Effects of electron and alpha-particle irradiations on the track-etching characteristics of biotite mica

Abstract

The effects of large doses of electrons and alpha particles upon the subsequent etching of fission tracks in biotite mica have been examined. 1 MeV electrons and 40 MeV alpha particles produce enhanced bulk etching of the mica at doses around 10₈ Gy (= 10¹⁰ rad). Biotite mica can record tracks due to Ne ions; and since the electron doses encountered around the Ne ion path are much lower than those found to produce enhanced etching, it seems unlikely that the etchability of such tracks can be explained in terms of the electron dose deposited by the track-forming ion.

The estimated numbers of displacements produced by elastic collisions between the electrons and the target atoms seem to be inadequate to account for the observed enhancement in bulketching rates, and it is likely that some additional damage-forming mechanism involving eledronic excitation is operative.