High resolution Fourier Stress Diffractometer

 

1 - Moderator
2 - Curved neutron guide
3 - Fourier chopper
4 - Straight neutron guide
5 - Backscattering detectors
6 - 90°- detectors
7 - Sample position
8 - PC based experiment control and data acquisition system
9 - Local Ethernet network for data transfer

 

Instrument Responsible:

 

Papushkin Igor
Russia, Moscow reg., Dubna, Joliot-Curie str., 6
tel. +7 (49621) 6-52-73
fax. +7 (49621) 6-58-82
e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

 

HRFD Group Staff

 

Main research areas

 

Investigations of internal mechanical stresses in materials are of current interest from both fundamental and applied points of view.
The respective scientific research is usually targeted at studying deformations and microdeformations in crystalline materials arising during structural phase transitions, deformations formed in multiphase systems, as well as the determination of characteristic crystallite sizes and dislocation density in relation to internal stresses.
The related applied research is aimed at determining deformations and stresses in industrial products with the subsequent formulation of technological recommendations. It includes, for example, experimental determination of residual stresses arising after various technological operations (welding, rolling, annealing, quenching, etc.), deformations arising under the action of cyclic (mechanical and thermal) loads and radiation exposure (including effects of neutron irradiation on martensitic transformations), hydrogenation, etc.
Also, a rapidly developing area of research is the study of new types of materials (composites, gradient materials, reinforced systems, cermets, shape-memory alloys, etc.) in order to determine their suitability for use in certain industrial products.

 

 Main parameters

 

Table 1. FSD main parameters

 

Curved neutron guide mirror, Ni-covered
length 19 m
cross-section at entrance 10 × 155 mm2
cross-section at exit 10 × 91.8 mm2
radius of curvature 2864.8 m
Straight neutron guide mirror, Ni-covered
length 5.01 m
cross-section at entrance 10 × 91.8 mm2
cross-section at exit 10 × 75 mm2
Moderator – sample distance 28.14 m
Chopper – sample distance 5.55 m
Fourier - chopper (disk) high-strength Al based alloy
outer diameter 540 mm
slit width 0.7 mm
number of slits 1024
maximal rotation speed 6000 rpm
maximal beam modulation frequency 100 kHz
Thermal neutron pulse width:  
low-resolution mode 320 μs
high-resolution mode 9.8 μs
High resolution detectors:  
BS- 6Li, time focusing
Astra Left ZnS, combined electronic & time focusing
Astra Right ZnS, combined electronic & time focusing
Low-resolution detectors 3He tubes
Wavelength interval 0.9 ÷ 8 Å
Flux at sample position:  
without Fourier chopper 1.8 × 106 n/cm2/sec
with Fourier chopper 3.7 × 105 n/cm2/sec

 

Table 2. Main parameters of high-resolution detectors on FSD

 

Detector Parameter BS- Astra Left
(1st element)
Astra Right
(1st element)
Scattering angle 2θ, ° 140.864 107.5 107.5
dhkl -range, Å 0.51 – 5.39 0.63 – 6.71 0.63 – 6.71
Δd/d (d =1 Å) 3.4 × 10-3 4.6 × 10-3 4.5 × 10-3
Δd/d (d =2 Å) 2.3 × 10-3 4.0 × 10-3 3.7 × 10-3
Solid angle Ω, str. 0.054 0.179 0.179

 

 

Sample environment

 

  • mirror furnace "MF2000" (room temperature < T < 1000°C);
  • 4-axis (x,y,z,rotation) "HUBER" goniometer for total strain tensor measurements;
  • testing machine TIRAtest for in situ sample studies under external load (up to 60 kN);
  • testing machine LM-20 for in situ sample studies under external load (up to 20 kN);
  • multi-slit radial collimator with spatial resolution of 2 mm;
  • nitride boron slit systems for forming incident and scattered neutron beams.

 

Publications

 

1) В.Л. Аксенов, А.М. Балагуров, Г.Д. Бокучава и др., “Нейтронный фурье - дифрактометр ФСД для анализа внутренних напряжений: первые результаты”, Сообщение ОИЯИ Р13-2001-30 (2001).

2) G.D. Bokuchava, V.L. Aksenov, A.M. Balagurov et al., “Neutron Fourier diffractometer FSD for internal stress analysis: first results”, Applied Physics A: Materials Science & Processing, v.74 [Suppl1] (2002) pp s86-s88.

3) E.S. Kuzmin, A.M. Balagurov, G.D. Bokuchava, V.V. Zhuk, V.A. Kudryashev, A.P.Bulkin, V.A.Trounov, “Detector for the FSD Fourier-diffractometer based on ZnS (Ag) /6LiF scintillation screen and wavelength shifting fiber readout”, Communication of JINR E13-2001-204, Dubna, 2001.

4) E.S. Kuzmin, A.M. Balagurov, G.D. Bokuchava, V.V. Zhuk, V.A. Kudryashev, “Detector for the FSD Fourier diffractometer based on ZnS (Ag) /6LiF scintillation screen and wavelength shifting fiber readout”, J. of Neutron Research, Vol. 10, Number 1 (2002) 31-41.

5) А.А. Богдзель, Г.Д. Бокучава, В.А. Бутенко и др., “Система автоматизации экспериментов на нейтронном фурье-дифрактометре ФСД”, Препринт ОИЯИ Р10-2004-21 (2004).

6) Balagurov A.M., Bokuchava G.D., Kuzmin E.S., Tamonov A.V., Zhuk V.V. “Neutron RTOF diffractometer FSD for residual stress investigation”, Proc. of European Powder Diffraction Conference (EPDIC IX), September 2-5, 2004, Prague, Czech Republic. Zeitschrift fur Kristallographie, Supplement Issue No. 23 (2006) 217-222.

7) Bokuchava G.D., Balagurov A.M., Sumin V.V., Papushkin I.V., “Neutron Fourier diffractometer FSD for residual stress studies in materials and industrial components”, Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques, Vol. 4, No. 6, pp. 879-890, 2010