RECENT ADVANCES IN SOFT X-RAY LASER EXPERIMENTS USING GERMANIUM AND COPPER PLASMAS

Soft x-ray gain coefficients of 1.7-4.1 cm-1 are measured on eight lines in the wavelength range of 196 to 286 Å using 3p-3s transitions in neon-like Cu19+ and Ge22+ ions. The lasant plasma is created by a high-power laser line-focused onto thin-foi1 and solid-slab targets. Measured wavelengths agree with calculations. A previously-reported anomaly in gain for a J=0 upper level is small in these experiments