Development of cost-effective 3D printing of SOA Hall thruster magnetic circuits

Electric propulsion (EP) for space applications has demonstrated tremendous benefit to a variety of NASA, military, and commercial missions. Critical NASA electric propulsion needs have been identified in the scope areas detailed below. Proposals outside the described scope shall not be considered. Proposers are expected to show an understanding of the current state of the art (SOA) and quantitatively (not just qualitatively) describe anticipated improvements over relevant SOA materials, processes, and technologies that substantiate NASA investment. To shape the magnetic fields necessary to achieve nominal operation, Hall-effect thrusters utilize a magnetic circuit that also forms the thruster structure. The magnetic circuit components direct magnetic flux (typically produced by electromagnetic coils) and may experience operational temperatures in excess of 500 C due to heating from the plasma discharge (proximity to plasma-wetted surfaces) and coil self-heating. Both low-carbon magnetic iron and cobalt-iron (Co-Fe) soft ferromagnetic alloys have been traditionally used for this application; low-carbon magnetic iron is typically cheaper with larger billet size availability, whereas Co-Fe soft ferromagnetic alloys are attractive due to high magnetic saturation and Curie temperature properties. The current SOA is to manufacture magnetic circuit components from billet/plate/rod stock material. NASA is seeking proposals to develop additively manufactured (AM) Hall thruster magnetic circuits that can achieve similar magnetic circuit topologies and structural integrity as magnetic circuits manufactured using traditional processes for operational thruster environments. This solicitation seeks the development and demonstration of the capability to additively manufacture (i.e, 3D print) a 5kW class Hall thruster magnetic circuit that has the magnetic, structural, and thermal performance as SOA traditional (wrought) manufactured magnetic circuit.