A Magnetically Enhanced Inductive Discharge Chamber for Electric Propulsion Applications

A magnetically enhanced inductive discharge was investigated for electric propulsion applications. The high plasma density produced by the source makes it attractive as an ion source for a gridded ion thruster or possibly a standalone ambipolar thruster. The discharge plasma is produced by a compact ldquostovetoprdquo spiral antenna that is similar to that used in plasma processing sources. Operation on argon to pressures as low as 1 mtorr was demonstrated at powers ranging from 100 to 250 W. Ion current as high as 1 A was extracted from a 10-cm-diameter device. Plasma properties and ion production efficiency are reported and commented upon.