According to one embodiment, a klystron includes a plurality of cavity resonators arranged next to each other on a coaxial line. The cavity resonators each comprise a cylindrical body, one and another drift tubes provided on respective sides of respective ends of the cylindrical body, one and another support and a space adjustment means which adjusts the space between the one and the other drift tubes. The cylindrical body comprises a projection projecting from one end surface parallel to the axial line, and the one support is provided to abut on the projection, and the space adjustment means presses the one support toward the projection and adjusts the space between the one and the other drift tubes by plastically deforming the projection.

According to one embodiment, a klystron includes a plurality of cavity resonators arranged next to each other on a coaxial line. The cavity resonators each comprise a cylindrical body, one and another drift tubes provided on respective sides of respective ends of the cylindrical body, one and another support and a space adjustment means which adjusts the space between the one and the other drift tubes. The cylindrical body comprises a projection projecting from one end surface parallel to the axial line, and the one support is provided to abut on the projection, and the space adjustment means presses the one support toward the projection and adjusts the space between the one and the other drift tubes by plastically deforming the projection.

Embodiments include a vacuum device, comprising: an enclosure configured to enclose a vacuum, comprising an external base forming at least a portion of the enclosure; an internal base within the enclosure; and at least one thermal dissipative strap assembly, comprising: an internal base thermal conductive base in contact with the internal base, an external base thermal conductive base in contact with the external base, and a flexible thermal dissipative strap coupling the internal base thermal conductive base to the external base thermal conductive base.

Embodiments include a vacuum device, comprising: an enclosure configured to enclose a vacuum, the enclosure including an external base including an opening; an internal base within the enclosure; and an adjustable support assembly adjustably coupling the internal base to the external base and extending through the opening, the adjustable support assembly comprising: a threaded shaft extending along a longitudinal axis and coupled to the internal base; a threaded hole component threadedly engaged with the threaded shaft and coupled to the external base such that the threaded hole component is axially constrained in a direction along the longitudinal axis relative to the external base independent of the threaded shaft; and a flexible component coupled to the external base and the threaded shaft and sealing the opening.

To suppress both influence of electron emission from a cathode side surface and consumption of energy to be supplied to a heater, while being provided with a grid, an electron gun of the present invention includes: a cathode capable of emitting electrons by heating; a grid capable of controlling the electron emission; and a cathode shield which is an conductor including a material portion located in the vicinity of a side surface of the cathode and facing at least a portion of the side surface via a gap or a heat insulating material, and not being made in direct physical coupling nor in direct physical contact with the cathode.

A klystron is provided. The klystron comprises an output cavity, an output waveguide, and a coupling port, the output waveguide is connected to a side wall of the output cavity through the coupling port, an additional cavity is provided on the side wall of the output cavity, the additional cavity is connected with the output cavity and extends from a position connected to the output cavity in a direction away from a central axis of the output cavity.

A klystron is provided. The klystron comprises an output cavity, an output waveguide, and a coupling port, the output waveguide is connected to a side wall of the output cavity through the coupling port, an additional cavity is provided on the side wall of the output cavity, the additional cavity is connected with the output cavity and extends from a position connected to the output cavity in a direction away from a central axis of the output cavity.

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 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 multi-frequency klystron has an electron gun which generates a beam, a circuit of bunch-align-collect (BAC) tuned cavities that bunch the beam and amplify an RF signal, a collector where the beam is collected and dumped, and a standard output cavity and waveguide coupled to a window to output RF power at a fundamental mode to an external load. In addition, the klystron has additional bunch-align-collect (BAC) cavities tuned to a higher harmonic frequency, and a harmonic output cavity and waveguide coupled via a window to an additional external load.