High power vircator research at physics international

Physics International reports the results of a three-phase program to explore the feasibility of constructing and operating a large array of high power, phase-locked vircators. The approach has been to study multiple high power sources in all the relative configurations that would be encountered in an array architecture. Resonant cavities enclosing the virtual cathodes reduce the bandwidth of the oscillations sufficiently to allow phase-locking. Locking is observed between sources generating microwave powers exceeding 1 GW. It is shown that high power sources can be “over-driven”: strong coupling between sources minimizes the duration of the transient to the locked state, but a limit exists beyond which instabilities defeat phase-locking. The time resolved variation in the final relative phase angle between locked sources and the duration of the transient to the final state both decrease with the initial frequency detuning between the sources.