1 Advanced neutron spectrometers for condensed matter studies at the IBR-2M reactor Anatoly M. Balagurov Frank Laboratory of Neutron Physics, JINR, Dubna, Russia Hydrogen: primary energy sources, energy converters and applications  Neutron scattering for condensed matter science.  IBR-2M pulsed reactor as a neutron source of third generation.  Performance of neutron scattering spectrometers at the IBR-2M.  Perspectives.

2 Neutron space and time domain S(Q, ω) ~ ∫∫e i(Qr – ωt) G(r, t)drdt l ~ 2π/Q, τ ~ 2π/ω ΔQ = (10 -3 – 50) Å -1 Δl = (0.1 – 6·10 3 ) Å For elastic scattering: Nanostructured materials are inside! Neutron scattering features: - Strong magnetic interaction, - Sensitivity to light atoms, - Sensitivity to isotopes, - Large penetration length, …

3 Success of neutron scattering experiment depends on: I. Parameters of a neutron source II. Performance of a spectrometer average power, pulse width, spectral distribution,... intensity, resolution, (Q, E)-range, available sample environment,... III. Team at spectrometer head of team, experience, contacts,...

4 Neutron sources for condensed matter studies I. Continuous neutron sources II. Pulsed neutron sources II-a. SPS W = 10 – 100 MW Const in time VVR-M, Russia IR-8, Russia, ILL, France LLB, France BENSC, Germany FRM II, Germany BNC, Hungary NIST, USA ORNL, USA … SINQ, Switzerland W = 0.01 – 1 MW Pulsed in time Δt 0 ≈ (15 – 100) μs II-b. LPS W = 2 – 5 MW Pulsed in time Δt 0 ≈ (300 – 1000) μs ISIS, UK LANSCE, USA SNS, USA KENS, Japan J-SNS, Japan IBR-2M, Russia ESS, Europe LANSCE (new) ???

5 TOF high-resolution diffractometer at LPS type source Δd/d ≈ for back scattering Neutron pulse after fast chopper Δt 0 ≈ (20 – 50) μs

6 Put into operation in 1994 in collaboration between: FLNP (Dubna), PNPI (Gatchina), VTT (Espoo), IzfP (Drezden) HRFD – High Resolution Fourier Diffractometer at IBR-2

7 For V=11,000 rpm & L=30 m R t = ( now) The utmost TOF resolution of HRFD HRFD resolution Diffraction patterns of Al 2 O 3 measured at ISIS (UK) and IBR-2 (Dubna). Resolution is the same, despite L is 5 times longer at ISIS.

8 Diffraction (6): HRFD, DN-2, SKAT, EPSILON, FSD, DN-6 SANS (2): YuMO, SANS-C Reflectometry (3): REMUR, REFLEX, GRAINS Inelastic scattering (2): NERA, DIN 13 spectrometers (3 new) Neutron spectrometers on the IBR-2M reactor

9 Spectrometers on existing pulsed neutron sources* * At a new SNS (Oak Ridge) neutron source 18 spectrometers are planning ** Numbers in brackets – spectrometers at the II Target Station Technique \ Source IBR-2(M) (Russia) ISIS** (UK) IPNS*** (USA) LANSCE (USA) KENS (Japan) Diffraction 6 (6)8 (+2)465 SANS 1 (2)2 (+1)211 Reflectometry 2 (3)2 (+3)222 Inelastic Scat. 3 (2)9 (+1)335 Total 12 (13)21 (+7) *** IPNS is closed in the very beginning of January 2008

10 Diffraction at the IBR-2M 1.HRFD* powders – atomic and magnetic structure 2.FSD* bulk samples – internal stresses 3.DN-2powders – real-time, in situ 4.DN-6microsamples – high-pressure (new project) 5.EPSILON** rocks – internal stresses 6.SKAT**rocks – textures * Fourier RTOF technique ** Long (~100 m) flight pass

11 Diffraction at the IBR-2M. Resolution. HRFD powders FSD internal stresses DN-2real-time, multilayers DN-6high-pressure EPSILON stresses SCAT textures Resolution becomes better for longer d-spacing!

