10MeV辐照型电子直线加速器迷道出口处的设计优化  

Optimizing design for the maze exit of a 10-MeV electron irradiation accelerator

作　　者：段宗锦 陈裕凯 任广益 何丽娟[1,2] 李裕熊[1,2] 陈志[1,2] 

机构地区：[1]中国科学技术大学国家同步辐射实验室,合肥230029 [2]中国科学技术大学核科学技术学院,合肥230027

出　　处：《核技术》2013年第11期13-17,共5页Nuclear Techniques

基　　金：国家自然科学基金项目(NFSC11375182)资助

摘　　要：辐照型电子直线加速器的应用已经越来越广泛,但是其辐射屏蔽优化一直是需要解决的问题,所以设计出既经济又有效的屏蔽方法是非常有意义的。本文叙述了对一台10 MeV的辐照型电子直线加速器迷道出口的剂量率所进行的经验公式计算和蒙特卡罗(Monte Carlo,Fluka)模拟,结合伽马探测器和微型数据采集器Mini-DDL(Mini Digital Data Logging)的连续实时测量结果进行了对比分析。分析结果显示,只要在迷道门处增加一个拐弯,就增加一次反散射,出口处的剂量率会下降一个量级以上,使其不仅低于剂量限值而且合理地达到尽可能低。这个结果是在基本没有增加额外成本的基础上实现的,符合辐射防护ALARA(as low as reasonably achievable)原则,为以后加速器的屏蔽设计提供了很好的参考。Abstract Background： Irradiation accelerator is being used more and more widely, but the optimizing of radiation shielding is always a problem to be solved. Purpose： To make the dose rates of the maze exit lower and the cost to achieve it less, it is of great significance to design a shielding which is cheap and effective. Methods： The radiation dose rates at different maze exits of a 10-MeV industrial electron linear accelerator were compared by formula and Monte Carlo （Fluka） method. A real-time measurement system composed of Mini Digital Data Logging （Mini-DDL） and Gamma detectors was also used. Results： With one corner added to the exit, another scattering would be generated. The dose rate of exit before changing was 3-4 gGy＇h-l while it was 200 nGy＇h-1 after that. Conclusion： The radiation dose rate at the exit will be reduced by one order of magnitude because of another scattering generated by the added turn to the maze exit. All of these do not increase any additional cost and conform to the ALARA （as low as reasonably achievable） principle. It provides a good reference for the future design of shielding for industrial electron linear accelerator.

关 键 词：辐照加速器 屏蔽优化 迷道出口 反散射 成本 Mini—DDL(Mini Digital Data Logging) 

分 类 号：TL508[核科学技术—核技术及应用]