractometers, where the resolution be-comes largely independent of the beam divergence andsample size. However, other scattering angles are also

convenient: for example, background suppression iseasiest near 90°, and lower angles provide the widest d-spacing range. “Radical” backscattering instruments,such as the early HRPD and OSIRIS, have no CW coun-terpart for some applications, and represent a trulyunique contribution of pulsed sources to the field of neu-tron scattering. Unlike L&A data, which are rarely reso-lution-limited, powder diffraction data collected at mul-tiple scattering angles cannot be easily merged, becauseof the difference in resolution. These data need either tobe kept separated or used in a combined “multi-his-togram” analysis. Although Rietveld refinement codescapable of handling multi-histogram data have existedfor several years, this computer-intensive and perceiv-ably “cumbersome” technique was not routinely em-ployed until recently. With the enormous increase in theavailable computing and visualisation power, however,multi-histogram refinements have finally come of age: aRietveld refinement of a moderately complex structure,based on data from 6 histograms, each with severalthousand points (Fig. 3), can converge in a matter of sec-onds on a fast desk-top PC. The vast detector array ofGEM was specifically designed to take advantage of thisnewly available power.

Incident spectrum and bandwidthGEM looks directly at a poisoned L-CH4 moderator,without any beam optics other than a series of 6 sets ofmotorised jaws, distributed along the beamline to definethe beam size, from a maximum of 40h×20v mm2 to aminimum of about 1h×1v mm2. The spectral flux forGEM, plotted in Fig. 4 as a function of wavelength,peaks at about 2 Å, and is sharply cut at long wave-lengths by a series of 2 choppers, which define the sin-gle-frame bandwidth to be 4.2 Å, thereby preventing

frame overlap. This bandwidth yields a d-spacing rangeof ∆d=2.1 Å in backscattering, clearly insufficient to tack-le large unit cells and magnetic structures. However, theextended 2θ coverage enables GEM to collect data up tod=40 Å (Q=0.15 Å-1). At the other extreme, the GEM col-limation was designed to make the best possible use ofshort-wavelength neutrons: good quality data havebeen collected up to Q=80 Å-1 (d=0.08 Å). This extendedrange means that GEM has an extraordinary flexibility intackling phenomena at a variety of lengthscales.

“Flux”and resolutionThe count rate of a diffractometer is defined by a combi-nation of instrumental factors, such as the incident fluxat the sample position, detector solid angle and detectorefficiency, as well as by the characteristics of the sample(volume and cross section for a given Bragg peak or Qpoint). Other important parameters in defining the over-all performances are the instrument resolution and thesignal-to-background ratio for reference samples. For apowder diffractometer, a useful parameter is the so-

Fig. 2. GEM detector installation, as of February 2000: The complete 90-degree and 20-degrees banks are visible. Neutrons travel towards the topof the picture.

Fig. 3. An example of multi-bank refinement of GEM data: multi-his-togram refinement plot for Ti4O7, a moderately complex crystal structure(courtesy of E. Kopnin). The space group is triclinic (I -1), with a =5.59446(4) b = 7.11835(5) c = 20.41873(14). All the coordinates for the 11atoms (all in general positions) as well as the isotropic Atomic Displace-ment Parameters, were freely refined, yielding values that agree with sin-gle-crystal data within few error bars.


21


called “effective flux” Φeff(d), which is linearly related tothe integrated intensity per second expected for a givenBragg peak at a d-spacing d by the following formula:

where V is the attenuation-corrected sample volume (incm3), f is the packing fraction, V0 is the unit cell volume

(in Å), mhkl is the reflection multiplicity and is thesquare of the structure factor (in barns). The “effectiveflux” of GEM, and, by comparison, that of another state-of-the-art high-flux diffractometer, D20 at the ILL areplotted in Fig. 5. The same comparison is made for theinstrument resolutions in Fig. 6. These data clearly illus-trate the complementarity between the two diffractome-ters: D20 has a higher “effective flux”, particularly at thelonger d-spacings. Conversely, GEM has significantlybetter resolution than D20 in the whole range, as well asa much larger small-d-spacing range. As one could easi-ly predict on the basis of these data, GEM excels in pro-ducing high-quality structural data, which are suitableof full Rietveld refinements (often including anisotropictemperature factors) of crystal structures of moderatecomplexity (Fig. 3), as well as data suitable for Fourier-transform methods, such as pair distribution function(PDF) analysis. Data on a typical “neutron-size” sample(a few grams) can be collected in just a few minutes (adiscussion of the factors limiting data collection rates onGEM is presented below). Conversely, D20 in the config-uration examined above* is faster, especially in the rangewhere magnetic peaks are observed, but can only tacklesimpler structures.

BackgroundLow intrinsic background is critical for a high-flux in-strument like GEM, where the typical user expects to seeweak signals from tiny samples. In these situations, theratio between signal and background noise, rather thanthe counting statistics on the signal itself, is often thelimiting factor. On TOF diffractometers, most of thebackground originates from fast neutrons that are mod-erated in the “blockhouse” (the instrument enclosure),filling it with a diffuse neutron “gas”. The detectors

must therefore be protected against leakage, and coveredwith neutron-absorbing material everywhere exceptalong the direct line of sight to the sample. On GEM,this was achieved by constructing a set of collimating“vanes”, both inside and outside the sample tank, whichconsisted of a metal frame covered in “crispy-mix” -aboron carbide/resin composite with a rough surface.Boron has a high absorption cross-section for thermalneutrons, whilst the hydrogenous resin slows down thefast neutrons so that they can be absorbed by the boron.In addition, the detector modules were individuallyshielded with borated material. The measured back-ground depends on the scattering angle and on wave-length, and is lowest near 90 degrees, where the back-ground-equivalent total cross section is ~3×1020 barns at1 Å (full open beam). This is equivalent to the incoherentscattering produced by 5 mg (0.8 mm3) of vanadium, en-abling measurements on tens of milligram-size crys-talline samples to be performed routinely (see Fig. 7).

Fhkl2

I neutrons/sec[ ] = •

Φeff

hkl hklV fV

m F

V0

2

0

* A new high-take-off configuration for D20 is currently being tested atthe ILL. In this mode, the performances of D20 are expected to be similarto those of GEM

Fig. 4. Spectral flux ∑ (flux per 0.1% bandwidth) on GEM at the sampleposition, obtained from Monte Carlo simulations. With logarithmic bin-ning, ∑ is proportional to the number of counts per bin for an incoherentscatterer.

Fig. 5. “Effective flux” comparisons between GEM (1st frame: 0.3-4.1 Å,2nd frame: 4.1-7.9 Å) and D20. Data for GEM are the resultof Monte Carlosimulations, in agreement with measurement ofscattering for coherentand incoherent scatterers, and are summedover all the detectors. The da-ta for D20 are an estimate based onthe published values of the flux in themedium-resolutionconfiguration (3.7 × 107) neutrons/cm2/sec, and arepurely indicative.


22


Hardware and softwareThe original instrument design and the subsequent de-velopment led to a number of innovations, both in thehardware and in the software. One requirement thatwas identified early on was that of constructing GEM inits entirety out of non-magnetic materials, to prevent theinstrument from being magnetised during high-field ex-periments. Furthermore, all the components sensitive tomagnetic field, the photo-multiplier tubes in particular,were shielded with µ-metal, a hard (and costly) workthat has now paid off with the acquisition of a 10 Teslacryomagnet (see below) A later addition to the instru-ment hardware was an innovative oscillating radial colli-mator (Fig. 8), designed to remove the coherent and in-coherent background generated by the sample environ-

ment (which is 3 orders of magnitude greater than theintrinsic instrument background.). With its 170, 80-cmhigh lamellae coated in isotopic 10B and equipped withan in-vacuo oscillating mechanism, this device requiredover 2 years of engineering development. It has, howev-er, worked flawlessly since its installation, and can re-duce the background by as much as 3 orders of magni-tude for cryostat and furnace experiments.The software requirements for a successful operation ofthe GEM scientific programme are particularly stringent.Data from almost 7000 individual detector elements,each containing 5000 time channels (a total of about 150Mbytes), need to be stored, focussed and often analysedin a time comparable to the measuring time. Measure-ment on non-crystalline materials typically last severalhours, even on GEM, and existing software, with appro-

priate modifications, proved to be adequate. However,completely new software was required for the crystal-lography programme, since the measuring times can beas short as 1 minute. To meet this challenge, we wrotethe ARIEL data reduction and visualisation programme,based on the IDL language platform, which can focusand display crystallographic data on-line, and generatethe required input files for Rietveld refinement (Fig. 9).More recently, the ARIEL capabilities were expanded bya sequential Rietveld module, which analyses the data asthey are produced and displays one or more of the re-fined parameters as a function of a sample environmentvariable (temperature, magnetic field, etc.). This kind offlexibility and user friendliness is crucial if GEM is tocompete successfully with CW diffractometers, whichhave a far simpler data structure.

Sample environmentAlthough most of the “standard” ISIS sample environ-

Fig. 6. Instrumental resolution of GEM (1st frame: 0.3-4.1 Å). The “best”resolution at each d-spacing is plotted, and a step downwards occurseach time a new bank is in range. An estimated curve for D20 is plottedfor comparison.

Fig. 7. Rietveld Refinement plot for a 2 mm2 sample of Yttrium Iron Gar-net (YAG), after an overnight data collection.

Fig. 8. D. Abbley and D. Maxwell inspecting the GEM oscillating radialcollimator as it was being installed in the sample tank.


23


ment kit can be used on GEM, a number of devices werespecially redesigned, to take maximum advantage of thewide detector coverage, both in and out of the equatorialplane. Particularly welcome is the recent addition of a 10Tesla cryomagnet, co-funded by RIKEN and the UK-Joint Research Equipment Initiative. It provides highmagnetic field, flawless temperature control betweenroom temperature and 1.5 K, sorption and dilution capa-bilities for temperatures down to the tens of millikelvinrange and, most importantly unhindered access to thewhole 2θ range of GEM.Science on GEMA number of highly topical science areas were cited asprime targets in the GEM proposal. In the field of crys-tallography, great emphasis was placed on the projectedability of GEM to map multi-dimensional phase dia-

grams of many classes of materials as a function of tem-perature, chemical composition, pressure, magnetic fieldand other parameters. Perhaps for the first time, on GEMone can create maps not only of lattice parameters andfractions of coexisting phases, but also of internal struc-tural parameters such as bond lengths, angles andanisotropic components of the atomic displacement ten-sor, as well as magnetic moments. As the phase dia-grams of materials such as ionic magnets and supercon-ductors become increasingly more complex and rich inexotic physical phenomena, this “imaging” capabilitywas deemed crucial for both physics and chemistry. Re-al-time and in-situ studies, such as reaction kinetics, an-nealing, cation migration, hydration, intercalation reac-tions, were also identified as a key component of theGEM programme, and one that provides a perfect matchto the instrument capabilities, both for basic researchand for “real” materials (cements, industrial alloys, etc.)The ability to obtain high-quality structural data on

small samples, traditionally a weak point of neutronpowder diffraction, would enable the study of a varietyof advanced materials that can only be prepared in smallquantities, such as those obtained by high-pressure syn-thesis, electrochemistry, or containing expensive iso-topes. The wide Q range and the exceptional stability ofthe GEM detectors make it perfectly suited for total scat-tering studies of partially disordered crystals using thePDF method.In the field of L&A materials, strong emphasis wasplaced on studies of amorphous materials in extremeconditions, such as liquid molten salts at high tempera-ture and pressures, studies of melting phenomena, su-percritical fluids etc. Also, the high flux, high stabilityand extended Q range of GEM was expected to providemajor breakthroughs in the study of small samples, in

Fig. 9. A screen shot of the ARIEL pro-gramme for crystallographic data re-duction and visualisation. The right-side window shows a colour plot ofthe detector response. The left-sidewindow shows parts of the data col-lected from different banks. Note thedifference in resolution between thediffraction patterns.

Fig. 10. Distribution of the published papers referring to GEM data byscientific area.


24


isotopic substitution experiments and in multi-compo-nent systems in general. It is still very much early days to assess the full scientificimpact of GEM, as many publications based on GEM da-ta are just now in the process of being submitted. Italiangroups have been particularly prompt in taking advan-tage of the GEM potential: 16% of the published GEMpapers are from Italian institutions. Successful experi-ments were performed in all the target scientific areas,and a number of publications are already in print (Fig.10). Clearly, GEM has demonstrated its ability to pro-duce superb structural refinements, often comparable to

those from single crystals, with data acquisition times ofthe order of a few minutes or less. Also, the earlypromises of a much improved stability with respect toexisting TOF instrumentation have been fulfilled. Whatfollows is a brief selection, meant to illustrate the capa-bilities of GEM in different areas of science.Chemistry: A variety of systems were investigated, in-cluding manganites, superconductors and other ioniccompounds 4, 5 6 7-13. In these experiments, the structuraland magnetic properties were typically monitored as afunction of temperature for a number of compositions.Several in situ experiments were performed on host-guest systems and on the synthesis and thermal evolu-tion of ferroelectrics 14. As part of the latter experiment,the formation of the ferroelectric perovskite BaZn1/3Ta2/3O3 (BZT) from its precursors was monitored insitu: Fig. 11 shows a particularly “colourful” presenta-tion of the data. Another interesting aspects of the chemistry programmeon GEM in the last 3 years have been the study of iso-topically enriched sample, with the aim of enhancing thecontrast for particular structural features by combiningdata from different isotopes15, 16, and the field of molecu-

lar magnets 17, 18. Both these applications are particularlychallenging for GEM, because they entail very smallsamples, which, in the latter case, have low orderingtemperatures and magnetic moments. Materials science: A few materials science experiments onpyrolisis reactions19-21, crystallisation experiments, andhigh-temperature annealing of superalloys22 tested thecurrent limits of the GEM data acquisition package, withcollection times of the order of 30sec. Unsurprisingly,the maximum data rate is determined by how fast thelarge data files can be stores, rather than by the neutronflux (see below). Battery materials such as manganese

spinels and related compounds, at different stages of thecharging cycles, are now routinely studied on GEM23.Although these studies have so far been performed exsitu (an electrochemical cell is presently being plannedfor GEM), they are nonetheless challenging, because thesample is typically recovered from the surfaces of anelectrode and weights a few milligrams. Unusually forneutrons, we employ a 1mm diameter quartz capillaryas a sample container.Physics: many of the early GEM highlights were pro-duced by physics research. Once again, some of thesereflected the unique ability of GEM to obtain structuralinformation on tiny samples, for example, of high-Tc su-perconductors synthesised in a multi-anvil high-pres-sure apparatus24, 25. Phase diagram mapping studieshave been undertaken by several groups. Here, GEMshines particularly in problems where magnetic ordering

Fig. 11. In situ formation of the ferroelectric perovskite BaZn 1/3Ta2/3 O3

upon heating. The figure is a composite of about 190 runs, taken at 7 minintervals (courtesy of R.I. Ibberson; see also reference 14).

Fig. 12. Short and long-range magnetic ordering in Pr0.35(Cay,Sr1-y)0.65

MnO3. The colour scale indicated the scattered neutron intensity. Oncooling, the short-range ferromagnetic ordering (diffuse scattering atlong d-spacing) evolves either into long-range ferromagnetic orderingthrough an intermediate antiferromagnetic phase (y=0.8) or antiferro-magnetic ordering (y=0.7, 0.6). The data are from the 10-degree (top) and20-degree (bottom) banks. Dramatic structural changes are evident in thehigher-angle data (reference 26).


25


on the short and long range is associated with peculiarstructural phenomena, as in the case of the Pr0.35(Cay,Sr1-y)0.65MnO3 phase diagram shown in Fig. 1226. The possibility of combining GEM data with higherresolution x-ray synchrotron or neutron diffraction datafor a highly accurate structural refinement was alsoquickly recognised. An example is the solution of theCuIr2S4 low-temperature structure, which is consistentwith a coupled spin-dimerisation and charge-orderingtransition 27. As an instrument at the interface between L&A andpowder diffraction, GEM has demonstrated to be ideallysuited for PDF studies of partially disordered crystallinematerials. A fruitful line of work has been that on“pathological” crystals with large amounts of disorder,where normal crystallographic methods fail28. For exam-ple, the average and local structures of the disorderedcrystalline cyanides CuCN, AgCN and AuCN have re-cently been determined from total neutron diffractionexperiments carried out on GEM 29-31. All three materialsconsist of strongly bonded infinite -M-CN-M-CN- chainsheld together by much weaker forces. It is remarkablethat Bragg diffraction in isolation is incapable of yieldingthe correct bond lengths in these apparently simple ma-terials. A particular point of note that in each materialthe metal-carbon and metal-nitrogen bond lengths areidentical. Whilst the interatomic distances within thechains are very well-defined, the inter-chain distancesare much less well-defined due to random displace-ments of the chains along the chain axes. At the oppositeend of the spectrum are studies of highly ordered crys-tals with a small amount of disorder produced by alloy-ing. Here, high real-space resolution (i.e., high Q) is es-sential to distinguish subtle differences in bond length,as shown by Peterson et al. 32 in the semiconductor seriesZnSe1-xTex. More “traditional” studies on vanadium/tel-lurium 33, 34 and phosphate 36 35 multi-component glasses,as well as on solutions 37 are now appearing in the press.