12 1. Chamber of the cold moderator. 2. Light water pre- moderator. 3. Flat water reflector. 4. Outer border of the reactor jacket. 300K water 20 K No4No4 N o 5 N o N o 1 N o 9 1 Combi-moderator at the central direction of the IBR-2M reactor, plan view

13 Diffraction patterns of TbFeO 3 measured at T mod =30 K and 300 K Cold moderators at the IBR-2M reactor Gain factor as a function of λ Neutron flux distributions as a function of λ

14 HRFD development Resolution: one of the best in the world Intensity: not high enough (Ω d ≈0.2 sr) ~500 KUSD 1.Neutron guide 2.Detector array 3.Correlation electronics Actual state Resolution: best among neutron diffractometers Intensity: 10 times better than now Could be

15 New diffractometer for micro-samples and high-pressure studies ChopperNeutron guide Ring-shape detectors Sample Ring-shape multi-element ZnS(Ag)/ 6 LiF detector Resolution: optimal for high-pressure studies Intensity: one of the best in the world Pressure: up to 7 GPa in sapphire anvils Actual state Intensity: 25 times better than now Pressure: GPa in natural diamond or mussonite Could be ~250 KUSD 1.Detector array 2.Neutron guide

16 GRAINS: complete reflectometry at the IBR-2M reactor Resolution: optimal, δλ/λ = (0.3 – 7)%, angular = (1 – 10)% Q-range: optimal, (0.002 – 0.3) Å –1 Intensity: one of the best in the world Parameters: Cost estimate = 1050 kEUR Contributions: - Germany, Hungary, - Romania, external. Reflectometry in vertical plane, Off-specular scattering, GISANS with polarized neutrons. Modes: FLNP: M. Avdeev, V. Lauter-PasyukGermany: H. Lauter V. Aksenov, V. BodnarchukPNPI: V. Trounov, V. Ul’yanov

17 A new reflectometer GRAINS at the IBR-2M reactor Main feature: vertical scattering plane → studies of liquid media

18 Frank Laboratory of Neutron Physics Condensed Matter Department Proposals for IBR-2M spectrometer complex development program Editors: Victor L. Aksenov, Anatoly M. Balagurov Dubna, 2006 The second edition of the proposals is under preparation.

19 Proposals for 2008 – ,000 K$ Development of existing spectrometers New spectrometers General-purpose projects 1.HRFD (SA) 2.FSD (SA) 3.DN-2 4.SKAT (BMBF) 5.EPSILON (BMBF) 6.YuMO 7.REMUR 8.DIN (RosAtom) 9.NERA (Poland) 1.DN-6 2.RTS 3.SANS-C 4.GRAINS 5.SESANS 6.SANS-P 1.Moderators 2.Detectors 3.Sample environment 4.Cryogenics 5.Electronics 3,000 K$ 2,700 K$ In total: 9.7 M$ for 4 years

20 Approved projects Projects with external support SCAT EPSILON GRAINS HRFD FSD DN-6 YuMO / SANS-C Priorities for 2008Priorities for Strategical necessity Projects without clear perspective REMUR, NERA, DIN, SESANS, SANS-P, DN-2, RTS

21 New science after Modern material science - nanostructures (catalysts, multilayers, porous materials, …), - materials for energy (electrochemistry, hydrogen, …), - biomaterials, polymers (soft-matter), - new constructive materials for atomic energy, - geological problems (earthquakes, waste deposit, …), … 2.Modern fundamental physics - complex magnetic oxides with strong correlations, - low-dimensional magnetism, - phase coexistence in crystals, …

22 User program at the IBR-2 spectrometers International experts’ commissions: I. Diffraction II. Inelastic Scattering III. Polarized neutrons IV. SANS Time-sharing (13 spectrometers) FLNP (35%) External regular (55%) External fast (10%) User statistics FLNP, 25% Germany, 17% Russia, 31% Poland, 5% France, 3% Others, 19% IBR-2 operational time: ~2000 hours/year Number of experiments: ~150 per year External users: ~100 per year

