Phototransferred thermoluminescence from phosphate using ultraviolet radiation

Abstract

In this paper, we present a study of the phototransference thermoluminescence (PTTL) of charges from deep traps in natural phosphate, using 254nm UV radiation. The natural material glow curve has one peak at 260°C, while the phototransfered glow curves has an additional peak at 150°C. The optimal conditions were illumination time of 180†min, and a preheating temperature of 500°C. The PTTL signal was found to be linear over the gamma (γ) dose range 0.1Gy-1000Gy. The efficiency of low dose reassessment reaches about 100 percent of the first readout. After two weeks of storage the PTTL signal was found to be 98 % of the original value. The results show the convenience of this method for the purpose of dose re-estimation over the dose range 0.1-5Gy. Such method is useful in radiation retrospective dosimetry and dating.