Near ultraviolet emission from nonequilibrium inert-gas plasmas. $\text{I}$. Experiment

The emission spectra of inert gases at densities of $10^{18}$–$10^{20}$ cm$^{-3}$ in plasmas produced by nanosecond electron beams with current densities of about $4$ A/cm$^2$ are studied experimentally. New data are obtained on the structure of the third UV continuum and on the time variation of the emission. Published experimental data are classified. Two bands are identified in the emission from heavy inert gases which are not associated with neutral dimers and trimers.