The aurora reflex-diode HPM source

This status report on the ongoing reflex-diode microwave source on Aurora documents the production of ~ 400 J microwave pulses below 1.0 GHz in pulses lasting ~ 100 ns. The energy is measured in radial waveguides. The diagnostics include waveguide directional couplers, waveguide card calorimeters, and free-field antennas. The energy extracted per arm is independent of the number of arms (up to eight). Attempts at increasing the microwave energy by varying anode material, anode/cathode spacing, or cavity length around the virtual cathode are inconclusive. Thin aluminum anode foils survive tens of shots without damage.