Reflex-triode geometry of the virtual-cathode oscillator

An eight-stage four-hundred kilovolt Marx bank, in connection with a 60 nanosecond pulse-forming line, is constructed and utilized as a pulsed source to power a planar version of the Virtual Cathode Oscillator (Vircator). Eight .1νF capacitors, charged to 50kV each, are switched in series by dry-air pressurized spark gaps. The energy from the bank charges a 23 ohm oil transmission line, breaking a peaking gap when the maximum voltage is reached, delivering a 60 ns-300kV pulse to the diode. The design of the Planar or "Reflex-Triode" geometry Vircator is based upon claims of high efficiency by Didenko et al. A previously constructed TTU Vircator includes a unique E-beam source, the "brush" cathode; in which a circular array of pins is used as an explosive field emission source to produce relatively high beam currents. The anode consists of a round wire mesh through which the E-beam passes, generating a dense cloud of negative charge known as a "Virtual Cathode". This initial phase of testing is composed of basic operation of the entire system and baseline output power and efficiency measurements.