Low-temperature (80-240 deg C) annealing characteristics of LiF:Mg, Cu, P

Thermal treatment of LiF:Mg, Cu, P in the range 80-240oC performed after typical annealing at 240oC for 10 min causes important modifications to the glow-curve structure and to the behaviour of the individual glow-peaks. The maximum glow-peak temperatures and the activation energies obtained by a glow-curve de-convolution procedure are varied as a function of pre-irradiation annealing at temperatures below 240oC. Initial rise measurements support the results obtained by the glow-curve de-convolution concerning the high values of the activation energy of glow-peak 4, as well as its variation as a function of the pre-irradiation annealing. The 'prompt' isothermal decay of glow-peak 4 at temperatures just below the maximum peak temperature consists of three components instead of one, which would be expected from the kinetic models. The second component corresponds to glow-peak 4 and also presents very high E and s values. The third one corresponds to a glow-peak at the high-temperature tail of peak 4. The first component was attributed to a mechanism competitive to the mechanism responsible for the main peak 4. (author)