Dynamics and correlated performance of a photo-triggered discharge-pumped HF laser using SF 6 with hydrogen or ethane

Abstract

, has been performed in Ne/SF6/H2 and Ne/SF6/C2H6 mixtures. Parameters involved have been the storage line capacitance and the circuit inductance, the capacitors charging voltage, the RH-molecule type and partial pressure, and the X-ray dose for the preionization. High laser performance has been achieved with C2H6: an output energy up to 3 J corresponding to a specific energy of 9.6 J/l at an efficiency of 4.7%, which strengthens the advantage of the photo-triggering technique to energize high-power HF lasers. However the optimum performance achieved with H2, 5.75 J/l and 3.5%, are lower. It is shown, through a time-resolved study of the electrical discharge and spatial dynamics correlated to laser power and energy measurements, that discharge instabilities are responsible for the poor laser performance of the mixture with H2. These instabilities, which lead to arc development, are characteristics of the discharge in Ne/SF6. It is demonstrated for the first time that addition of a heavy hydrocarbon, such as C2H6, to that mixture induces the discharge stabilization so that the laser emission arises in a homogeneous active medium. This effect allows us to achieve better laser performance than with H2.