This paper presents simulation results for three modes of pumping of a XeCl-laser under radiation pulse duration of 10, 30, and 50 ns. Temporal evolutions of pump power and laser radiation, energy of pumping and lasing, densities of electrons and HCI(i) molecules in the ground and vibrationally excited states have been simulated for each mode. Rate dependences ofthe processes of XeCl** excimer molecules formation, such molecules quenching by electrons and heavy
particles of plasma N(i), and induced radiation rate vs. time have been also obtained. For two modes of pumping with radiation durations of 30 ns and 50 ns, simulation data are compared with experimental results taken from the literature available. The simulated temporal evolutions of discharge current, radiation power, and lasing energy are in good agreement with the experimental results. There are no literature data regarding a laser with a pulse duration of 10 ns. The properties of laser operation at decreased pumping duration up to 10 ns are presented. Kinetic processes effect on radiant energy and laser efficiency has been analyzed. It follows from the analysis of calculation results that formation of excimer molecules takes place with high efficiency. Quenching processes of excimer molecules by electrons and heavy particles is the main factor leading to decrease in radiant energy, and therefore laser efficiency.