Advanced neutron spectrometers for condensed matter studies at the IBR-2M reactor
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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. Neutron scattering for condensed matter science. IBR-2M pulsed reactor as a neutron source of third generation.

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Advanced neutron spectrometers for condensed matter studies at the IBR-2M reactor

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Advanced neutron spectrometers for condensed matter studies at the IBR-2M reactor

Anatoly M. BalagurovFrank Laboratory of Neutron Physics, JINR, Dubna, Russia

  • 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.

Hydrogen: primary energy sources,

energy converters and applications


Neutron space and time domain

S(Q, ω) ~ ∫∫ei(Qr – ωt) G(r, t)drdt

l ~ 2π/Q, τ~ 2π/ω

For elastic scattering:

ΔQ = (10-3 – 50) Å-1

Δl = (0.1 – 6·103) Å

Nanostructured materials are inside!

  • Neutron scattering features:

  • Strong magnetic interaction,

  • Sensitivity to light atoms,

  • Sensitivity to isotopes,

  • Large penetration length, …


Success of neutron scattering experiment depends on:

I. Parameters of a neutron source

average power, pulse width, spectral distribution, ...

II. Performance of a spectrometer

intensity, resolution, (Q, E)-range, available sample environment,...

III. Team at spectrometer

head of team, experience,contacts,...


Neutron sources for condensed matter studies

I. Continuous neutron sources

II. Pulsed neutron sources

W = 10 – 100 MW

Const in time

II-a. SPS

II-b. LPS

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

Δt0≈ (15 – 100) μs

W = 2 – 5 MW

Pulsed in time

Δt0≈ (300 – 1000) μs

ISIS, UK

LANSCE, USA

SNS, USA

KENS, Japan

J-SNS, Japan

IBR-2M, Russia

ESS, Europe

LANSCE (new)

???


Fermi chopper with 2 slit packages

21.79 m

22.5 m

23.5 m

29.9 m

6 Disc choppers

49.6 m

73.4 m

Magnet (25 T)

TOF high-resolution diffractometer at LPS type source

Neutron pulse after fast

chopper Δt0≈ (20 – 50) μs

Δd/d≈ 0.001 for back scattering


HRFD – High Resolution Fourier Diffractometer at IBR-2

Put into operation in 1994 in collaboration

between: FLNP (Dubna), PNPI (Gatchina),

VTT (Espoo), IzfP (Drezden)


HRFD resolution

The utmost TOF

resolution of HRFD

For V=11,000 rpm & L=30 m

Rt=0.0002 (0.0009 now)

Diffraction patterns of Al2O3 measured at ISIS (UK) and IBR-2 (Dubna). Resolution is the same, despite L is 5 times longer at ISIS.


Neutron spectrometers on the IBR-2M reactor

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)


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

*** IPNS is closed in the very beginning of January 2008


Diffraction at the IBR-2M

  • HRFD* powders – atomic and magnetic structure

  • FSD* bulk samples – internal stresses

  • DN-2powders – real-time, in situ

  • DN-6microsamples – high-pressure (new project)

  • EPSILON** rocks – internal stresses

  • SKAT**rocks – textures

* Fourier RTOF technique

** Long (~100 m) flight pass


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!


1

2

No 1

No4

4

  • Chamber of the cold moderator.

  • Light water pre-moderator.

  • Flat water reflector.

  • Outer border of the reactor jacket.

20K

No 5

300K

No 6

water

3

No 9

Combi-moderator at the central direction of the IBR-2M reactor, plan view


Cold moderators at the IBR-2M reactor

Gain factor as a function of λ

Diffraction patterns of TbFeO3 measured at Tmod=30 K and 300 K

Neutron flux distributions as a function of λ


HRFD development

Actual state

Resolution: one of the bestin the world

Intensity: not high enough (Ωd≈0.2 sr)

  • Neutron guide

  • Detector array

  • Correlation electronics

Could be

Resolution: best among neutron diffractometers

Intensity: 10 times better than now

~500 KUSD


New diffractometer for micro-samples and

high-pressure studies

Chopper

Neutron guide

Sample

Actual state

Ring-shape detectors

Ring-shape multi-element

ZnS(Ag)/6LiF detector

Resolution: optimal for high-pressure studies

Intensity: one of the best in the world

Pressure: up to 7 GPa in sapphire anvils

  • Detector array

  • Neutron guide

Could be

Intensity: 25 times better than now

Pressure: 20-30 GPa in natural diamond or mussonite

~250 KUSD


GRAINS: complete reflectometry at the IBR-2M reactor

FLNP: M. Avdeev, V. Lauter-PasyukGermany: H. Lauter

V. Aksenov, V. BodnarchukPNPI: V. Trounov, V. Ul’yanov

Parameters:

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

Modes:

Cost estimate = 1050 kEUR

Contributions:

- Germany, Hungary,

- Romania, external.

