β射线吸收剂量参考辐射场测量研究  

Measurement Research of Reference Radiation Field for Absorbed Dose of βRay

作　　者：王红玉[1] 刘川凤 杭仲斌 侯金兵[1] 魏可新[1] 宋明哲[1] WANG Hongyu;LIU Chuanfeng;HANG Zhongbin;HOU Jinbing;WEI Kexin;SONG Mingzhe(China Institute of Atomic Energy,Beijing 102413,China;East China University of Technology,Nanchang 330013,China)

机构地区：[1]中国原子能科学研究院,北京102413 [2]东华理工大学,江西南昌330013

出　　处：《原子能科学技术》2021年第10期1870-1878,共9页Atomic Energy Science and Technology

摘　　要：β射线对于人体皮肤的浅表剂量的监测是外照射个人剂量监测的重要部分。为研究建立β辐射剂量国防计量最高标准,依照ISO 6980国际标准,对名义活度分别为3.7 GBq的^(147) Pm、460 MBq的^(90) Sr+^(90) Y和3.7 GBq的^(85) Kr 3种放射源的辐射场特性进行研究。实验得到^(147) Pm、^(90) Sr+^(90) Y和^(85) Kr放射源分别在20、30、30 cm带展平过滤时的剩余最大能量为0.16、2.00、0.58 MeV。β污染、光子污染及辐射场均匀性在规定值的±5%以内,均满足ISO 6980标准要求。利用外推电离室对测量点处带展平过滤的皮肤组织等效材料的吸收剂量率进行测量,对涉及到的电离室有效面积及入射窗引起的散射和衰减等修正因子进行了详细的计算,测量得到^(147) Pm、^(90) Sr+^(90) Y和^(85) Kr分别在距源20、30、30 cm处的吸收剂量率分别为8.352、39.24、154.08 mGy/h,并与出厂证书给出的剂量值进行对比,最大相差0.52%,在可接受范围内。The personal superficial absorbed dose measurement is an important component of personal dose monitoring for external exposure.In order to establish the absorbed dose standard ofβradiation dose,the characters of the radiation fields of the sources of ^(147) Pm with nominal activity of 3.7 GBq,^(90) Sr+^(90) Y with nominal activity of 460 MBq and ^(85) Kr with nominal activity of 3.7 GBq were researched.The residual maximum energy of ^(147) Pm,^(90) Sr+^(90) Y and ^(85) Kr separately was 0.16,2.00 and 0.58 MeV with the corresponding beam-flattening filters.βparticle contamination,photon contamination and uniformity of the dose rate were both within±5%of the specified value in ISO 6980,which all meet the requirements of ISO 6980.The absorbed dose rate of the tissue equivalent material of the measurement point was measured by extrapolation chamber.The area of the ionization and the correction for the attenuation and scattering of the enter window and other correction factors were calculated detailedly.The absorbed doses of the source of ^(147) Pm,^(90) Sr+^(90) Y and ^(85) Kr at the measurement point 20,30 and 30 cm away from the source separately are 8.325,39.24 and 154.08 mGy/h,respectively,which is close to the value offered by the factory.

关 键 词：Β射线 吸收剂量 外推电离室 

分 类 号：TL84[核科学技术—核技术及应用] TB98[一般工业技术—计量学]