Numerical Study of Plasma Behavior in a Magnetoplasmadynamic Thruster Around Critical Current

摘要

A self-field magnetoplasmadynamic thruster is numerically studied for an argon mass flow rate of 0:8 = .Wenfocus on the plasma behavior around the critical current, atwhich full propellant ionization is theoretically expected.nAt a discharge current higher than the critical current, the Hall parameter is large at the anode surface, which leadsnto an obliquely skewed current profile. This skewed current profile, together with the voltage–currentncharacteristics, show that the Hall effect plays an important role around the critical current. When operating thenmagnetoplasmadynamic thruster above the critical current, it is shown that the current concentration and the gasndensity depletion at the anode edge induce a shortage of current carriers. To circumvent the carrier shortage at highndischarge currents, we employ a segmented anode. It is found that a segmented anode is effective for suppressing thencurrent concentration and the plasma density depletion on the anode surface without degrading the performance ofnthe thruster.