Electron density measurements of a rapid Z-pinch discharge using an He-Ne laser Michelson interferometer

The use of a He-Ne laser Michelson interferometer is described for the measurement of electron density in a very rapid Z-pinch discharge. A simple modification of the Michelson interferometer light-collecting optics allows very high spatial resolution measurements to be performed. An a priori estimation of errors is essential to make a correction to the observed fringe shifts, assuming a certain distribution of the refractive index in the plasma. Two major sources of error found to cause fringe shifts are well accounted for and corresponding corrections are applied to obtain the true radical electron density distributions. (author)