Molecular propellants for ion thrusters

Emissive Membrane Ion Thrusters and Their Applications

The mechanism of operation of a new thruster concept that utilizes solid-state ionic membranes to convert molecules into ions and transmit them to a surface from which they can be extracted into energetic beamlets thereby producing thrust is described. Results of recent experiments are used to estimate the performance of the thruster and the masses of various components required for it to perfo...

Fundamental Ion–surface Interactions in Plasma Thrusters

Ion thrusters offer the potential to enable many future interplanetary robotic missions presently under consideration by NASA. To realize the benefits offered by these low thrust devices, the sputtering mechanisms that are responsible for the degradation of thruster components over time must be well understood. Predictions of thruster life depend directly on the material removal rates from thru...

“Electrodeless” Plasma Cathode for Neutralization of Ion Thrusters

Significant progress has been made in the characterization of the necessary parameters required to create an effective Radio Frequency (RF) plasma based electron source. Such a device has the promise of comparable current densities to and longer operational lifetimes than hollow cathodes. The operational lifetime of hollow cathodes is ultimately limited by cathode deterioration. RF sources prov...

Investigation of the Feasibility of Fullerene Propellant for Ion Thrusters

Analytical Model of Electron Backstreaming for Ion Thrusters

Analytical equations historically used to predict the onset of electron backstreaming in ion thrusters tend to underestimate significantly the accel grid voltage required to block electron backflow from the beam plasma because they neglect detailed beamlet focusing and space charge effects inside the grid apertures. We present corrected analytical equations that provide a good estimate of the m...