Effects of Spatial Harmonics on Thermal Neutron Spectra Measured by Time-of-Flight Method.

書誌事項

タイトル別名
  • Effects of Spatial Harmonics on Thermal

この論文をさがす

抄録

<BR>Spatial effect-the variations in space of transient neutron flux noted in pulsed neutron experiments, and which is ascribable to the occurrence in moderator of spatial harmonicss studied on the measured flight time spectra of neutrons reentering the atmosphere from parametrically varied depths of a graphite moderator. Measurements were made using moderator slabs of two different axial lengths, to examine the influence of differences in moderator size on the spatial effect. The master equation representing the scalar neutron flux as function of time and energy is solved by a semi-analytic method that takes account of spatial harmonics. Simulation of the solution thus obtained of the master equation proved to reproduce the measured flight time spectra with good accuracy. It was indicated that the spatial effect on the thermal neutron spectrum is stronger with a larger than with a smaller moderator slab. The neutron temperature in graphite moderator was calculated by formula fitted in Maxwellian distribution to the peaks of the thermal neutron spectra. It was indicated that in a graphite moderator of 120cm axial length, spatial harmonics caused a variation of more than 40K in neutron temperature between depths in moderator differing by 30cm.

収録刊行物

被引用文献 (1)*注記

もっと見る

参考文献 (11)*注記

もっと見る

詳細情報 詳細情報について

問題の指摘

ページトップへ