Future challenges and opportunitiesThe GEM beamline and detector banks will be complet-ed by the end of 2003, with the addition of a very lowangle detector (which is already built and tested, andawaits installation), and the construction of an “adden-dum” to the 90-degree bank, to close the gap with back-scattering. Meanwhile, the development of kit designedto enable a variety of bench-top experiments to bebrought to the beamline is continuing, in partnershipwith several user groups. There is, however, a numberof challenges that need to be met to realise the full po-tential of GEM, particularly in the area of electronics anddata handling. In many cases, sub-second data collec-tion times would be sufficient on GEM for completestructural refinements of crystalline materials. However,

“practical” data acquisition times are of 30 sec or more,due to the need to transfer the large GEM data. We arelooking forward to installing a new PC-based instru-ment control programme, which will work together withthe already installed Data Acquisition Electronics (DAE-II). The new system will not only reduce dramatically,the dead time between standard runs, but will also openup the possibility to perform truly kinetic sub-second ex-periments, both in the “one-shot” and “stroboscopic”modes. On a longer-term prospective, we are striving toimplement on GEM the concept of a “virtual instru-ment”, by bringing to bear the opportunities providedby the “e-science” and robotics technologies. The GEMuser of the future will be able to control remotely, fromhis/her home institution, all aspects of the instrumentoperation, including sample changes, and to process anddisplay the data instantly.

Beyond GEM: towards the ISIS second-target stationNo matter how excellent GEM has demonstrated to be,instrument scientists always dream of the next instru-ment, which will be even better. Thinking about how toimprove on GEM, three wishes naturally come to mind:better resolution, higher count rate at long d-spacing(the region of magnetic peaks) and the need to combineshort-range structure with longer-range inhomogeneitiesfor L&A materials. Understanding these inhomo-geneities is often crucial to establishing why particularmaterials behave the way they do, so it is becomingmore important to determine both types of structure in asingle experiment. These wishes may be about to be re-alised with the construction of the second target station(TS-II) at ISIS, which is optimised for long-wavelengthneutron production. Proposals are about to be submit-ted for three new instruments that, to a greater or lesserdegree, have been inspired by GEM. The high-resolu-tion magnetic diffractometer WISH promises an order ofmagnitude higher count rate at long d-spacing with evenbetter resolution. The “radical” backscattering instru-ment HRPD-II will have an even better resolution thanthe existing HRPD, but with GEM-like count rate forsome applications. Finally, the L&A diffractometer NIM-ROD is designed to measure both short range structurewith excellent spatial resolution (<0.1Å) and intermedi-ate range order (concentration fluctuations, density fluc-tuations) out to ~100Å in crystalline solids, amorphoussolids, liquid mixtures, large molecule solutions, interca-lation compounds, critical fluids, engineering and poly-meric materials. The aim will be to measure both short-range and intermediate-range structures so that an accu-rate large-scale model of the local structure can be estab-lished. Isotope substitution will be widely used. If thisportfolio is approved, the future of powder and L&A dif-fraction at ISIS is assured for the foreseeable future.


26


Appendix I: GEM instrument parametersModerator: Liquid CH4, T=110 K

Primary flightpath 17 m

Choppers: 2 disks (50 Hz)+1 “nimonic” (T0, 50/100 Hz)

Single-frame bandwidth ∆λ = 4.1 Å

Q-range: 0.05 Å-1 ≤ Q ≤ 80 Å-1

d-range 100 Å ≤ d ≤ 0.1 Å

Slits: 6.352m/8.145m/10.265m/12.675m/

15.350m/16.550m, all motorised.

Detectors ZnS scintillators, covering a 4 sterad solid angle.

Bank Mean angle Min Angle Max Angle L2 Resolution 2 theta DQ/Q

0 2° 1.1° 3.2° 2.8-2.9m* 5 - 10%*

1 9° 5.6° 12.5° 2.2-2.4m 4.7%

2 17° 13.8° 21.0° 1.48-2.10m 2.4%

3 35° 24.8° 45.0° 0.65-1.40m* 1.7 - 2%*

4 62° 49.9° 74.9° 1.03-1.44m 0.79%

5 92° 79.0° 104.0° 1.38m 0.51%

6 146° 141.9° 149.2° 1.54-1.74m 0.34%

7 159° 149.3° 169.3° 1.04-1.39m 0.35%

Collimation: B4C vanes + oscillating radial collimator.

Sample environment: All standard ISIS equipment + dedicated 10 Tcryomagnet.

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37 J. C. Wasse, S. Hayama, S. Masmanidis, S. L. Stebbings, and N. T.Skipper, Journal of Chemical Physics 118, 7486 (2003).

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1-IntroductionNeutron Spectroscopy is one of the most powerful diag-nostic techniques available to the scientific research inthe field of condensed matter. This technique, widelyemployed among the technologically most advancedcountries, is not as well spread within the Italian scientif-ic community, as the level of the GDP (Gross DomesticProduct) and the political and social weight of this coun-try would deserve. Among the various reasons responsi-ble for the present situation, the absence of national neu-tron sources available to the scientific community is oneof the most serious. Indeed, the beginning of the ‘70switnessed an absolute minimum, in Italy, of the neutronscattering activities, related to the Italian disengagementfrom any research activity in the nuclear energy field.Since then, the role of CNR has been of fundamental im-portance in the field of the neutron scattering. First, inthe mid ‘70s, a know-how core of the community waspreserved thanks to the agreement between CNR andENEA to run the instrumentation installed at the TRIGAreactor (Casaccia, Roma, Italy). Then, since mid ‘80s, acooperation activity was started with the Rutherford Ap-pleton Laboratory (RAL, UK), where a new generationpulsed neutron source (ISIS) was under construction. Asa consequence, the downward trend for the neutronscattering activity was reversed and the Italian neutronscattering community begun to grow. The building ofthe PRISMA spectrometer, by ISM-CNR during the peri-od 1985-1995, and the following realisation of theTOSCA spectrometer, by IEQ-CNR in the period 1996-2002, has witnessed a steady growth, both in qualitativeand quantitative terms, of the Italian neutron scatteringcommunity.Today, thanks to the joint efforts of CNR, which has es-tablished a cooperation agreement with ISIS at 5% ofutilisation level, and of INFM, which has established asimilar agreement at 3% level with ILL (Grenoble,France), the Italian neutron community has reached alevel of maturity that compares favourably with othercountries in the European Union. Nonetheless, the size ofthe community has not yet reached the average Euro-pean level, commensurate to GDP or to the populationsize. It is worthwhile noting that ISIS represents theworld’s most powerful pulsed neutron source, whilst ILLrepresents the world’s most powerful neutron research

reactor. The international situation for the Italian neutroncommunity in the European context is also testified bythe positions of Prof. F. Barocchi, who is presently Chair-man of the European Neutron Scattering Association,and of Prof. A. Deriu who is the present Scientific Secre-tary of the ESS (European Spallation Source) Council.Concerning the CNR involvement, it should be recalledthat according to the International Scientific Co-opera-tion Agreement signed in 1996 between CNR and ISIS(CCLRC, UK), it was stated that CNR would seek finan-cial support for the construction of an Italian NeutronTest Station to be realised downstream from the TOSCAspectrometer (which was also taking part in the generalterms of the agreement). It was agreed that some 50% ofthe total instrument time would be made available to theItalian scientists.The CNR Neutron Spectroscopy Advisory Committee,has thoroughly discussed this matter. Because of the lackof national neutron sources, and considering the recentengagement of Italy, and of CNR in particular, in theMemorandum of Understanding concerning the overalldesign of the European Spallation Source (ESS), theCommittee considered the realisation of the Italian Neu-tron Test Station at ISIS of strategic importance and de-cided to give its sponsorship to the project.The realisation of the TOSCA project was carried outtaking into account this possibility and a sufficient spacewas allocated to host the Italian Neutron Test Station. Atthe same time, the Managing Council of CNR had decid-ed to financially support the construction of the interme-diate neutron shutter between TOSCA and the ItalianNeutron Test Station by extending the Strategic ProjectTOSCA for a 3rd year.The TOSCA spectrometer is now completed and a newagreement, covering the period 2002-2008, has beensigned between CNR and CCLRC. This agreement in-cludes also the construction, in the near future, of a new,advanced, liquids and amorphous time-of flight (TOF)diffractometer (NIMROD). Meanwhile, the CNR Neu-tron Spectroscopy Advisory Committee stressed the im-portance of starting the realisation of the Italian NeutronExperimental Station (INES). It is worthwhile mention-ing that the Committee, evidencing the importance thatsuch a Test Station would assume in the applied-sciences(Chemistry and Materials Science, Earth Sciences, Crys-

INES - Italian Neutron Experimental StationRealisation of a neutron diffractometer, downstreamfrom the TOSCA spectrometer, at ISIS (UK)Agreement CCLRC-IFAC: 001 (January, 2003)

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tallography, etc.) and aiming to an enlargement of theItalian neutron scattering community, had explicitly re-quired that INES should be equipped with a powderneutron diffraction instrument, and urged the constitu-tion of a national project team, chaired by M. Zoppi. Atpresent, the Project Team members are A. Albinati andM. Catti (Milano), O. Moze (Modena), F. Sacchetti (Peru-gia), R. Triolo (Palermo), and the staff of IFAC-CNR in-volved in neutron spectroscopy (i.e. U. Bafile, M. Celliand D. Colognesi). The Project Team is open to the col-laboration of the whole Italian community, representedby the Italian Neutron Scattering Association (SISN). Inthis context, a most valuable contribution has been givenby P.G. Radaelli (see enclosure).It should be stressed that neutron diffraction is a veryimportant tool for solving problems in materials science,earth science, and crystallography, in general. In addi-tion, neutron diffraction plays an important role in tech-nological problems where the localisation and the quan-titative measurement of residual stress and strains caninfluence the performances of manufacts. Finally, weshould never forget that neutrons are characterised byan extremely weak cross section at the atomic level andtherefore their penetration length can easily reach sever-al cm in almost all materials, including metals, wherethey can outperform X-rays. This makes neutrons an al-most ideal probe for non-invasive, non-destructive evalua-tion of the microscopic bulk features of almost any mate-rial. In this field, apart from the obvious technologicalapplications, another very important potential use ofneutron diffraction is, potentially, in the field of scienceapplied to the study of cultural heritage artefacts.Last, but not least, the realisation of the Italian NeutronExperimental Station would constitute a training oppor-tunity, for young researchers, on a world class pulsedneutron source instrument as well as a test station formaterials and detectors. As a matter of fact, it is impor-tant to point out that several Italian research groups areinvolved in developing innovative neutron detectors,whilst CNR itself is engaged in the preliminary R&D ac-tivity of the European Spallation Source whose realisa-tion is expected to be completed in some ten years time(http://www.kfa-juelich.de/ess/CUR/ESS_ curren-tRD.html).

2-Technical FeaturesThe TOSCA beam line looks at the ambient water moder-ator and therefore is rich in epithermal neutrons. Howev-er, the installation of a nimonic chopper to eliminate thevery high-energy neutrons from the primary beam, withthe aim of reducing the background noise, made somechange in this scenario. The chopper, placed at 9.6 m fromthe water moderator, is set to give an opening time at 724µs and a closing time at 10339 µs. These times are evaluat-

ed assuming that the proton beam hits the spallation tar-get at t=0. Recalling that ISIS operates at 50 Hz, an overalltime-period of 20 ms should be taken into account. In Fig.1 we report the flux measured by the TOSCA monitorplaced at 15.75m from the water moderator.

The nimonic chopper is optimised for the best perfor-mances of the TOSCA spectrometer, which is located at17.00 m distance from the water moderator, with notime-overlap effect. The INES position, instead, isplanned to be located at 22.8 m. Adding a secondaryflight path of 1.0 m, we obtain a total flight path of 23.8m which implies time-overlap effects (see Fig. 2).

A simple calculation, based on the nominal parameters,would give for INES a time-window between 5.59 msand 20.0 ms. However, taking into account that theframe overlap can be neglected when the intensity of theslow neutrons is lower than, say, 0.1% of the fast ones,

Fig. 2. Flux calculated at INES position (total flight path L=23.8m) evi-dencing the frame overlap effect.

Fig. 1. Flux measured by the TOSCA monitor placed at 15.75m from thewater moderator. The two vertical lines represent the nominal opening(λ=0.298 Å) and closing (λ=4.261 Å) of the chopper..

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the effective time window can be extended down to 3.8ms. We assume, therefore, a valid time-interval 3.8 ms <t < 20.0 ms and hence that the effective wavelengths forINES are limited between 0.632 and 3.324 Å.Geometrical (and logistic) constraints suggest (unless aspecial design will be developed) that the scattering an-gles would be in the range between 8° and 172°. Theminimum angle (8°) gives Qmin = 0.26 Å-1 and Qmax =1.39 Å-1. Instead, the maximum angle (172°), gives Qmin= 3.77 Å-1 and Qmax = 19.83 Å-1. A radial distribution ofdetectors, placed at 100 cm distance from the sample po-sition (cf. the technical notes by P.G. Radaelli, attached tothe present report) imply that 3He detectors of 1cm di-ameter can be displaced by ≈1° from each other (centre-centre distance = 1.74 cm, i.e. sufficient to leave somespace for shielding and the mechanical environment).This implies that the second detector (at 9°) covers a Q-range [0.30 - 1.55] Å-1, while the third detector’s range(at 10°) is [0.33 - 1.73] Å-1. Thus an extended Q-intervalbetween 0.26 and 19.83 Å-1 could be continuously cov-ered by a set of 165 detectors placed between 8° and 172°scattering angle.The corresponding interval in terms of d-spacing, i.e. thedistance between neighbouring scattering planes in thecrystal structure, is given by the Bragg’s law:

(1)

where 2θ is the scattering angle, λ is the neutron wave-length, and d is the distance between two lattice planes.Given the relation connecting the incident wavelength,scattering angle and momentum transfer Q:

(2)

the relation between d and Q is:

(3)

Thus, for 2θ = 8°, dmin = 4.53 Å and dmax = 23.83 Å,whilst for 2θ = 172° dmin = 0.32 Å and dmax = 1.67 Å, i.e.a rather good interval for a general-purpose powder dif-fractometer. In fact, for the atomic elements, the averagelattice parameter ranges between 2.27 Å (hcp, a-parame-ter of Be) to 6.13 Å (fcc, a-parameter of Xe). By contrast,complex materials may have these parameters doubled,or even tripled, but they cannot change by orders ofmagnitude. As a consequence, unless very peculiar peri-odic structures have to be studied, a neutron diffrac-tometer like INES can give rather useful information.As far as the resolving power is concerned, one shouldconsider that the total flight path of INES will be ratherlong at 23.8 meters. In order to evaluate the resolvingpower it is important to take into account all the relevant

terms. From the definition of the momentum transfer(Eq. 2) it is easy to obtain the relative error on Q:

(4)

Here, the relative error on the wavelength is de-termined by two main contributions:A) the intrinsic time-width of the neutron pulse,B) the total uncertainty on the whole flight path (L).In both cases, the only way of decreasing the error is tomake the total flight path as long as possible. In practice:

(5)

The first contribution is fixed by the characteristics (i.e.shape and size) of the moderator and cannot bechanged. Since INES looks at the same neutron beam-line of TOSCA, this contribution can be obtained know-ing the design characteristics of the coupled poisonedambient water moderator. This is expressed by a wave-length and time dependent flux-function ϕ (λ,t). In prac-tice, the time-width of the pulse is rather sharp (2-3 µsec)for short wavelengths (epithermal neutrons). For longerwavelengths, instead, the thermal neutrons (with aGaussian distribution) become predominant and thewidth of the time distribution reaches a value of the or-der of 40-50 µsec. At any rate, since the wavelength dis-tribution is evaluated from the time-profile, we have tointegrate the flux-function over λ in order to obtain thetime-profile of the neutron pulse:

(6)

The resulting time half-width is ∆t=23 µsec and the first(time) term in Eq. 5 turns out (before squaring) between1x10-3 and 6x10-3, depending on the wavelength. In con-trast, the second term, determined by the total flightpath, (also, before squaring) is ~2x10-4 (obtained by as-suming similar sizes of the sample and detector, i.e. ~1cm). It is important to point out that the effect of the totalflight path is much smaller than the one determined bythe time uncertainty. This means that one could use ex-tended samples (or detectors) without deteriorating toomuch the resolving power of the instrument.As far as the angular contribution is concerned, the mo-mentum transfer uncertainty is mainly determined bythe angular size of the sample and the detector, with re-spect to each other. By assuming again 1 cm as a stan-dard transverse dimension for the detector, and a sec-ondary flight path of 1 m, we obtain a ratio of 1% which,in turn, should be scaled by the angular factor θ /tan(θ),

