用于校准<sup>192</sup>Ir医用源的阱型电离室

用于校准¹⁹²Ir医用源的阱型电离室

摘要: 研制了一种用于校准医用¹⁹²Ir源的阱型电离室。该电离室的灵敏体积约为271 cm³，在极化电压约为300 V时，电离室的离子收集效率约为99.96%，总位置灵敏度变化小于0.3%。该阱型电离室对¹⁹²Ir的响应因子为0.230 nA/GBq，其相对合成不确定度为1.5%，与IAEA校准过的阱型电离室比对，在不确定度范围内一致。

Abstract: A welltype ionization chamber was developed for calibrating ¹⁹²Ir sources with high dose-rate. The chamber has a sensitive volume of about 271 cm³ with 99.96% efficiency of ions collection at 300 V chamber bias, and the variation of source move sensitivity is less than ±0.3% for source position. The chamber has a response of 0.230 nA/GBq with uncertainty of 1.5%. Comparing with a chamber calibrated by IAEA, the result is in agreement with each other.