Efficient 58-GHz relativistic orotron with combined mode selection

Abstract

This article presents time-dependent numerical modeling of V-band relativistic orotron: a high-power microwave generator with a TM03 oscillation mode in an oversized (D/λ ∼ 2.7) electrodynamic structure and diffractive output in the TM02 mode. Single-mode operation of the oscillator is ensured by the cyclotron selection of the working axisymmetric mode, with simultaneous depression of competing non-axisymmetric modes by means of cutting longitudinal slits in the wall of the slow-wave structure. The simulated output microwave power is 350 MW with a power conversion efficiency of 31% when using a 3.6 kA, 310 keV electron beam transported in the 3.9 T magnetic field. The simulation employed 2.5D axisymmetric and 3D Cartesian versions of the KARAT code.

Investigation and suppression of asymmetric modes competition in Cerenkov device by conductivity anisotropic material loading

“…Many technical methods have been proposed for suppressing symmetric mode competition [18,19], but discussions on asymmetric mode competition are scant. To date, the main methods for suppressing asymmetric modes are improving the uniformity of the electron beam and optimising the output structures [12,15,[20][21][22]. It is difficult to improve the uniformity of the electron beam in an explosive emission cathode, which is widely used in HPM sources.…”

Code KARAT in simulations of power microwave sources including Cherenkov plasma devices, vircators, orotron, E-field sensor, calorimeter etc.

“…A high-power V-band relativistic orotron on a TM03 oscillation mode has an ovesized (D/k | 2.7) electrodynamic structure and diffractive output in the TM02 mode [3]. Single-mode operation of the oscillator is ensured by the cyclotron selection of the working axisymmetric mode, with simultaneous depression of competing non-axisymmetric modes by means of cutting longitudinal slits in the wall of the SWS.…”

PIC-simulation of efficient cherenkov X-band and V-band HPM sources with moderately relativistic electron beams

“…A scheme of V-band high power microwave oscillator of orotron type [3] with oversized (D/λ ~ 2.7) electrodynamic structure is presented. The proposed device operates the axisymmetric TM 03 mode of a rippled circular waveguide, while the output mode is TM 02 .…”

“…In the orotron being considered, the resonant magnetic field (energy of electromagnetic wave is converted into kinetic energy of electrons rotating in magnetic field) is about 3.0 T. It is near the field of the selected excitation of TM 03 mode observed in the simulations. Indeed, for this mode, the squared amplitude of radial electric field (which determines the intensity of cyclotron absorption of any symmetrical TM waves) is proportional to As for competing non-axisymmetric modes, they can be depressed by interrupting the azimuthal conductivity of the electrodynamic structure (for example, by cutting longitudinal slits through its wall [3]). …”