Φ( ) ( , )t d t=∞∫ λ ϕ λ0

∆ ∆ ∆λλ

=

+

2 2 2t

tL

L

∆λ λ( )

2222

λλ∆

+

θθ∆

=

∆=

∆

tanQ

Q

d

d

Qd

π=2

Q =4πλ

θsin

θ=λ sind2

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where 2θ is the scattering angle. This implies a large con-tribution from the angular factor for the forward scatter-ing case. Going to back scattering, the angular term be-comes smaller and smaller, and the resolving power ismainly determined by the other term, namely . The situation is depicted in Fig. 3.It should be pointed out, however, that using squashed3He detectors, in the forward scattering banks, woulddrastically decrease the effect of the angular term, thusimproving the resolution. This situation is depicted in Fig.4 (note the different scale in Figs. 3 and 4, respectively).Concerning the efficiency of the 3He detectors, we notethat the available wavelength on INES ranges between0.632 and 3.324 Å. In Fig. 5 the calculated average effi-ciency is reported for three types of detectors. Namely,

the round detector (10 bar, 1 cm diameter), the squasheddetector (20 bar) placed with the flat side (depth 2.5 mm)or the sharp side (depth 14 mm), respectively, looking atthe sample. Here average means that the round detectorefficiency has been averaged by integrating over thecross section of the cylinder (see P. Verkerk, PhD Thesis,pag. 96). The squashed detectors have been approximat-ed by a rectangular section.However, Fig. 5 does not tell all the truth. In fact, in or-der to compare the various detectors, the effective solidangle should be considered. By assuming a constantheight of the detectors (10 cm) and the same secondaryflight path of 1 m, we arrive to the conclusions shown inFig. 6 which gives the calculated overall efficiency re-duced by the respective solid angle. It appears, as ex-pected, that the geometrical condition with the squasheddetector placed with the sharp side looking at the sam-ple, though the most effective from the point of view ofthe resolving power, becomes the least effective with re-

gard to the counting rate. It is important to consider,however, that one could imagine a design with three orfour different detector banks, placed at slightly differentdistances from the sample, in order to cover more effi-ciently the solid angle and recovering a factor 3 or 4 inthe black line of Fig. 6 without loss in the resolvingpower. Of course, the feasibility of such a solution isstrictly bound to the available budget, but should beconsidered as a possible option at the time of the finaldesign.

3-Scientific ApplicationsThere exists a clearly identifiable need in the Italian neu-tron scattering community for a General Purpose Neu-tron Test Station. In this context, the first and most gen-

eral-purpose needed instrument appears to be a PowderDiffractometer. A wide range of options concerning sam-ple environment (temperature, pressure, and magneticfield) is also required, associated with such an instru-ment, in order to cover the largest possible potential-user community. At present, the Italian scientific com-munity involved in condensed matter physics consists ofgroups engaged in activities covering a rather extensiverange of interests such as magnetism and superconduc-tivity, structural physics and chemistry, materials, lifeand earth sciences, as well as engineering applications.All these activities will gain advantages from an instru-mental facility devoted to a non-destructive microscopiccharacterisation. Possible development topics for thecommunity, include:- geological samples under pressure- hard magnets, magneto-resistive materials, magneto-

caloric effect compounds- hydrogen storage materials and metal hydrides

∆λ λ( )

Fig. 4. Calculated resolution for secondary path 100 cm and squashed3He detectors of 2.5 mm thickness.

Fig. 3. Calculated resolution for secondary path 100 cm and round 3Hedetectors of 1 cm diameter.

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- superconductors (both high Tc and conventional) - lithium and hydrogen ionic conductors- zeolites- molecular magnets- microscopic stress and strain in engineering

components.In all these instances, neutron diffraction has repeatedlyshown its well known and extremely attractive features.Moreover, for magnetic materials, a requirement whichsets these apart from other materials is the absolute ne-cessity to access long d spacing (up to 10-15 Å).The two essential characteristics of the proposed GeneralPurpose Powder Diffractometer, resolution and intensity,will be tuned to fulfil the largest requirements of the po-tential scientific user community. The inverse relation-

ship which unfortunately exists between the two willthus need to be taken into account when the final designspecifications of the instrument will be set.Assuming for INES a useful angular range between 8°and 172°, the momentum transfer available to the dif-fractometer will be in the interval between Q=0.26 Å-1

and Q=19.83 Å-1. For a comparison, this is similar to theQ-range available on the D4 diffractometer at ILL and iseven more extended than that available on D20. This re-flects in an interval, for the d-spacing, between d=0.3 Åand d=23.8 Å, i.e. fully within the majority of the re-quested features.It is also extremely interesting to observe that a possibleoption for rotating the squashed 3He detectors in itshousing, would transform INES from a high resolution,low count rate, diffractometer to a lower resolution buthigher counting rate machine. It is important to point outthat this change of configuration appears rather simple,in principle, and can be obtained just by a simple me-

chanical device that could be operated under computercontrol from the users. In practice, this option turns outto be rather expensive and its realization will depend onthe amount of financing available to the project.As a powder diffractometer, taking into account theavailable d-spacing range, INES could be used in manydifferent fields. For example, it could be used in thestructure determination of superionic conductors, thestructural refinement of high temperature superconduc-tors, and the structural determination of metallic alloys.Another interesting field of application for INES wouldbe in the earth science where it could easily resolve thecrystal structures of geological samples. In the field ofmetallurgy, it is interesting to have direct experimentalaccess to the quantitative amount and localisation of the

residual stresses following, for example, some localisedthermal treatment like soldering or brazing. Neutron dif-fraction can give answers to many questions. However, afield where neutron diffraction, and INES in particular,can give an extremely useful contribution is in the quan-titative determination of the structure and the phasecompositions of metal artefacts of archaeological origin.A test experiment carried out recently on ROTAX hasshown extremely interesting results on archaeologicalbronzes.Since the research interests of the community appear tocover rather broadly areas where high resolution or highintensity is needed, the resolution and intensity charac-teristics of the instrument need to be tailored very care-fully to these requirements. Finally, it should be taken in-to account that an open design, as the one proposed here,will allow using the neutron beam of INES for generaltesting purposes and neutron detectors development.This is extremely important, taking into account the en-

Fig. 5. Detection efficiency for the various choices of the 3Hedetectors.

Fig. 6. Overall efficiency for the various choices of the 3He detectors,taking into account the detector’s solid angle.

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gagement of CNR in the Memorandum of Understand-ing concerning the R&D activities for ESS.

4-Structure of INESThe general idea is to build the diffractometer using onehalf of the available space covering an interval of scatter-ing angles between 8° and 172°, at least at a first stage.The sample region should be rather large, so that largeobjects (e.g. mechanical or archaeological artefacts)could be hosted in the sample position. This, in turn,could be equipped with temperature regulation devices(CCR cryostat and furnace) and a high pressure facilityin order to allow an extended experimental interval bothin temperature and in pressure. Using this configuration,the other half of the available scattering angle will beavailable for general neutron-test purposes.An interesting and comparatively new feature of thisdiffractometer will be the production of angle-dispersiveprofiles across the full 2q range from time-of-flight mea-surements. This result is expected to be obtained by thedata reduction strategy of angle-dispersive, rather thanconventional wavelength-dispersive, focussing. The pro-cedure is made necessary by the limited Dl wavelengthspread available, but it may present some attractive as-pects particularly from the point of view of methodolo-gy. For instance, crystal structure analysis by conven-tional Rietveld refinement may take advantage, in somecases, from the use of angle-dispersive data. Further, thepeak shape functions needed to represent Bragg profilesare affected by the choice of angle- rather than wave-length- dispersion, and a development work will be re-quired to model such functions suitably.A further possibility, mainly suggested by the recent testexperiments on archaeological bronzes, concerns thepossibility of collecting information on textures. Sincemounting an extended sample on a goniometer hardlyguarantees that the scattering sample remains un-changed upon rotation, it would be important to collectcomplementary information from a set of extra detectorbanks placed in the vertical plane at 90° scattering angle.A possible option in this direction is contemplated in theenclosed preliminary design.The possibility of accessing the fast neutrons emergingfrom a spallation source is of fundamental importance ininstrument design. Any instrument project is usuallycarried out on well known concepts. However, the opti-misation of the performances needs a more practical ap-proach. As an example, we recall that during the devel-opment of TOSCA a test was carried out for a possibleinverse geometry crystal analyser design of the forwardscattering section [C. Petrillo, F. Sacchetti, M. Celli, M.Zoppi, and C. Checchi; An inverse geometry neutron scat-tering spectrometer with graphite venetian blind crystal

analyser and a para-hydrogen filter, Nuclear Instrumentsand Methods in Physics A 441 (2000) 494]. This optionwas discarded, in the end, because of the pressures fromthe TOSCA international user community. However, wehad shown, very clearly, that such a solution would haveproduced a high resolution instrument, working in anenergy range that is not covered, at the moment, by thepresent inelastic spectrometers.In conclusion, in the present proposal we prefigure aTest Station that, initially, will be equipped with a pow-der TOF diffractometer and a sample environment sec-tion leaving, however, enough space for general instru-mentation testing and training of young researchers.

A-powder diffractometerThe overall preliminary design is enclosed. This de-scribes a powder diffractometer with a range of scatter-ing angles between 8° and 172°, in the horizontal plane,with the neutron detectors placed at 1m from the sample.Thus, a linear region of the order of 2.8 m length will beavailable for the detectors. Considering typical 3He neu-tron detector of 1 cm diameter, and allowing for somedead space for mechanical spacing and shielding (for ex-ample, displacing the detectors by 1°, one another) onecould imagine to build 9 detector banks, each composedby 15 detectors, for a total of 135 detectors. Three morebanks could be located in the vertical plane, at 90° scat-tering angle, for the sake of collecting information ontextures.Each detector bank should mechanically hold the detec-tors and the shielding material that, in turn, would givea partial collimation for the secondary neutrons. It is alsopossible to imagine that the secondary neutrons couldfly in the vacuum of the sample container tank and thenin a controlled atmosphere ambient (argon) before reach-ing the detectors. Finally, it will be important to carefullydesign the collimation in the secondary flight path in or-der to reduce the background noise or the scatteringfrom unwanted regions of the sample (this is particular-ly important for large samples used in residual stressanalysis and archaeological artefact characterization).

B-sample environment regionThis section will be designed in full agreement with thestandards of the Sample Environment department ofISIS. However, we should be able to obtain a rather largevolume for the sample area that will be capable of host-ing particularly large samples. In this respect, based onour test experiment on the archaeological bronzes, weshould provide a positioning device that allows for analmost perfect localisation of the desired portion of thesample. Some crossed beam optical device (for example,a diode-laser beam) should work rather well to this aim.Also, we remind that the primary neutron beam should

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be in vacuum and so does the sample. Therefore, itshould be possible to manipulate the sample holder us-ing an electromechanical device operated from outsidethe sample container.In addition, considering that a wide temperature rangeis planned for same samples, a He closed circuit cryostatand a furnace should complete the equipment of thesample environment region.Given the rather large sample area, it will be not diffi-cult, in the future, to equip the sample environment re-gion with a medium-high pressure device to performhigh pressure experiments. In this field, a strict collabo-ration with the high pressure staff of ISIS will be bothwelcome and necessary.

5-Scientific SupportConcerning the scientific support for the present project,we remind that some research activities currently ex-ploited at IFAC-CNR could take advantage of the ItalianNeutron Experimental Station INES. Moreover, otherItalian groups (either with CNR or with University De-partments) will take full advantage of this instrument.These research activities are concerning material science,at large, magnetic materials, crystallography, earth sci-ences, and liquid matter, in general.

CNR - Istituto di Fisica Applicata “Nello Carrara”(Firenze)1 - Characterisation of bronze artefacts of archaeological origin(U. Bafile, L. Bartoli, M. Celli, S. Siano, M. Zoppi)With respect to a thermal neutron source, there is an in-trinsic advantage in using neutron diffraction on apulsed source. In the former case, it is necessary to movepart of the experimental setup in order to change themomentum transfer. In TOF diffraction, instead, thechange in the momentum transfer is obtained by chang-ing the wavelength of the incident neutrons and a staticsetup can be used. The difference assumes a fundamen-tal importance when the sample has a non-symmetricgeometric shape like in ancient, archaeological artefacts.A preliminary test, carried out on the ROTAX diffrac-tometer, has given extremely interesting results. Thisnovel activity, which we predict will open an extensiveresearch field, is carried out in cooperation with the localarchaeological authorities (Soprintendenza Archeologicadi Firenze: M. Miccio; Museo Archeologico di Chiusi:I.M. Iozzo; Soprintendenza Archeologica di Ancona: Dr.G. De Marinis) and with Dr. W. Kockelmann (RAL).2 - R&D activity on neutron detectors.(P. Fabeni, G.P. Pazzi, M. Pucci, M. Zoppi,)Research activity on new scintillation neutron detectorswill be of fundamental importance for the developmentof the peculiarities of the European Spallation Source. In

practice, the neutron detection process reduces to the ab-sorption of the particle by a nucleus and the followingdecay from the excited state with a energy release to theneighbouring atoms. In this process, one of the finalstages of the decay chain is the transmission of an opticalsignal (photons produced by the energy decay) to a pho-tomultiplier.One important step, necessary in the optimisation of thisprocess, is to understand the photon propagation in thesolid matrix containing the neutron absorbers nuclei,and to study the global efficiency of the process as afunction of the chemical and physical composition of thematrix. To date, the most used scintillation detectors usea glass matrix. The optical workshop of our Institute hasgained, in the past years, an excellent reputation inbuilding integrated optical devices and fibre coupling ofoptical signals.

Physics Department “E. Amaldi”- University Roma-TreThere is deep interest in neutron diffraction techniquesapplied to the field of cultural heritage, in particular onancient potteries and bones of archaeological origin.Some small angle neutron diffraction experiments havebeen already carried out and more experiments areplanned on ROTAX (Prof. M.A. Ricci).An important cooperation activity could also be estab-lished with the Department of Earth Sciences, finalisedto the study of materials of geological interest at highpressures.

Physics Department - University of Roma Tor VergataResearch and Development of new high-energy neutrondetectors is a current important activity carried out with-in the TECHNI project (Prof. C. Andreani) in strict coop-eration with the University of Milano-Bicocca (Prof. G.Gorini). The possibility of using a test beam line lookingat the ambient water moderator will be helpful in this re-search area.

Physics Department, University of PerugiaThere is a live interest in developing diagnostic tech-niques for testing and quality control of crystal mono-chromators for neutron spectroscopy. Test of microstripSi detectors will be also an important activity, which iscarried out in cooperation with the University of Milano-Politecnico (Prof. C. Petrillo). Moreover the INES beamline could be extremely fruitful in testing low angle in-elastic scattering. This possibility can be exploitedthanks to the long evacuated incoming flight path (Prof.F. Sacchetti).Neutron diffraction represents a very promising ar-chaeometric tool and the knowledge of its potential inthe examination of artefacts of nearly all shapes andmaterials, in a truly non-destructive manner, is still at a

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very early stage of exploitation by the relevant scientif-ic community. In particular, TOF neutron diffractionwill be able to provide a combined information onphase identification, phase fraction determination, mi-crostructure, and textures of archaeological objects(Prof. R. Rinaldi).

Physics Department, University of ModenaCurrent research interests are magnetic interactions andstructures in rare-earth intermetallics, compounds andalloys, permanent magnet materials, magnetic refriger-ants. Neutron powder diffraction is extensively used forthe determination of the magnetic structures of thesematerials. Most of these measurements are performed atISIS using the diffractometers ROTAX and POLARIS.The availability of a dedicated diffractometer will resultin the development of further collaborative research pro-jects, for example with the Department of Earth Sciences(Prof. Baraldi), on the quantitative phase analysis of an-cient ceramics originating from the Mutina (Modena)area (both pre-Roman and Roman) (Prof. O. Moze).

Materials Science Department,University Milano-BicoccaExtensive research activity is being carried out on themechanisms of ion mobility in lithium and hydrogenionic conductors, for which a structural characterisationby powder neutron diffraction is absolutely necessary.This activity is currently performed on standard ISIS in-strumentation. The new INES diffractometer is expectedto give rise to novel opportunities for testing new sci-ence and/or explorative experiments that are now of dif-ficult realization. (Prof. M. Catti).

