Transient collisional excitation X-ray laser generation with picoseconds laser pulses

We have observed lasing on Ne-like 3s-3p line from titanium (32.4nm), Ni-li ke 4p-4d line from silver (13.9nm) and tin (11.9nm) with the transient coll isional excitation (TCE) scheme that uses combination of a long prepulse (s imilar to ns) and a short main pulse (similar to ps). A gain coefficient of 23cm(-1) was measured for plasma length up to 4mm with silver slab targets . We have also observed lasing on Ne-like and Ni-like lines with new TCE sc heme that used pico-seconds laser pulse to generate plasma and observed str ong improvement of x-ray laser gain coefficient. A gain coefficient of 14cm (-1) was measured for plasma length up to 6mm with tin targets.