The dispersion relation of azimuthal electromagnetic surface waves on a magnetized plasma column surrounded by a metallic cylindrical dielectric lined slow-wave waveguide is obtained. The permissible frequency region for these waves in E-and B-mode is presented. Furthermore, the graphs of frequency spectra and radial dependence of fields on the external magnetic field strength, geometric dimensions of the waveguide, radius of plasma column and thickness of dielectric are investigated.

The theory of ion-channel guiding in a helical wiggler is presented. Electron motion in the combined ion electrostatic and wiggler magnetostatic fields is analyzed in the absence of the radiation field. The Phi function that determines the rate of change of axial velocity with energy is derived and studied numerically. A detailed analysis of the pendulum equation and the gain equation in the low-gain-per-pass limit are presented. It is shown that the gain for stable group I orbits is positive, while for group II orbits the gain is negative in the negative mass regime and positive in the positive mass regime.

An analysis of the azimuthally symmetrical, high-frequency eigenmodes of a cylindrical metallic waveguide partially filled with a magnetized plasma is presented. Equations that permit calculation of the dispersion curves for four families of electromagnetic and electrostatic modes are derived. Numerical solutions are presented to facilitate the development of devices for generation of high-power electromagnetic radiation, charged particle acceleration, and other applications of plasma waveguides. The dependence of the cutoff frequencies, and dispersion curves of various modes on the ratio of the plasma radius a to the waveguide radius R is studied in detail. Space-charge modes are found to be strongly dependent on the radius ratio a/R. The coupling of the dispersion curves of different modes and the variation of the cutoff frequencies of HE waveguide and cyclotron modes with cyclotron frequency are illustrated for the partially filled waveguide.

The wiggler pumped ion-channel free electron laser (WPIC-FEL) is treated and the classes of possible single-particle electron trajectories in this configuration are discussed in the paper. A new region of orbital stability is seen in the negative mass regime. A kinetic description of WPIC-FEL is given. Vlasov-Maxwell equations are solved to get the linear gain in a tenuous-beam limit, where the beam plasma frequency is much less than the radiation frequency and the self-field effects can be ignored.

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