Mo靶X射线空气比释动能及校准因子测量

摘要

With the low-energy primary standard parallel free-air ionization chamber estimating the rate of air kerma from the molybdenum target at the point of 600 mm away from the X-ray tube,ionization current was measured by absolute measurement method,the air kerma rate of the mammography radiation quality from 25 kV to 35 kV can be calculated with the corrction factors.The calibration factor can be eatimated by the tranfer chamber RC6M at the same point,which the maxmium difference compared with the value of BIPM of 0.13%,meeting the requirement of uncertainty.%使用低能X射线自由空气基准电离室对乳腺Mo靶X射线场的空气比释动能进行量值复现,利用绝对测量方法测得电离电流值,结合相关修正因子计算得到该辐射场中600 mm处四个辐射质的空气比释动能值;在同一点处使用传递电离室RC6M进行测量,得到该电离室的刻度因子,与BIPM所测得的刻度因子相差最大为0.13%,在不确定度范围内相符.