Provided is an X-ray tube which includes a first electrode, a second electrode spaced apart from the first electrode, a target disposed in a lower portion of the second electrode, an emitter on the first electrode, a third electrode which is positioned between the first electrode and the second electrode and includes an opening at a position perpendicularly corresponding to the emitter, and a spacer provided on the third electrode and surrounding the second electrode. The spacer includes a first section located adjacent to the third electrode and a second section disposed on the first section. The spacer includes a ceramic insulator and conductive dopants dispersed within the ceramic insulator. A concentration of the conductive dopants in the first section of the spacer is greater than a concentration of the conductive dopants in the second section. The third electrode is in contact with the first section of the spacer.

A computer tomograph operates by rigidly arranged x-ray tubes, which are components of emitter-detector elements, which form an emitter-detector ring opened by relocating one emitter-detector element. Each x-ray tube includes a cathode emitting electrons, and an anode arrangement having an anode. Each cathode has an orientation angle relative to the geometrical center axis of the computer tomograph. A tangential plane on the focal spot of the anode has a surface normal, which includes an anode angle with the center axis. X-ray radiation emitted from the focal spot is directed in a center radiation angle to an x-ray detector axially offset relative to the x-ray tubes. The quotient from the sum of the orientation angle, radiation angle and anode angle is between two ninths and two. Each cathode, interacting with an electrode arrangement of the x-ray tubes, produces a focal spot on one of selectable positions on the anode arrangement.

Various methods and systems are provided for a cathode of an X-ray imaging system, the cathode comprising a cup and a ceramic insulator having a convex outer surface mating with corresponding pockets on the cup surrounding the ceramic insulator.

An x-ray tube can include an x-ray window sealed to a mount. An inner-collimator can be adjacent to, but not sealed to, the x-ray window. The inner-collimator can be sandwiched between the x-ray window and an insulating-layer. The insulating-layer can span an inner-collimator-aperture of the inner-collimator, forming an isolated cavity at the inner-collimator-aperture. Walls of the cavity can include the x-ray window, the inner-collimator, and the insulating-layer. The x-ray tube can have a light weight, can block x-rays in undesirable directions, and can shape the x-ray beam.

The present invention provides an emitter, which comprises carbon nanotubes and is excellent in the efficiency of electron emission, and an X-ray tube comprising the same.

Provided are an on-chip miniature X-ray source and a method for manufacturing the same. The on-chip miniature X-ray source includes: an on-chip miniature electron source; a first insulating spacer provided on an electron-emitting side of the on-chip miniature electron source, where the first insulating spacer has a cavity structure; and an anode provided on the first insulating spacer, where a closed vacuum cavity is formed between the on-chip miniature electron source and the anode. The on-chip miniature X-ray source has the advantages of stable X-ray dose, low working requirements for vacuum, fast switch response, capability of integration and batch fabrication, and can be used in various types of small and portable X-ray detection, analysis and treatment devices.

A planar filament 11.sub.f can include multiple materials to increase electron emission in desired directions and to suppress electron emission in undesired directions. The filament 11.sub.f can include a core-material CM between a top-material TM and a bottom-material BM. The top-material TM can have a lowest work function WF.sub.t; the bottom-material BM can have a highest work function WF.sub.b; and the core-material CM can have an intermediate work function WF.sub.c (WF.sub.t<WF.sub.c<WF.sub.b). A width W.sub.t of the filament 11.sub.f at a top-side 31.sub.t can be greater than its width W.sub.b at a bottom-side 31.sub.b (W.sub.t>W.sub.b). This shape makes it easier to coat the edges 31.sub.e with the bottom-material BM, because the edges 31.sub.e tilt toward and partially face the sputter target. This shape also helps direct more electrons to a center of the target 14, and reduce electron emission in undesired directions.

An X-ray radiator and an X-ray assembly are disclosed. The X-ray radiator according to an embodiment has an evacuated X-ray tube housing, mounted to be rotatable about a rotation axis, the X-ray tube housing including an anode and an electron source. The anode is arranged within the X-ray tube housing non-rotatably relative to the X-ray tube housing and is configured to generate X-ray radiation via electrons impacting upon a focal spot of the anode, the electron source being mounted substantially stationary within the X-ray tube housing relative to the rotation axis. The electron source has a main emitter and at least one subsidiary emitter for emitting electrons. The electron emission of the main emitter and/or of the at least one subsidiary emitter is controllable such that a spatial movement of the focal spot due to a movement of the electron source is reduced.

Provided is an X-ray tube. The X-ray tube includes a cathode electrode, an anode electrode vertically spaced apart from the cathode electrode, an emitter on the cathode electrode, a gate electrode disposed between the cathode electrode and the anode electrode, the gate electrode including an opening at a position corresponding to the emitter, and a spacer provided between the gate electrode and the anode electrode. The spacer includes an insulator and conductive dopants doped in the insulator.

Systems and methods are provided for improving thermal management strategies of a cathode assembly of an x-ray tube. In one embodiment, an x-ray tube comprises an anode assembly and a cathode assembly, wherein the cathode assembly includes one or more elements that include an internal porous section for controlling a flow of heat within the cathode assembly during operation of the x-ray tube. In this way, heat conduction to temperature sensitive aspects of the cathode assembly may be reduced, while enabling sufficient heat transfer to other parts of the cathode assembly to minimize deformation.