医用加速器治疗室防护门辐射屏蔽厚度两种核算方法的探讨  

Study on the Radiation Shielding Calculation of Therapeutic Room Door of Medical Accelerator by Two Methods

作　　者：赵新春[1] 周艳[1] 陈掌凡[1] 张会敏[1] 谢萍[1] 苏旭[2] 

机构地区：[1]广西壮族自治区疾病预防控制中心,广西南宁530028 [2]中国疾病预防控制中心辐射防护与核安全医学所

出　　处：《中国辐射卫生》2014年第1期14-16,19,共4页Chinese Journal of Radiological Health

基　　金：卫生行业科研专项资助项目(201002009)

摘　　要：目的寻求简易可靠的方法优化核算医用加速器机房防护门口处辐射屏蔽的厚度。方法采用简易法和IAEA 47号报告对某15 MV医用加速器机房门的屏蔽厚度进行核算。结果按照国家标准规定的剂量限值,采用IAEA 47报告核算机房门屏蔽厚度,对于标称能量≥10 MV的加速器,γ射线与散漏射线的总屏蔽厚度值都要大于简易法的核算值,中子屏蔽厚度值不一定要大;对于标称能量<10 MV的加速器(不需屏蔽中子),IAEA 47报告核算的屏蔽厚度值不一定要大。结论 IAEA 47报告计算繁琐复杂,所需利用的参数和需利用难以准确的数据较多,计算繁冗容易出现纰漏。因此,我们选取两种方法核算,选取较大值进行设计,在随后加速器工作场所防护验收检测中,辐射屏蔽都可行,符合国家标准的要求。Objective To seek simple and reliable optimization calculation method for the radiation shielding thickness of the therapeutic room door of medical accelerator. Methods To calculate radiation shielding thickness of the therapeutic room door of a 15 MV medical accelerator by using simple method and the IAEA Safety Report Series No. 47 method. Results Ac- cording to the national standard dose limit, Using IAEA 47 report accounting machine door shield thickness for nominal energy ≥ 10 MV accelerator,the total shielding thickness of Gamma ray and leak radiation is greater than that obtained by simple method, but the neuron shielding thickness value is not always greater. For nominal energy 〈 10 MV accelerator （ No shielding neutron） ,the neuron shielding thickness value is not always greater than that obtained by simple method. Conclusion Be- cause of the complex calculation, many parameters and data （ not always accurate） are used ; the calculation is easy to make booboo. Thus, we use two methods to calculate and select a greater value of them to design. The results show that the radiation shielding is feasible to meet the requirements of national standard in the subsequent accelerator workplace protection accept- ance testing.

关 键 词：医用加速器 辐射剂量 辐射防护 辐射屏蔽厚度 

分 类 号：R144[医药卫生—公共卫生与预防医学]