球坐标系下中子输运方程泄漏项的简便推导

A Brief Method for Derivation of Streaming Term Expression for Neutron Transport Equation in Spherical Geometry Coordinate System

采用一种恰当的方法,简便地推导出中子输运方程泄漏项在球坐标系下的表达式,该方法避免直接寻求二面角与中子飞行距离之间的复杂微分关系,转而寻求二面角与其他平面角之间的几何关系,再利用其他平面角与中子飞行距离之间的微分关系(通常是已知的或比较容易推导得到),便可间接推导出中子输运方程泄漏项在球坐标系下的表达式。该方法与传统方法推导得到的表达式完全一致,且推导过程直观、物理图像清晰。

An ingenious method has been discussed to provide a brief way for the derivation of the streaming term expression in the spherical geometry coordinate system.Instead of finding the differential relationship between the dihedral angle and the neutron transport distance,finding the geometry relationship between the dihedral angle and other plane angles is much easier.And then the differential relationship(easy to be derived)between the other plane angles and the neutron transport distance can be used to derive the expression of the streaming term in the spherical geometry coordinate system indirectly but easily.This method makes the derivation process easy and intuitive,with clear physical picture.