論文

査読有り
2013年7月

Effects of gauge volume on pseudo-strain induced in strain measurement using time-of-flight neutron diffraction

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
  • Hiroshi Suzuki
  • ,
  • Stefanus Harjo
  • ,
  • Jun Abe
  • ,
  • Pingguang Xu
  • ,
  • Kazuya Aizawa
  • ,
  • Koichi Akita

715
開始ページ
28
終了ページ
38
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1016/j.nima.2013.03.031
出版者・発行元
ELSEVIER SCIENCE BV

Spurious or pseudo-strains observed in time-of-flight (TOF) neutron diffraction due to neutron attenuation, surface-effects and a strain distribution within the gauge volume were investigated. Experiments were carried out on annealed and bent ferritic steel bars to test these effects. The most representative position in the gauge volume corresponds to the neutron-weighted center of gravity (ncog), which takes into account variations in intensity within the gauge volume due to neutron attenuation and/or absence of material in the gauge volume. The average strain in the gauge volume was observed to be weighted towards the ncog position but following an increase in the size of the gauge volume the weighted average strain was changed because of the change in the ncog position when a strain gradient appeared within the gauge volume. On the other hand, typical pseudo-strains, which are well known, did appear in through-surface strain measurements when the gauge volume was incompletely filled by the sample. Tensile pseudo-strains due to the surface-effect increased near the sample surface and exhibited a similar trend regardless of the size of the gauge volume, while the pseudo-strains increased faster for the smaller gauge volume. Furthermore, a pseudo-strain due to a change in the ncog position was observed even when the gauge volume was perfectly filled in the sample, and it increased with an increase in the size of the gauge volume. These pseudo-strains measured were much larger than those simulated by the conventional modeling, whereas they were simulated by taking into account an incident neutron beam divergence additionally in the model. Therefore, the incident divergence of the incident neutron beam must be carefully designed to avoid pseudo-strains in time-of-flight neutron diffractometry. (c) 2013 Elsevier B.V. All rights reserved.

Web of Science ® 被引用回数 : 10

リンク情報
DOI
https://doi.org/10.1016/j.nima.2013.03.031
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000319252300004&DestApp=WOS_CPL
ID情報
  • DOI : 10.1016/j.nima.2013.03.031
  • ISSN : 0168-9002
  • eISSN : 1872-9576
  • Web of Science ID : WOS:000319252300004

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