Transient high gains at 196 angstrom produced by picosecond pulse heating of a preformed germanium plasma

Simulations are presented for a collisionally pumped germanium slab target X-ray laser, irradiated with a 1 ns, 5 x 10(12) W cm(-2) background pulse and a 2 ps, 10(15) W cm(-2) main pulse, which starts 900 ps after the beginning of the background pulse. Plasma regions with electron temperatures and densities of similar to 1 keV and 10(21) cm(-3) result in high small signal gain coefficients on the J = 0-1 transitions at 196, 193 and 132 Angstrom. Raytracing calculations indicate the possibility of obtaining saturated output al 196 Angstrom for similar to 5 ps from a 1 cm length target if a travelling wave pumping scheme can be implemented. The calculations also suggest that significant output at 132 Angstrom, should be observed with a far field deflected angle of similar to 8 mrad.