Verification of transient RIC in polyethylene using numerical methods

Current transients in radiation induced conductivity (RIC) of low-density polyethylene (LDPE) exposed to 17 ns bremsstrahlung pulses were studied. Three models of the RIC relaxation, to 30 μs after the pulse, have been tested numerically. Strong influence of the measuring circuit on the experimental results was taken into consideration. Verification shows that the RIC relaxation immediately after the excitation consists of the combination of at least two exponential components with markedly different relaxation times. This supports our thesis, that the charge transport in LDPE during the 30 μs period after the RIC excitation by means of bremsstrahlung is occurring in the conduction band as a shallow-trap-limited, nondispersive current