Department of Structural Chemistry,University of MilanoUnderstanding the nature of the metal-hydrogen bond isof paramount importance in the study of catalyticprocesses involving hydrogen transfers such as hydro-genation reactions. In particular powder diffraction atmedium to high resolution will play an extremely im-portant role in the study of the mechanism of the hydro-gen adsorption in inorganic complexes, binary andternary metal hydrides (carried out in collaboration withIFAC-CNR), by characterising the nature of the adsorbedspecies (e.g. H vs. H2 ) and the structural changes in-duced upon hydrogenation and/or doping of the start-ing materials. These studies require structural determi-nations to be carried out at various temperatures (in therange 20 – 400K) and possibly as a function of pressure(Prof. A. Albinati).

Mineralogy Department, University of MilanoTexture analysis of precious and large or heavy objects ina complete stationary experimental set-up, which is pos-sible on TOF neutron diffraction instruments equippedwith a wide 3-dimensional detector arrangements, willallow neutron structural studies beyond the currentthreshold level. Combined texture and microstructuralanalysis of metal objects can give complementary infor-mation on the different manufacturing conditions andprocesses. This will have important consequences for ar-chaeometric purposes. (Prof. G. Artioli).

Marco ZoppiIFAC - C.N.R.

COMMISSIONI SCIENTIFICHE


The Italian scientific community, which uses neutronsand muons as probe for the microscopic analysis of mat-ter will be forever indebted with the Consiglio Nazionaledelle Ricerche (CNR). The latter has indeed sponsoredthese techniques since the early 80’s, by signing agree-ments for the access of the Italian researchers from CNR,Universities and Industry to the neutron facilities in Eu-rope and supporting their research with proper actions.The CNR has trust a small community and given thenecessary opportunities and funding for a harmonicgrowth in all areas where neutron spectroscopy canachieve deep contributions to the Science. Indeed neu-tron spectroscopy, a technique that can be used in multi-disciplinary research, perfectly fits the mission of aCouncil such as CNR. When in 1997 the Istituto di Fisica della Materia (INFM)has agreed to finance and support primarily the neutronspectroscopy research performed at reactor based inter-national facilities (ILL and LLB), the CNR has focused itsaction on the Italian participation to the research per-formed using neutrons and muons from acceleratorsources. This has been achieved through the agreementbetween the CNR and the Council for the Central laborato-ry of the Research Council (CCLRC) for the access of the

Italian researchers to the ISIS facility and by signing theMoU for the development of the European SpallationSource (ESS) project. The beam time allocated by the ISISpanels to experimental proposal submitted by Italian sci-entists has been over the duration of the agreement evenhigher than what expected on the base of the participa-tion percentage (see Figure 1), in acknowledgment of thescientific quality of the neutron research performed inItaly. In view of these successful results CNR has recent-ly renewed the agreement for the access to the ISIS facili-ty for the period 2003-2006.It has to be stressed that the action of CNR in support ofthe research with neutrons and muons at ISIS is not lim-ited to the funding for access to the facility. In particularthe most incisive action is the financing of specific in-strumentation, designed by Italian researchers in collab-oration with their partners in the UK, built in Italy andinstalled at the facility. Participation to instrumental de-velopment has been essential in order to increase the ex-pertise and robustness of our community and has been aqualifying prerequisite for the Italian participation to theESS project and the access for funding from the Euro-pean Community for R&D in neutron spectroscopy.PRISMA and TOSCA have been the first two spectrome-

ACTIONS OF CNR IN SUPPORT OF THESCIENTIFIC RESEARCH BASED ON NEUTRONSAND MUONS SOURCES

Figure 1.

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ters built in Italy within the agreement with ISIS andthey are available for all the users since their first opera-tion. A particular mention has to be made of the most re-cent instrumental development funded within theCCLRC-CNR agreement: the Italian Neutron Station IN-ES. An agreement between CCLRC and the Istituto diFisica Applicata “Nello Carrara” (IFAC-CNR) for the de-velopment and utilisation of this neutron test and devel-opment area has been signed at the beginning of thisyear. The INES area will be used for testing and develop-ing equipment and neutron scattering techniques andfor training and development. The facility will be avail-able to the whole of the Italian neutron scattering com-munity as represented by the “Commissione di Studioper il Coordinamento delle Attività di SpettroscopiaNeutronica del CNR”, as well as other scientists accred-ited by CCLRC. Access to this facility will be decided,on about an equal basis, by a separate mutual agreementbetween CCLRC and IFAC. IFAC shall assign, from thestart of the INES experimental equipment installationprogramme and for the duration of this Agreement, onescientist to work at CCLRC. This scientist shall be in-volved in the installation and responsible for the opera-tion of the experimental equipment on INES (see articleby M. Zoppi in this issue for a description of INES). As in previous case, a novel instrumental developmentwill be associated to the latest CCLRC-CNR agreementsigned last year. In consideration of the high impact thatinstrumental development has on the scientific commu-

nity, the CNR Neutron Committee has individuated inthe NIMROD diffractometer proposed for the secondtarget the next project of interest for the Italian commu-nity (Annex II). NIMROD, as previously PRISMA andTOSCA will be built within a collaboration between ISIS,CNR and Universities researchers.Promotion and formation of personnel are the other twosignificant tasks that complete the action of CNR in sup-port of the research performed with neutrons andmuons. Among this activities I want to mention the sup-port for travel and subsistence expenses of researchersperforming experiments at ISIS and the sponsorship ofthe Scuola di Spettroscopia Neutronica Francesco Paolo Ricci,held every two years in Palau.Over the last eighteen years the partnership betweenCNR and CCLRC for the access to the ISIS facility hasbeen fruitful and successful, in terms of increased collab-orations between Italian and British researchers on bothfundamental science and R&D for instrumentation. Con-sequently I want to conclude this report by congratulat-ing with ISIS staff for the recent award of British Gov-ernment funding for the second target (ISIS II project)and wishing that this will be an opportunity for consoli-dating our partnership.

M.A. Ricci Chairman of the

CNR Neutron Committeeure


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This proposal requests a Near and InterMediate Range OrderDiffractometer (NIMROD) as a day one instrument on theSecond Target Station at ISIS. Uniquely, NIMROD will pro-vide continuous access to particle separations ranging fromthe interatomic (< 1Å) through to the mesoscopic (> 300Å).This is the characteristic dimension of fullerenes and smallprotein molecules, i.e. the true nanoscale. As such, the instru-ment will open up major opportunities for novel and timelyscience, in areas where the primary aim is to relate molecular-level structure to the phase and function of materials. The properties of many scientifically and technologicallyimportant materials arise from a subtle balance betweenshort-, medium- and long-range interactions. Traditional-ly the structural correlations on these length scales areprobed using separate wide- and small-angle diffractionexperiments. TS-II at ISIS now provides a unique oppor-tunity to build a diffractometer that can probe a broadrange of structural correlations simultaneously. This ap-proach makes possible the development of a coherent pic-ture of the complex relationship between structure andproperties. The rationale is to relate changes in local mole-cular environment to larger scale processes, such as pro-tein folding in solution, confinement in microporous me-dia, and phase behaviour and nucleation. In summary: • NIMROD is a unique instrument specification, which

relies on the longer wavelengths of TS-II to increasethe upper limit of the accessible correlation lengths,while also extracting atomic resolution from the short-er wavelengths. The instrument bridges the tradition-al gap between SANS and wide-angle neutron scatter-ing, by using a common calibration procedure for allQ-scales. The data obtained from NIMROD will there-fore enable the development of detailed and wellcon-strained models of complex scattering systems.

• NIMROD is backed by a broad-based, internationallyrecognised, user community. For example, in the re-cent International Assessment of University Researchin Chemistry in the UK (EPSRC & RSC, 2003) its use

of central neutron facilities was highlighted: “UKchemists were among the first worldwide to exploit thepower of neutron scattering and synchrotron radiation toprobe the behaviour of complex systems: for example, thestructure and dynamics of aqueous solutions, ionic liquids,and polymers at interfaces. Work in these areas continues tobe competitive internationally.”

• NIMROD will strengthen the synergy between experi-ment and theory, and is supported by internationallyleading theoreticians. Importantly, the instrument cov-ers length scales that are only now being viewed as ac-cessible to atomistic computer simulations. In thiscontext, we note that our community is responsiblefor recent advances in quantitative data analysis ofdiffraction from disordered materials. Techniquessuch as Reverse Monte Carlo (RMC) and EmpiricalPotential Structure Refinement (EPSR) allow us toproduce real-space molecular models of complex sys-tems, which can be compared directly with the experi-mental data.

The beneficiaries from the design of this instrument in-clude the principle scientific disciplines, as well as moreapplied areas such as chemical engineering, oil and gasrecovery, environmental science, renewable energy, sepa-ration technology, food science, biomaterials and phar-macology.

Scientific Case.NIMROD will enable new science and technology wher-ever the molecular and mesoscale structures of disor-dered, or partially disordered, materials are related totheir properties and function. As such, the case for thisinstrument underpins the core science areas of TS-II: Ad-vanced Materials, Soft Condensed Matter, BiomolecularSciences, and Chemical Structures, Kinetics and Dynam-ics. In each of these areas, potential users of NIMRODdescribe specific new examples relevant to their researchinterests. This demonstrates broad-based enthusiasm for

Annex IISIS SECOND TARGET STATION PROJECTBeamline Name: NIMROD

External Co-ordinator:Dr. Neal Skipper Department of Physics and Astronomy University College London, Gower Street, London WC1E 6BT. Tel: 0207 679 3526 Fax: 0207 679 1360 [email protected]

ISIS Contacts: Prof. Alan Soper & Dr. Daniel Bowron ISIS Facility, Rutherford Appleton Laboratory, Oxon OX11 0QX. Tel: 01235 44 5543 Fax 01235 44 [email protected], [email protected]


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the instrument, and in the context of the TS-II timescalethese letters of support also provide a forward-look intogrowth areas served by NIMROD. It is clear that understanding of disorder over the NIM-ROD length scales will, in the future, become increasing-ly necessary to resolve major scientific and technologicalchallenges. Core issues centre on the behaviour of bio-logical molecules in solution, and the need to control theproperties of increasingly complex liquids, glasses andcomposite/template materials. In each case, the sub-Ångstrom resolution structural data available fromNIMROD are a prerequisite to detailed understanding.Further opportunities will stem from the ability of the

instrument to exploit site-specific isotope substitution ondilute species, to first and second order difference levels.For example, measurement of the local and mesoscopicstructure of the proton environment via H/D labelling isa key to understanding hydrogenbonding and associat-ed liquids, and in developing hydrogen storage media.

Complex and Confined Liquids Complex fluids and solutions are ubiquitous in scienceand technology: NIMROD offers outstanding new op-portunities for the study of these systems. We anticipatemajor drives to understand and control the solvent me-diated interactions that lead to solute association andconformational changes, and to design chemically selec-tive solvents. Further impetus is given by the recent syn-thesis of nanoporous media of well-defined geometry,which opens up new possibilities in studying importanteffects in confined fluids. These substrates have dual sta-tus as an arena in which to investigate novel physical

and chemical phenomena in reduced-dimensions, and asa test-bed for storage, separation, release, and catalysistechnology. All of these areas demand structural infor-mation on the nanometer length scales that are targetedwith NIMROD. When allied with high stability detectorarrays, the instrument realistically opens the possibilityfor routine studies of ternary and higher complexitymolecular mixtures, at chemically and biochemically rel-evant solute concentrations. • Biological Molecules in Solution. NIMROD will excel

in structural studies of biomolecules in solution, andwill supersede the currently available worldwide suiteof neutron instruments. It would, for the first time, en-

able us to relate changes in solvent structure directlyto biosolute conformation. In a recent example of suchwork, performed on SANDALS, it was shown thatpressure induced unfolding of myoglobin in aqueoussolution is associated with changes in the water struc-ture. However, this work was frustrated by the upperlength-scale accessible on the instrument, a limit thatwould be significantly increased on NIMROD. Anoth-er example of biomolecular relevance that has recentlycaptured the interest of the user community is thestudy of disaccharides, and their utilization as biopro-tectants through effects such as glassification.

• Confined Fluids. A large number of natural and indus-trial processes depend on the properties of confinedfluids, with numerous fundamental and practicalquestions remaining unanswered. When combinedwith new classes of nanoporous materials, such asMCM silicas, studies on NIMROD are likely to be piv-otal: all the relevant length-scales are accessible to this


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one instrument. Confinement allows one to deeply un-dercool liquids, and thereby to enter regions of thephase diagram inaccessible to the bulk liquid. Thecommunity will exploit this to probe the role of struc-tural frustration and adsorption of systems as diverseas complex liquids, glass-formers, polymer melts, andhydrogen. High-resolution (sub-Ångstrom) studies ofthe solid-liquid interface are planned within the two-dimensional pores of lamellar hosts, such as clays.Crucial questions centre on the nature and extent oflayering and solvent density. Here again, the ability ofNIMROD to extend atomic resolution over hundredsof Ångstroms will lead to qualitatively new science.

• Electronic Liquids. Current understanding of electronlocalisation/delocalisation in the liquid state is ham-pered by a dearth of structural information over thelength-scales that are crossed as one moves from aninsulating (electron localised) to conducting (electrondelocalised) state. The study of electronic liquids, suchas metal-ammonia type solutions or liquid semicon-ductors, is therefore an area in which NIMROD willplay a leading role. Furthermore, this instrumentwould allow us to probe directly the structure of theexotic species that exist in these systems, for examplepolarons, bipolarons, electron channels, and excitonicatoms.

• Ionic Liquids and Mesophase Systems. Room temper-ature ionic liquids are an environment friendly medi-um, of very low vapour pressure, in which one cancontrol the selectivity of many organic reactions. Todate, detailed structural studies of such liquids havebeen limited to short chain materials. NIMROD would

enable us to study much longer chain lengths, therebygiving access to new classes of ionic liquids. For exam-ple, by increasing the amphiphilic nature of the cation,ionic liquid crystals can be formed. These have exten-sive mesophase ranges, and are thermally very stable.In addition, they have potential as oriented solventsthat can impart selectivity in reactions by ordering thereactants.

• Molecular Liquids. Understanding multicomponentliquids is an increasingly important aspect of modernsolution chemistry. As the number and complexity ofmolecular species increases, the necessity to probelonger length scales rises. Often, indirect in-solution

molecular effects can play a critical role in chemicalphenomena such as reaction product chirality, andpolymorphism. The need to understand the role of in-termediate range order in solvent media is anotherarea of rising importance. Many chemical and bio-chemical processes require biphasic solvents for effi-cient operation, especially when reaction intermedi-ates and products have different solubilities in nonpo-lar or polar media. No existing neutron instrument hasthe range of characteristics required to probe suchprocesses: NIMROD will therefore make a unique con-tribution.

Functional and Composite Materials NIMROD will probe the important structural correla-tions in a wide range of disordered and partially disor-dered solids. This will allow us to understand the rela-tionships between structure and properties, and increas-ingly to tailor materials to their function. Examples in-


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clude optically and biologically active glasses, ionic con-ductors, advanced polymers, electrode materials, and se-lective molecular storage/release media. The relevanceof NIMROD also extends to many advanced composites,where nanometer-scale particles or inclusions are em-bedded in a solid or liquid matrix. This broad class ofmaterials includes colloidal and liquid crystal disper-sions, sol-gel systems, polymer-inorganic composites,magnetic media, and intercalation compounds.·• Porous Media and Intercalates. The proposed devel-

opment of NIMROD is particularly timely for studiesof this class of materials, which includes templatedglasses, nanoporous polymer networks, zeolites, andgraphitic and inorganic intercalation compounds. Keytargets in this research are the ability to control the ar-chitecture of the host material, and the host-guest in-teractions. This will have impact in applications suchas hydrogen storage, battery electrodes, supercapaci-tors, and organic and radioactive waste containment.Again the benefits of NIMROD are clear – it will en-able us to expand the host superlattice to hundreds ofÅngstroms while retaining atomic resolution.

• Optical, Biocompatible, and Conducting Glasses.Amorphous and glassy solids find increasing applica-tion across a wide range of modern technological ap-plications. Examples include materials such as a-Si:Has an amorphous semiconductor, rare-earth doped fi-bre optics in amplifiers or lasers, and amorphous mag-netic materials. To date, there is little information onthe key functional mesoscopic length scales which re-late to the correlation lengths characteristic of conduc-tion electron mean free paths, optical and composi-tional inhomegeneities, voids, and the length scale ofmagnetic interactions. Instrumental capabilities in thisarea are also expected to make a significant impact inimproving our understanding of the glass transition inelectrolyte glasses. An exciting emerging theme is thatof bio-active and bio-compatible glasses, for use in tis-sue growth and replacement.

