advanced neutron spectrometers for condensed matter studies at the ibr-2m reactor
DESCRIPTION
Advanced neutron spectrometers for condensed matter studies at the IBR-2M reactor. Anatoly M. Balagurov Frank Laboratory of Neutron Physics, JINR, Dubna, Russia. Neutron scattering for condensed matter science. IBR-2M pulsed reactor as a neutron source of third generation. - PowerPoint PPT PresentationTRANSCRIPT
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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) ~ ∫∫ei(Qr – ωt) G(r, t)drdt
l ~ 2π/Q, τ ~ 2π/ω
ΔQ = (10-3 – 50) Å-1
Δl = (0.1 – 6·103) Å
For elastic scattering:
Nanostructured materials are inside!
Neutron scattering features:- Strong magnetic interaction,- Sensitivity to light atoms, - Sensitivity to isotopes,- Large penetration length, …
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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, ...
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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, RussiaIR-8, Russia,ILL, FranceLLB, FranceBENSC, GermanyFRM II, GermanyBNC, HungaryNIST, USAORNL, USA…SINQ, Switzerland
W = 0.01 – 1 MW Pulsed in timeΔt0 ≈ (15 – 100) μs
II-b. LPS
W = 2 – 5 MW Pulsed in timeΔt0 ≈ (300 – 1000) μs
ISIS, UKLANSCE, USASNS, USAKENS, JapanJ-SNS, Japan
IBR-2M, RussiaESS, EuropeLANSCE (new)???
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TOF high-resolution diffractometer at LPS type source
49.6 m
21.79 m
22.5 m
23.5 m
29.9 m
73.4 m
Magnet (25 T)
Fermi chopper with 2 slit packages
6 Disc choppers
Δd/d ≈ 0.001 for back scattering
Neutron pulse after fast
chopper Δt0 ≈ (20 – 50) μs
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Put into operation in 1994 in collaboration
between: FLNP (Dubna), PNPI (Gatchina),
VTT (Espoo), IzfP (Drezden)
HRFD – High Resolution Fourier Diffractometer at IBR-2
Y 1 2 3H ig h reso lu tio n0 .1 %
Y 1 2 3M ed iu m reso lu tio n1 %
0 .7 1 .0 1 .3 1 .6 1 .9 2 .2 2 .5d , Å
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For V=11,000 rpm & L=30 m
Rt=0.0002 (0.0009 now)
The utmost TOF resolution of HRFD
HRFD resolution
Diffraction patterns of Al2O3 measured at
ISIS (UK) and IBR-2 (Dubna). Resolution is
the same, despite L is 5 times longer at ISIS.
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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
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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) 4 6 5
SANS 1 (2) 2 (+1) 2 1 1
Reflectometry 2 (3) 2 (+3) 2 2 2
Inelastic Scat. 3 (2) 9 (+1) 3 3 5
Total 12 (13) 21 (+7) 11 12 13
*** IPNS is closed in the very beginning of January 2008
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Diffraction at the IBR-2M
1. HRFD* powders – atomic and magnetic structure
2. FSD* bulk samples – internal stresses
3. DN-2 powders – real-time, in situ
4. DN-6 microsamples – high-pressure (new project)
5. EPSILON** rocks – internal stresses
6. SKAT** rocks – textures
* Fourier RTOF technique
** Long (~100 m) flight pass
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Diffraction at the IBR-2M. Resolution.
HRFD powders
FSD internal stresses
DN-2 real-time, multilayers
DN-6 high-pressure
EPSILON stresses
SCAT textures
0 1 2 3 4 5 6 7 8d , Å
0 .0 0 0 1
0 .0 0 1
0 .0 1
0 .1
Res
olut
ion,
d/d
H R F D
D N -2 /D N -6
TO F_R eso lu t_C om
F S D S K A T /E P S IL O N
Resolution becomes better
for longer d-spacing!
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1. Chamber of the cold moderator.
2. Light water pre-moderator.
3. Flat water reflector.
4. Outer border of the reactor jacket.
300K
water
20K
No4
No 5
No 6
2
4
3
No 1
No 9
1
Combi-moderator at the central direction of the IBR-2M reactor, plan view
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Diffraction patterns of TbFeO3
measured at Tmod=30 K and 300 K
Cold moderators at the IBR-2M reactor
6 0 K
v99-1w
30 K3 0 0 K
0 2 4 6 8 1 0
W avelength (Å)
Inte
nsit
yv99-45r
R = I(3 0 K ) / I (3 0 0 K )
1 2 3 4 5 6 7W a v e le n g th (Å )
1
1 0
2
4
6
8
2 0
Rat
io
S ca tter in g o n V
D iffra ctio n o n S P B
y99-hc
H R F D , D 1T m o d= 3 0 K
0 .5 1 .0 1 .5 2 .0 2 .5 3 .0 3 .5 4 .0
d (Å )In
tens
ity
Y b F eO 3a= 5 .5 6 Åb= 7 .5 6 Åc= 5 .2 3 Å
H R F D , D 1T m o d= 3 0 0 K
Gain factor as a function of λ
Neutron flux distributions as a function of λ
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HRFD development
Resolution: one of the best in the world
Intensity: not high enough (Ωd≈0.2 sr)
~500 KUSD
1. Neutron guide
2. Detector array
3. Correlation electronics
Actual state
Resolution: best among neutron diffractometersIntensity: 10 times better than now
Could be
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New diffractometer for micro-samples and high-pressure studies
Chopper Neutron guide
Ring-shape detectors
Sample
Ring-shape multi-element
ZnS(Ag)/6LiF detectorResolution: optimal for high-pressure studiesIntensity: one of the best in the worldPressure: up to 7 GPa in sapphire anvils
Actual state
Intensity: 25 times better than nowPressure: 20-30 GPa in natural diamond or mussonite
Could be
~250 KUSD
1. Detector array
2. Neutron guide
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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-Pasyuk Germany: H. Lauter
V. Aksenov, V. Bodnarchuk PNPI: V. Trounov, V. Ul’yanov
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A new reflectometer GRAINS at the IBR-2M reactor
Main feature: vertical scattering plane → studies of liquid media
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Frank Laboratory of Neutron Physics
Condensed Matter Department
Proposalsfor IBR-2M spectrometer complex
development program
Editors: Victor L. Aksenov, Anatoly M. Balagurov
Dubna, 2006
The second edition of the proposals is under preparation.
