自制球形空腔电离室的性能测试

摘要

为建立和完善250～600 kV段X射线空气比释动能基准,自主研制了一系列石墨空腔电离室作为基准电离室,以球形空腔电离室为例,在参考辐射场上对其性能进行了相关测试,包括电离室的饱和特性、重复性以及漏电情况.结果显示电离室的工作电压为600V,重复性好于0.1％,漏电流值小于30fA,本套电离室的性能符合相关要求.%A series of graphite ionization chambers are devebped to establish the X-ray air kerma standard,whose voltage are between 250 kV and 600 kV.The spberical one is set as an example and several tests are made on the reference radiation field,including saturation,repeatability and leakage current effect.The results show that the operating voltage is 600 kV,the repeatability is under 0.1％ and the leakage current is under 30 fA.So the self-made spherical graphite ionization chamber fulfils the design demands.