Demonstration and study of a discharge‐pumped, table‐top soft‐x‐ray laser

We review results of the first demonstration of large soft‐x‐ray amplification in a discharge‐created plasma. A fast compressive capillary discharge was utilized to create elongated plasma columns with length‐to‐diameter ratios in excess of 500:1 having the required density and temperature for soft‐x‐ray amplification by collisional excitation of Ne‐like ions. The most recent measurements, conducted in capillary discharges up to 20 cm in length, have yielded an amplification of ∼exp(14) in the 46.9 nm line of Ne‐like argon. The dependence of the laser line intensity with discharge parameters and the dynamics of the capillary discharge plasma column under lasing conditions are reported. Prospects for laser operation at shorter wavelengths are discussed.