Fast and small capillary discharge: MHD simulation.

Theoretical investigation of the dynamics of plasma discharge, excited by the fast 6 ns FWHM current pulse with 4.5 kA peak in 0.8 mm diameter channel inside the alumina capillary filled with the Ar, is performed by the methods of computer simulation: One-dimensional two-temperature MHD model that takes into account plasma dynamics as well as the ablation of the wall material has been explored. Simulations and the range of Ar initial pressure of 100 - 500 mTorr show that hot dense uniform plasma core is formed at the center of the discharge channel. The parameter of this core are favorable for soft x-ray lasing at 46.9 nm due to the generation of population inversion in plasma by the collisional electron excitation of Ne-like Ar IX ions.