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Gholamzadeh Z. ,
Bavarnegin E. ,
Lamehi Rachti M.,
Mirvakili S.M., Joze-Vaziri A.
May 2017
In the name of Allah the most beneficent the most merciful
Neutron diffraction (ND) Neutron diffraction (ND)
2
Sensitivity of neutrons to H, D, Li, C, N, O light elements
Identifying ability of neutrons for adjacent elements in
element periodic table
Involving an magnetic momentum
Identifying of isotopes
Recognition of light element in adjacent to heavy elements
High penetrating depth in materials
Unique properties of neutrons Unique properties of neutrons
3
Pr Ta O Cl powder patternsPr2Ta2O7Cl2 powder patterns
4
Applications of NPD Applications of NPD
Structure analysis
Investigation of Partially crystalline compounds
A new class of aperiodic crystals
Hydrogen bonds
Static and dynamic disorder
displacements
Magnetic structure and order
Study of ionic conductors
Study of H-Storage materials
Hydration/dehydration studies
Oxidation/reduction studies
Nano materials
Pharmacy studies
Composites
Cement
Lithium batteries
Residual stress analysis in materials
5
Budapest 10 MW reactor Budapest 10 MW reactor
Thermal flux: 2.3 1014 n/cm2.s Thermal flux: 2.3×1014 n/cm2.s
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20 MW FRM II Reactor 20 MW FRM II Reactor
Thermal neutron flux: 8 1014 n/cm2.s Thermal neutron flux: 8×1014 n/cm2.s
7
30 MW HANARO Reactor 30 MW HANARO Reactor
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9
10
11
5 MW Tehran 5 MW Tehran
Research Reactor
12
13
Nuclear codes Nuclear codes
14
Vitess 1.0 (1999)→ Vitess 3.3a (2012)
VITESS is a virtual instrumentation tool for neutron scattering at pulsed and continuous sources
It has an uncomplicated modular structure
Twelve coordinates describe each trajectory: time, wavelength (λ), probability
weight, position, flight direction (cosα, cosβ, cosγ), spin-state (S1, S2, S3)
It designed to track many particle types over broad ranges of energies.
The code is used for design of accelerator spallation targets, particularly for neutron scattering
facilities
Investigations for accelerator isotope production and destruction programs, including
the transmutation of nuclear waste
Research into accelerator-driven energy sources
15
Simulated neutron flux from the TRR
reactor 37
cm whose
face the
incident
Simulated neutron flux from the TRR
reactor when transmitted through an 0.37
cm thick plate of oriented graphite whose
face makes an angle of 11˚ with the
incident beam.
Measured neutron flux from a heavy
water through
an oriented
graphite of 11
Measured neutron flux from a heavy
water reactor when transmitted through
an 0.37 cm thick plate of oriented
graphite whose face makes an angle of 11˚ with the incident beam
Benchmark study of Vitess Benchmark study of Vitess
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PG crystal PG crystal
d-spread PG(002): 0.2 - 2´ 10-3
d-spacing PG(002): 3.332 Å
Thickness, width, height 0.2, 7.5, 5
Mosaic factor 2
d range factor 3
d spread Gaussian 17
NPD facility of TRR NPD facility of TRR
Neutron spectra on wavelength at the beginning of NPD D channel Neutron spectra on wavelength at the beginning of NPD D channel
facility of TRR 18
MCNPX Data MCNPX Data
Neutron spectra on wavelength at the Neutron spectra on wavelength at the
exit of first collimator
Neutron spectra on energy at the Neutron spectra on energy at the
exit of first collimator
19
MCNPX Data MCNPX Data
Neutron flux intensity on wavelength Neutron flux intensity on wavelength
after monochromator reflection
Neutron flux intensity on wavelength at the sample position Neutron flux intensity on wavelength at the sample position
(122 cm from the second collimator) 20
Vitess Data Vitess Data
Thermal neutron flux variation on Thermal neutron flux variation on
filter thickness
Fast neutron flux variation on filter Fast neutron flux variation on filter
thickness 21
Neutron flux at sample position Neutron flux at sample position
22
Diffraction
Facility
Power
(MW)
Source Flux
(n/cm2/s)
Sample
Volume
Sample
Flux
(n/cm2/s)
NIST
Cu-311/15′ 20 4*1014 10 cm3 4*105
NIST
Cu-311/7′ 20 6*1014 10 cm3 2*105
MURR
PSD-II 10 6*1013 0.35 cm3 to 1 cm3 1.35*105
NCSU
NPDF 1 2.7*1012 0.35 cm3 to 1cm3 0.64*105
Single
crystal
σt –b at
0.02eV
σt –b at
1 meV
t-cm Plane
Attenuation factor
En>1 eV 0.02
eV 1meV
Silicon 0.4 1.0 22.71 111 10 1.57 3.11
Bismuth 2.0 0.7 7.87 111 10 1.66 1.19
Lead 7.0 2.4 6.45 111 10 4.30 1.65
Sapphire 0.6 1.0 6.9 001 10 1.09 1.16
Al O (Sapphire) Al2O3 (Sapphire)
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Transmission of fast neutrons from Sapphire Transmission of fast neutrons from Sapphire
24
Neutron filters Neutron filters
25
Single
crystal
Mosaic
spread
FWHM-
degree
Thickness
cm
Neutron
transmissio
n
En < 0.025
eV
%
Neutron
transmissio
n
En > 1 eV
%
Attenuatio
n
factor Eγ≈
2 MeV
Plane
Silicon 0.15 25 80 <10 12 111
Bismuth 0.20 5 75 <10 7.2 111
Lead 0.15 10 90 <7 43 111
Sapphire 0.08 7.5 85 <8.5 4.5 100 67Ge 0.10 7 91 <10 5.5 111
Neutron guide Neutron guide
26
Conclusions Conclusions
27
Historical temples in
Yazd and Shiraz city
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