INTERFEROMETER MEASUREMENTS IN PULSED PLASMA-EXPERIMENTS

The interferometer measurements are extremely informative in plasma ex periments allowing direct evaluations of the electron density. The pri mary goal of the work presented, is to build a laser interferometer wh ich meets the requirements of the highest possible simplicity, economy , convenience and ease of construction. These requirements are success fully satisfied while maintaining high sensitivity (+/-0.5 degrees-of phase shift) and a wide density range (10(14) and 10(19) cm(-2)-line-i ntegrated) of the interferometer. In our experiments we used a low ave rage power (5 mW) He-Ne laser without complicated and costly stabiliza tion or detection environments. The He-Ne laser interferometer with th e Michelson arrangement was used to measure the line-integrated plasma densities in various plasma experiments. Time-and spatially-resolved density measurements were performed for a plasma opening switch, a las er produced plasma, an electrothermal launcher and railgun plasmas.