Influence of cusp-shaped magnetic fields on plasma density and thrust in an RF plasma thruster with a magnetic nozzle

In a radiofrequency (RF) plasma thruster device utilizing a cusp-shaped magnetic field, we investigate the dependence of plasma parameters on operational conditions. Among the conditions, this study focused on the cusp-field condition and found that the axial profiles of the plasma parameters vary depending on the field conditions. The plasma density profile is affected by the distance between the cusp point and the position of the RF antenna. When the cusp strength increases, the cusp condition enhances plasma density and the total thrust, which is the sum of the thrust components of the electron static pressure and diamagnetic current. We propose an ideal cusp point concerning the antenna position for optimal performance in the thruster device. This paper highlights how cusp-shaped magnetic fields influence electron dynamics as an operational index of the RF plasma thruster with a magnetic nozzle.