Ion engine

An ion engine has a propellant supply system, means, including a high frequency generator, for the ionization of the electrically neutral propellant present in gaseous form in a discharge chamber closed off by a perforated bottom, an acceleration electrode, and means for the neutralization of the accelerated ion beam. The discharge chamber forms part of a high frequency resonator with the perforated bottom closing off one end of this resonator and with the resonator generating a standing electric wave having a node at the bottom. The resonator is a lambda /4 resonator, where lambda is the wave length of the electric wave, and the high frequency generator is arranged inside the resonator at the end opposite the bottom. The high frequency generator preferably is a disk seal triode or a Farnsworth tube.