A simulation of deep dielectric charging induced by dielectric temperature and energetic electrons

In this paper, a computer numerical simulation of one-dimensional deep dielectric charging (DDC) of spacecrafts induced by temperature and energetic electrons has been developed. It provides a method for spacecraft engineers to analyze the phenomena of DDC in spacecrafts and then to predict whether or when electrostatic discharging (ESD) will occur. The simulation code is developed to analyze the influence of different magnitude of dielectric temperature and energetic electrons flux on deep dielectric charging/discharging occurrence. In the simulation, we find that there exists an ESD inception energetic electron flux threshold. The flux threshold decreases with the decrease of dielectric temperature. It is interesting that there exists a critical dielectric temperature (250 K for low-density polyethylene) in the DDC process. Below the critical temperature or above that, respectively, the energetic electron flux and the dielectric temperature are the dominated influencing factors in the DDC process. Then, considering the DDC electric field and the charging time, we present a rough prediction of discharging occurrence probability with varied flux of energetic electrons and dielectric temperature.