Hall-effect thruster
In spacecraft propulsion, a Hall-effect thruster (HET, sometimes referred to as a Hall thruster or Hall-current thruster) is a type of ion thruster in which the propellant is accelerated by an electric field. Based on the discovery by Edwin Hall, Hall-effect thrusters use a magnetic field to limit the electrons' axial motion and then use them to ionize propellant, efficiently accelerate the ions to produce thrust, and neutralize the ions in the plume.