GAMMA-RADIATION-INDUCED CHANGE IN THE ACTIVATION-ENERGY OF TL TRAPS IN LIRBSO4TL

Thermoluminescence (TL) measurements were carried out for pure and dop ed LiRbSO4, with different concentrations of thallium (Tl). The glow-c urve range of measurement is between room temperature up to 300-degree s-C. The radiation absorbed dose is in the range 56-3.2 x 10(5) Gy. Th e results show that both pure and doped samples have glow peak tempera tures that are dose dependent, and vary between 70-80-degrees-C and 14 0-170-degrees-C for pure and doped samples respectively. Doped samples display double peaks that increase with dopant concentration up to ab out 0.7% wt. The second peak which occurs at high temperature increase s linearly with dose up to 4500 Gy. From the results it is proposed th at LiRbSO4 doped with 0.7% Tl can be used for dosimetric purposes in t his range. The activation energies of structural transitions are estim ated and the results are discussed on the basis of radiation-induced s table dipoles in the random field system.