chapter
Helicon Source for Electric Propulsion
ByFrancis F. Chen
Pages 6

Electric thrusters are usually in one of two forms—gridded ion thrusters or Hall thrusters. Each of these accelerates ions and requires an injector of electrons to neutralize the ion beam. Ambipolar thrusters eject neutralized plasmas with equal numbers of ions and electrons. Helicon thrusters are a new type being developed, which utilize both the high ionization efficiency of magnetized helicon discharges to produce dense plasma and the properties of an expanding magnetic field to accelerate the ions.