• Sol-Gel Materials and Colloidal Dispersions. Sol-gelsystems are finding an increasing number of applica-tions, including optical coatings, filters, or ultra lowexpansion materials. In addition to local structure,low-Q data are vital to obtain information about theircomposition, homogeneity and mesoscopic structure,and thereby to tailor their useful properties to specifictasks. Similar arguments make NIMROD well suitedfor studies of those colloidal dispersions of particlessuch as fullerides, and metallic and ice clusters, inwhich the characteristic structural correlations extendto a few hundred Ångstroms.

Phase Behaviour and Nucleation A forte of NIMROD is its ability to measure, on the same

sample and at the same time, structure over a widerange of length scales in the region of a phase transition(liquid-liquid separation, crystallisation, metal-nonmetaltransition, magnetic ordering, ionic conductivity inglasses), as a function of thermodynamic parameters orcomposition. This information is a prerequisite for un-ravelling the underlying mechanisms in numerous nu-cleation, growth and phase separation processes. • Clathrate formation. Understanding the formation,

decomposition and inhibition of gas clathrate hy-drates is critical to tackling technological challengesposed by these materials, from pipe blocking to ex-ploiting methane resources in sediments and per-mafrost. There is also new interest in the control ofgrowth and luminescent properties of semiconductorclathrates. This area of research requires structural da-ta from NIMROD, to follow disordered guest-hostand guest-host-additive systems from the early stagesof formation to the evolution of crystalline structuresfrom these amorphous phases.

• Nucleation. The ability to measure small- and wide-angle diffraction simultaneously will allow us to focuson the mechanisms of a number of nucleation andgrowth processes, particularly the growth of crystalsfrom pure liquids and solutions. The structure andproperties of many solid materials is strongly depen-dent on the history of crystallisation, leading to poly-morphs with widely different properties. Specific ex-amples are that of ice formation in the presence of ad-ditives, such as sugars, and growth of metal crystalsfrom the melt.

• Phase Behaviour of Multicomponent Liquids. There iscurrently no instrument that allows one to measurethe mixing and phase behaviour of multicomponents.Recent experiments point towards chemically relevantmicrosegregation between organic and aqueous phas-es, but the important length scales are missing fromthe picture. The instrument would also open up thenew field of density-driven phase changes in liquidsand amorphous solids at constant composition, andallow observation of structural transitions among sur-face layers of longer-chain hydrocarbons adsorbedfrom multicomponent solutions. The latter systemsare common to many commercial detergents, as theyare cheap and offer high performance. In this context,many of the restrictions on molecule size and shapewould be lifted.

In summary, NIMROD is a unique instrument thatbridges the accessible length scales traditionally coveredby small-angle and wide-angle techniques. The instru-ment therefore opens up whole fields of qualitatively newscience, and complements current initiatives for fabricat-ing functional materials and nanometre scale devices.


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Outline Design Specification:The fundamental idea behind NIMROD is to obtain dif-fraction data over a wide range of Q, both low and high,in a single experiment. Target Station II, with its 10Hzrepetition rate and optimised targetmoderator configu-ration, is an ideal source specification for NIMROD: • NIMROD requires an incident flight path of at least

20m, and a secondary flight path up to 7m, to achievea sufficiently small beam divergence and penumbrathat the smallest scattering angles are reached withadequate resolution. Building a shorter flight path in-strument with the same Q coverage and resolutionwould significantly compromise the count rate at allQ values.

• As a consequence NIMROD will require a time frameof at least 68ms to access the full wavelength range, 0 -10Å, in a single pulse. It is therefore ideally suited tothe 100ms time frame of TS-II, without the need forthe pulse removing and frame overlap choppers thatwould be needed on TS-I.

• The low-Q capability of NIMROD is only possible byvirtue of the excellent long-wavelength flux of the op-timised coupled moderator available on TS-II. In thecrucial low-Q region NIMROD outperforms SAN-DALS by a factor of up to 10 in count rate, even aftertaking account of the 1 in 4 pulse rate of TS-II com-pared to TS-I, and with better resolution. Such perfor-mance is not available on any of the TS-I moderators.

NIMROD will build on the successful SANDALS detec-tor technology with specialised ZnS/glass sandwich de-tectors that are typically 70% more efficient than theequivalent 3He detector of the equivalent size. The de-tector electronics will follow the highly stable GEM de-sign, which should deliver the required 0.1% stabilityover 24 hours as required to make full use of the avail-able count rate on this diffractometer. This will increasethe accessible concentration range for isotope differenceexperiments by a factor of 3 for second order differenceexperiments and a factor of 10 for first order differenceexperiments compared to SANDALS. NIMROD will view the coupled cold moderator, whichproduces excellent fluxes of cold neutrons. Given thatthe resolution requirement (DQ/Q) is ~2% for most ofthe Q range, and that at the low scattering angles ofNIMROD the resolution is dominated by geometric con-siderations, the broad pulses of this moderator do not af-fect the resolution significantly. For disordered solids, itis proposed to build a 90° detector bank with resolution~0.5% to significantly enhance the performance at high-Q. The contributions from this higher angle bank havenot been included in the performance characteristics giv-en below, since detectors at 90° scattering angles can on-ly be used for hydrogen-free samples.

Moderator Coupled cold Incident Wavelengths 0.05Å – 10Å Q-range 0.02Å-1 – 100Å-1 Resolution ~10%∆Q/Q, 2θ = 0.5°-5°; 2%∆Q/Q, 2θ =12°-90°;0.5%∆Q/Q. Total Length 30m L1, L2 20m, 1-7m Flight path Straight/tapered Detectors 10 x 200 x 20mm in rows parallel to beam, andover full range of azimuthal angles, ±90°. <0.1% stabilityrequired. Beam size 30mm wide x 30mm high Detector tank Vacuum, no beam windows visible by de-tectors Sample environment Standard, multi-position samplechanger.

Performance The estimated count-rate and resolution of NIMROD iscompared with the current SANDALS in the followinggraphs. C-number measures the count rate expected for 1cm3 ofvanadium placed at the sample position. The projectednumbers are based on the most recent estimates of tar-get/moderator performance for both target stations andtakes account of the different frequencies of the two tar-get stations. At low Q NIMROD outperforms SAN-DALS, while at high Q SANDALS is better by a factor of2 or 3 compared to NIMROD. If a way could be found toextract an epithermal neutron beam directly from the re-flector, and combine this with a guide for long wave-length neutrons, then the performance of NIMRODcould be enhanced even further. In practice experiencewith liquids on SANDALS indicates that data beyond20Å-1 are rarely needed, and up to this Q value NIM-ROD is still highly competitive.

Other Features One idea currently being investigated is the possibilityof putting a Fermi chopper (and corresponding NIMON-IC chopper) in the incident beam line, with a view to do-ing low resolution inelastic scattering measurements onsome samples. Placzek (inelasticity) corrections remainan unsolved problem for hydrogen-containing materialsand it could be a useful feature to have the ability to lookat the inelastic response of some materials in the anglerange being used by the diffraction pattern. In addition arotating Debye-Scherrer collimator is proposed whichwill serve to reduce low angle backgrounds substantial-ly. Some form of tapered neutron guide will almost cer-tainly be needed in the incident beam to correct for grav-ity effects on the longer wavelength neutrons.


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Letters of support receivedName Affiliation Area of interest

Dr Ashok Adya University of Abertay DundeeMicroporous media and electrolytes Dr. Christiane Alba-Simionesco Universite Paris-SudConfined and supercooled liquids and glasses Dr. Paul Anderson University of BirminghamPorous media, composites and hydrogen storage Prof. Carla Andreani University of Rome Tor VergataHydrogenous molecular liquids, confined systemsDr Adrian Barnes University of BristolElectronic liquids and liquid metal alloys Dr. Chris Benmore Argonne National LaboratoryFunctional and composite materialsDr. Daniel Bowron ISISHydrogen bonded liquids and solvation Dr Piers Buchanan Kings College LondonSuperionic liquids and clathrate hydrates Prof. Eugene Bychkov Université du LittoralFunctional glasses Dr. Stuart Clarke University of CambridgeLiquid adsorption and colloidal dispersions Dr. Jason Crain University of EdinburghPhase behaviour of molecular liquids Prof. Roger Davey UMISTNucleation and crysytallisation Prof John Dore University of KentLiquids under confinement Dr. Sofia Diaz Moreno ESRFMolecular liquids and reaction media Dr. Luis Fernandez Barquin Universidad de CantabriaMagnetic nanaparticles and composite materials Prof. John Finney University College LondonBiomolecular liquids and nucleation Prof. Henry Fischer Laboratoire LURE, ParisLarge molecules and biological solutions Prof Neville Greaves University of AberystwthHigh temperature liquids and silicate glasses Dr. Alex Hannon ISISStructure of glasses Prof. Jean-Pierre Hansen University of CambridgeTheory of liquids Dr. John Harding Chair, CCP5Computer simulation of condensed matter Dr. Chris Hardacre University of BelfastIonic liquids and nucleation Dr Simon Hibble University of ReadingFunctional materials and nucleation Prof. Robert Hillman University of LeicesterNanostructured and porous media Dr Diane Holland University of WarwickAdvanced functional materials Dr. Uwe Hoppe Universitat Rostock

Crystallisation of glass ceramics Dr. Kathy Johnson University of LiverpoolComplex liquids and particles in solution Dr Dave Keen University of OxfordFramework structures and disordered magnetics Prof. Mike Klein University of PennsylvaniaComputer simulation of complex systems Dr. Carolyn Koh King’s College LondonClathrate hydrates Prof. Salvatore Magazu Università di MessinaCryoprotectants in biological solutions Prof. Robert McGreevy ISISDisordered materials Prof. Paul McMillan Royal InstitutionAmorphous and nanocrystalline materials Prof. Geoff Mitchell University of ReadingFunctional polymers and organic materials Dr. George Neilson Bristol UniversityBiological and electrolyte solutions Prof Bob Newport University of KentSol-gels and bioactive glasses Dr. Hugh Powell University of DurhamWaste containment in clays Dr. Silvia Ramos ESRFMolecular liquids and ionic solutions Prof. Maria Antonietta Ricci, Chair CNRComplex liquids and disordered materials Prof. Rob Richardson University of BristolConformation in colloids and liquid crystals Prof. Peter Rossky University of Texas at AustinModelling of complex and biological systems Dr Philip Salmon University of BathFast-ion conductors and polymer electrolytes Prof. Roger Sinclair University of ReadingPoorly crystalline materials and magnetism Dr. Neal Skipper University College LondonElectronic liquids and confined fluids Prof. Mark Smith University of WarwickSol-gels and bioactive glasses Prof. Alan Soper ISISLiquids and disordered materials Dr. Jan Swensson Chalmers UniversityPolymer composites and biomaterials Dr Matt Tucker University of CambridgeMineral physics and radionuclide containment Dr Beau Webber University of KentMesostructured porous materials Prof. Adrian Wright Universiy of ReadingNanoheterogeneities in glasses Prof. Marco Zoppi CNR, FirenzeHydrogen storage and confined fluids


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In his contribution to the Special Issue of this Notiziario(April 2002), Prof. Toigo – the INFM President – por-trayed the role and the policy of INFM on Large ScaleFacilities for Neutron Research. One year later, we are inthe position to report on what happened, which initia-tives and projects were supported, at both the level oflarge investments and disseminated support to the sci-entific community, and what has been the impact on theresearch in the field of neutron scattering. The actionsundertaken by INFM in the field are sketched in the fig-ure and are briefly reviewed here.

Participation to ILL – The Institut Laue-Langevin inGrenoble, the world’s most productive neutron researchcentre, has just renewed its intergovernmental conven-tion until the end of 2013. Nine countries are currentlyscientific partners of the ILL and INFM signed the part-nership agreement for Italy in 1997. During 2002 the Ital-ian participation to the ILL reached the level of 3.5%,thanks to a special contribution for the construction andinstallation of the new guide for cold neutrons on theH24 beam exit. The increased level of participation hadan immediate and tangible response in the increasednumber of experimental proposals from the Italian com-munity. I remark that all along the years of the ILL-INFM agreement, i.e. since 1997, the proposals submit-ted by the Italian community have always doubled the

quota of beam time paid under the contract, and that thepercentage of proposals approved by the internationalselection panels has typically exceeded the allowed quo-ta reaching even levels of 5%. This data has to be takenas an indicator of the excellence of the Italian proposalsthat have successfully passed the panel selection. A sec-ond positive signal of the vitality of the Italian neutroncommunity comes from the increased number of newusers of the technique, which in 2002 registered a growthof about 15% compared with the period 1997-2001. It isalso a promising data the wide scientific spread of the

user community over the fields of Chemistry, Physics,Material Science and Biology. CRGs at the ILL – An aspect of primary interest, whichcharacterizes the INFM participation to the ILL, is theopportunity, through the CRG (Collaborative ResearchGroup), to build, develop and run an instrument in-stalled on the neutron beams provided by the ILL HighFlux Reactor. Under the CRG, the neutron spectrometeris operated at ILL through an INFM-funded and ILL-in-dependent management team, that also runs its own re-search programme made up by specific proposals fromthe Italian scientific community. At present, INFM isleading two CRGs, namely IN13 (CRG-A and IT/FR co-operation) and BRISP (CRG-B and IT/D cooperation),that make available 50% and 30% of the beam time, re-

BIG & SMALL INFM INITIATIVES FOR NEUTRONSDURING 2002


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spectively, to ILL for public allocation. While IN13, aninelastic high-resolution backscattering spectrometer, issuccessfully running after the upgrading phase, BRISP, athermal neutron Brillouin spectrometer, is under con-struction. So far, the BRISP project has been on schedulewith respect to the forecast and the commissioningphase is expected to begin by the end of 2003. I want toemphasise that CRGs bring significant benefits to theItalian scientific community in a number of differentways: CRGs provide a framework within which innova-tive teams can operate, expanding the human and scien-tific resources; thanks to the reserved beam time, CRGsoffer more opportunities for exploring new techniquesand for carrying out difficult experiments; finally, be-cause of the flexible organisation, CRGs provide moreopportunities for training young scientists and PhD stu-dents in neutron-based research. Exploiting the benefitsof running a CRG, the Italian community has the oppor-tunity of capitalizing those human and scientific re-sources which are the indispensable ground for the ad-vance and the expansion of the neutron scattering com-munity and technique in our country. LLB – During 2002, the collaboration between INFMand the Laboratoire Leon Brillouin in Saclay has beenmaintained at a cost which does not reflect the beamtime effectively allocated to Italian users. Thisfavourable situation is partly the result of long-date,well-established and very active scientific collabora-tions between LLB scientists and groups belonging toseveral Italian Universities, that carry out research pro-grammes of common interest. I want to emphasize thatthe characteristic for the LLB Reactor of being a medi-um-size installation, joined to the existence of diffusedcollaboration programmes, that is the established pres-ence of a rather large user community mostly focusedon SANS (Small Angle Neutron Scattering) and Materi-al Science (DIANE), make this source an ideal candi-date for developing bilateral agreements within the Eu-ropean Community.Accelerator Sources – On the recognition that futurelarge-size neutron sources may only be based on accelera-tors, INFM signed the MoU for the development of theESS project for the years 2001-2003 and contributed tothe technical programme on the neutron target, by in-vesting human resources on the ESS-Central ProjectTeam based at the Forschungszentrum in Juelich. I wishto remark that, at present, the ISIS source is the world-leading accelerator-based source and that the Italiancommunity has profited of the access to the ISIS infra-structures thanks to the agreement signed by CNR andISIS and established since 1985. Through EU funding un-der FP-5, and now FP-6, programmes, INFM has con-tributed to the construction of advanced instrumentationinstalled at ISIS and has promoted research projects

based on ISIS instruments by appointing young scien-tists under post-doc and contract positions.Personnel – One of the major goals of the INFM policyin support of the neutron research has been the appoint-ment of qualified young researchers, in schedule withthe planned development programme. During 2002 andbeginning 2003, five new researchers have been appoint-ed to work on the CRGs projects and INFM can nowcount on seven researchers involved in the developmentof IN13 and BRISP.Support – Among the small-budget initiatives of INFM,that however have a primary impact on the growth ofthe neutron community, are the numerous support &promotion programs among which I want to recall theyearly grant for neutron-oriented PhD projects, the fi-nancing of research stages for degree students at the ma-jor neutron installations, the financial support to theusers of ILL and LLB during the execution of the experi-ments, the awards for the finest thesis and PhD thesis inthe field of fine structure of matter investigated by neu-tron techniques. During 2002, INFM contributed, togeth-er with CNR, to the organization of the VI-edition of thenational neutron scattering school in Palau.As a final comment, I want to bring to the attention ofthe reader the evidence of a lively community of Italianresearchers which make use of the neutron techniques,and whose scientific necessities are still not completelycovered by the complementary and different internation-al agreements managed by INFM and CNR.

