THEORETICAL-STUDIES ON MICROSCOPIC AND MACROSCOPIC NONUNIFORMITIES INELECTRIC-DISCHARGE-EXCITED XECL LASERS

The stability of the pumping discharge for XeCl (Ne/Xe/HCl) lasers is investigated by using different one-dimensional models, considering bo th bulk discharge instabilities and filamentary ones. It is found that the bulk stability in a XeCl laser discharge can be improved, under c ertain conditions, due to the vibrational excitation of HCl molecules: this effect is studied by using different models for the HCl vibratio nal kinetics. It is established that the very short instability time f ound in experiments cannot be explained as a result of bulk instabilit y of the discharge. On the other hand a satisfactory comparison with e xperiments can be obtained by adding to the model a simplified microin stability which develops in the discharge.