HIAF高能辐照终端感生放射性

Induced Radioactivity at High-energy Irradiation Terminal of HIAF

本工作是基于蒙特卡罗模拟软件FLUKA对高能强流重离子加速器(HIAF)高能辐照终端感生放射性进行初步研究。该终端可运行质子最高能量为9.3 Ge V,最大流强是1.45×10^(12)pps(particle per second)。研究内容包括:(1)预测高能辐照终端内活化物质的放射性活度特性;(2)预测不同冷却时间高能辐照终端内残余剂量率分布。研究结果表明,HIAF正常运行时高能辐照终端内的感生放射性主要受束流垃圾桶活化产生的放射性核素影响。当加速器连续运行100天冷却4小时,垃圾桶表面残余剂量率为2.375 m Sv·h^(-1)。终端内空气中^(13)N和^(15)O动态饱和比浓度大于其对应的导出空气浓度。冷却水中^(13)N和^(15)O的活度大于对应的ALImin。该研究是HIAF辐射防护基础研究以及加速器环境影响评价的一项重要内容。

The Monte Carlo code FLUKA was used to predict the induced radioactivity of high-energy irradiation terminal of HIAF. The maximum energy of proton is 9.3 Ge V, and the maximum current is 1.45×1012 pps（particle per second）. In this study we were to predict：（1） the activity properties of activated substances in the experimental terminal;（2） the residual dose rate distribution in the experimental terminal at different cooling time. The results indicate that the induced radioactivity in the high energy irradiation terminal of the HIAF is mainly affected by the radionuclide induced in the beam dump. The residual dose rate on the surface of the beam dump is 2.375 m Sv·h^（-1）, after 100 d irradiation and 4 h cooling. The dynamic saturation ratio of 13N and 15O induced in the air inside the terminal is higher than its corresponding derived air concentration. The activity of13N and15O induced in cooling water is higher than its ALImin. This study is a part of radiation protection basic research and environmental impact assessment for HIAF.