Radiation-induced conduction under high electric field (1×106 to 1×108 V/m) in polyethylene-terephthalate

Radiation-induced conduction in polyethylene-terephthalate (PET) has been measured under high electric field (1.0×106 to 1.6×108 V/m). In a 6-μm-thick PET film, saturation of the radiation-induced current occurs at field strengths above 1.2×108 V/m. This has been demonstrated by the thickness and dose rate dependence of the induced current. Radiation-induced conductivity increases monotonically with field strength, then shows a saturation tendency. This may be explained by geminate recombination. Above 1×108 V/m, slowly increasing radiation-induced current appears. This may be caused by electron injection from the cathode, enhanced by the accumulation of the hetero space charges near it.