High power vircator source development

The vircator in its modern form is an essentially new class of microwave tube. It has the attributes of conceptual simplicity, high output power capacity and wide tunability. Frequencies ranging from 800 MHz to over 40 GHz have been witnessed. These features have already been demonstrated experimentally at MRC, on a small scale. Furthermore, experimental work in other laboratories, and the results of particle code simulations, have clearly indicated that the vircator is a source of extraordinarily high power. Hence, it has some unique applications. The virtual cathode oscillator results when the beam current injected into a waveguide or cavity resonator exceeds the space-charge limiting current. The limiting current is defined by the beam energy and waveguide or resonator geometry. The lack of a stable steady state equilibrium for the beam under these conditions results in formation of a virtual cathode, which is a stable oscillatory state of the electron beam