C. PetrilloChairman of the

NFM Neutron Committee

ATTIVITA’ ITALIANA


Recentemente il Governo di Victoriaha programmato la realizzazione delprimo sincrotrone australiano checomporterà sicuramente una svoltastorica nella ricerca australiana ed inparticolare nel campo della fisica deimateriali. L’iniziativa raccoglie le es-igenze di ricercatori e scienziati delleuniversità e dei centri di ricerca aus-traliani, i quali, principali attori dellosviluppo congiunto di piani nazion-ali di ricerca di base ed applicata, in-tendono, grazie al nuovo laborato-rio, sviluppare maggiormente attiv-ità di ricerca di tipo precompetitivo.In questa logica, l’Ufficio Scientificodi questa Ambasciata ha ritenuto op-portuno investire in una attività dicooperazione scientifica e tecnologi-ca fra i due Paesi.

1. Conferenza Italo-Australiana "FutureDirections in Spectroscopy and Imagingwith Synchrotron Radiation"Dal 2 al 5 febbraio scorso si è tenutaa Lorne (cittadina nel Victoria), laConferenza "Future Directions inSpectroscopy and Imaging with Syn-chrotron Radiation", promossa ed or-ganizzata dall’Ufficio Scientifico di

questa Ambasciata in collaborazionecon il Governo di Victoria, il Com-monwealth Department of Educa-tion Science and Training di Canber-ra, Australian Academy of Techno-logical Sciences and Engineering, ilCSIRO e La Trobe University di Mel-bourne. Tale iniziativa è il risultato diun’azione maturata nel corso dellaMostra Convegno IATICE di Mel-bourne lo scorso marzo ed, in parti-colare, durante un incontro tra ilLaboratorio di Luce di SincrotroneElettra di Trieste, le Università LaTrobe e Monash di Melbourne ed ilCSIRO (Department of Manufactur-ing Science & Technology). Da taleincontro é nata una prospettiva dicollaborazione che coinvolge diverse

Università ed alcuni centri di ricercadei due Paesi e che vede, nel work-shop di Lorne, il momento di con-fronto finalizzato all’avvio di unaproficua attività.La delegazione Italiana era costituitada: Prof. Fulvio Parmigiani dell’Uni-versità Cattolica di Brescia, Prof.Maria Novella Piancastelli dell’Uni-

versità di Roma Tor Vergata, Dott.Lorenzo Avaldi del CNR (Istituto diMetodologie Inorganiche e dei Plas-mi di Roma), Dott. Giorgio PaolucciDirettore della Divisione Sperimen-tale del Laboratorio Elettra di Triestee dal Laboratorio Elettra la Dott.ssaGiuliana Tromba, il Dott. KevinPrince e il Dott. Andrea Goldoni. Alla conferenza hanno partecipatocirca quaranta ricercatori e docentidelle principali università e centri diricerca australiani che operano nelsettore della fisica in generale e del-l’uso del sincrotrone in particolare.Tema principale della conferenza èstato la presentazione delle attivitàdel Laboratorio Elettra di Trieste mi-rato ad un confronto tra metodologiee strumenti sviluppati, nell’ambitodi laboratori di sincrotrone, nelleseguenti aree di ricerca:- Spettroscopia di nuovi materiali e

in fase gassosa;- microscopia per nanotecnologie,

biologia e scienze ambientali;- radiografia ed immagini di riscon-

tro utilizzate in ambito medico;- litografia a raggi x.Numerosi sono stati gli interventi fi-nalizzati a individuare aree strate-giche di comune interesse che sfrut-tano soprattutto le potenzialità dellastruttura italiana; rilevante é stato,inoltre, l’interesse australiano nelcollaborare con l’Italia sia nella suacomponente scientifica e tecnologicache imprenditoriale.

2. Conferenza Australiana "AustralianSynchrotron Users Workshop"La conferenza di Lorne è stata pro-grammata nel periodo succitato perconsentire ai ricercatori italiani dipartecipare anche al workshop orga-nizzato dal Governo di Victoria daltitolo "Australian Synchrotron UsersWorkshop" tenutosi a Melbourne

STATO DELLA COOPERAZIONE ITALO-AUSTRALIANOSUI LABORATORI DI LUCE DI SINCROTRONE

45

ATTIVITA’ ITALIANA

46


dal 29 al 31 gennaio u.s.. Infatti, ilGoverno di Victoria ha programma-to la realizzazione del primo sincro-trone australiano e il convegno diMelbourne è stato organizzato alfine di informare l’intera comunitàscientifica australiana delle speci-fiche del nuovo "laboratorio di luce"e le relative nuove opportunità sci-entifiche e tecnologiche che ne de-riverrebbero. La realizzazione del "Laboratorio diluce" nasce dalla necessità di effet-tuare esperimenti nei settori della bi-ologia, della geologia, della fisica edella farmaceutica che fino ad oggisono condotti presso altri centri in-ternazionali quali: APS (AdvancedPhoton Source) in USA, Spring8 inGiappone, Hsinchu in Taiwan eBessy in Germania. L’evento di Melbourne, a cui hannopartecipato oltre 300 fra scienziati,ricercatori, esperti internazionali edimprenditori dell’industria high techdel settore, è stato aperto dal Pre-mier dello Stato del Victoria SteveBracks e dal Ministro per l’Inno-vazione John Brumby. La conferen-za è stata organizzata dalla "Aus-tralian Synchrotron Team", organis-mo preposto, per conto del Governodi Victoria, alla gestione della realiz-zazione del nuovo sincrotrone, dal-l’attuale fase di progetto allacostruzione del laboratorio. Nel corso dei tre giorni si sono evi-denziate e discusse le opportunitàche il nuovo Centro di ricerca potràgarantire, in particolare nelleseguenti aree tematiche:- cristallografia di proteine;- biofisica, in particolare per lo stu-

dio di proteine legate alla patolo-gia dell’Alzheimer, ed in generalealle malattie muscolari;

- radiografia ed immagini di riscon-tro utilizzate in ambito medico;

- nuovi materiali, nanotecnologie,semiconduttori, litografia e mi-cromeccanica, nuove memorie percomputer, etc;

- scienze ambientali, analisi dell’in-quinamento, e del suo effetto sulle

specie vegetali;- scienze della terra, geologia, chimi-

ca dei minerali etc.Il progetto del sincrotrone a Mel-bourne attualmente può contare suun finanziamento approvato dalGoverno di Victoria di circa 157 mil-ioni di dollari Australiani a cui si ag-giungeranno circa 50 milioni di A$dalle Università del Victoria e un ul-teriore finanziamento, non ancoradefinito, dal Governo Federale diCanberra. Il Laboratorio sarà realiz-zato nei pressi della Monash Uni-versity a circa 10 Km dalla City esarà operativo entro il 2007.

3. ConclusioniIn questo contesto è stato ritenutoopportuno che il Laboratorio Elettradi Trieste, ritenuto il centro di eccel-lenza italiano nel settore, potessenon solo partecipare alla presen-tazione del sincrotrone australianoma che potesse presentare la sua fa-cility alla comunità scientifica aus-traliana ed, in particolare, chepotesse essere considerato comemodello per il nuovo Laboratorio disincrotrone di Melbourne. In effetti dal punto di vista scientifi-co, l’impressione generale è che laricerca australiana nei campi oggettodel workshop di Lorne soffra di unritardo rispetto al panorama inter-nazionale ed anche a quello italiano,dovuto all’assenza di un’infrastrut-tura di ricerca come Elettra e noncolmato dalle ridotte esperienze deiricercatori australiani in altri paesi.Questo porta ad una scarsadefinizione dei progetti da imple-mentare sulla nuova macchina aus-traliana e quindi l’intervento dellacomunità scientifica italiana, in par-ticolare dal laboratorio Elettra,potrebbe portare loro un grandebeneficio.Anche dal punto di vista tecnologi-co-imprenditoriale sarebbe neces-sario un intervento di ditte alta-mente qualificate, come quellecresciute con l’esperienza del Labo-ratorio Elettra e quindi, come

richiesto dagli australiani, sono stateindividuate, e riportate nei proceed-ings, alcune imprese italiane che op-erano nel settore del sincrotrone epertanto inserite nel contesto delleattività del Laboratorio Elettra.A conclusione dei due eventi è statoistituito un gruppo di lavoro italoaustraliano che consentirà la pro-grammazione di alcune attività dicooperazione, quali la ricerca di fi-nanziamenti per scambio di espertie di studenti e, in particolare, la veri-fica, nelle rispettive realtà locali (Sta-to di Victoria, Regione Friuli VeneziaGiulia, Università, Centri di Ricercaed imprese ad alto contenuto tecno-logico del territorio), della possibilitàdi creare a Melbourne, in concomi-tanza della realizzazione del sincro-trone australiano, una joint ventureitalo-australiana finalizzata a fornireconsulenza nel settore.

Robert LeckeyGiorgio PaolucciNicola Sasanelli

PROGETTO E.S.S.


The ESS project is going through adifficult phase, however the discus-sion continues on the political levelacross Europe. Several critical politi-cal events happened in this period,causing the change in the timing andpace of the project.The assessment by the German Sci-ence Council ranked the ESS behindtwo other major investments in in-frastructure in Germany, and airedsome rather critical comments aboutthe use for neutrons in the future.The latter has been strongly criti-cized in the press and the WR hasdeclared its readiness to re-evaluateESS. But while the Bonn documents,which are the product of a huge ef-fort of a large number of the best sci-entists throughout Europe, have notbeen evaluated at all, it seems that afull new proposal is required forsuch a re-evaluation. In December2002 at a meeting between the WR,the secretaries of state of the threeGerman Länder involved and theGerman partners FZJ and HMIagreed on a procedure whereby theWR would first assess the sciencecase, based on a number of specificquestions, and only later discuss siteaspects of the potential Germansites. The questions received by theESS last January 2003, however, arenot specific at all, deal with site as-pects as well, and are in fact virtual-ly the same as the questions receivedin 2001. As a consequence, the situa-tion with respect to a new evaluationis still very much open. There arepressure for a fast re-assessment ofthe ESS project, but this is still debat-ed within the German partners.The European long and mediumterm need for neutron scattering fa-cilities was first class large scale fa-cilities to be discussed by a newlyformed European forum ESFRI (Eu-ropean Strategy Forum on ResearchInfrastructures). To prepare for this

discussion ESFRI created a WorkingGroup on Neutron Sources toanalyse the european situation andspecifically look at three specific sce-narios for the future provision ofneutrons: 1. Build ESS with two 5 MW target

stations as proposed in Bonn 2002. 2. Build the 5 MW long pulse target

station first. 3. Build either a 1 MW upgrade of

the short pulse ISIS facility or a 1MW version of AUSTRON.

In all of the above mentioned op-tions the Millennium Programme atILL and the second target station atISIS, were considered as part of thebaseline option. The WorkingGroup Report on neutrons clearlydemonstrated that the full ESS or astaged approach starting with thelong pulse Target Station were af-fordable and the most cost-effectivesolutions. Other scenarios wouldbring Europe in a competitive, butnot leading position relative to the

US and Japan until they would re-alise their plans for upgrading theirfacilities, which could start immedi-ately after the end of construction. On January 16, 2003, ESFRI met todiscuss the results of this study.There was basically no discussion ofthe report, as the representatives ofGermany and UK expressed theirunwillingness to support the ESS inthe short term. The meeting was in-stead devoted to prepare the follow-ing recommendations:ESFRI:(a) notes that there exists a “base-

line” option, which has potentialfor growth through a series ofplans for facility upgrades, tosupport scientific activities in themedium term;

(b) understands that there is not suf-ficient support from the MemberStates for the realisation of a nextgeneration European SpallationSource in the short term;

(c) recognises that a major new Euro-

ESS: THE DISCUSSION CONTINUES

47

PROGETTO E.S.S.

48


pean neutron facility is necessaryin the long term, therefore a deci-sion is necessary in the mediumterm;

(d) therefore draws attention to theneed for continuing work on thescientific and technical capabili-ties to underpin future develop-ments in this and related areas;

(e) the final report of the WGNS willbe made available to the public(e.g. through the ESFRI website).

The ESFRI meeting had direct conse-quences on ESS. The Council of theEuropean Spallation Source met inZürich on January 22, 2003, to dis-cuss the implications of these con-clusions. The Council decided to re-duce the technical work and concen-trate efforts on political attempts toget an earlier decision. Accordingwith the new circumstances of theproject, the private company ESSGmbH, thought to facilitate themanagement of the ESS project, hasnot been established.In Germany the three Länder inter-ested to host ESS, North-Rhine West-falia, Sachsen and Sachsen-Anhalt,still pursue their aims. In the federalParliament, motions have been intro-duced to reproach the federal gov-ernment for not being transparentand not discussing its proposals inParliament before taking any deci-sion. A hearing took place on April 2in the Parliament in Berlin, wherethe representatives of the majorityparty were asked not to attend. The Scandinavian bid is still aliveand 4 Ministers of the swedish gov-ernment are involved in the fight forthe next generation spallationsource. However, the ESS Scandina-vian Consortium thinks that a peri-od of time of some years would bethe most appropriate one for a deci-sion. The Yorkshire bid is also alive andtrying its best for having ESS at Sel-by, but they are now facing a strongopposition by the central govern-ment representatives, since the sec-ond target station at ISIS have been

funded officially on April 8, 2003.The intention of the UK authoritiesis not to have a new neutron sourceon their agenda until after the nextGovernment Spending Review –meaning a delay of up to 5 years.The Committee for Industry, Interna-tional Trade, Energy and Research ofthe European Parliament will devotea session to ESS on May 22 in Brus-sels, where ESS representatives willdescribe scientifical, social, politicaland economical aspects of the ESSproject.In the short term, the ESS organiza-tion will assist everyone who cancontribute to clarify in their countrythe decision making and the deci-sions made or not made about ESS,or more generally the ESFRI reportand to press for proper assessmentin the event of any decisions. Thatpertains to Germany, the UK but al-so others. In addition, ESS must pre-pare for how to continue if the viewthat there will be no short-term deci-sion about a new major facility inEurope prevails, the evident interestis to try and limit the delay in get-ting a decisions as much as possible,to be involved in designing andbuilding instruments for the mostadvanced facilities and to maintainthe technical capabilities to build at alater time the world’s best spallationsource. This requires a ‘home’ forESS and a small organization thatcan liaise with politics, co-ordinateactivities, and carry out the planningaccording to a new time schedule.Consultations are being carried outat present to make sure that as soonas the present ESS Council will ceaseto exist and the new organizationwill take over.Letters of support for the ESS projecthas been sent by the Neutron RoundTable and the European NeutronScattering Association to all the Eu-ropean governments and the Euro-pean Commissioner Busquin. Theletters want to be a clear sign of thesupport of the European users forthe ESS, which represents the future

of the activity in Europe and theworld lead in this field. This is ex-tremely important for the future ofthe young generation of europeanscientists, which will be most affect-ed by these political decisions.

F. Carsughi

SCUOLE E CONVEGNI

49


Il 26 e 27 Giugno 2003 si è svolto, presso l’Istituto Nazionale di Fisica della Materia a Genova, il Congresso SISN per ladurata di quattro giornate di comunicazioni orali di 20 minuti ciascuna più una mezza giornata dedicata all’Assem-blea. Durante l’Assemblea, si sono anche svolte comunicazioni di interesse e discussioni di argomenti di politica neu-tronica, sia nazionale che internazionale.Presente anche una sessione Poster dedicata ai giovani con premiazione dei migliori.Gli argomenti scelti per due mezze giornate sono stati:- Applicazioni della neutronica ai beni culturali (organizzata da Alberto Albinati: e-mail: [email protected] )- Biofisica e neutronica (organizzata da Alessandro Paciaroni: e-mail: [email protected])

Scientific Committee

A. Albinati, F. Aliotta, C. Andreani, U. Bafile, F. Barocchi, F. Carsughi, A. PaciaroniSecretary SISNFrancesco AliottaConsiglio Nazionale delle RicercheIstituto per i Processi Chimico-FisiciVia La Farina 237, 98123 MessinaFax: 090 2939 902 Tel: 090 2939 528 (*522, *183, *693)e-mail: Francesco Aliotta [email protected]

L’organizzazione del congresso SISN è stata curata da Roberta Rossi presso l’INFM di Genova.

