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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.

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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 m23.5 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 23H ig h reso lu tion0 .1%

Y 1 23M 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 powdersFSD internal stressesDN-2 real-time, multilayersDN-6 high-pressureEPSILON stressesSCAT 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 esolu 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

60 K

v99-1w

30 K300 K

0 2 4 6 8 1 0

W avelength ( Å)

Inte

nsity

v99-45r

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

68

2 0

Rat

io

S ca tter in g on V

D iffra ction o n S P B

y99-hc

H R F D , D 1T m od= 3 0 K

0 .5 1 .0 1 .5 2 .0 2 .5 3 .0 3 .5 4 .0d (Å )

Inte

nsity

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 worldIntensity: not high enough (Ωd≈0.2 sr)

~500 KUSD

1. Neutron guide2. Detector array3. 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-elementZnS(Ag)/6LiF detector

Resolution: 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 array2. 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 kEURContributions: - 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 EPSILONGRAINS

HRFD

FSDDN-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/yearNumber of experiments:

~150 per yearExternal users:

~100 per year

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Condensed Matter Department at FLNP

10

14

8

4

9 97

10

6

3

02468101214161820

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 ~ 4Heads of directions 4Group at spectrometer ~ 3x13 = 39Technical group 5Additional techniques ~ 5Scientific groups ~ 10 ~ 67

There exists a substantial deficiency of permanent staff personnel

1999: 52 + 28 = 802007: 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 srδ – scattering probability, 0.1

(1 )

(11 0 )

(20 0 )

(2 11 )

(2 )m ol-e

0

1 0

2 0

3 0

4 0

Inte

nsity

per

0.2

sec

7 0 9 0 1 1 0 1 3 0 1 5 0 1 7 0 1 9 0C 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, kW

1200 1000 2000 5000

Pulse width, μs

15 - 100 15 – 100 350 1000 ?

Frequency, s-1

60 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 m2. 1D PSD – 5 3. 2D PSD – 4 4. Large aperture det-s – 65. Choppers – 66. Neutron optics devices7. Spin analyzers & polarizers8. Electronics & computing9. 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. ScheffzükSpokesman 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.