A system for injecting radio frequency (RF) pulses into an RF linear accelerator (RF LINAC) cavity is described. In accordance with the description an RF power amplifying element, typically a compact planar triode (CPT), is directly mounted to an outside of a hermetically sealed RF cavity. The direct mounting of the RF power amplifying element places the antennaresponsible for coupling power into the RF cavityphysically on the RF cavity side of a hermetic high-voltage (HV) break. The RF input, RF circuitry, biasing circuitry, and RF power amplifier are all outside of the vacuum cavity region. The direct mounting arrangement facilitates easy inspection and replacement of the RF power amplifier, the RF input and biasing circuitry. The direct mounting arrangement also mitigates the deleterious effects of multipactoring associated with placing the RF power amplifier and associated RF circuitry in the vacuum environment of the RF LINAC cavity.

The invention relates to a cathode arrangement comprising: a thermionic cathode comprising an emission portion provided with an emission surface for emitting electrons, and a reservoir for holding a material, wherein the material, when heated, releases work function lowering particles that diffuse towards the emission portion and emanate at the emission surface at a first evaporation rate; a focusing electrode comprising a focusing surface for focusing the electrons emitted from the emission surface of the cathode; and an adjustable heat source configured for keeping the focusing surface at a temperature at which accumulation of work function lowering particles on the focusing surface is prevented.

In the present invention, a flat emitter is formed by the formation of emitter material wires into a unitary non-porous flat emitter structure. The wires are formed with increased yield and tensile strength as a result of the manner of the formation of the emitter material or metal into the wires that is transferred to the flat emitter. To form the flat emitter, the wires are encapsulated and subjected to sufficient temperatures and pressure in a hot isostatic pressing treatment/process to increase the density of the wires into a solid sheet without the presence of voids or pores in the sheet. In forming the emitter sheet in this manner, the strength properties from the wires are retained within the sheet to provide the emitter with increased creep resistance and a consequently longer useful life in the x-ray tube.

An electron emission apparatus, an electron gun, and a method of fabrication of the electron gun are provided. The electron gun includes a cathode, a Wehnelt, and an anode. The cathode is configured to provide an electron beam. The Wehnelt has a bore. The bore is configured to pass the electron beam. The anode is disposed proximate to the cathode. The diameter of the bore of the Wehnelt and the offset between the Wehnelt and the cathode satisfy a predetermined dimensional relationship. The predetermined dimensional relationship is at least a function of a diameter of the bore of the anode and a distance between the Wehnelt and the anode.

The disclosed embodiments relate to a charged particle source module for generating and emitting a charged particle beam, such as an electron beam, comprising: a frame including a first frame part, a second frame part, and one or more rigid support members which are arranged between said first frame part and said second frame part; a charged particle source arrangement for generating a charged particle beam, such as an electron beam, wherein said charged particle source arrangement, such as an electron source, is arranged at said second frame part; and a power connecting assembly arranged at said first frame part, wherein said charged particle source arrangement is electrically connected to said connecting assembly via electrical wiring.

A magnetically microfocused electron emission source apparatus is disclosed. The apparatus may include a magnetic emitter unit, wherein the magnetic emitter unit comprises an emitter. Further, the magnetic emitter unit may include one or more magnetic portions formed from one or more magnetic materials, wherein the one or more magnetic portions of the magnetic emitter unit are configured to generate a magnetic field proximate to a tip of the emitter of the magnetic emitter unit for enhancing focusing of the emitted electrons from the electron emitter.

Electron gun systems with a particular inner width dimension, sweep electrodes, or a combination of a particular inner width dimension and sweep electrodes are disclosed. The inner width dimension may be less than twice a value of a Larmor radius of secondary electrons in a channel downstream of a beam limiting aperture, and a Larmor time for the secondary electrons may be greater than 1 ns. The sweep electrode can generates an electric field in a drift region, which can increase kinetic energy of secondary electrons in the channel.

A field emission cathode device and method for forming a field emission cathode device involve a cathode element having a field emission surface disposed in spaced-apart relation to a gate electrode element so as to define a gap between the field emission surface and the gate electrode element. The gate electrode element extends laterally between opposing anchored ends. The gate electrode element is arranged to deform away from the field emission surface in response to heat, so as to increase the gap between the field emission surface and the gate electrode element.

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.