Numerical investigation of internal plasma currents in a magnetic nozzle

Two-dimensional fully kinetic particle-in-cell simulations of an electrodeless plasma thruster, which uses a magnetic nozzle, were conducted to investigate the thrust generation induced by the internal plasma current. The results clearly show that the $\mathbf{E}\times \mathbf{B}$ and diamagnetic current densities are the major components of the internal plasma current. The simulated pressure structures reproduced the experimentally observed structures well. The results for various magnetic field strengths reveal that the $\bf{E} \times \bf{B}$ effect decreases and the diamagnetic effect becomes dominant with an increase in the magnetic field strength; this demonstrates the significant contribution of the diamagnetic effect in thrust generation.