  • Reflectometry in vertical plane,

  • Off-specular scattering,

  • GISANS with polarized neutrons.


A new reflectometer GRAINS at the IBR-2M reactor

Main feature: vertical scattering plane→ studies of liquid media


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.


Proposalsfor 2008 – 2011

Development of existing

spectrometers

New

spectrometers

General-purpose

projects

  • HRFD (SA)

  • FSD (SA)

  • DN-2

  • SKAT (BMBF)

  • EPSILON (BMBF)

  • YuMO

  • REMUR

  • DIN (RosAtom)

  • NERA (Poland)

  • Moderators

  • Detectors

  • Sample environment

  • Cryogenics

  • Electronics

  • DN-6

  • RTS

  • SANS-C

  • GRAINS

  • SESANS

  • SANS-P

2,700 K$

3,000 K$

4,000 K$

In total: 9.7 M$ for4years


Priorities for 2008

Priorities for 2009 - 2011

Approved projects

Strategical necessity

YuMO / SANS-C

FSD

DN-6

Projects with external support

Projects without clear perspective

REMUR, NERA, DIN, SESANS, SANS-P, DN-2, RTS

SCAT

EPSILON

GRAINS

HRFD


New science after 2010

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, …), …

Modern fundamental physics

- complex magnetic oxides with strong correlations,

- low-dimensional magnetism,

- phase coexistence in crystals, …


User program at the IBR-2 spectrometers

International experts’

commissions:

Time-sharing (13 spectrometers)

FLNP (35%)

I. Diffraction

II. Inelastic Scattering

III. Polarized neutrons

IV. SANS

External

fast (10%)

External

regular (55%)

User statistics

IBR-2 operational time:

~2000 hours/year

Number of experiments:

~150 per year

External users:

~100 per year

Others, 19%

FLNP, 25%

France, 3%

Poland,

5%

Germany,

17%

Russia, 31%


Condensed Matter Department at FLNP

JINR staff38

Member States staff28

Professor4

Doctor of science10

Candidate of science 26

Ph.D. + students11

1999: 52 + 28 = 80

2007: 38 + 28 = 66

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

Age distribution

There exists a substantial deficiency of permanent staff personnel


  • 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.


Ambitious goal for Condensed Mater Department,

Frank Laboratory of Neutron Physics,

and

Joint Institute for Nuclear Research:

Experimental complex based on the IBR-2M reactor for fundamental and applied investigations of advanced and nanostructured materials.


From White-Egelstaff law-book for

thermal neutron scattering (~1970):

Law 2:

Neutrons are to be avoided where there is an alternative!

New version:

Neutrons can be applied everywhere, even if an alternative there exists!

For studies of nanostructured materials as well !


Thank you !


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


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.


Diffraction at the IBR-2M. Intensity.

Mo powder measured in

1 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


IBR-2M pulsed reactor (with cold moderators)

is the source of third generation*)

*) For 2nd generation sources W is between 6 – 200 kW (IPNS, KENS, LANSCE, ISIS)


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


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


Phase transformations of high pressure heavy ice VIII.

Time-resolved experiment witht = (1 – 5) min.

Ih

Ice VIII

Ic

hda

Time & temperature scale

TOF scale

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.


Project EPSILON/SKAT:

Investigation of strain/stress and texture

on geological samples

Spokesman from JINR:Dr. Ch. ScheffzükSpokesman from Germany:Dr. habil. A. Frischbutter

EPSILON-MDS

SKAT

New neutron guide

Could be

~106 EUR

Intensity: 10 times better than now


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).


Polarized neutron scattering at the IBR-2M

  • REMURmagnetic multilayers – magnetic structures

  • 2.GRAINSinterface science in physics, biology, chemistry

  • (new project)

  • 3. REFLEXreflectometry in horizontal plane,

  • now is used in test mode


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?


Criteria which could be used for the evaluation

Modern and interesting science.

Correspondence to the IBR-2M features.

Top level parameters.

Active and effective team.

External support (financial, technical, …).


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


Research reactors in the JINR Member States

Russia

Czechia

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)

I. Řeź, LVR-15 (1970, 10 MW)

Germany

I. Munich, FRM-II (2005, 20 MW)

II. Berlin, BENSC (1973, 10 MW)

Hungary

I. Budapest, BNC (1970, 10 MW)

The enhanced flux and new instrument concepts will allow to improve the resolution in both space and time ==> “new science”!


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.


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