Spur effects on electron scavenging in an irradiated low temperature glass

Abstract

Glassy samples containing various electron scavengers in glycol/water and sodium hydroxide matrices have been exposed to X-rays and U.V. light at 77 K, the latter causing ionizations by biphotonic absorption in tryptophan. Trapped electron yields are measured by E.S.R. and optical absorption. The two types of irradiation might be expected to yield different values for the efficiencies of the scavengers because of the non-uniform X-ray production of electrons in spurs. Taking the experimental accuracy into account, such differences are not found, and possible explanations are suggested. The large spur effects found by other investigators are in contrast both to our experimental results and to a theoretical evaluation performed. Their results might be explained by effects of optical bleaching during U.V. irradiation.