23 Condensed Matter Department at FLNP Age distribution JINR staff38 Member States staff28 Professor4 Doctor of science10 Candidate of science 26 Ph.D. + students11 What staff do we need? CMD administration ~ 4 Heads of directions 4 Group at spectrometer ~ 3x13 = 39 Technical group 5 Additional techniques ~ 5 Scientific groups ~ 10 ~ 67 There exists a substantial deficiency of permanent staff personnel 1999: = : = 66

24  IBR-2 is one of the best neutron sources in the world and the only existing advanced neutron source among JINR Member States.  Existing spectrometers are comparable with that at other advanced pulsed neutron sources; some of them are unique.  Experimental potential of the complex is much higher than that existing now.  All spectrometers are accessible for international community in a frame of accepted proposals.  Period 2008 – 2010 is most convenient for global development of neutron spectrometers.  Adequate financial support is urgently needed.

25 Experimental complex based on the IBR-2M reactor for fundamental and applied investigations of advanced and nanostructured materials. Ambitious goal for Condensed Mater Department, Frank Laboratory of Neutron Physics, and Joint Institute for Nuclear Research:

26 Law 2: Neutrons are to be avoided where there is an alternative! From White-Egelstaff law-book for thermal neutron scattering (~1970): New version: Neutrons can be applied everywhere, even if an alternative there exists! For studies of nanostructured materials as well !

27 Thank you !

28 Neutron spectrometers on the ISIS spallation source (RAL, UK) Diffraction (8): GEM, HRPD, PEARL, POLARIS, ROTAX, SXD, ENGIN-X, INES SANS (2): SANDALS, LOQ Reflectometry (2): CRISP, SURF Inelastic scattering (9): HET, MAPS, MARI, MERLIN, PRISMA, IRIS, OSIRIS, TOSCA, VESUVIO 21 spectrometers

29 from MEETING REPORT “Consultancy on the Status of Pulse Reactors and Critical Assemblies” IAEA, 16 – 18 January 2008 The IBR-2 reactor at Joint Institute on Nuclear Research, Dubna is a unique facility internationally, and is being refurbished/modernized to continue to serve as an international centre of excellence for neutron sciences.

30 Mo powder measured in 1 min (1) and 0.2 sec (2). Intensity / Counting rate I ≈ Φ 0 · S · Ω/4π · δ [n/s] ≥ 10 6 n/s Φ 0 – neutron flux at a sample, 10 7 n/cm 2 /s S – sample area, 5 cm 2 Ω – detector solid angle, 0.2 sr δ – scattering probability, 0.1 Diffraction at the IBR-2M. Intensity.

31 IBR-2M pulsed reactor (with cold moderators) is the source of third generation* ) Source Parameter SNS, USA (SPS) JSNS, Japan (SPS) IBR-2M, JINR (LPS) ESS, Europe (LPS) Status ? Power, kW Pulse width, μs – ? Frequency, s >20 * ) For 2 nd generation sources W is between 6 – 200 kW (IPNS, KENS, LANSCE, ISIS)

32 Resources which are needed to complete the program Technical needs: 1. Neutron guides – ~ 300 m 2. 1D PSD – D PSD – 4 4. Large aperture det-s – 6 5. Choppers – 6 6. Neutron optics devices 7. Spin analyzers & polarizers 8. Electronics & computing 9. Sample environment: refrigerators, thermostats, magnets, acoustic technique… Financial needs (in KUSD): A. Development (9) – 4,105 (456) B. New projects (6) – 2,991 (499) Total (15): 7,096

33 Hydrogen materials: what can we learn with neutrons? Location of H, OH, H 2 O in crystal: coherent elastic, diffraction. Dynamics of H, OH in crystal:incoherent inelastic. Diffusion of H, H 2 O in solids or liquids:quasielastic incoherent. Clustering of H, nanostructures:coherent elastic, SANS. Exchange membrane, hydration/dehydration:diffraction, reflectometry. Quantitative analysis:incoherent scattering / absorption. H (and Li) are the most important Elements for fuel cells and batteries! Proton exchange membrane

