Effects of a surface discharge on the space charge distributions in e-irradiated Teflon and Kapton films

An experimental simulation of charging and discharging of polymer films subjected to e-irradiation was conducted. The charge profiles in the irradiated films are measured using the laser-induced pressure wave propagation method. As this method is reproducible and nondestructive, the evolution of the charge density can be recorded at various steps of the irradiation process, until a discharge occurs. The method is applied to in situ measurements of space charge distributions in a vacuum environment up to high charging levels. The effects of a surface discharge on the charge profile in e-irradiated FEP and Kapton films were investigated. The results are of interest in connection with spacecraft charging during magnetic storms.<>