Multi-channel two-dimensional MPD arcjet

A multichanneled MPD arcjet, which approximated an ideal two-dimensional discharge, was successfully operated in a quasi-steady mode. This device allows easy access to the discharge region by means of optical techniques for obtaining particle species, temperature distribution, and current patterns. Such data are analyzed in order to clarify the correlation between the thrust performance and plasma condition. It was found that the onset phenomenon should be more clearly defined by Isp, which strongly depends on the electrodes design, than the parameter J-squared/m, very low electron temperature of 0.3 eV was found to prevail in H2 propellant, which explained the current concentration on the cathode tip due to dissociative energy absorption of molecular propellant. 7 references.