Dependence of thermoluminescence in LiF:Mg,Cu,Na,Si phosphor on Na dopant concentration and thermal treatment

Abstract

A new phosphor, LiF:Mg,Cu,Na,Si, has been developed in this laboratory for thermoluminescence. The thermoluminescence dependence on the concentration of Na dopant between 0 mol% and 0.45 mol% and thermal treatment between 240°C and 310°C was investigated. With an increase of Na concentration, the TL sensitivity and the main peak increase when the annealing temperature is less than 300°C. With an increase of annealing temperature, the position of the main glow peak shifts markedly towards higher temperatures, irrespective of Na concentrations. The height of the main peak depends strongly on the annealing temperature. TL sensitivity remains stable at annealing temperatures from 260°C to 300°C for 0 mol% Na concentration, from 250°C to 300°C for 0.05 mol% Na concentration, from 260°C to 290°C for 0.1 mol% Na concentration, from 260°C to 280°C for 0.2 mol% Na concentration, from 250°C to 270°C for 0.35 mol% Na concentration, or from 260°C to 280°C for 0.45 mol% Na concentration. The ratio of the intensity annealed at 310°C to the intensity annealed at 260°C seems to be reduced with an increase of Na concentration. Thermal susceptibility of LiF:Mg,Cu,Na,Si appears to be associated with the Na concentration. The lower the Na concentration, the less sensitive the TL is to annealing temperature. The optimum Na dopant concentration was found to be 0%.