Multigroup cross-section library generation for deterministic electron-transport calculation

Compared with the continuous-energy Monte Carlo simulation, the multigroup deterministic electron-transport method offers improved computational efficiency with comparable accuracy, provided that the multigroup cross-section library is pre-generated. Unfortunately, the open-source ENDF mode in NJOY fails to produce accurate data. To this end, the reaction-processing models are improved for ionization and elastic scattering in the ENDF mode, replacing the original feed functions recovered from the Electron-Photon Interaction Cross Sections (EPICS) with the feed functions provided by differential cross-section formulas and empirical parameters from the EL03 database. The reliability of the improved ENDF mode was validated through tests involving homogeneous single-element problems, homogeneous compound problems, and a heterogeneous Self-Powered Neutron Detector (SPND) problem. The results demonstrate that the performance of the improved ENDF mode has been significantly enhanced, with the calculated total flux and flux distributions aligning closely with those from both the CEPXS-BFP code and the Monte Carlo code.