Magnetoplasmadynamic two-stage microcathode arc thruster for CubeSats

摘要

The addition of the acceleration stage to a micro-cathode vacuum arc thruster (μCAT) increases the thrust and the specific impulse. This improves the control of small satellites' orbital parameters and, therefore, the overall efficiency of this thruster for CubeSats. In this article, we show that the second accelerating stage based on the magnetoplasmadynamic (MPD) approach allows improvements not only to the thrust (almost twice, from 9 to 18 μN), but the thrust-to-power ratio (in 53%, from 3.2 to 4.9 μNW~(?1)) of the low-power (several W) miniature (several cm-size) μCAT, firing at a pulse repetition rate of 10 Hz. A significant advantage of the μCAT-MPD approach is the griddle construction, a design that helps to overcome the loss of ions along the grid cells in the case of gridded ion acceleration stage.