论文部分内容阅读
漏电流是影响小型电离室测量照射量或吸收剂量精确度的重要因素。因此,应用小型电离室时,照射场的照射量率或吸收剂量率必须足够大,以使漏电流的影响可以忽略。但是,在慢性照射的生物效应实验中,照射场的照射量率或动物体(或模体)内吸收剂量率很小,致使漏电流在测量中所占比例相当大,如果不进行校正,可能使测量结果产生较大的系统误差。笔者结合低剂量率吸收剂量测量实验,研究了治疗级0.6cm~3小型电离室用于低剂量率测量时漏电流的校正问题,并将校正后的吸收剂量与使用超薄型热释光剂量计(TLD)测量结果作了比较。
Leakage current is an important factor that affects the accuracy of a small ionization chamber to measure the amount of radiation or absorbed dose. Therefore, when a small ionization chamber is used, the irradiation dose rate or the dose rate at the irradiation field must be sufficiently large so that the influence of the leakage current can be neglected. However, in experiments of biological effects of chronic irradiation, the radiation dose rate at the irradiation field or the dose rate absorbed in the animal body (or the phantom) is so small that the leakage current is quite large in the measurement and if not corrected The measurement results have a greater systematic error. Combined with low dose rate absorbed dose measurement experiments, the author studied the correction of leakage current when the treatment level 0.6cm ~ 3 small ionization chamber was used for low dose rate measurement, and compared the corrected absorbed dose with the use of ultra-thin thermoluminescence dose TLD measurements were compared.