Thermoluminescence characteristics of unannealed and a high temperature annealed green beryl

Abstract

The thermoluminescence characteristics of natural green beryl are reported. Aliquots of the sample used were irradiated using a beta source at a dose rate of 0.1 Gy/s. The glow curves measured at 1 °C/s from aliqouts irradiated to a dose of 1 Gy have peaks at 74, 166, 280 and 422 °C. Only the peak temperature value of the peak at 166 °C is dose dependent, changing from 158 °C for aliquot irradiated to a dose of 0.1 Gy to 190 °C for aliquot irradiated to a dose of 100 Gy. Tm-Tstop and GCD analyses revealed that the peak which appears at 166 °C consists of two overlapping components near 165 and 187 °C. All the peaks are affected by thermal quenching to varying degrees. Activation energy values of the glow peaks calculated using GCD and E-Tstop analyses are in good agreement. Exposure of pre-irradiated beryl to light bleaches luminescence stored in it by the irradiation. TL emission in natural beryl may be dependent on previous thermal history in the environment.