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 ta rget X-ray laser, irradiated with a 1 ns, 5 x 10(12) W cm(-2) backgrou nd pulse and a 2 ps, 10(15) W cm(-2) main pulse, which starts 900 ps a fter the beginning of the background pulse. Plasma regions with electr on temperatures and densities of similar to 1 keV and 10(21) cm(-3) re sult in high small signal gain coefficients on the J = 0-1 transitions at 196, 193 and 132 Angstrom. Raytracing calculations indicate the po ssibility of obtaining saturated output al 196 Angstrom for similar to 5 ps from a 1 cm length target if a travelling wave pumping scheme ca n be implemented. The calculations also suggest that significant outpu t at 132 Angstrom, should be observed with a far field deflected angle of similar to 8 mrad.