Experimental Studies of Anode and Cathode Materials in a Repetitive-Driven Axial Vircator

An axial vircator has been designed in which it is simple to change the anode and cathode for testing different anode-cathode configurations and materials. The vircator is driven by a 500 kV, 500 J repetitive Marx generator with a pulse repetition frequency of 10 Hz. The materials are tested with bursts of 10 pulses at 10 Hz and the time between bursts is a few minutes. Velvet cloth, graphite, machined stainless steel as cathodes and stainless steel mesh, etched stainless steel, stainless steel wires and tungsten wires as anodes are examples of different materials that have been tested. During the tests with different materials, the vircator was radiating into an anechoic chamber. The current through and voltage over the vircator are monitored as well as the radiated microwave field in the chamber. For rating the performance of the different materials, parameters as maximum radiated field, radiation frequency, vircator impedance, and number of shots before the material is deteriorated are compared.