Space Charge Accumulation in Polytetrafluoroethylene at Different Temperatures

Summary

A satellite operates in a harsh environment including high vacuum, thermal cycle, and radiations. The temperature of the insulator is influenced by the satellite position in the orbit, and would vary in a wide range, such as from -100 oC to 100 oC. Consequently, the surface or internal charging and discharging behaviour of insulator would be very different during the operation of a satellite. This paper investigates the space charge accumulation properties in polytetrafluoroethylene (PTFE) at different temperatures at high electric fields by a bipolar charge transport (BCT) model. The BCT model consists of carrier transfers at the interfaces between electrodes and insulating materials, carrier conductions at shallow traps, charge trapping-detrapping and charge recombination processes. The carriers' injection at the electrode-material interface complies with the Schottky Law. The shallow trap controlled mobility is assumed a constant, and just one deep trap level is set for the charge trapping-detrapping process. The non-linear charge continuity equation, charge trapping-detrapping recombination dynamic equations, and Poisson's equation are solved numerically to simulate the space charge accumulation processes in PTFE. The BCT simulations are carried out in the temperature range from -100 oC to 100 oC. The charge transport and space charge accumulation properties are obtained at different temperatures and different electric fields. The results show that the temperature can significantly affect the charge accumulation and thus the electric field in the material.

Additional informations

Authors

Kim Yu Mim, Liu Mengjia, Heo Jeong Hyeok, Dragomir, Park Jung Hong, Kim Joon Yeon