Abstract

The achievement of saturated soft-X-ray laser output at drive energies well below the kilojoule level has become a primary issue in X-ray laser research. Saturation has been demonstrated on the collisionally-pumped 3p-3s transitions in neon-like ions of Zn, Ge, Se, and Y at drive laser powers of order 1 TW. Intense J=0-1 lasing was observed when the prepulse technique was introduced, in which a low-energy pulse irradiates the target a few nanoseconds before the main pulse [1,2]. Here we report on the experimental demonstration of saturated 3p-3s, J=0-1 soft-X-ray lasing at 25.5 nm in neon-like iron with the aid of a novel double-prepulse technique. Using two 0.5% prepulses, 2 ns and 5 ns before the 100-ps main pulse, respectively, gain saturation was observed at a pump power of 300 GW, corresponding to an irradiance of -12 TW/cm².

© 1998 IEEE