RECENT RESULTS ON DEVELOPMENT OF A TABLE-TOP SOFT-X-RAY LASER

Gain measurements have been performed in a recombining carbon plasma g enerated by a line focussed Nd-glass laser beam on a multi-fin target with the aim of developing a ''table-top'' soft X-ray laser. With a la ser beam of only 4 J (2ns) and a 6 mm long target gain up to 7.1 cm-1 was measured for the C VI 18.2 nm line (gain-length approximately 4.3) . During these measurements high gain (6.5 cm-1) was also measured for the first time on the C VI 13.5 nm line (4-2 transition). These measu rements were done, in the process of preparation for two-target experi ments. High gain was measured independently for two separate, identica l 6 mm targets. Changes in the influx into the plasma of iron ions fro m ''cooling'' blades significantly affected the location of the gain r egion and can be used as a mechanism to control the gain region in two -target experiments.