A Simple Relation for Effective Neutron Temperature in Cold Moderators with Lattice Vibrational Modes
スポンサーリンク
概要
- 論文の詳細を見る
The effective neutron temperature in cold hydrogenous solid moderators is analyzed in phonon approximation with use made of two simple models representing the frequency distribution of lattice vibrations, and simple relations are derived between the variation of the effective neutron temperature and the moderator temperature, as also, an equation expressing the limiting neutron temperature in a moderator at absolute zero temperature.Good agreement is obtained between the calculated and experimental results in cold light water ice. It is indicated that unbounded cooling of the moderator is not necessarily effective in improving the moderating efficacy, in the case of slowing-down by lattice vibrations; it generally suffices to cool the moderator down to the limiting neutron temperature.It is revealed that approach of the neutron temperature to the limiting value is largely determined by the shape of the frequency distribution of the lattices, while the limiting value itself is influenced by such parameters as the Debye temperature, the molecular mass and the ratio of absorption to the scattering cross section in the moderator. As a result of the present analysis, a general method for comparing and evaluating various solid moderators for cold neutrons has been established for practical use.
論文 | ランダム
- 書評 今野日出晴著『歴史学と歴史教育の構図』
- 歴史のひろば 沖縄戦「集団自決」の検定をめぐって--教科書執筆者の立場から
- 歴史のひろば 日韓の歴史認識の違いを越えて--『向かいあう日本と韓国・朝鮮の歴史--前近代編』出版の意義
- 生涯学習のなかの大学教育の意義 (大学は,いま)
- 原始・古代(第1巻・第2巻) (歴史学研究会・日本史研究会編「講座日本歴史」は通史たりうるか)