ESR Studies on the Yield of Peroxy Radicals in PTFE Irradiated by Deuterons

Abstract

Radicals in PTFE (polytetrafluoroethylene, Teflon) sheets irradiated by 2 MeV deuteron beam in vacuum and exposed to air have been studied by ESR at 9 GHz and at room temperature. An asymmetric line with a main peak of width 23±1 gauss at g=2.0174±0.0007 is observed, which is very stable under open air at room temperature. This type of centers has been concluded to be the peroxy chain radicals. The number of radicals produced is concluded to be proportional to the number of incident deuterons, the yield being 2000±420 radicals per one incident deuteron. However, the radical density comes to an upper limit of (1.36±0.11)×10¹⁹ radicals/cm³, or one radical per (3820±304) C–F bonds, at a dose higher than (3.43±0.45)×10¹³ deuterons/cm².