Particle-in-Cell Modeling of Axial and Coaxial Virtual Cathode Oscillators

The objective of this paper is to report findings based on the particle-in-cell (PIC) modeling of the axial and coaxial virtual cathode oscillators in order to validate the experiments already performed on these devices over the years. In addition to this, observations regarding validation and similarities between the simulations and the experiments have been reported, with an emphasis on analysis of device parameters such as e-beam voltage, current density, and microwave power. Theoretical aspects of a virtual cathode oscillator (vircator) and some of the key experimental works have been revisited. Investigation is done on the power generated in a coaxial vircator, and various cavity modifications have been tested for the coaxial vircator using the MAGIC3D, PIC tools suite, in order to search for improvement in the device efficiencies. Also, the axial vircator has been modeled to comment on the particle energies, device design, and beam quality associated with it.