Effect of residual thermoluminescence on the radiation induced sensitization of some TL phosphors

The effect of the high temperature residual TL (RTL) peak on the sensitization of the dosimetric peak in CaSO4:Dy, CaSO4:Tm and Cal2:Dy phosphors was studied and it was found that the sensitization factor (S/S0) is dependent on the intensity of the RTL peak. On bleaching the RTL peak intensity by a factor of approx. equal to16 by means of intense UV irradiation (253.7 nm), it was possible to bring down the sensitization factor for CaSO4:Dy from a value of 2.6 to 1.0. A similar effect has also been observed in CaSO4:Tm and CaF2:Dy phosphors. The shape and also the position of the main dosimetric peak is dependent on the intensity of the RTL peak. (orig.)