中子慢化积分方程的数值解

本文对同心环几何条件,用Lobatto求积公式近似求解了中子慢化积分方程,得到了比较精确的超热能谱,并由此算出了共振积分。用逐步递推方法计算慢化源,用予制的P_ij表内插求首次碰撞几率,大量节省了机器时间。同时,本文用多能级公式计算²³⁵U、²³⁹Pu核的共振截面,从而使共振峰间的重叠和干涉也得到了考虑。用文献提供的模型做了校核计算,取得比较满意的结果。

THE NUMARICAL SOLUTON OF NEUTRON MODERATING LNTEGRAL EQUATION

For multi-region co-centre cylinder cell the numaricll solution of neutron moderating integral equation is a approximate solution using Lobatto quatrature formula. It can get more accurate epithermal energy spectrum, therefore resonance integral, group cross-section and self-shielding factor of resonance as well.Using the method of step by step recurrece to calculate moderating souece and the premade table of P_ij to interpolate collision probability, a great deal of computing time could be saved. In this paper resonance cross-section for ²³⁵U, ²³⁹Pu were calculated using multi-level formula so as to consider interference and overlap ping effect between resonances.A check calculation has been made based on the model provided by Ref.^7]and the both results agree well eath other.