The Study on Radiation Shielding of Neutrons and Phtons for Proton and Heavy-ion Accelerators with Energy up to 400 MeV.

这项研究旨在估算数百MeV能量的质子和重离子加速器的中子和光子辐射屏蔽。分析是通过使用大型计算机进行辐射传输计算完成的。(1)对各种材料的屏蔽性能进行了数值计算，得到了从热到几百MeV(400 MeV)的能量范围内各种材料的辐射传输性能。材料有铅、铁、重混凝土、混凝土、水、石墨、大理石、石蜡等，这些都是有效的高能中子和光子的屏蔽材料。中子和光子输运计算采用Sn型输运计算程序(一维：ANISN程序和二维：DOT3.5程序)。所用横截面为Alsmiller等人的横截面。研究结果对其他大型加速器的一般屏蔽设计具有一定的参考价值。(2)屏蔽性能评估方法在实际加速器装置中的应用该方法在实际的大型加速器装置上进行了应用尝试。在这里，我们采用了在质子和重离子束的真实条件下的日肯环回旋加速器(SSC)。对加速器室屏蔽厚度、天光效应的估算和束流抛射屏蔽组件的设计进行了讨论。计算方法也是Sn型输运计算程序。所得结果以图表的形式总结出来，可供其他大型蓄热室的屏蔽设计参考。(3)在高能加速器上进行了中子和光子剂量学基础实验和初步实验。

This research aims at the estimation of the neutron and photon radiation shielding at the proton and heavy ion accelerator with several hundred MeV energy. The analysis was done by radiation transport calculations using a large scale computer. The results in 1987 and 1988 are summarized as followings.(1) Estimation of shielding performance of various material by numerical calculation the radiation transmission performance for various materials were obtained by numerical solution at the energy region from thermal to several hundreds MeV (up to 400 MeV). The materials are lead, iron, heavy concrete, concrete, water, graphite, marble, paraffin etc. These were valid as a shielding material for high energy neutrons and photons. The neutron and photon transmission calculations were done by Sn type transport calculation codes (1-dimensional: ANISN code and 2-Dimensional: DOT3.5 code). The used cross sections were those of Alsmiller et al. The results are convenient for the general shielding design for other large accelerators. (2) Application of this shielding performance estimation method to the actual accelerator facility The application was attempted to an actual large-scale accelerator facility. Here we take up RIKEN Ring cyclotron (SSC) under the real condition of proton and heavy ion beam. The discussions were done for the shielding thickness of the accelerator room, the estimation of skyshine effect and the design of beam dump shielding assemblies. The calculational method was also Sn type transport calculational code. The obtained results were summarized as figures and tables for the usage of shielding design of other large scale accrelerator facilities. (3) Basic and preliminary test was done for dosimetry of neutrons and photons at the high energy accelerator.