Onset of the magnetized arc and its effect on the momentum of a low-power two-stage pulsed magneto-plasma-dynamic thruster
Denis B. Zolotukhin, Keir Daniels, Lubos Brieda, Michael Keidar
Abstract
A new type of plasma accelerator---a low-power $(<30\phantom{\rule{0.28em}{0ex}}\mathrm{W})$, miniature (cm-sized), two-stage pulsed magneto-plasma-dynamic thruster---has been proposed. Being magnetized by an axially symmetric dc magnetic field of \ensuremath{\sim}200 mT, the vacuum arc discharge demonstrates a threshold behavior: Parameters such as thrust and the thrust-to-power ratio rapidly jump after a certain dc voltage (\ensuremath{\sim}30 V) is applied on the accelerating electrode. We show that such an effect improves the thrust (from \ensuremath{\sim}2 to \ensuremath{\sim}210 \textmu{}N), efficiency (from \ensuremath{\sim}1% to 50%), and thrust-to-power ratio (from \ensuremath{\sim}0.5 to \ensuremath{\sim}18 \textmu{}N/W).