Effect of low temperature on threshold voltage for solar panel ESD ground tests

Solar panel failure is putatively caused by electrostatic charge and discharge. An investigation of its causes and efforts to determine measures for the future require both verification under as realistic a space environment as possible and enhanced ground tests. A plasma chamber was developed at the Tsukuba Space Center to carry out charge/discharge tests to verify low-Earth-orbit satellites solar panel durability against electrostatic discharge (ESD). This paper describes results of solar panel ESD tests at extremely low temperatures. The primary arc inception threshold voltages at 160 K and 230 K were similar at room temperature. In contrast, the rate of primary arc inception of 230 K was five times and the rate of primary arc inception of 160 K was ten times as much as that at 300 K at applied voltage 200 V. We also measured the capacitance C and dielectric constant epsiv_tau of the cover glass, which shows high resistivity and which is fairly constant over many frequencies. Apparently, the dielectric constant values have a slight influence on the rate of primary arc inception.