用可见光双反射法测定热解石墨的各向异性因子  

Determination of anisotropy factor of graphite by visible light bireflectory method

作　　者：张纯[1] 李继红[1] 

机构地区：[1]清华大学核能技术设计研究院

出　　处：《清华大学学报（自然科学版）》1998年第7期15-17,共3页Journal of Tsinghua University(Science and Technology)

基　　金：国家"八六三"高技术项目

摘　　要：石墨广泛地用做核反应堆慢化材料、反射层材料和堆芯结构材料，在高温气冷堆中还用来做燃料元件。石墨材料的择优取向程度，对于它在反应堆中安全使用是一个重要的性能参数。有两种测定石墨择优取向程度的方法。一种方法是用Ｘ射线衍射技术测极图，得到培根各向异性因子ｆＢＡ；另一种方法是依据石墨晶体对可见光的双反射现象，得到表征石墨择优取向程度的另一参数——光学各向异性因子ｆＯＡ。本文描述了用Ｄ／ｍａｘ－３Ｂ型Ｘ射线衍射仪测定ｆＢＡ和用ＭＰＶ－２型显微镜光度计测定ｆＯＡ的实验过程，给出了测量结果，讨论了两种方法各自的优缺点。对于热解石墨样品，用所述测量方法得到的ｆＢＡ和ｆＯＡ是等同的。In nuclear reactors, graphite is used widely as moderators, reflectors, constructive materials of reactor core and fuel elements in high temperature gas cooled reactors. The degree of preferred orientation of graphite materials is an important property for its safety use in nuclear reactors. Two methods have been used to determine the graphite's degree of preferred orientation. One is determination of pole figure by Xray diffraction technology to obtain the Bacon anisotropy factor, fBA, the other is to determine the optical anisotropic factor, fOA according to the bireflectory phenomenon to visible light by graphite crystal. Two experimental procedures were described to determine the fBA by Xray diffractor model D/max3B and to determine the fOA by microscope photometer model MPV2. For the two methods, the measurement results were given and the advantages and disadvantages were discussed. It is concluded that the fBA and fOA obtained by the two methods for the pyrolytic graphite samples are identical.

关 键 词：石墨 各向异性因子 可见光双反射法 反应堆材料 

分 类 号：TL342[核科学技术—核技术及应用]