Range and Depth Dose Distribution of Low Energy Charged Particles in Dosimetry Glasses

摘要

A new method for the direct determination of particle ranges and depth dose distributions in silver-activated phosphate glasses is based on the successive removal of extremely thin surface layers from the exposed glass by chemical etching ('peeling') and measurement of the residual radiophotoluminescence between successive etchings. Glass composition, etching chemicals and etching speed can be varied within wide limits. The experimental technique, using Yokota-type dosimeter glasses and 28% NaOH at 60C (etching speed 0.12 microns/min.) is briefly described. As examples for the practical application of the method, measurements using several types of radiation sources (aqueous solutions of 3H, 63Ni and 35S, solutions and thin and thick solid sources of 239Pu, 237Np and 235U, monoenergetic protons, deuterons and He(+) ions in a wide energy range) were made. Accuracy, possibilities and limitations of the method are briefly discussed. Possible sources of error are: discoloration of the glass because of very high surface doses; incertainties in the determination of the etching speed; etching speed along charged particle tracks higher than the bulk etch rate for ions of very high LET. (Author)