Time and Temperature Dependence of Irradiation Effects in Solid Dielectrics

Decay of the electron distribution injected into a polymeric solid at 2MeV was investigated by measuring the charge released during a triggered discharge. From the decay time constant τ=ρε, resistivity ρ was calculated. For polymethylmethacrylate, the variation of ρ with temperature yielded an activation energy or trap depth W≈0.6 eV. Discharges resulting in Lichtenberg figures were also produced in polystyrene and polypropylene. Trap depths were estimated to be W≈0.6 eV for polystyrene and W≳0.4 eV for polypropylene.