A Low-Cost Metallic Cathode for a Vircator HPM Source

Recent research efforts at TTU include the testing of a rapidly charged, rep-rated Marx generator driving a reflex triode vircator [1]. As expected, the burning of the cathode material (ordinary cloth velvet), was the primary failure mechanism during repetitive operation. In an effort to achieve a repetitive vircator (>10 Hz), we are exploring a low-cost, all-metal cathode. The cathode is made from aluminum with a patterned surface. A typical pattern is composed of peaks and troughs with dimensions on the order of tens of microns. The pattern is achieved with a simple, low-cost chemical etching process. Results include current, voltage, and microwave waveforms from two solid metal cathodes and a cloth velvet cathode.