Abstract: A collector included in an electron tube is covered with a carbon nanotube layer over a required area on the surface thereof.

Abstract: The invention relates to a device for generation of microwaves comprising a coaxial virtual cathode oscillator (1) with an outer cylindrical tube forming a cathode (2) and connected to a transmission line (8) for feeding the cathode (2) with voltage pulses, and an inner cylindrical tube, at least partially transparent for electrons, forming an anode (3) and connected to a transmission device (8) for outputting microwave radiation generated by the formation of a virtual cathode (4) inside an area enclosed by the anode. Through the introduction of a centre conductor (5) arranged to coincide with the centre axle (19) for the cathode's (2) outer cylindrical tube and in electrical connection with the tube a device for generation of microwaves is obtained having improved energy efficiency and better broadband performance.

Abstract: An electron gun that generate an electron flow and the application of this gun to produce rf energy or for injectors. The electron gun includes an electrostatic cavity having a first stage with emitting faces and multiple stages with emitting sections. The gun also includes a mechanism for producing an electrostatic force which encompasses the emitting faces and the multiple emitting sections so electrons are directed from the emitting faces toward the emitting sections to contact the emitting sections and generate additional electrons and to further contact other emitting sections to generate additional electrons and so on then finally to escape the end of the cavity. A method for producing a flow of electrons.

Abstract: An electron gun that generates multiple electron bunches and the application of this gun to produce rf energy. The electron gun includes an rf input cavity having a first side with multiple emitting surfaces and a second side with multiple transmitting and emitting sections. The gun also includes a mechanism for producing a rotating and oscillating force which encompasses the multiple emitting surfaces and the multiple sections so electrons are directed between the multiple emitting surfaces and the multiple sections to contact the multiple emitting surfaces and generate additional electrons and to contact the multiple sections to generate additional electrons or escape the cavity through the multiple sections. A method for producing multiple electron bunches.