REDUCTION OF X-RAY LASER DRIVER ENERGY

Future development of X-ray lasers (XRL) applications goes through a r eduction of the driver energy. Amplification close or inside the ''wat er window'' using the Li-like recombination scheme was tested. A gain of similar to 0.8 cm(-1) at 5.77 nm (Ca17+) was measured. On the other hand, at LULI the use of low energy prepulse has permitted to achieve a very efficient saturated X-ray laser working on the 0-1 line (21.2 nm) on the Ne-like collisional scheme. The 5 MW, 200 mu m transverse c oherence length XRL is extremely well suited for applications.