Emission and Excitation Spectra of Thallium-Activated Potassium Chloride at Low Temperatures

Abstract

Measurements are reported on the emission spectrum and excitation spectrum for emission of thallium-activated potassium chloride at low temperatures. The emission spectra derived from Williams' computed configuration coordinate curves are not in close agreement with those observed experimentally. It is shown that the simple one-dimensional treatment of the configuration coordinate curves cannot account for all the absorption and emission data in a self-consistent way. At 300°K and 77°K the excitation spectra for the 3050 A emission and the 4750 A emission are found to be different. It is suggested that these two emissions may arise from different thallium centers rather than from two excited states of the same center as proposed by Johnson and Williams.