CSR(cooling storage ring)按计划将于2005年底建成调束,届时从12C到238U的重离子将可以分别被加速到900和400MeV的能量.HIRFL(兰州重离子加速器Heavy Ion Research Facility in Lanzhou)将用作CSR的注入器.为了CSR的屏蔽设计,本文利用现有的实验数据计算了由于束流损失产生的中子及其能谱、角分布,同时也估算了屏蔽体外表面的中子剂量、环境中子剂量及天空返照中子剂量.在源项计算中使用了400MeV/u12C+Cu反应的中子产额、能谱、角分布的实验数据.计算表明,CSR对环境剂量影响最大的是天空返照中子.
The construction of CSR (cooling storage ring) which includes a main ring (CSRm) and an experimental ring (CSRe) will be finished at the end of 2005. Heavy ions of carbon to uranium will be accelerated up to 900MeV/u and 400MeV/u at intensity of 108 pps. The HIRFL (heavy ion research facility in Lanzhou)will be used as the injector. For the shielding design of CSR, the secondary neutrons due to the ion beam loss,their spectra and angular distributions were estimated based on the experimental results. The dose equivalent outside the shielding surface and in the surrounding environment and the neutron skyshine dose equivalent were also estimated in this study. The experimental result, neutron yield, spectrum and angular distribution for 400MeV/u 12C+Cu reaction were used for estimating the source term of shielding design. It is found that the most important environmental radiation impact component of CSR is the skyshine neutrons.