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

6

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

8

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

16

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)

23

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