Linear theory of cusptron microwave tubes

Abstract

Stability properties of the negative-mass instability in a rotating annular electron beam (E layer) are investigated, in connection with applications on the cusptron microwave tubes. The analysis is carried out for an infinitely long E layer propagating through a magnetron-type conducting wall and propagating parallel to an applied axial magnetic field. It is assumed that the E layer is thin and very tenuous. A closed algebraic dispersion relation of the negative-mass instability is obtained, including the important influence of conducting boundaries on the mode control in microwave generation and amplification. It is shown that for typical present experimental beam parameters, the gain of the cusptron normalized to the excitation frequency can be comparable to that of the gyrotron. Moreover, under the appropriate geometric configuration, perturbations with azimuthal mode number N are dominantly unstable. This optimizes the microwave power output of the radiation with frequency ω≂Nωc, where ωc is the electron cyclotron frequency and N is the resonator number in the conducting wall.

Sensitivity of a Relativistic Backward-Wave Oscillator to Budker's Parameter

“…The present work is based on a self-consistent linear Vlasov analysis [12] of the relativistic backward-wave oscillator [13]. The analysis presented here is similar to that performed recently in the analysis of the cusptron [14].…”

Theory of Magnetron Amplifier in a Helix-Loaded Waveguide With the Inner Dielectric Material

“…In [13], the stability behavior of the gyrotron amplifier including inner dielectric material has been investigated. In [14]- [16], the higher harmonic amplification has been obtained in the gyrotron operation by making use of a magnetron-type waveguide.…”

An Experimental Sixteenth Harmonic Cusptron Device

“…The magnetic field requirement is, however, reduced if the device is operated efficiently at a high cyclotron harmonic. A promising way to enhance the harmonic interaction is to maximize the finite Larmour radius effect by using an axis-encircling beam (3)(4)(5)(6)(7). Such a rotating electron beam can be produced by passing an axially moving hollow beam through a cusp magnetic field.…”