Theoretical aspects of the electronical devices operating due to interaction between annular electron beams and the azimuthal surface waves

The paper considers physical basis of the electronical devices operating due to the beam or dissipative instability of the azimuthal surface waves (ASW). The ASW are the electromagnetic surface waves with extraordinary polarization (with field components Er, Eψ, Hz), they propagate across the axial external steady magnetic field B̄o ∥ z̄ in the metal cylindrical waveguide with cold plasma filling. The ASW fields are described by Maxwell equations. To solve the problem we use the Fourier method and numerical simulation of the obtained equations. The ASW excitation under the conditions of the beam and dissipative instabilities due to the electron beam motion is examined. We also study the correction to the ASW eigenfrequencies caused by the waveguide chamber noncircularity. The ASW delaing leads to the negative frequency correction. The ASW energy can be emited from the narrow slot in the metallic chamber of the waveguide. We found the optimum wavenumber range where increments values are much greater than those of the ASW decrement caused by their energy radiation.