Pinching discharge in nitrogen filled capillary as a tool for soft x-ray laser recombination pumping

Abstract

Population inversion at the Balmer quantum transition of hydrogen-like nitrogen N⁶⁴ ions may result in lasing. The corresponding laser radiation wavelength is 13.4 nm. Collisional recombination, taking place during the decay of pinching capillary discharge, is judged as principle pumping process. To design a proper experiment we have performed computer simulations of plasma dynamics and ion kinetics. Gain factor of 1 cm⁻¹ spanning time interval of 1 ns is predicted for optimized capillary radius of 1.5 mm, filling pressure 1 kPa, electric current peak of 50 kA and quasiperiod of 160 ns.