Axial temperatures and electron densities in a flowing cascaded arc: model versus experiment

A Fabry-Perot interferometer is used to measure argon ion line profiles in a strongly flowing cascaded arc plasma. Heavy-particle temperatures, electron densities, and electron temperatures are derived from the Doppler width, the Stark width and the line/continuum ratio respectively. The electron temperatures are also obtained from the electrical conductivity of the plasma. The plasma parameters along the arc channel are values averaged over the arc cross section and are determined with an accuracy of 2-5%. Comparison of the measurements with model calculations is also made, to improve understanding of the plasma processes in the arc channel.