离散纵标S_N方法的几个问题及直接积分方法对两类穿透实验的计算

DISCUSSION ON CERTAIN PROBLEMS IN SN-METHODS AND CALCULATIONS FOR PENETRATION EXPERIMENTS WITH DIRECT INTEGRAL METHOD

本文用直接积分方法对离散纵标S_N方法在步长上的限制(?)∑(?)Δx/2<|μm|,纯吸收介质深穿透通量偏低等问题做了分析。从格式上说明了产生上述现象的原因及直接积分方法为什么能较好地解决深穿透问题,并且给出了两类14MeV中子穿透实验的计算结果:14MeV中子在^(232)Th,^(235)U,^(238)U和^(239)Pu脉冲球中的泄漏谱计算和14MeV中子在数种结构材料中的穿透率计算。

By using direct integral method,this paper analyses problems on restrietion for the spatial mesh Σ~tr△x//2<|μ_m| in discrete ordinate S_N-methods and problems on deep-penetration in pure absorption medium as well as shows why direct integral method can meet the deep-penetration problems. The results from computing two kinds of penetration experiments are also glven-the neutron spectra from ^(232), ^(235), ^(238), and ^(239)Pu after bombardment with 14-MeV neutrons and the penetration rate of 14-MeV neutrons in various structural material.