Hybrid PIC-DSMC simulation of a Hall thruster plume on unstructured grids

Hall thrusters and other types of electric propulsion have become a tempting alternative to traditional chemical propulsion systems due to the high specific impulses they provide at relatively high efficiencies. Unlike conventional chemical propulsion systems, electric propulsion devices do not rely on the internal energy stored within their propellant. Instead, an external power source is used to impart energy to the working fluid. As no inherent limitation due to the propellant exists, a high Isp is attainable which translates to a highly desirable mass savings. Higher exhaust velocities and thus higher specific impulses are only constrained by the power processing unit (PPU) which provides the external energy and is the primary contributor to the electric propulsion system’s mass. By trading Isp against PPU mass, Hall thrusters are found to fall in an optimum operation regime well-suited for missions such as station-keeping and orbit transfers.