Particle simulation of a Hall thruster plasma plume

Effects of the propellant, propellant mass-flow rate, and discharge voltage on the characteristics of the plume of small Hall thrusters are studied using a particle-in-cell Monte Carlo collisions program. It is shown that with the same discharge voltage and mass flow, the divergence angle of the xenon plume is smaller than that of argon and is not linearly dependent on the propellant mass flow rate. Moreover, the effect of the discharge voltage on the plume divergence angle can be significant. As the discharge voltage increases from 100 to 300 V, the plume divergence angle decreases, but in the range 300-400 V, it increases with the discharge voltage. The obtained data can be useful for the design and improving the efficiency of Hall thrusters.