【摘要】 针对后装治疗用¹⁹²Ir放射源的参考空气比释动能率的量值急需进行溯源。参考国际通例,由指型电离室（PTW-30013）在⁶⁰Coγ射线和250 k V X射线下的空气比释动能校准因子推导得出¹⁹²Irγ射线的空气比释动能校准因子,从而测定¹⁹²Ir放射源参考空气比释动能率标准值,进而完成对井型电离室的参考空气比释动能率校准。通过不确定度评定得出:¹⁹²Ir放射源的参考空气比释动能率的不确定度为3.6%,井型电离室校准因子的不确定度为3.8%。更多还原

【Abstract】 There is an urgent need for traceability of the reference air kerma rate for the¹⁹²Ir source for high-dose-rate after-loading. Referring to the international general practice,the calibration factor of the¹⁹²Ir gamma ray is derived from the calibration factor of air kerma of finger ionization chamber under⁶⁰Co gamma ray and 250 k V X-ray,so as to determine the standard value of the¹⁹²Ir gamma ray reference air kerma rate,and then the calibration of reference air kerma rate of well type ionization chamber is completed. The results show that the uncertainty of the¹⁹²Ir gamma ray reference air kerma rate is 3. 6%,and that of calibration factor of well type ionization chamber is 3. 8%.更多还原