Abstract: This invention relates to a high-performance gyrotron for the production of electromagnetic millimeter or submillimeter waves with a quasi-optical resonator. The latter is formed by two concave mirrors (1, 2) placed mutually opposite one another on an optical axis. For increasing the decoupling efficiency as well as for reducing the radiation into the environment the quasi-optical resonator is placed in a housing (4), which at least in sections is electrically conductive.

Abstract: A device for guiding an electron beam from an electron gun to a microwave resonator in a microwave source operating according to the gyrotron principle, including a beam duct for guiding the electron beam, wherein the beam duct encloses the electron beam and has an electrically highly conductive surface area. For damping unwanted wave modes inside the beam duct, a plurality of damping openings are provided in the surface area of the beam duct. The characteristic aperture size (a) of the damping openings is larger than the wavelength of the modes to be damped. A particularly simple implementation employs wire mesh with an appropriate mesh size used as the material for the surface area of the beam duct.

Abstract: A quasioptical gyroklystron for generating high power quasioptical radiation. A mildly relativistic electron beam gyrating in a static magnetic field is passed through a first open mirror resonator where a small change in the transverse electron energy takes place (either an increase or decrease depending on the relative phase between the electron gyration and the resonator wave fields). This small change than leads to slower (or more rapid) gyration of those electrons that have gained (or lost) energy in the first resonator. The length of the drift region between the first and a second open mirror resonator is adjusted so that rapidly gyrating electrons overtake slowly gyrating ones at the entrance to the second resonator. Thus the particles arrive at the second resonator strongly bunched in gyration phase. The fields in the first resonator are generated by feedback of a small amount of energy from the wave mode in the second resonator with a .pi.