球谐函数有限元程序NECP-FISH的开发及其在聚变堆包层中子学分析中的应用

The spherical harmonic finite element method is used to solve the neutron transport equation with unstructured meshes, which has the ability to deal with complex geometry and can avoid the ray effect caused by discrete ordinate method. The spherical harmonic multi-scale finite element method was derived from the weak form of the first-order transport equation. A neutronics analysis code NECP-FISH was developed based on the derived method. Through the developed interface program in SALOME, the visual modeling and results visualization were realized. Finally, this program was used to calculate helium cooled ceramic blanket. The neutron flux density, tritium breeding ratio (TBR) and nuclear heating calculated by NECP-FISH are in good agreement with those of Monte Carlo code NECP-MCX. The relative deviation of TBR is 0.56% and the nuclear heating deviations of all regions are less than 6%.