34 Time / temperature scale: T start =94 K, T end =275 K. The heating rate is ≈1 deg/min. Diffraction patterns have been measured each 5 min. Phase VIII is transformed into high density amorphous phase hda, then into cubic phase Ic, and then into hexagonal ice Ih. Ice VIII Ic Ih Phase transformations of high pressure heavy ice VIII. Time-resolved experiment with  t = (1 – 5) min. hda TOF scale Time & temperature scale

35 Spokesman from JINR:Dr. Ch. Scheffzük Spokesman from Germany:Dr. habil. A. Frischbutter Investigation of strain/stress and texture on geological samples Project EPSILON/SKAT: EPSILON-MDS SKAT Intensity: 10 times better than now Could be New neutron guide ~10 6 EUR

36 Diffraction at the IBR-2M. General conclusion. Unique complex with world top opportunities in: - extremely high-resolution (HRFD), - extremely high-intensity (DN-6, DN-2), - applied studies (FSD, EPSILON, SKAT).

37 Polarized neutron scattering at the IBR-2M 1.REMURmagnetic multilayers – magnetic structures 2.GRAINSinterface science in physics, biology, chemistry (new project) 3. REFLEXreflectometry in horizontal plane, now is used in test mode

38 Resolution at pulse neutron source. Elastic scattering. R = [(Δt 0 /t) 2 + (Δ  /tg  ) 2 ] 1/2 For Δt 0 ≈ 350 μs, L ≈ 25 m, λ ≈ 4 Å TOF contribution is ~1%. Geometrical contribution is: ~(0.05 – 0.2)% for back scattering ~(5 – 10)% for SANS and reflectometry TOF component in resolution function is not important for: SANS and Reflectometry It is not very important for: single crystal diffraction, magnetic diffraction… Powder diffraction: structural studies, stress analysis, low symmetry textures?

39 Criteria which could be used for the evaluation 1.Modern and interesting science. 2.Correspondence to the IBR-2M features. 3.Top level parameters. 4.Active and effective team. 5.External support (financial, technical, …).

40 Proposals at the IBR-2 reactor, JINR, Dubna IBR-2 operational time: ~2000 hours/year Number of experiments: ~150 per year External users: ~100 per year

41 Research reactors in the JINR Member States I. Dubna, IBR-2 (1984, 2 MW, pulsed) II. “RCC KI” Moscow, IR-8 (1957, 8 MW) III. Gatchina, VVR-M (1959, 16 MW) IV. Yekaterinburg, IVV-2M (1966, 15 MW) V. Obninsk, VVR-M (1960, 12 MW) RussiaCzechia Germany Hungary I. Munich, FRM-II (2005, 20 MW) II. Berlin, BENSC (1973, 10 MW) I. Budapest, BNC (1970, 10 MW) I. Řeź, LVR-15 (1970, 10 MW) The enhanced flux and new instrument concepts will allow to improve the resolution in both space and time ==> “new science”!

42 Neutron Techniques (developed at the IBR-2) DINSDeep Inelastic Neutron Scattering INSInelastic Neutron Scattering LNDLaue Neutron Diffraction NBSNeutron Back-Scattering NDNeutron Diffraction NHolNeutron Holography NINeutron Interferometry NPolNeutron Polarimetry NRadNeutron Radiography NRefNeutron Reflectometry NTomNeutron Tomography NSENeutron Spin-Echo PolNPolarized Neutrons PSTPhase-Space Transformation QENSQuasi-Elastic Neutron Scattering SANSSmall Angle Neutron Scattering TASTriple-Axis Spectrometry TOFTime-Of-Flight (techniques) USANS Ultra SANS ZFNSEZero-Field NSE At the IBR-2 the techniques are developed, which are the most effective for condensed matter studies and above all for studies of nano- structured materials.