Technique of Dynamical Observation of Atomic Scale Structural Change and Initial Stage of Neutron Radiaton Damage

本文仅对中子辐照作一简要介绍：参考RTNS-Ⅱ聚变中子辐照的结果，用裂变反应堆JMTR进行控制辐照已取得稳步进展。特别强调的是，在名古屋大学高压电子显微镜实验室建立了辐射危害控制区，首次成功地对中子辐照样品进行了电子辐照。由碰撞级联产生的非常小的点缺陷团簇的性质被可靠地从它们在电子辐照下的行为中确定。本论文研究了不同材料中中子辐照缺陷的退火行为，以了解级联中团簇的形成机制以及中子辐照过程中温度变化的影响。(1)小间隙原子团簇的一维易运动被认为是中子辐照诱导位错结构的晶体学取向依赖性的原因。(2)通过对小缺陷团簇生长和收缩过程的观察和分析，推断出点缺陷反应的随机涨落，使我们认识到碰撞级联形成的胚体生长间隙团簇的成功概率很小。(3)利用局域电子辐照实验检测了金属原子的一维运动;（4）发展了间歇电子辐照技术，测量了缺陷的基本参数。

Only the brief description is made on neutron irradiation : a steady progress has been made with controlled irradiation with the fission reactor JMTR,referred to the results of fusion neutron irradiaton with RTNS-II.Specially emphasized is the first success of the electron irradiation of neutron irradiated samples, by establishing radiation harzard control area in the High Voltage Electron Microscopy Laboratory of Nagoya University. The nature of very small point defect clusters produced by collision cascades was identified reliably from their behavior under electron irradiation. Annealing behavior of neutron irradiation induced defects in various materials was pursued to understand both the formation mechanism of the clusters from cascades and the effect of temperature variation during eutron irradiaton.The other dynamical observation of various defect behavior under high energy electron irradiation disclose the followings. (1) One dimensional easy motion of small interstitial clusters was found to be responsible for the crystallographic orientation dependence of neutron-irradiation-induced dislocation structures. (2) Stochastic fluctuation of point defect reactions deduced from the observation and analysis of the growth and shrinkage of small point defect clusters made us to understand the very small success probability of the growth of interstitial clusers from the embryo made by collision cascades. (3) One dimensional motion of interstital atoms was detected by localized electron irradiation experiment, and (4) fundamental defect parameters were measured by the development of intermittent electron irradiation technique.