Comments on the Effect ofγ-Irradiation on Positronium Formation in Polymers at Low Temperatures

Quantitative description of the effect of γ-irradiation of PE and PMMA on positronium formation on the trapped electrons at low temperatures is suggested. The consideration shows that, at least in these substances, the number of the trapping centers is probably enough to localize all ortho-positronium, and therefore the intensity of the long-lived positronium component is dependent mostly on the probability of Ps formation but not on the number of the trapping centers.