Interstitial centre and thermoluminescence in KCl:Sr irradiated at 80K

Thermoluminescence, optical absorption and thermally stimulated currents in irradiated KCl:Sr (80 ppm) have been studied between 80 and 300K. The emission spectrum and the low curve which exhibits eleven peaks below 300K have been obtained. It has been found that the glow peaks induced by irradiation can be regenerated by photostimulation at 80K with light which is absorbed either in the F band, or in the D3 band, or in the Hayes-Nichols band F*-centre emission has also been found to occur in F-photostimulated samples at the same temperatures at which the glow peaks appear in X-irradiated samples. The evolution with dose of glow peaks occurring at and above 200K indicates that their intensity goes through a maximum of increasing doses. Some features of the current spectrum are related to polarisation of impurity-vacancy dipoles. The results are consistent with existing data on the thermal stability of interstitial trapped centres. It is concluded that the observed glow peaks are not related to thermal release of electrons or holes but to thermoluminescent processes which involve the recombination of radiation-induced lattice defects such as F+H and F-+H.