Plasma dynamics in a helicon thruster

Universidad Politécnica de Madrid Madrid 28040, Spain

Abstract

Internal and external plasma dynamics in a helicon thruster are discussed through several theoretical models. Main plasma processes inside the helicon source are: wave energy absorption, gas ionization, magnetic confinement, Hall current formation, and subsonic plasma flow. The processes taking place in the external divergent magnetic nozzle are: axial supersonic acceleration, radial rarefaction, Hall current evolution, thrust increment, and downstream detachment. The possible formation of a current-free double layer (CFDL) is discussed too. Emphasis is put in aspects affecting the propulsive capabilities of the device, such as specific impulse and thrust efficiency.