Fast Measurement of Dielectric Conductivity for Space Application by Surface Potential Decay Method
Rong-Hui Quan1**, Kai Zhou1, Mei-Hua Fang1, Wei-Ying Chi2, Zhen-Long Zhang3
1College of Aeronautics and Astronautics, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 2Shanghai Institute of Space Power Sources, Shanghai 200040 3National Space Science Center, Chinese Academy of Sciences, Beijing 100190
Abstract：Surface potential decay of polymers for electrical insulation can help to determine the dark conductivity for spacecraft charging analysis. Due to the existence of radiation-induced conductivity, it decays fast in the first few hours after irradiation and exponentially slowly for the remaining time. The measurement of dark conductivity with this method usually takes the slow part and needs a couple of days. Integrating the Fowler formula into the deep dielectric charging equations, we obtain a new expression for the fast decay part. The experimental data of different materials, dose rates and temperatures are fitted by the new expression. Both the dark conductivity and the radiation-induced conductivity are derived and compared with other methods. The result shows a good estimation of dark conductivity and radiation-induced conductivity in high-resistivity polymers, which enables a fast measurement of dielectric conductivity within about 600 min after irradiation.
2017, Vol. 34 
