Improving the efficiency of collisionaly excited X-ray lasers using multiple 100ps pulses

摘要

A series of multi-pulse pumping schemes have been investigated for enhancing the efficiency of the 196A J=0-1 Ne-like germanium X-ray laser. All of the multiple short-pulse pumping schemes investigated exhibited greater than an order of magnitude enhanced efficiency over the approxns pump-;ulse schems. Hydro-atomic simulations showed agreement with the experimentaly observed trends in the ionisation balance attained as the intensity and separation of the pulses in the double puse scheme were varied. Using two pulses separated by approx2ns with a approx0.1:1 intensity ratio, saturated output was observed at the 20MW level, for a total pump energy of approx200J. For this mode, a double target was used with a approx60ps delay between the arrival of the pump beams at each target for quasi-travelling wave operation.