Compact Induced Current Hall Thruster

Conventional Hall thrusters are difficult to scale to very small sizes. The proposed concept is a new type of compact plasma accelerator that addresses these scaling issues. It resembles a Hall thruster, taking advantage of the heritage of this proventechnology, but the current is driven inductively. It has the advantage of needing no cathode. While inductive coupling has been successfully demonstrated, it was forced to large planar devices. Differences in the concept proposed here will allow thethruster to scale to much smaller size.In the Phase I program, Busek Co. and our research partner Worcester Polytechnic Institute (WPI) will analyze and model the induced current thruster using a suite of in-house plasma simulation and thruster design tools. The theoretical and practical sizelimits of the concept will be determined. Experiments will be performed to characterize the B-field rise time to support design of the pulsed coil and magnetic structure.At the conclusion of Phase I, the detailed design of a prototype thruster and pulse driver electronics will be prepared.In Phase II, the prototype thruster will be built and tested in existing thruster test facilities at Busek to measure and characterize the performance and further optimize the design. There will be many applications for the small, induced current thruster. Not only will this technology be useful for small spacecraft and formation flying, as currently envisioned by the Air Force, but it may also be desirable for larger thrusters forcombined primary and ACS propulsion. The large planar inductive thrusters that were tested years ago had long operating life. We expect that this much smaller inductive device will have that advantage too. Because the discharge operates a high plasmadensity it can also find application in ion beam processing such as etching and milling.