デュオプラズマトロン型低電力MPD推進機

抄録

This report is concerned with the developement of a simple low-thrust plasma thruster, composed of a Duoplasmatron-type plasma source and a magnetic nozzle. The results of the experiment with various kind of propellants showed moderate thrust efficiencies (up to 31%) in wide range of specific impulse (400-8, 000sec), and high ionization efficiency. Such experimental results demonstrate its capability as a low-thrust plasma thruster. On the present device, in which a diverging magnetic field (magnetic nozzle) is applied to the discharge and exhaust region, there are several possible plasma acceleration mechanisms. The results of diagnostics of plasma beams in this device suggested that the prevailing acceleration mechanisms are (1) acceleration by magnetic expansion process and (2) acceleration by converting rotational kinetic energy to directed kinetic energy.