Ultraviolet Laser Oscillations of Multiple Ionized Ions in Z-Pinch Discharge

Abstract

Pulse laser oscillations from multiple ionized N, O and rare gases were observed in the ultraviolet region for the Z-pinch discharge. Optimum value of gas pressure, oscillation time and its pressure dependence were examined for laser oscillations. It has been found that oscillations from different ions occur in the increasing order of ionization after the breakdown of discharge. The line Aril λ4765 A showed an anomalous behavior. Calculation is made on two different models for ionization and excitation of plasma. The first one is concerned with ionization and excitation by thermal electrons during plasma compression. The second one is concerned with direct excitation of laser oscillation by runaway electrons. The calculation based on the former explains the temporal sequence of laser oscillations ; and that on the latter explains the anomalous behavior of ArII λ4765 A line.