COMSOL法模拟测氚电离室静电场  

Electric Field Simulation of Ionization Chamber Used in Tritium Measurement in Tail Gas of Molten Salt Reactor

作　　者：钱楠[1] 王广华[1] 黄豫[1] 曾友石[1] 包广粮[1] 吴胜伟[1] 刘卫[1] QIAN Nan;WANG Guang-hua;HUANG Yu;ZENG You-shi;BAO Guang-liang;WU Sheng-wei;LIU Wei(Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Jiading Campus,Shanghai 201800,China)

机构地区：[1]中国科学院上海应用物理研究所,上海200180

出　　处：《核电子学与探测技术》2018年第1期11-15,共5页Nuclear Electronics & Detection Technology

基　　金：中国科学院战略性先导科技专项(XDA02050100)资助

摘　　要：使用COMSOL软件对电离室内部电场进行仿真,分别模拟高压丝根数为3、6、12、18、24、30、36、42、48根时电离室内部静电场。静电场靠近收集极处等势线呈圆形,靠近高压丝处等势线呈波浪分布。选取半高处与等势线同直径圆环上各点电势为评价标准。当该线上偏差最大的电压与标准值越接近,可认为丝壁式高压极与圆柱形高压极所形成电场一致性越高。从结果可知,最优高压丝根数为30根,两个电场的差距在5%以内。之后,在电场内随机布置自由电子,模拟电离产生的离子对。通过模拟估算出收集极收集效率。通过模拟可知增加顶部及底部高压极丝后收集效率没有明显改变。将电离室外壳改为绝缘材料后,收集效率明显改善,当高压极达到30根时,收集效率达到最大值97%。In this study, the electric field of ionization with different numbers of high voltage wires, such as 3, 6, 12, 18, 24, 30, 36, 42, 48, were simulated by COMSOL software. The equipotential line of electric field near the collector is round. The equipotential line of electric field near the high volte wires present as undulate. The voltage on the circle which height was half tall and the radius was 13 cm were set as standard. When the maximum deviation of the voltage on the line was closed to the standard value, the electric field formed by the wire and the cylindrical pole could be considered as the same. From the results, the optimum number of wires is 30. The difference of electric field between two types chambers were less than 5%. After that, collection efficiency was simulated as well. Increasing the number of the high voltage electrode at top and bottom of effective area could not improve the electron collection efficiency. Making the ionization chamber shell as an insulator can effectively improve the electrons collection efficiency. When the number of high voltage electrodes reached 30, the collection efficiency reached 97%.

关 键 词：氚测量 电离室 静电场 

分 类 号：TB98[一般工业技术—计量学]