Compression zone formation in plasma streams generated by MPC device operating with gases of different mass

摘要

This paper presents analysis of compression zone formation in plasma streams generated by compact magnetoplasma compressor operating with argon and helium. The main aim for this investigation is characterization of plasma in compression zone in dependence on initial concentration of working gas. The initial concentration was changed by variation of residual gas pressure in vacuum chamber. The mass flow rate was kept constant. It was possible due to 10 times difference between He and Ar masses. Thus, decrease of residual pressure from 10 Torr for helium till 1 Torr for argon allows keep the mass flow rate in spite the initial density value decreases in 10 times. The temporal and spatial distributions of plasma density were measured in plasma stream and in the compression region in both cases. It was shown with spectroscopy that plasma density in compression region increased up to 3.5 times with decreasing initial concentration in 10 times. The obtained result is in agreement with analytical estimation that follows from the Bernoulli equation. Plasma dynamics in compression region is also discussed.