FISSION FRAGMENT ETCH PIT FORMATION IN MICA, QUARTZ AND FELDSPAR CRYSTALS UNDER VARYING ETCHING CONDITIONS

Abstract

Studies have been made concerning the fission fragment etch pit formation characteristics of mica, quartz, and feldspar crystals under varying etching conditions. The results indicate that different crystallographic planes in natural quartz and feldspar crystals show varying degree of anisotropy in the angular distribution of etched tracks. Generally speaking, a) the etching efficiencies of these crystals at first improve with the increasing etching time and then become almost constant, and b) the boiling solution of NaOH produces more isotropic distributions than HF. The above mentioned anisotropy has been explained on the basis of differences in Vg and Vt. along different crystallographic planes of these two crystals. Mica track detector is found to have fairly isotropic characteristics for fission fragment etch pit formation.