TY - JOUR
T1 - Further Improvement of the RITS Code for Pulsed Neutron Bragg-edge Transmission Imaging
AU - Sato, H.
AU - Watanabe, K.
AU - Kiyokawa, K.
AU - Kiyanagi, R.
AU - Hara, K. Y.
AU - Kamiyama, T.
AU - Furusaka, M.
AU - Shinohara, T.
AU - Kiyanagi, Y.
N1 - Funding Information:
This work was partially supported by Photon and Quantum Basic Research Coordinated Development Program from the Ministry of Education, Culture, Sports, Science and Technology, Japan.
Publisher Copyright:
© 2017 The Authors.
PY - 2017
Y1 - 2017
N2 - The RITS code is a unique and powerful tool for a whole Bragg-edge transmission spectrum fitting analysis. However, it has had two major problems. Therefore, we have proposed methods to overcome these problems. The first issue is the difference in the crystallite size values between the diffraction and the Bragg-edge analyses. We found the reason was a different definition of the crystal structure factor. It affects the crystallite size because the crystallite size is deduced from the primary extinction effect which depends on the crystal structure factor. As a result of algorithm change, crystallite sizes obtained by RITS drastically approached to crystallite sizes obtained by Rietveld analyses of diffraction data; from 155% to 110%. The second issue is correction of the effect of background neutrons scattered from a specimen. Through neutron transport simulation studies, we found that the background components consist of forward Bragg scattering, double backward Bragg scattering, and thermal diffuse scattering. RITS with the background correction function which was developed through the simulation studies could well reconstruct various simulated and experimental transmission spectra, but refined crystalline microstructural parameters were often distorted. Finally, it was recommended to reduce the background by improving experimental conditions.
AB - The RITS code is a unique and powerful tool for a whole Bragg-edge transmission spectrum fitting analysis. However, it has had two major problems. Therefore, we have proposed methods to overcome these problems. The first issue is the difference in the crystallite size values between the diffraction and the Bragg-edge analyses. We found the reason was a different definition of the crystal structure factor. It affects the crystallite size because the crystallite size is deduced from the primary extinction effect which depends on the crystal structure factor. As a result of algorithm change, crystallite sizes obtained by RITS drastically approached to crystallite sizes obtained by Rietveld analyses of diffraction data; from 155% to 110%. The second issue is correction of the effect of background neutrons scattered from a specimen. Through neutron transport simulation studies, we found that the background components consist of forward Bragg scattering, double backward Bragg scattering, and thermal diffuse scattering. RITS with the background correction function which was developed through the simulation studies could well reconstruct various simulated and experimental transmission spectra, but refined crystalline microstructural parameters were often distorted. Finally, it was recommended to reduce the background by improving experimental conditions.
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U2 - 10.1016/j.phpro.2017.06.044
DO - 10.1016/j.phpro.2017.06.044
M3 - Conference article
AN - SCOPUS:85030453231
VL - 88
SP - 322
EP - 330
JO - Physics Procedia
JF - Physics Procedia
SN - 1875-3892
T2 - Neutron Imaging for Applications in Industry and Science Proceedings of the 8th International Topical Meeting on Neutron Radiography ITMNR-8, 2016
Y2 - 4 September 2015 through 8 September 2015
ER -