Electron Transportation Simulation for Spacecraft Internal Charging Based on Reverse Monte Carlo Method

To make an estimation of the internal charging effect caused by the high energy electrons, a high-efficient 3-D transportation simulation code for satellite has been developed based on a reverse Monte Carlo (RMC) method implemented in Geant4. Charge production distribution, dose distribution in the sensitive volume has been simulated via forward Monte Carlo (FMC) and RMC, respectively, for the same geometry construction. Simulation results show that the computing time is significantly reduced in this RMC electron transportation simulation, especially when the sensitive volume is much smaller than the entire geometry. As an example, the computing time of RMC for a sensitive volume accounting for 0.0001% in the entire structure is only 1/500 of that of FMC. Difference of the results between RMC simulation and traditional Monte Carlo simulation is less than 10%.