抄録
Polypropylene (PP) film is generally used as insulating material for many kinds of electrical and electronic equipments because of its excellent electrical insulation performance. We investigated the electrical conduction and the charge storage of the thin PP films by means of electron beam irradiation with the energy lower than 10 keV as one new attempt. As results, in the case of electron irradiation with higher energy than 2.5 keV, PP film charged up negatively. From the negative charge decay characteristics after electron beam irradiation within this energy region, the volume resistivity of the order of 1016-1017 Wm was obtained and decreased with increase of electric field in the bulk of the PP film. On the other hand, in the case of electron irradiation with lower than 2.5 keV, positive charging occurred. This threshold energy of about 2.5 keV is thought to be the energy at which secondary electron emission yield becomes one.
