Gamma-ray induced photoconductivity in pyrex, quartz, and vycor

Results of an experimental investigation are reported on photoconductive response of Pyrex, Quartz and Vycor. This research was conducted as a feasibility study for developing a new gamma dose measurement device based on the principle of photoconductivity. However, data collected in this study are equally valuable for various other applications where these materials are to be used in high radiation field. Our experiments and analyzes indicated that the selected dosimeter materials exhibit photoconductivity and respond to changes in gamma dose rate within a useful range. Pyrex glass suffered radiation damage at a relatively high dose rate of 0.25 Gys^-1. Quartz and Vycor exhibit significant advantages over Pyrex as dosimeter material. However, their limit of operability was found to be at a dose rate of approximately 28 mGy s^-1. Vycor dosimeter in particular appears promising for gamma measurement applications. From an endurance point of view, Quartz appears to be the most suitable material for applications in high dose rate conditions, in that photo-currents in Quartz were observed to be minimum