3 MeV电子辐照加速器通风管道辐射场计算  

Radiation field calculation of ventilation duct for 3-MeV electron irradiation accelerator

作　　者：阎明洋[1] 陈志[1] 王遥[1] 李裕熊[2] 於国兵 顾先宝 

机构地区：[1]中国科学技术大学核科学技术学院,合肥230027 [2]中国科学技术大学国家同步辐射实验室,合肥230029 [3]安徽省辐射环境监测站,合肥230071

出　　处：《核技术》2013年第8期31-36,共6页Nuclear Techniques

基　　金：国家自然科学基金资助项目(NSFC11375182);中央高校基本科研业务费专项资金(WK2140000004)资助

摘　　要：工业辐照加速器运行过程中产生臭氧,需在辐照室内设置通风管道。由于辐照室内的光子会进入通风管道内,从而带来辐射剂量。为定量评估管道出口处的辐射场,本文利用蒙特卡罗程序MCNP模拟计算了管道出口处的剂量率。结果表明,管道口的开设位置、管道内反散射界面的数量对出口处的剂量率影响显著,靶正下方的剂量率高出辐照室拐角处的剂量率约两个数量级,每增加一个反散射界面,出口剂量率衰减约3个数量级。得出管道的设置方案,方案中的长度和深度已优化配比。在靶下方开设多曲折型管道,管道的长度应满足约3 m,深度约80 cm,在辐照室拐角处开设U型管道,管道的长度应满足约6 m,深度约1 m。Background： Ozone will be produced when the accelerator runs. Because ozone can cause corrosive damage to metal, ventilation duct has to be set in the irradiation room to discharge ozone. Purpose： Photons go into the ventilation duct, and then produce additional radiation. To do the quantitative assessment of radiation field at the outlet of duct, the simulate calculation of radiation doses at the outlet has been done. Methods： The Monte Carlo code of MCNP can analog the electronic and photon transport, so that using MCNP can solve the problem. Results： The result shows that the location and the number of backscattered interface of duct significantly affect the dosage rate while the size of duct doesn＇t. Increasing a backscatter interface can lower dosage rate attenuation about three orders of magnitude. The dosage rate under the target is two orders of magnitude than that in the comer. The setting project of duct is drawn and the ratio of length and depth has been optimized. The duct should be about 3-m long and 80-cm deep when the multi-tortuous duct is placed under the target, and U-shaped duct should be about 6-m long and 1-m deep when it is set at the comer of irradiation room. Conclusions： In order to reduce dosage rates and economic costs, the shape of duct and the location of duct are designed critically. And according to the actual situation, the project is flexible.

关 键 词：辐射场 臭氧 通风管道 MCNP 

分 类 号：TL508[核科学技术—核技术及应用]