Lasing on Be II transitions in a recombining plasma produced by a ruby laser

A laser beam consisting of a train of pulses has been used along with a screen preventing plasma expansion in order to observe, for the first time in the case of a recombining laser plasma, emission in the ultraviolet range from transitions of the ions in the plasma. Spectrograms and oscilloscope traces show that the screen greatly intensifies the emission of the recombination-populated states at large distances from the target and greatly prolongs the emission in the working lines. The temporal characteristics of the emission in the continuum are not affected by the screen. The use of a resonator increases the heights of the line emission tails by a factor of five to eight, reaching the height of the initial emission peak at the maximum.