PROGRAMMA

CONGRESSO SISNGenova, 26-27 Giugno 2003

8:30-9:00 Registration

9:00-9:15 Welcome

9:15-9:45 R. Felici

9:45-10:15 R. Rinaldi

"Neutron scattering on archaeological

artefacts"

10:15-10:45 S. Siano

"Neutron diffraction studies of ancient

bronzes"

10:45-11:15 Coffee Break

11:15-11:45 A. Botti

"SANS on archaeological artefacts: limits

and perspectives"

11:45-12:15 M. Zoppi

"The Italian station INES, applications to

Cultural Heritage "

12:15-12:45 Instrumentation Projects

(15 minutes each talk)

BRISP Spectrometer at ILL IN13

Spectrometer at ILL

26th June

SCUOLE E CONVEGNI

50


12:45-14:30 Lunch

14:30-15:00 L. Bove

"Collective dynamics of liquid gallium

at 315 K and 973K"

15:00-15:30 A. Pietropaolo

"A novel technique for neutron

spectroscopy at the eV energies"

15:30-16:00 C. Mondelli

"Inelastic neutron study of molecular

nanomagnets"


16:15 Assemblea Soci

27th June

9:00-9:45 K. Ross

"Neutron scattering from hydrides"

9:45-10:30 G. Zaccai

"Dynamical-Functional relations in

proteins, membranes and cells

investigated by inelastic neutron "

10:30-10:45 A. Deriu

"Biophysics at future high intensity

neutron sources: from model systems

towards complex macromolecular a

assemblies"


11:15-11:45 F. Natali

"Neutron investigation of lipid-protein

interaction in model systems"

11:45-12:15 R. Cordone

"Structure-dynamics coupling in tehalose

coated MbCO: a comparison between

FTIR and neutron (IN16 and IN13) data"

12:15-12:45 A. Orecchini

"Effect of the environment on the

picosecond protein dynamics"

12:45-14:15 Lunch

Instrumentation Projects

14:15-14:30 VESUVIO and e.VERDI Spectrometers

at ISIS

14 :30-15:00 A. De Francesco

"Lysozyme picosecond dynamics during

protein unfolding in non-aqueous

environment"

15:00-15:30 F. Mariani

"SANS investigations of biological

systems"

15:30-16:00 S. Imberti

"Solvation of ion OH- in water"

16:30-17:00 D. Colognesi

"Phonon density of states from a

crystal-analyzer inverse-geometry

spectrometer: molecular and ionic

solids"

SCUOLE E CONVEGNI

51


Scientific Committeee

Lucio RandaccioPaola SpadonAdriana ZagariNicola LovergineGilberto ArtioliSimona QuartieriGianluca CascaranoRiccardo SpagnaGiuseppe FilippiniMaddalena PedioMassimo AltarelliGiorgio PaolucciCarlo Maria BertoniClaudio FurlaniSettimio MobilioGianni StefaniVincenzo LombardiAntonio FranciosiPaolo PerfettiCalogero Natoli

Organizing Committee

Gilberto VlaicEnnio ZangrandoSilvano GeremiaLetizia PierandreiMichela BassaneseAndrea GoldoniIlde Weffort

JOINT CONGRESS AIC-SILSTrieste, 21-25 July 2003

The XI SILS National Congress is held as a Joint Congress together

with the XXXIII National Congress of the Italian Crystallographic As-

sociation (AIC). The meeting is organized in common microsymposia

between the two Societies and in indipendent sessions.

During the common microsymposia aspects of interest for both the

Societies will be treated, therefore they will be dedicated mainly to

the study of the structural properties of the matter. In particular one

microsymposium will be dedicated to studies in Archeometry and an-

other to spectroscopies applied to structural properties.

The independent session of the SILS “Studies with Synchrotron Radia-

tion” will be dedicated to the presentation of the best results achieved

with synchrotron radiation during the last years, mainly in fields not

covered by the microsimposia of the Joint Meeting.This session will be

held on Wednesday 23rd July 2003 and forsees contributed oral talk

(20 minutes) and a poster session.

Further Information on Congress:

http://www.elettra.trieste.it/AICSILS/

ITALIAN CRYSTALLOGRAPHIC ASSOCIATION (AIC)(XXXIII NATIONAL CONGRESS)

ITALIAN SYNCHROTRON LIGHT SOCIETY (SILS)(XI NATIONAL CONGRESS)

SCUOLE E CONVEGNI

52


The congress program will consist of plenary lectures (60 min), invited (30 min) andcontributed (20 min) talks.

It will be divided into the following seven microsymposia.

Tuesday July 22nd

1) Diffraction in Materials Science2) Progress of Structural Biology Promoted by Synchrotron Sources

Wednesday, July 23rd

3) Structural Crystallograpy4) Experiments, Modelling and Theories on Crystal Growth Mechanisms at the Atomic- and Nano-scale”5) Studies with Synchrotron Radiation

These microsymposia will be held in parallel sessions.

Thursday, July 24th

6) Spectroscopic Methods for Structural Investigations

Friday, July 25th

7) Archeometry

POSTERS

Posters will be exposed during all the period of the Congress.

A formal poster session will be held on Wednesday 23 rd .

Best posters will be awarded during the social dinner, on Thurdsday 23 rd evening.a

PROGRAM

SCUOLE E CONVEGNI

53


VII SCUOLA NAZIONALE DI LUCE DI SINCROTRONESanta Margherita di Pula (Cagliari), 15-26 Settembre 2003

I Direttori della Scuola

Prof. Settimio MOBILIO Dip. di Fisica "E. Amaldi" Università di Roma TreVia della Vasca Navale 8400046 RomaTel. 0655177097

Prof. Gilberto VLAICDip. di Scienze ChimicheUniversità di TriesteVia Giorgieri 1 - 34127 TriesteTel. 0405583931 - Fax 0405583903

eLaboratori Nazionali di FrascatiVia E. Fermi 4000044 Frascati (Roma)Tel. 0694032288 - Fax 0694032304E-mail: [email protected]

Sincrotrone Trieste SCpASettore EsperimentiS.S. 14 Km. 163.534012 Basovizza, TriesteTel. 0403758030 - Fax 0403758565E-mail: [email protected]

La SILS (Società Italiana di Luce di Sincrotrone) organizza la VII

Scuola Nazionale di Luce di Sincrotrone, Santa Margherita di Pula

(Cagliari) 15 – 26 settembre 2003

Le lezioni copriranno in maniera approfondita le singole tematiche;

non è comunque necessaria nessuna conoscenza preliminare della

Luce di Sincrotrone e delle sue applicazioni. La lingua ufficiale sarà

l'italiano, solo alcune lezioni saranno eccezionalmente tenute in lin-

gua inglese.

SCOPI DELLA SCUOLA

Come per le sei edizioni precedenti (1990, 1992, 1995, 1997, 1999

e 2001) la Scuola intende offrire a persone già operanti nel campo

della Luce di Sincrotrone o interessate ad entrarvi una panoramica

attuale delle caratteristiche e potenzialità dell'uso della stessa. Le

possibilità di ricerca con L. S. saranno affrontate sia da un punto di

vista teorico che sperimentale e viste nella loro connessione a varie

discipline (chimica, fisica, biologia, scienze della terra) e a diversi tipi

di materiali.

IscrizioniIl numero di partecipanti alla Scuola é limitato a 50 persone. Le domande verranno accettate in ordine crono-logico di arrivo ai Direttori della Scuola. La tassa di iscrizione é fissata in 260 euro.

Scadenze temporali30-5-2003 Invio della domanda di iscrizione ai Direttori della Scuola31-6-2003 Invio ai partecipanti da parte dei Direttori della Scuola del programma definitivo e della scheda di

prenotazione alberghiera30-7-2003 Pagamento Tassa di Iscrizione; prenotazione alberghiera

Borse di Studio "Carla Cauletti"La SILS, per facilitare la frequenza della Scuola, mette a disposizione alcune borse di studio intitolate allamemoria di Carla Cauletti; le borse saranno assegnate da una apposita Commissione SILS dopo la chiusuradelle iscrizioni. Chi intende richiedere un sostegno economico è pregato di inviare il proprio curriculum-vitae alProf. Gilberto Vlaic. Il numero delle borse a disposizione e la loro entità non può essere al momento quantifica-to, vista la contingente situazione economica del finanziamento alla ricerca in Italia.

SCUOLE E CONVEGNI

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La Scuola si articolerà in circa 70 ore di lezione, in cui verranno trattati i seguenti argomenti:- Produzione e proprietà della L. S.- ELETTRA e ESRF: descrizione delle facilities; attività italiana a ESRF- Interazione radiazione-materia- Assorbimento di raggi X (EXAFS e XANES)- Diffrazione di raggi X (cristallo singolo, polveri, scattering anomalo, MAD, DAFS)- Spettroscopie di fotoemissione da livelli di valenza e di core (solidi e gas); fotoemissione

risolta in tempo e in spin- Scattering a basso angolo- Scattering anelastico- Onde stazionarie- Dicroismo magnetico e naturale- Tecniche di microscopia e microspettroscopia con L. S.- Le applicazioni delle singole spettroscopie a vari tipi di materiali, tra i quali: biomolecole;

materiali magnetici; catalizzatori; superfici (proprietà elettroniche e strutturali).

Sessione PosterCi sembra utile organizzare in modo del tutto informale una sessione poster riguardante i la-vori che ciascuno svolge o intenderebbe svolgere utilizzando la L. S., in modo da favorire gliscambi di idee e la nascita di collaborazioni tra i partecipanti alla Scuola.

Sede della ScuolaSala congressi Hotel Flamingo, Santa Margherita di Pula (CA) S.S. 195, Km. 33.800.

Sistemazione alberghieraI partecipanti saranno alloggiati presso l'Hotel Flamingo o presso l'Hotel Mare e Pineta. I due alberghi sono inriva al mare, situati all'interno di un parco privato di pini marittimi e di eucaliptus e distano tra loro circa 5minuti a piedi. Il complesso è dotato di piscina, spiaggia privata, minigolf e campi da tennis. La Direzione del-l'Albergo ci ha riservato 15 camere al Flamingo e 30 camere al Mare e Pineta. I pasti saranno serviti presso ilFlamingo.Prezzi di pensione completa per persona in camera doppia con servizi (bevande escluse):

Hotel Flamingo**** 69 euro/giorno (supplemento singola 11 euro/giorno)Hotel Mare e Pineta*** 57 euro/giorno (supplem. doppia uso singola 15 euro/giorno)Riduzione tripla/quadrupla 25%

Le condizioni di miglior favore praticate ai partecipanti saranno valide anche nel fine settimana precedente e inquello successivo alla Scuola. Le prenotazioni alberghiere e le spese di soggiorno andranno regolate esclusiva-mente con la Direzione dell'Albergo. Carte di credito accettate: American Express.

Hotel Flamingo & Mare e Pineta HotelSS 195 KM. 33.80009010 S. Margherita di Pula (CA)Tel. 0709208361 - Fax 0709208359

PROGRAMMA

SCUOLE E CONVEGNI

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Altre informazioniIl tempo in Sardegna a settembre é generalmente buono; le temperature medie oscillano tra i 18 e i 28 °C. Poichési tratta di un periodo di alta stagione turistica é consigliabile (specie se si viaggia con auto al seguito) prenotarei viaggi con largo anticipo.

VII Scuola Nazionale di Luce di SincrotroneSanta Margherita di Pula (Cagliari) 15 – 26 settembre 2003

SCHEDA DI ISCRIZIONE

Da spedire via fax o e-mail al Prof. Mobilio o al Prof. Vlaic

Nome e cognome ...............................................................................................................................................................................................................................

Qualifica ......................................................................................................................................................................................................................................................

Indirizzo ......................................................................................................................................................................................................................................................

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Telefono ................................................................................................................ Fax .........................................................................................................................

E-Mail .............................................................................................................................................................................................................................................................

Eventuale richiesta motivata di finanziamento (*)

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Prevedo di partecipare alla sezione poster con un lavoro dal titolo:

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Verserò la somma di euro 260 quale tassa di iscrizione appena ricevuta conferma della mia ammis-sione da parte degli organizzatori (entro il 30 luglio 2003). Entro la stessa data provvederò a in-viare la scheda di prenotazione alberghiera (che mi sarà fornita dalla Direzione della Scuola).(*) La SILS mette a disposizione alcune borse di studio intitolate alla memoria di Carla Cauletti.Inviare curriculum vitae al Prof. Gilberto Vlaic.

VARIE

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CALENDARIO

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August 3-8, 2003 SAN DIEGO, CALIFORNIA

SPIE Symposium on Nanocrystal Optics 2003URL: http://www.infm.it

August 4-7, 2003 VENEZIA, ITALY

Polarised Neutrons and Synchrotron X-rays forMagnetism.A satellite of the International Conference of Magnetism,Rome 2003.URL: http://venice.infm.itURL: http://www.icm2003.mlib.cnr.it

August 10-24, 2003 ARGONNE, IL, USA

Fifth National School of Neutron and X-ray ScatteringContact: Ray Osborn or dean Haeffnere-mail: [email protected]: http://www.dep.anl.gov/nx

August 21-22, 2003 PRETORIA, SOUTH AFRICA

African Neutron Diffraction meetingContact: Andrei Ventre or Chick Wilsone-mail: [email protected]; [email protected]: http://www.sacrs.org.za/andm.index.html

August 26-30, 2003 GRENOBLE, FRANCE

Highly Frustrated Magnetism 2003Contact: H.Mutkae-mail: [email protected]: http://www.grenoble.cnrs.fr/hfm2003/

September 3-6, 2003 MONTPELLIER, FRANCE

ECNS2003: 3rd European Conference on neutronScatteringURL: http://www.ldv.univ-montp2.fr:7082/~ecns2003/

September 8-9, 2003 MANCHESTER, U.K.

2nd International Conference MECA-SENS: StressEvaluation by Neutron and Synchrotron Radiation URL: http://www.mecasens.org

September 8-18, 2003 OXFORD, ENGLAND

Eighth Oxford Summer School on Neutron ScatteringContact: Chick Wilsone-mail: [email protected]: http://www.isis.rl.ac.uk/conferences/osns2003

September 14-18, 2003 SORRENTO, NAPOLI, ITALY

EUCAS 2003: 6th European Conference on AppliedSuperconductivityURL: http://www.infm.it

September 14-19, 2003 STARA LESNA, SLOVAKIA

SSPD ‘03: Structure Solution from Powder DiffractionData

September 15-26, 2003S.M.DI PULA, CAGLIARI, ITALY

VII Scuola Nazionale di Luce di SincrotroneE-mail: [email protected] [email protected]

September 22-25, 2003 TRIESTE, ITALY

DyProSo XXIX Conferente/Elettra (DynamicalProperties of Solids)Contact: Ilde Weffort (secretary)e-mail: [email protected]: http://www.elettra.trieste.it/dyproso

October 15-18, 2003 BADAJOZ, SPAIN

First International Meeting on Applied Physics(APHYS-2003)

October 20-21, 2003 LOS ALAMOS NEW MEXICO, USA

Sixth LANSCE User Group MeetingContact: [email protected]: http://lansce.lanl.gov/conferences/LUG6/index.htm

Nov 28 - Dec 2, 2005 SYDNEY, AUSTRALIA

2005 International Conference on Neutron ScatteringMore information to follow soon

SCADENZE

58


Scadenze per richieste di tempo macchina presso alcuni laboratori di Neutroni

BENSCLe scadenze per il prossimo call for proposals sono il 15 settembre 2003 e il 15 marzo 2003

ILLLa scadenza per il prossimo call for proposalsè il 26 febbraio 2004

ISISLe scadenze per il prossimo call for proposalssono il 16 ottobre 2003 e il 16 aprile 2004

LLB-ORPHEE-SACLAYLa scadenza per il prossimo call for proposalsè il 1 ottobre 2004per informazioni: Secrétariat Scientifique du LaboratoireLéon Brillouin, TMR programme, Attn. Mme C. Abraham, Laboratoire Léon Brillouin,CEA/SACLAY, F-91191 Gif-sur-Yvette, France.Tel: 33(0)169086038; Fax: 33(0)169088261 e-mail: [email protected]://www-llb.cea.fr

SINQLe scadenze per il prossimo call for proposalssono il 15 Maggio ed il 15 Novembre 2003To be addressed to Scientific Coordination OfficeWHGA/147 Paul Scherrer InstituteCH-5232 Villigen PSI, SwitzerlandPhone: +41 56 310 2087Fax: +41 56 310 2939e-mail: [email protected]

Scadenze per richieste di tempo macchinapresso alcuni laboratori di Luce di Sincrotrone

ALSLe prossime scadenzesono il 15 marzo 2004 (cristallografia macromolecolare)e il 1 giugno 2004 (fisica)

BESSYLe prossime scadenzesono il 4 agosto 2003 e il 15 febbraio 2004

DARESBURYLe prossime scadenzesono 31 ottobre 2003 e il 30 aprile 2004

ELETTRALe prossime scadenzesono e il 31 agosto 2003 e il 28 febbraio 2004

ESRFLe prossime scadenzesono il 1 settembre 2003 e il 1 marzo 2004

GILDA(quota italiana) Le prossime scadenzesono il 1 novembre 2003 e il 1 maggio 2004

HASYLAB(nuovi progetti) Le prossime scadenzesono il 1 settembre 2003,il 1 dicembre 2003 e il 1 marzo 2004

