Magnetically enhanced vacuum arc thruster

TLDR

A hydrodynamic model of vacuum arc thrusters and their plumes is presented. The study investigates how magnetic fields affect plume expansion and plasma generation in vacuum arc thrusters. The authors analyze two configurations: the magnetically enhanced co‑axial vacuum arc thruster (MVAT) and the vacuum arc thruster with ring electrodes (RVAT). The magnetic field markedly reduces radial plume expansion, the MVAT’s predicted plasma density profiles agree with experiments, and in the RVAT the field causes jet deceleration that explains the observed non‑monotonic ion‑current density dependence.

Abstract

A hydrodynamic model of the vacuum arc thruster and its plume is described. Primarily an effect of the magnetic field on the plume expansion and plasma generation is considered. Two particular examples are investigated, namely the magnetically enhanced co-axial vacuum arc thruster (MVAT) and the vacuum arc thruster with ring electrodes (RVAT). It is found that the magnetic field significantly decreases the plasma plume radial expansion under typical conditions. Predicted plasma density profiles in the plume of the MVAT are compared with experimental profiles, and generally a good agreement is found. In the case of the RVAT the influence of the magnetic field leads to plasma jet deceleration, which explains the non-monotonic dependence of the ion current density, on an axial magnetic field observed experimentally.