DISPERSION CHARACTERISTICS OF WAVES IN A WAVE-GUIDE WITH AN ANNULAR PLASMA-COLUMN

A detailed analysis of waves in a cylindrical waveguide containing an annular plasma column is presented. Dispersion relations for four fami lies of electromagnetic and electrostatic modes are derived and solved numerically to study the characteristics of azimuthally symmetrical a nd nonsymmetrical eigenmodes. The general result which is obtained for the annular plasma is reduced to be used for the thin annular and sol id configurations. Figures are presented to illustrate the dependence of frequencies on the plasma radii and the cyclotron frequency. Intera ction of the dispersion curves of HE waveguide modes with cyclotron mo des is demonstrated graphically. The presented results may be used in the studies of free-electron type devices for generation of high-power electromagnetic radiation. (C) 1998 American Institute of Physics. [S 1070-664X(98)02211-3].