1 Thrust Improvement of the Magnetically Enhanced Vacuum Arc Thruster (MVAT)

Abstract: The Magnetically enhanced Vacuum Arc Thruster (MVAT) is a solid propellant micro-thruster based on a pulsed vacuum arc thruster (VAT) that produces precisely controlled impulse bits. The addition of a co-axial magnetic field to the VAT enhances the thrust efficiency of the thruster and collimates the plasma plume, which reduces contamination of the spacecraft. Alameda Applied Sciences Corporation, along with team member Aerojet, is developing a TRL 5 readiness level MVAT thruster with an integrated Power Processing Unit (PPU). The PPU is an inductive energy store driver that uses the 20V bus voltage to generate both the 1 kV spike needed to trigger the arc as well as the energy to generate the axial magnetic field and the vacuum arc. Since the magnetic field coil is also the primary energy store, there is no mass penalty for the MVAT relative the VAT. This paper presents thrust stand measurements and retarding potential analyses to characterize the improvement of thrust performance with the application of the magnetic field. Nomenclature B = Magnetic Field l = magnetic coil length I = Peak current in PPU N = Number of turns r = radius of magnetic coil Rp = Power Processing Unit (PPU) circuit resistance I