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Proposals for 2008 – 2011
4,000 K$
Development of existingspectrometers
New spectrometers
General-purposeprojects
1. HRFD (SA)2. FSD (SA)3. DN-24. SKAT (BMBF) 5. EPSILON (BMBF)6. YuMO7. REMUR8. DIN (RosAtom)9. NERA (Poland)
1. DN-62. RTS3. SANS-C4. GRAINS5. SESANS6. SANS-P
1. Moderators2. Detectors3. Sample environment4. Cryogenics5. Electronics
3,000 K$2,700 K$
In total: 9.7 M$ for 4 years
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Approved projects
Projects with external support
SCAT
EPSILON
GRAINS
HRFD
FSD
DN-6
YuMO / SANS-C
Priorities for 2008 Priorities for 2009 - 2011
Strategical necessity
Projects without clear perspective
REMUR, NERA,
DIN, SESANS,
SANS-P, DN-2, RTS
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New science after 2010
1. 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, …
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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%)
Externalregular (55%)
Externalfast (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
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Condensed Matter Department at FLNP
10
14
8
4
9 9
7
10
6
3
0
2
4
6
8
10
12
14
16
18
20
20-24 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60-64 65-70
Age distribution
JINR staff 38Member States staff 28
Professor 4Doctor of science 10Candidate of science 26Ph.D. + students 11
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: 52 + 28 = 80
2007: 38 + 28 = 66
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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.
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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:
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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 !
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Thank you !
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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
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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.
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Mo powder measured in1 min (1) and 0.2 sec (2).
Intensity / Counting rate
I ≈ Φ0 · S · Ω/4π · δ [n/s] ≥ 106 n/s
Φ0 – neutron flux at a sample, 107 n/cm2/s
S – sample area, 5 cm2
Ω – detector solid angle, 0.2 sr
δ – scattering probability, 0.1
(1 )
(1 1 0 )
(2 0 0 )
(2 1 1 )
(2 )m ol-e
0
1 0
2 0
3 0
4 0
Inte
nsit
y pe
r 0.
2 se
c
7 0 9 0 1 1 0 1 3 0 1 5 0 1 7 0 1 9 0
C h a n n e l n u m b e r
0
2 0 0 0
4 0 0 0
6 0 0 0
8 0 0 0
1 0 0 0 0
Inte
nsity
per
1 m
in
Diffraction at the IBR-2M. Intensity.
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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 2008 2009 2010 2015 ?
Power,
kW1200 1000 2000 5000
Pulse width,
μs15 - 100 15 – 100 350 1000 ?
Frequency,
s-160 25 5 >20
*) For 2nd generation sources W is between 6 – 200 kW (IPNS, KENS, LANSCE, ISIS)
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Resources which are needed to complete the 2007 - 2010 program
Technical needs: 1. Neutron guides – ~ 300 m
2. 1D PSD – 5
3. 2D 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
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Hydrogen materials: what can we learn with neutrons?
Location of H, OH, H2O in crystal: coherent elastic, diffraction.
Dynamics of H, OH in crystal: incoherent inelastic.
Diffusion of H, H2O 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
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Time / temperature scale: Tstart=94 K, Tend=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
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Spokesman from JINR: Dr. Ch. Scheffzük
Spokesman from Germany: Dr. habil. A. Frischbutter
Investigation of strain/stress and textureon geological samples
Project EPSILON/SKAT:
EPSILON-MDS
SKAT
Intensity: 10 times better than now
Could beNew neutron guide
~106 EUR
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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).
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Polarized neutron scattering at the IBR-2M
1. REMUR magnetic multilayers – magnetic structures
2. GRAINS interface science in physics, biology, chemistry
(new project)
3. REFLEX reflectometry in horizontal plane,
now is used in test mode
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Resolution at pulse neutron source. Elastic scattering.
R = [(Δt0/t)2 + (Δ/tg)2]1/2
For Δt0 ≈ 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?
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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, …).
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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
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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)
Russia Czechia
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”!
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Neutron Techniques (developed at the IBR-2)
DINS Deep Inelastic Neutron ScatteringINS Inelastic Neutron ScatteringLND Laue Neutron DiffractionNBS Neutron Back-ScatteringND Neutron DiffractionNHol Neutron HolographyNI Neutron InterferometryNPol Neutron PolarimetryNRad Neutron RadiographyNRef Neutron ReflectometryNTom Neutron TomographyNSE Neutron Spin-EchoPolN Polarized NeutronsPST Phase-Space TransformationQENS Quasi-Elastic Neutron ScatteringSANS Small Angle Neutron ScatteringTAS Triple-Axis SpectrometryTOF Time-Of-Flight (techniques)USANS Ultra SANSZFNSE Zero-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.