Temperature depeпdence of stationary radiolumiпescence in two levels system

Starting from the well known equations describing the kinetics of variations in the concentrations of free and localized charges in a crystal, we give an interpretation of the dependence of the intensity of stationary radioluminescence (RL) on temperature and on the concentration of chromium impurities in heavily doped ruby. Calculations are carried out for a band model containing one electronic and one hole level for arbitrary occupation of the traps. According to the results obtained, the experimentally observed independence of the intensity of stationary RL on the activator concentration can be explained in terms of the above model if it is assumed that there is no recombination. It is found that after a sudden drop in the stationary RL intensity in the R lines as the temperature is lowered, the level of luminescence in heavily doped ruby should remain unchanged during irradiation. This conclusion is in complete agreement with the available experimental data.