Additively manufactured anodes in a relativistic Planar Magnetron

Recent experiments on the UM Recirculating Planar Magnetron (RPM), have explored the use of 3-D printed components in a HPM system. The system was driven by MELBA-C, a Marx-Abramyan system which delivers a -300 kV voltage pulse for 0.3-1.0 us, with a 0.13-0.31 T axial magnetic field applied by a pair of electromagnets. Anode blocks were printed from Water Shed XC 11122 photopolymer using a stereolithography process, and prepared with either a spray-coated or electroplated finish. Both manufacturing processes were compared against baseline data for a machined aluminum anode, demonstrating improvements in pulsed magnetic field penetration, while maintaining similar performance for power output, oscillation frequency, and mode stability. Residual gas analysis indicated similar outgassing behavior, with a higher incidence of gas spikes for the plastic anodes. With over 100 shots on each 3-D printed structure, there was no evidence of beam-induced degradation.