Article ID Journal Published Year Pages File Type
5365427 Applied Surface Science 2008 4 Pages PDF
Abstract

Depth-dependent positronium (Ps) formation and annihilation study of Co-60 γ-irradiated polyethylene and polytetrafluorethylene were performed. After 30-month aging, no free radicals effect on Ps formation was detected for the studied polymers. Efficient trapping of back-diffusion positrons was observed in heavily irradiated samples, where Ps formation probability near polymer surface and in the bulk turns to be equivalent to each other. Results shown that positron annihilation Doppler broadening in polytetrafluorethylene is prevailingly influenced by high momentum electrons of fluorine atoms instead of Ps intensity.

Related Topics
Physical Sciences and Engineering Chemistry Physical and Theoretical Chemistry
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