Radiation induced aggregation and thermoluminescence of copper centers in KC1

Abstract

The influence of the impurity aggregation state on the absorption and luminescence spectra of KCl:Cu irradiated at room temperature has been studied. Unirradiated samples excited with UV light show two main emission bands at 400 and 420 nm, ascribed to isolated Cu⁺ ions and copper aggregates respectively. The same emission bands appear in the thermoluminescence spectra. The F and M bands show annealing steps simultaneous with the glow peaks. It is shown that the radiation induced Cu⁻ and Cu⁰ centers can be electrically compensated by anion vacancies. It is suggested that radiation induces impurity aggregation as well as anion interstitial aggregation. Thermal release of interstitials may excite isolated Cu⁺ ions and copper aggregates, either through energy transfer from F + H recombination or by H+α→ Vk, Vk + Cu⁰ reactions.