Natural quartz: A useful detector for in-core measurements

Abstract

Experiments have been carried out to study the track registration and retention properties of natural quartz crystals. The results indicate that important characteristics such as the critical angle of etching ( θ c ), the etchable track formation efficiency (η), the maximum etched track length ( l max) and the track stability against high temperature annealing depend upon the particular crystallographic plane. It has also been observed that a natural quartz crystal is more efficient than fuzed silica (Vitreosil) for the registration and retention of fission fragment latent damage trails at elevated temperatures. Preliminary results indicate that gamma doses below ∼200 Mr do not affect the above-mentioned properties of these crystals. The experiments seem to suggest that a natural quartz crystal is probably the only known insulating solid in which the fission tracks are fairly stable, (a) at temperatures as high as ∼800 °C (maintained for a few hours), and (b) under fairly severe background conditions. It may therefore prove to be an extremely useful track detector for measurements in high temperature and radiation environments such as reactor cores.