THE TIME-DEPENDENT DEVELOPMENT OF THE MACROSCOPIC INSTABILITY OF A XECL-STAR LASER DISCHARGE

The discharge properties of a small XeCl* laser with a 1.1.20 cm3 lasing volume are investigated. The laser uses the X-ray-triggered switchless mode and is operated with Ne as buffer gas at 6 bar (Xe: 100 mbar HCl: 2,5-20 mbar). The macroscopic development of the discharge cross section observed by streak exposures and interferometric measurements is compared with a simplified one-dimensional model described in this paper. The model accounts for the field inhomogeneity of the Chang electrodes and the spatial variation of the preionization. With the help of this model, mechanisms responsible for the observed macroscopic instabilities are explained.