Effect of Electron Beam Irradiation on Epoxy and Its Stability

Neat epoxy samples with a thickness of 2 mm were prepared. The samples' surfaces were irradiated by an electron beam adjusted to 20 keV and 5×10
^-4
A/m
²
for 2 min. The surface potential decay (SPD) and surface resistivity of samples, including non-irradiated samples and irradiated ones, were conducted. Seven days later, the tests were conducted again. The trap level and density were also calculated. The results show that electron beam irradiation changes the trap characteristics of the samples' surfaces and this change gradually diminishes over time. The experiment found that the surface trap energy was deepened because of irradiation. After standing for a while, it was found that the trap level has a tendency to change to what it is before irradiation. On this basis, we tested the surface resistance characteristics before and after the irradiation. The results show that the surface resistance increases after irradiation while slightly decreases a few days later, which is consistent with the surface trap change.