小波尺度函数展开在连续能量中子输运方程计算中的应用

小波展开能够很好地拟合剧烈变化的函数,近年来已被应用于模拟中子角注量率随角度剧烈变化的问题,并取得了令人满意的结果.中子能谱在共振区具有剧烈震荡的特性,本文介绍了利用能群与小波尺度函数展开相耦合来离散连续能量中子输运方程中能量自变量的方法.对中子注量率在共振区关于能量用小波尺度函数进行拟合,而在快中子区和热中子区利用分群计算的方法.初步的数值结果表明,该方法使有效增殖系数计算精确,并能够得到中子注量率在共振区随能量的精细分布,对共振自屏蔽的精确计算具有重要意义.

Application of Wavelets Scaling Function Expansion to Continuous-Energy Neutron Transport Calculation

Wavelets expansion method can simulate the functions oscillating violently. It has been applied to simulate the violently variety of the angular flux, and has obtained satisfactory results. Neutron spectrum has violent oscillations within the resonant energy range. This paper introduces a method to discretize the energy variable of neutron transport equation by coupling the multi-group method and wavelets expansion method, which simulates the energy-dependent angular flux with wavelets scaling function within the resonant energy range and uses multi-group method within fast and thermal neutron energy ranges. The preliminary calculation results indicate that this method can obtain the accurate k-inf, as well as determine the fine-structure energy distribution of the angular flux, which is significant to resonance self-shielding calculation.