Pulse discharge stability in the convective-cooled fast-flow lasers

The gasdynamic and thermal processes affecting the discharge stability and uniformity in convective-cooled high repetition rate CO2-lasers are investigated. The theoretical analysis shows that the processes in the electrode regions are mainly responsible for the specific features and magnitude of the initial disturbances. The model is explored for the thermal-ionizing instability development under the typical conditions of the pulse discharge in dense gases. It is found that such an instability may serve as a factor limiting the duration of the volume discharge used to excite atmospheric-pressure lasers. A qualitative agreement is observed between the theoretically predicted and experimental results obtained in the study of the effect of the temperature and gas composition in the cathode region on the discharge stability and uniformity.