Plasma microthruster based on spark discharge with a liquid metal cathode

The parameters of low-inductance vacuum spark discharge with an In–Ga liquid metal eutectic cathode have been experimentally studied. The application of a constant magnetic field of a permanent magnet significantly modifies the character of plasma flow in discharge, which ensures a significant (1.5- to 2-fold) increase in the cathodic jet impulse. The proposed discharge provides high propulsion characteristics: jet impulse per unit energy stored amounts up to about 10 ($\mu$N s)/J, which is close to the best-known values for analogous ion sources with solid metal cathodes.