Soft X ray amplification in 3 and 4 mm diameter capillaries

Laser pulses with energy of ~10 μJ are generated at 46.9 nm on the 3p-3s transition of the Ne-like Ar by a fast capillary discharge setup in both 3- and 4-mm channels. The dependence of the laser output pulse energy on the pressure of Ar gas is measured for 3-mm-diameter capillaries at currents of 2