Charging and discharging phenomena in simulated space environment

Large space platform needs to be operated at high voltage. When a solar array has a negative voltage more than 200 V with respect to the plasma, arcing occurs. Experiments are carried out in order to elucidate charging and discharging phenomena on a solar array in simulated space environment and find mitigation techniques against arcing. Arcing occurs at the triple junction, where solar cell coverglass, insulator, interconnector and conductor meet, because of the field enhancement. Once an arc occurs, the current is supplied through the plasma by the charge stored on the insulator surface nearby. It is found that transparent film placed in front of the solar array is effective to suppress the arcing onset and the arc current, because the film acts as the shield to prevent ions from charging the coverglass and the arc currents from flowing through the plasma