LURELa prossima scadenza è il 30 ottobre 2004

MAX-LABLa scadenza è approssimativamente febbraio 2003

NSLSLe prossime scadenzesono il 30 settembre 2003, il 31 gennaio 2004 e il 31 maggio 2004

FACILITIES

59


ALS Advanced Light SourceBerkeley Lab, 1 Cyclotron Rd, MS6R2100, Berkeley,CA 94720tel: +1 510.486.7745 fax: +1 510.486.4773http://www-als.lbl.gov/Tipo: D Status: O

ANKAForschungszentrum Karlsruhe Institut fürSynchrotronstrahlung Hermann-von-Helmholtz-Platz 176344 Eggenstein-Leopoldshafen, Germanytel: +49 (0)7247 / 82-6071 fax: +49-(0)7247 / 82-6172http://hikwww1.fzk.de/iss/

APS Advanced Photon SourceBldg 360, Argonne Nat. Lab. 9700 S. Cass Avenue,Argonne, Il 60439, USAtel:+1 708 252 5089 fax: +1 708 252 3222http://epics.aps.anl.gov/welcome.htmlTipo: D Status: C

ASTRIDISA, Univ. of Aarhus, Ny Munkegade, DK-8000 Aarhus,Denmarktel: +45 61 28899 fax: +45 61 20740http://www.aau.dk/uk/nat/isaTipo: PD Status: O

BESSY Berliner Elektronen-speicherring Gessell.fürSynchrotron-strahlung mbHBESSY GmbH, Albert-Einstein-Str.15, 12489 Berlin,Germany,tel +49 (0)30 6392-2999 fax +49 (0)30 6392-2990http://www.bessy.deTipo: D Status: O

BSRL Beijing Synchrotron Radiation Lab.Inst. of High Energy Physics, 19 Yucuan Rd.PO Box 918,Beijing 100039, PR Chinatel: +86 1 8213344 fax: +86 1 8213374http://solar.rtd.utk.edu/~china/ins/IHEP/bsrf/bsrf.htmlTipo: PD Status: O

CAMD Center Advanced Microstructures & DevicesLouisiana State University, Center for AdvancedMicrostructures & Devices, 6980 Jefferson Hwy., BatonRouge, LA 70806tel: (225) 578-8887 fax. (225) 578-6954 Faxhttp://www.camd.lsu.edu/Tipo: D Status: O

CHESS Cornell High Energy Synchr. Radiation SourceWilson Lab., Cornell University Ithaca, NY 14853, USAtel: +1 607 255 7163 fax: +1 607 255 9001http://www.tn.cornell.edu/Tipo: PD Status: O

CLSCanadian Light Source, University of Saskatchewan, 101Perimeter Road, Saskatoon, SK., Canada. S7N 0X4http://www.cls.usask.ca/Tipo:D status:C

DAFNEINFN Laboratori Nazionali di Frascati, P.O. Box 13,I-00044 Frascati (Rome), Italytel: +39 6 9403 1 fax: +39 6 9403304http://www.lnf.infn.it/Tipo:P Status: C

DELTAUniversität Dortmund,Emil Figge Str 74b,44221 Dortmund, Germanytel: +49 231 7555383 fax: +49 231 7555398http://prian.physik.uni-dortmund.de/Tipo: P Status: C

DIAMONDDiamond Light Source Ltd, Rutherford AppletonLaboratory, Chilton, Oxon OX11 0QXhttp://www.diamond.ac.uk/Tipo:D status:C

L U C E D I S I N C R OT R O N ESYNCHROTRON SOURCES WWW SERVERS IN THE WORLD(http://www.esrf.fr/navigate/synchrotrons.html)

FACILITIES

60


ELETTRASincrotrone Trieste, Padriciano 99, 34012 Trieste, Italytel: +39 40 37581 fax: +39 40 226338http://www.elettra.trieste.itTipo: D Status: O

ELSA Electron Stretcher and AcceleratorNußalle 12, D-5300 Bonn-1, Germanytel:+49 288 732796 fax: +49 288 737869http://elsar1.physik.uni-bonn.de/elsahome.htmlTipo: PD Status: O

ESRF European Synchrotron Radiation Lab.BP 220, F-38043 Grenoble, Francetel: +33 476 882000 fax: +33 476 882020http://www.esrf.fr/Tipo: D Status: O

EUTERPECyclotron Lab.,Eindhoven Univ. of Technol, P.O.Box 513,5600 MB Eindhoven, The Netherlandstel: +31 40 474048 fax: +31 40 438060Tipo: PD Status: C

HASYLABNotkestrasse 85, D-2000, Hamburg 52, Germanytel: +49 40 89982304 fax: +49 40 89982787http://www-hasylab.desy.de/Tipo: D Status: O

INDUS Center for Advanced Technology, Rajendra Nagar,Indore 452012, Indiatel: +91 731 64626http://www.ee.ualberta.ca/~naik/accind1.htmlTipo: D Status: C

KEK Photon FactoryNat. Lab. for High Energy Physics, 1-1, Oho,Tsukuba-shi Ibaraki-ken, 305 Japantel: +81 298 641171 fax: +81 298 642801http://www.kek.jp/Tipo: D Status: O

KurchatovKurchatov Inst. of Atomic Energy, SR Center,Kurchatov Square, Moscow 123182, Russiatel: +7 95 1964546Tipo: D Status: O/C

LNLS Laboratorio Nacional Luz SincrotronCP 6192, 13081 Campinas, SP Braziltel.: (+55) 0xx19 3287.4520 fax: (+55) 0xx19 3287.4632http://www.lnls.br/Tipo: D Status: C

LUREBât 209-D, 91405 Orsay ,Francetel: +33 1 64468014; fax: +33 1 64464148http://www.lure.u-psud.frTipo: D Status: O

MAX-LabBox 118, University of Lund, S-22100 Lund, Swedentel: +46 46 109697 fax: +46 46 104710http://www.maxlab.lu.se/Tipo: D Status: O

NSLS National Synchrotron Light SourceBldg. 725, Brookhaven Nat. Lab., Upton, NY 11973, USAtel: +1 516 282 2297 fax: +1 516 282 4745http://www.nsls.bnl.gov/Tipo: D Status: O

NSRL National Synchrotron Radiation Lab.USTC, Hefei, Anhui 230029, PR Chinatel +86-551-5132231,3602034 fax +86-551-5141078http://www.nsrl.ustc.edu.cn/en/enhome.htmlTipo: D Status: O

PohangPohang Inst. for Science & Technol., P.O. Box 125Pohang, Korea 790600tel: +82 562 792696 fax: +82 562 794499http://pal.postech.ac.kr/english.htmlTipo: D Status: C

FACILITIES

61


Siberian SR CenterLavrentyev Ave 11, 630090 Novosibirsk, Russiatel: +7 383 2 356031 fax: +7 383 2 352163http://ssrc.inp.nsk.su/english/load.pl?right=general.htmlTipo: D Status: O

SLSSwiss Light Source, Paul Scherrer Institut, CH-5232Villigen PSIhttp://sls.web.psi.ch/view.php/about/index.htmlTipo: D Status: OSPring-82-28-8 Hon-komagome, Bunkyo-ku ,Tokyo 113, Japantel: +81 03 9411140 fax: +81 03 9413169http://www.spring8.or.jp/top.htmlTipo: D Status: C

SOLEILCentre Universitaire - B.P. 34 - 91898 Orsay Cedexhttp://www.soleil.u-psud.fr/Tipo: D Status:C

SOR-RING Inst. Solid State PhysicsS.R. Lab, Univ. of Tokyo, 3-2-1 Midori-cho Tanashi-shi,Tokyo 188, Japantel: +81 424614131 ext 346 fax: +81 424615401Tipo: D Status: O

SRC Synchrotron Rad. CenterUniv.of Wisconsin at Madison, 3731 SchneiderDriveStoughton, WI 53589-3097 USAtel: +1 608 8737722 fax: +1 608 8737192http://www.src.wisc.eduTipo: D Status: O

SRRC SR Research Center1, R&D Road VI, Hsinchu Science, Industrial Parc,Hsinchu 30077 Taiwan, Republic of Chinatel: +886 35 780281 fax: +886 35 781881http://www.srrc.gov.tw/Tipo: D Status: O

SSRL Stanford SR Laboratory2575 Sand Hill Road, Menlo Park, California, 94025,USAtel: +1 650-926-4000 fax: +1 650-926-3600http://www-ssrl.slac.stanford.edu/welcome.htmlTipo: D Status: O

SRS Daresbury SR SourceSERC, Daresbury Lab, Warrington WA4 4AD, U.K.tel: +44 925 603000 fax: +44 925 603174E-mail: [email protected]://www.dl.ac.uk/home.htmlTipo: D Status: O

SURF IIIB119, NIST, Gaithersburg, MD 20859, USAtel: +1 301 9753726 fax: +1 301 8697628http://physics.nist.gov/MajResFac/surf/surf.htmlTipo: D Status: O

TERAS ElectroTechnical Lab.1-1-4 Umezono, Tsukuba Ibaraki 305, Japantel: 81 298 54 5541 fax: 81 298 55 6608Tipo: D Status: O

UVSORInst. for Molecular ScienceMyodaiji, Okazaki 444, Japantel: +81 564 526101 fax: +81 564 547079Tipo: D Status: O

D = macchina dedicata

PD = parzialmente dedicata

P = in parassitaggio

O = macchina funzionante

C = macchina in costruzione

D = dedicated machine

PD = partially dedicated

P = parassitic

O = operating machine

C = machine under construction

FACILITIES

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Atominstitut Vienna (A)Facility: TRIGA MARK IIType: Reactor. Thermal power 250 kW.Flux: 1.0 x 1013 n/cm2/s (Thermal);1.7 x 1013 n/cm2/s (Fast)Address for information:1020 Wien, Stadionallee 2Prof. H. RauchTel: +43 1 58801 14111;Fax: +43 1 58801 14199E-mail: [email protected]://www.ati.ac.atWap: wap.ati.ac.at

NRU Chalk River LaboratoriesThe peak thermal flux 3x1014 cm-2 sec-1Neutron Program for Materials Research National Research Council Canada Building 459, Station 18 Chalk River Laboratories Chalk River, Ontario Canada K0J 1J0Phone: 1 - (888) 243-2634 (toll free)Phone: 1 - (613) 584-8811 ext. 3973Fax: 1- (613) 584-4040http://neutron.nrc-cnrc.gc.ca/home.html

Budapest Neutron Centre BRR (H)Type: Reactor. Flux: 2.0 x 1014 n/cm2/sAddress for application forms:Dr. Borbely Sándor, KFKI Building 10,1525 Budapest, Pf 49, HungaryE-mail: [email protected]://www.iki.kfki.hu/nuclear

FRJ-2 Research Reactor in Jülich (D)Type: Dido reactor. Flux: 2 x 1014 n/cm2/sProf. D. Richter, Forschungszentrums Jülich GmbH,Institut für Festkörperforschung,Postfach 19 13, 52425 Jülich, GermanyTel: +49 2461161 2499; Fax: +49 2461161 2610E-mail: [email protected]://www.kfa-juelich.de/iff/Institute/ins/Broschuere_NSE/

FRG-1 Geesthacht (D)Type: Swimming Pool Cold Neutron Source.Flux: 8.7 x 1013 n/cm2/sAddress for application forms and informations:Reinhard Kampmann, Institute for Materials Science,Div. Wfn-Neutronscattering, GKSS, Research Centre,21502 Geesthacht, GermanyTel: +49 (0)4152 87 1316/2503; Fax: +49 (0)4152 87 1338E-mail: [email protected]://www.gkss.de

HMI Berlin BER-II (D)Facility: BER II, BENSCType: Swimming Pool Reactor. Flux: 2 x 1014 n/cm2/sAddress for application forms:Dr. Rainer Michaelsen, BENSC,Scientific Secretary, Hahn-Meitner-Insitut,Glienicker Str 100, 14109 Berlin, GermanyTel: +49 30 8062 2304/3043;Fax: +49 30 8062 2523/2181E-mail: [email protected]://www.hmi.de/bensc

IBR2 Fast Pulsed Reactor Dubna (RU)Type: Pulsed Reactor.Flux: 3 x 1016 (thermal n in core)Address for application forms:Dr. Vadim Sikolenko,Frank Laboratory of Neutron PhysicsJoint Institute for Nuclear Research141980 Dubna, Moscow Region, Russia.Tel: +7 09621 65096; Fax: +7 09621 65882E-mail: [email protected]://nfdfn.jinr.ru/flnph/ibr2.html

ILL Grenoble (F)Type: 58MW High Flux Reactor.Flux: 1.5 x 1015 n/cm2/sScientific CoordinatorDr. G. Cicognani, ILL, BP 156,38042 Grenoble Cedex 9, FranceTel: +33 4 7620 7179; Fax: +33 4 76483906E-mail: [email protected] and [email protected]://www.ill.fr

N E U T R O N INEUTRON SCATTERING WWW SERVERS IN THE WORLD(http://www.isis.rl.ac.uk)

FACILITIES

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IPNS Intense Pulsed Neutron at Argonne (USA)for proposal submission by e-mailsend to [email protected] or mail/FAX to:IPNS Scientific Secretary, Building 360Argonne National Laboratory,9700 South Cass Avenue, Argonne,IL 60439-4814, USAPhone: 630/252-7820, FAX: 630/252-7722 http://www.pns.anl.gov/

IRI Interfaculty Reactor Institute in Delft (NL)Type: 2MW light water swimming pool.Flux: 1.5 x 1013 n/cm2/sAddress for application forms:Dr. A.A. van Well, Interfacultair Reactor Institut,Delft University of Technology, Mekelweg 15,2629 JB Delft, The NetherlandsTel: +31 15 2784738;Fax: +31 15 2786422E-mail: [email protected]://www.iri.tudelft.nl

ISIS Didcot (UK)Type: Pulsed Spallation Source.Flux: 2.5 x 1016 n fast/sAddress for application forms:ISIS Users Liaison Office, Building R3,Rutherford Appleton Laboratory, Chilton,Didcot, Oxon OX11 0QXTel: +44 (0) 1235 445592;Fax: +44 (0) 1235 445103E-mail: [email protected]://www.isis.rl.ac.uk

JAERI (J)Japan Atomic Energy Research Institute,Tokai-mura, Naka-gun,Ibaraki-ken 319-11, Japan.Jun-ichi Suzuki (JAERI);Yuji Ito (ISSP, Univ. of Tokyo);Fax: +81 292 82 59227 telex: JAERIJ24596http://www.ndc.tokai.jaeri.go.jp/

JEEP-II Kjeller (N)Type: D2O moderated 3.5% enriched UO2 fuel.Flux: 2 x 1013 n/cm2/sAddress for application forms:Institutt for Energiteknikk K.H. Bendiksen,Managing Director,Box 40, 2007 Kjeller, NorwayTel: +47 63 806000, 806275;Fax: +47 63 816356E-mail: [email protected]://www.ife.no

LLB Orphée Saclay (F)Type: Reactor. Flux: 3.0 x 1014 n/cm2/sLaboratoire Léon Brillouin (CEA-CNRS)Submissio by email at the following address :[email protected]://www-llb.cea.fr/index_e.html

NFL Studsvik (S)Type: 50 MW reactor. Flux: > 1014 n/cm2/sAddress for application forms:Dr. A. Rennie,NFL Studsvik, S-611 82 Nyköping, SwedenTel: +46 155 221000; Fax: +46 155 263070/263001E-mail: [email protected]://www.studsvik.uu.se

NIST Research Reactor, Washington, USANational Institute of Standardsand Technology-Gaithersburg,Maryland 20899 USACenter Office:J. Michael Rowe, 6210, DirectorNIST Center for Neutron [email protected]://www.ncnr.nist.gov/

FACILITIES

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NRI Rez (CZ)Type: 10 MW research reactor.Address for informations:Zdenek Kriz, Scientif SecretaryNuclear Research Institute Rez plc, 250 68 RezCzech RepublicTel: +420 2 20941177 / 66173428Fax: +420 2 20941155E-mail: [email protected] / [email protected]://www.nri.cz

PSI-SINQ Villigen (CH)Type: Steady spallation source.Flux: 2.0 x 1014 n/cm2/sContact address:Paul Scherrer InstitutSINQ Scientific Coordination OfficeCH-5232 Villigen PSIPhone: +41 56 310 2087Fax: +41 56 310 2939E-mail: [email protected]://sinq.web.psi.ch

SPALLATION NEUTRON SOURCE, ORNL (USA)http://www.sns.gov/

TU Munich FRM, FRM-2 (D)Type: Compact 20 MW reactor.Flux: 8 x 1014 n/cm2/sAddress for information:Prof. Winfried Petry,FRM-II Lichtenbergstrasse 1,85747 GarchingTel: 089 289 14701Fax: 089 289 14666E-mail: [email protected]://www.frm2.tu-muenchen.de

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