A transmitting antenna includes a first and a second vacuum tube. Each respective vacuum tube includes at least a grounded cathode, a control grid that receives a respective a respective signal, and a plate electron collector. A first spherical ball is connected by a first conducting wire to the plate electron collector of the first vacuum tube. A second spherical ball connected by a second conducting wire to the plate electron collector of the second vacuum tube. Output of the transmitting antenna is produced by an electromagnetic wave that is radiated from conduction current in each of the first and second conducting wires. In another aspect of the invention, first and second spherical balls are connected by conducting wires to the collectors of respective charged particle beam vacuum tubes in which a charged particle beam gun produces a beam of finite length of electrons or ions within the vacuum tube that moves within the vacuum tube at a controlled speed to generate an electromagnetic wave.

An apparatus, system, and method for performing electron beam modulation includes an input pulser to provide an electromagnetic pulse; a radio frequency (RF) filter to filter the electromagnetic pulse; a nonlinear transmission line to receive the electromagnetic pulse, and generate a backward wave RF oscillation of a predetermined frequency to travel in a direction opposite that of the electromagnetic pulse; and an electron beam generating device including an anode and a cathode, the electron beam generating device to receive a combined electromagnetic pulse from the RF filter and the backward wave RF oscillation from the nonlinear transmission line to cause excitation of a modulated voltage between the anode and cathode, and to cause the electron beam generating device to emit an electron beam that is modulated at the predetermined frequency of the backward wave RF oscillation.

A non-cryogenic electro-permanent magnet for use in a gyrotron comprises a plurality of toroidal-shaped sets of electromagnet coils and a plurality of toroidal-shaped permanent magnets, each permanent magnet comprising a plurality of arc segment blocks. Each set of the coils is separated from an adjacent set of the coils by one or more of the permanent magnets disposed between the adjacent sets of coils, such that the coils and the permanent magnets are arranged concentrically to form an open central bore. A combination of magnetic fields in the permanent magnets and magnetic fields in the coils generates a substantially uniform axial magnetic field in the bore.

A large electron tube includes: a tubular collector; and a magnetic body disposed outside the collector and having no axial symmetry with respect to a center axis of the collector. This makes it possible to inhibit parasitic oscillation that occurs inside the collector.

A cylindrical waveguide with a mode converter transforms a whispering gallery mode from a gyrotron cylindrical waveguide with a helical cut launch edge to a quasi-Gaussian beam suitable for conveyance through a corrugated waveguide. This quasi-Gaussian beam is radiated away from the waveguide using a spiral cut launch edge, which is in close proximity to a first mode converting reflector. The first mode converting reflector is coupled to a second mode converting reflector which provides an output free-space HE11 mode wave suitable for direct coupling into a corrugated waveguide. The radiated beam produced at the output of the second mode converting reflector is substantially circular.

Disclosed are methods and devices suitable for generating electron beams and pulses of radiation. Specifically, in some disclosed embodiments, multiple emitting electrodes of a ferroelectric emitter are sequentially activated, generating a relatively long electron beam pulse that is substantially a series of substantially consecutive short electron beam pulses generated by the sequentially-activated individual emitting electrodes.

A main power supply 51 supplies power to a main voltage circuit 5 applying a voltage to an electron gun unit 2a and a collector unit 26, a body power supply 31 supplies power to a body voltage circuit 3 applying a voltage to a body unit 25 and the collector unit 26, and a body power supply stabilization circuit 33 maintains an input/output voltage varying between an electron gun side supply line 51b of the main power supply 51 in the main voltage circuit 5 and a body side supply line 31b of the body power supply 31 in the body voltage circuit 3 at a predetermined output voltage.

According to one embodiment, a klystron includes a high-frequency interaction unit, a main magnet arranged in a ring shape around the high-frequency interaction unit, an output waveguide, an auxiliary magnet arranged in a ring shape opposing the output waveguide, an output unit for extracting high-frequency power from the output waveguide, and an output adjustment mechanism which adjusts the output of the high-frequency power extracted from the output unit by deforming the output waveguide. In the output adjustment mechanism, the output waveguide is deformed by engaging a distal end of a jig inserted from an outside of the auxiliary magnet via a jig insertion hole with an engagement member and pushing or pulling the engagement member.