ON THE LIFETIME OF KCL-AG+ FLUORESCENCE

The fluorescence of Ag+ in KCl was investigated in the range 20-300 K, in particular by performing accurate lifetime measurements. It was fo und that, among the models proposed in the literature, the model intro duced by Pedrini gives the most reasonable explanation of the Ag+ de-e xcitation mechanism: two excited states in thermal equilibrium are inv olved in the emission process, one of which is metastable and lying ju st below the emitting level. A discussion of the decay properties of A g+ and Cu+ impurities in alkali halides is presented.