Experimental investigation of MHD impact on argon plasma flows by variation of magnetic flux density

Abstract

The interaction between a probe body and argon plasma flow is investigated to examine to what extent the probe head temperature and the bow shock distance can be influenced by applying a strong magnetic field. The experiments are performed using a strong permanent magnet installed inside a probe body with a spherical, coated probe head. Former investigations showed strong influence on the bow shock geometry but also on the inflow plasma jet. Several boundary conditions have been varied to evaluate their influence toward the experiment. For an uncoated probe head the measured MHD impact was found to be of the same order of magnitude as for the coated case. Electrical isolation of the probe toward the vacuum chamber yielded only slight influence. The variation of the field strength was realized by changing the amount of magnet segments installed. Pictures were analyzed to minute the MHD interaction for each test case. It was found that the bow shock distance increased and the temperature of the probe head decreased while increasing the magnetic field density. This analysis precedes a thorough characterization of the plasma condition.