Study on Transport Properties of Charged Particles in Plasmas Based on GEANT4 and the Modified LP Theory

Abstract: For controlled nuclear fusion, it is of significance to develop a comprehensive simulation environment for Inertial Confinement Fusion(ICF) . This environment must accurately calculate the energy loss of charged particles in high-temperature, high-density plasma, and simulate the physical parameters of fusion reactions and products. This study presents a novel implementation of a modified Li-Petrasso (MLP) energy loss theory within the Geant4 framework, to address the critical challenge of simulating charged particle transport in high-temperature, high-density plasma for ICF research. The modified theory integrates binary collision terms, collective plasma effects, and quantum degeneracy corrections, enabling accurate calculations of stopping power, mean collision path, and energy transfer dynamics for particles such as recoil alpha particles, deuterons, and tritons under extreme plasma conditions. This work provides a detailed introduction to how to embed and calculate this process within Geant4 and verifies the correctness of the embedded model. Full simulation of the fusion process is also conducted. The results demonstrate that the improved Geant4 can effectively handle the energy loss of charged particles in such environments, calculate important fusion parameters like neutron energy spectrum and energy transfer ratios, and observe the production of ultra-high-energy neutrons. Comparisons with experimental fusion data show significant improvements in consistency, validating the improved Geant4's validity and accuracy. This work has, for the first time, achieved full simulation of charged particle energy loss and secondary neutron spectrum of ICF using Geant4, providing valuable insights into ICF characteristics and aiding in the development of more accurate fusion simulations.