Provides a survey of the progress in the field, an evaluation of the state of the art, and trends of future developments. Covers: klystrons; magnetrons; vircators, reflex-diodes; Cherenkov devices. Extensive bibliography.

The book presents results of a comprehensive study of various features of eigen electromagnetic waves propagating across the axis of plasma filled metal waveguides with cylindrical geometry. The authors collected in one book material on various features of surface flute waves, i.e. impact of waveguide design on wave dispersion, wave damping influenced by various reasons, impact of plasma density and external magnetic field inhomogeneity on the wave, and impact of waveguide corrugation and electric current on the wave. A variety of present surface waves applications and possible future applications is also included. Using the method of successive approximations it is shown how one can solve problems, which concern real experimental devices, starting from simple models. The book applies to both professionals dealing with problems of confined plasmas and to graduate and post-graduate students specializing in the field of plasma physics and related applications.

This book presents a comprehensive theoretical study of the electromagnetic eigenwaves propagating perpendicular to the axis of symmetry in various cylindrical waveguide-structures filled with magneto-active plasma. It is the second, updated and significantly expanded edition of our book “Surface Flute Waves in Plasmas. Theory and Applications”, published in 2014 in the “Springer Series on Atomic, Optical, and Plasma Physics”. First, the text is complemented by a study of the wave energy rotation around the axis of the waveguides. Second, excitation of these waves by an electron beam gyrating around the axis is investigated in detail. “Surface waves” means that these waves only propagate along plasma surfaces and not in uniform infinite plasmas. Their wave amplitudes decrease with going away from the plasma boundary into the plasma depth. “Flute” means that the axial wavenumbers kz of the waves in plasma cylinders are assumed to be zero, and the waves only propagate in azimuthal direction. In this case, the surfaces of constant density resemble fluted Greek columns. However, the presence of a small but finite kz can be taken into account by the method of successive approximations, using the theory of surface flute waves as zeroth approach. A variety of present applications of surface waves and possible future applications are also included. The book applies to both professionals dealing with physical and technological problems of confined plasmas and to graduate and post-graduate students specializing in the fíelds of electrodynamics, plasma physics and related applications.

This report presents an update of the experimental achievements published in the review “State- of-the-Art of High-Power Gyro-Devices and Free Electron Masers”, Journal of Infrared, Millime-ter, and Terahertz Waves, 41, No. 1, pp 1-140 (2020) related to the development of gyro-devices (Tables 2-34). Emphasis is on high-power gyrotron oscillators for long-pulse or continuous wave (CW) operation and pulsed gyrotrons for any applications.