Analysis of thermoluminescent glow peaks of zoisite under beta irradiations

In this study, the thermoluminescence (TL) properties of natural crystal of zoisite were investigated after beta ((90)Sr) irradiation at room temperature (RT). Zoisite, of chemical formula Ca(2)Al(3)(SiO(4))(Si(2)O(7))O(OH), is found in Minas Gerais State, Brazil as natural mineral of silicate, member of the epidote group. The glow curve of a natural sample submitted to a heat treatment at 600 degree C is composed of two broad peaks, centered at about 110-130 degree C and another one at about 205-210 degree C. A heating rate of 4 degree C s(-1) was used in the temperature range from RT to 300 degree C. The additive dose, T(m)-T(stop) thermal cleaning, initial rise, variable heating rate and computerized glow curve deconvolution methods have shown mat the glow curve is a superposition of six peaks at 100, 130, 155, 175, 200 and 230 degree C. The trapping parameters for the individual peaks have been calculated. The TL dose response of 130 and 200 degree C peaks has a linear response. Zoisite is a candidate for a TL dosimeter because of its high sensitivity.