Initial distribution and tunneling recombination of cation-electron pairs in irradiated rigid materials as studied by ITL measurement

Abstract

Time dependence of the intensity of isothermal luminescence (ITL) from polyethylene terephthalate and polyethylene adipate irradiated at low temperature was observed over a long period of time after irradiation. The ITL decay obeys a law I(t) = I 0 (1s+αa) m as a function of time t. All of the parameters, I 0, α and m, depend on irradiation time and/or dose rate under which were irradiated. The ITL process can be interpreted as due to recombination of the carbon-electron pair through electron tunneling to cation. The distribution of the separation distances of cation-electron pairs can be obtained by Laplace inverse transformation of the ITL decay function based on an electron tunneling model. The distribution of cation-electron pairs is discussed for different irradiation condition.