Population inversion in a discharge plasma with neck-type instabilities

An analysis is made of the feasibility of using strong plasma outflow from focus-type constrictions of an axial-discharge plasma column. Selective ion recombination as a result of charge transfer with ions carrying a smaller charge in the main plasma column or with neutral atoms in the residual gas in the discharge chamber can create a population inversion for transitions in the soft x-ray and VUV parts of the spectrum. General problems encountered in the investigated system are discussed and quantitative estimates are obtained of the population inversion of levels participating in the 4 → 3 transitions in Li-like oxygen ions formed, with the effective charge Z = 6, in pinch discharges with pulsed gas admission and a current of several hundreds of kiloamperes.