Transient optical absorption induced by an electron pulse in KPb ₂Cl₅ crystals

The efficiency of formation and time evolution of radiation-induced structural defects and pulsed luminescence in KPb₂Cl₅ crystals under the action of a single electron pulse (E = 250 keV, τ = 20 ns) have been investigated. The spectra (1.1-3.8 eV) and relaxation kinetics (time interval 5 × 10^-8-5 s) of transient optical absorption and the pulsed cathodoluminescence spectra and decay kinetics (1.4-3.1 eV) have been measured in the temperature range 80-300 K. It is revealed that the induced optical density and its time evolution depend strongly on temperature, and the absorption relaxation time contains several components and reaches several seconds at T = 300 K. The decay kinetics of transient absorption and pulsed cathodoluminescence kinetics have different orders and are controlled by different relaxation processes.