Development of a Lorentz Force Accelerator Injector for the VASIMR Engine

We report on the effort to develop a Lorentz Force Accelerator for use as a plasma injector for the VASIMR(Variable Specific Impulse Magnetoplasma Rocket) engine. Advantages of the LFA, also known as a magnetoplasmadynamic thruster, include simplicity of construction, the ability to use a wide variety of propellant gases without modification, and minimal power processing requirements. As a plasma source for the VASIMR engine, its feature of ejecting plasma in a tightly collimated jet allows it to inject plasma through the loss cone of the VASIMR magnetic field into the engine's central cell. This passage from weak to strong magnetic field regions may result in a desirable increase in plasma density in the central cell. Work to date has focused on achieving reliable start-up and steady-state operation.