60Coγ射线辐照装置辐照场的剂量测量与分析

Dose measurement and analysing of radiation field of 60Coγ irradiation device

为使60Coγ射线辐照装置正常运行,对剂量测量系统进行了校准,对60Coγ射线辐照装置辐照场的剂量进行了检测,对辐照产品进行了剂量跟踪。结果表明,自制的低量程重铬酸银剂量计在3年中本底值标准偏差<0.3%,具有较好的稳定性;NDAS比对的测量偏差在±3%以内,与中国计量科学研究院的测量结果一致;放射源3层排列时垂直方向剂量不均匀度为1.12,呈均匀分布,水平方向剂量率分布表现为离源板越近剂量率越高,剂量率下降越快,离源板越远剂量率越低,剂量率下降越慢,呈非均匀分布。骨炎灵颗粒产品箱内吸收剂量分布为两端高中间低,不均匀度为1.38。产品箱中最低剂量点剂量为每流程1.00 kGy,这个剂量值是产品辐照剂量控制的关键参数。

In order to make the 60Co gamma irradiation device run normally,the dosimetry system was calibrated,the dose of the irradiation field of the gamma irradiation device was measured,and the dose tracking of the irradiated products was carried out.The results show that the standard deviation of background value of low range silver dichromate dosimeter is less than 0.3%in 3 years,and the measurement deviation of NDAS ratio is within±3%,which is consistent with the measurement results of national metrology institute.When the three layers of radioactive sources are arranged,the dose inhomogeneity is 1.12 in the vertical direction,which is uniform distribution.The horizontal dose rate distribution shows that The closer it get to the source plate,the higher the dose rate is,the faster the dose rate decreases;The farther away from the source plate,the lower the dose rate is,the slower the dose rate decreased.and which is non-uniform distribution.The absorbed dose distribution in the box of Guyanling granule was high at both ends and low in the middle,and the inhomogeneity was 1.38.The minimum dose point dose in the product box is 1.00 kGy,which is the key parameter of product irradiation dose controlhas.