Effects of initial ion velocity, magnetic field and plasma density profiles in simulating the plasma plume in a Hall thruster.

Hall thrusters have high thrust-to-power ratio, efficiency and specific impulse. Therefore, less propellant mass is required for small satellite missions compared to chemical thrusters. In electric propulsion technology, the thrust is generated by the acceleration of ions in a cross-field plasma configuration. The fast ion bombardment near the exit channel is the main cause of erosion of the walls, which limits the lifetime of Hall thruster. The magnetic field profile controls the exhaust-beam divergence, motion of the energetic particles from the plume and erosion of outer surface of the device, which affects performance of the thruster. So, it is necessary to study the effect of different profiles of the magnetic field and density, and ion velocity on the plasma plume in addition to the impact of collisions between the plasma species. In this paper, we have investigated these effects on the plasma plume potential by considering Gaussian and super-Gaussian profiles for the density. The plasma plume is found to acquire larger potential, if the magnetic field of higher strength is used. The potential of the plasma plume attains a peak value outside the acceleration channel. The peak of the plume potential gets shifted more outside in the case of Gaussian density profile when the position of the magnetic field peak is shifted towards the cathode. [ABSTRACT FROM AUTHOR]