OBSERVATION OF SATURATED LASING ON THE 3P-3S, J=0-1 TRANSITION AT 25.5 NM IN NEON-LIKE IRON USING A DOUBLE-PREPULSE TECHNIQUE

We report on the demonstration of saturated gain on the 3p-3s, J = 0-1 transition at 25.5 nm in Ne-like iron using a double-prepulse techniq ue in which the 100-ps duration main pulse is preceded by two 0.5% pre pulses at 2 and 5 ns, respectively. With this pumping scheme iron targ ets with different radii of curvature were irradiated in order to opti mize the configuration with respect ts the X-ray laser output. The mea surements are compared with the data obtained applying only a single 1 00-ps prepulse at 5 ns. A gain length of gl approximate to 16.5 was me asured indicating that saturation in the Ne-like iron plasma has been reached for a pump power below 300 GW. (C) 1998 Elsevier Science B.V. All rights reserved.