A field emission electron source and a method of manufacturing the same. A field emission electron source comprises an emitting electrode and an extractor gate electrode. The emitting electrode comprising a plurality of particles with nanosharp protrusions. The extractor gate electrode comprises a metal. The extractor gate electrode is formed in a same plane as the emitting electrode. The extractor gate electrode is formed surrounding the emitting electrode. A method of manufacturing a field emission electron source comprises forming an emitting electrode comprising a plurality of particles with nanosharp protrusions using a direct ink writing (DIW) printer. The method comprises forming an extractor gate electrode comprising a metal using the DIW printer.

The present disclosure relates to a CNT X-ray source apparatus, and more particularly, to a CNT X-ray source apparatus configured to maximize utilization of the internal space of a CNT X-ray tube body, having grooves made of an insulating material, and provided with a base portion for supporting a plurality of electrodes. With this configuration, mass production is possible. The CNT X-ray source apparatus of the present disclosure includes a cathode electrode; an emitter provided on the cathode electrode and responsible for emitting electrons; a gate electrode disposed above the cathode electrode and spaced apart from the cathode electrode by a predetermined interval; a focusing electrode for preventing scattering of electrons emitted from the emitter; and a base portion responsible for supporting one or more of the cathode electrode, the gate electrode, and the focusing electrode and formed of an insulating material. In this case, one or more grooves for accommodating at least one of the cathode electrode, the gate electrode, and the focusing electrode are formed in the base portion.

In a cylindrical guard electrode (5) provided on the outer peripheral side of an electron generation part (31) of an emitter (3), a distal end section (5A) 5 positioned in the emission direction of an electron beam (L1) from the electron generation part (31) includes: a distal end inner-peripheral-side part (A1) having an inner-peripheral-side curved surface portion (a1) convex in the emission direction; a distal end outer-peripheral-side part (A2) having an outer-peripheral-side curved portion (a2) convex in the emission direction; and a 10 distal end middle part (A3) positioned between the distal end inner-peripheral-side (A1) and the distal end outer-peripheral-side part (A2). The distal end middle part (A3) has a flat surface portion (a3) between the inner-peripheral-surface portion (a1) and the outer-peripheral-side curved surface portion (a2) so as to extend in the direction therebetween.

Some embodiments include an x-ray source, comprising: an anode; a field emitter configured to generate an electron beam; a first grid configured to control field emission from the field emitter; a second grid disposed between the first grid and the anode; and a middle electrode disposed between the first grid and the anode wherein the second grid is either disposed between the first grid and middle electrode or between the middle electrode and the anode.

A vacuum container is configured so that an opening on one side and an opening on another side in the longitudinal direction of a cylindrical insulating body are sealed with an emitter unit and a target unit respectively; and a vacuum chamber is provided on the inner peripheral side of the insulating body. The emitter unit is provided with: a moving body located on the one side in the longitudinal direction in the vacuum chamber and supported so as to be movable in the longitudinal direction via a bellows; and a guard electrode located on the outer peripheral side of the moving body. An emitter section having an electron generating section is formed at a tip section of the moving body on the other side in the longitudinal direction by subjecting the surface of the tip section to film formation processing.

An X-ray tube according to an embodiment of the inventive concept includes a cathode structure; an anode structure spaced vertically from the cathode structure, a gate electrode structure disposed between the cathode structure and the anode structure, an emitter array disposed between the cathode structure and the gate electrode structure, a tube sheath configured to connect the cathode structure and the anode structure, and a fixing unit connected with the gate electrode structure. The cathode structure includes a first rotation shaft and a cathode connected with the first rotation shaft as one body. The gate electrode structure includes a second rotation shaft and a gate electrode connected with the second rotation shaft through a bearing, and the second rotation shaft is connected with the first rotation shaft by a coupling unit. The gate electrode includes a gate electrode substrate and a protruding part that protrudes from the gate electrode substrate toward an emitter. The protruding part of the gate electrode includes a gate hole that vertically overlaps the emitter. The fixing unit includes a ferromagnetic structure attached to one surface of the gate electrode substrate and disposed on an outer portion of the substrate and a permanent magnet disposed adjacent to the ferromagnetic structure with the tube sheath therebetween.

Some embodiments include an x-ray source, comprising: an anode; a field emitter configured to generate an electron beam; a first grid configured to control field emission from the field emitter; a second grid disposed between the first grid and the anode; a third grid disposed between the first grid and the anode; and a middle electrode disposed between the first grid and the anode wherein the second grid is either disposed between the first grid and middle electrode or between the middle electrode and the anode; wherein the third grid is a mesh grid.

A field emission cathode device and formation method involves a rotating field emission cathode including a field emission material deposited on a surface thereof, the field emission cathode rotating about an axis and being electrically connected to ground, and a planar gate electrode extending parallel to the surface of the rotating field emission cathode and defining a gap therebetween. A gate voltage source is electrically connected to the gate electrode and is arranged to interact therewith to generate an electric field, with the electric field inducing a portion of the surface of the rotating field emission cathode adjacent to the gate electrode to emit electrons from the field emission material toward and through the gate electrode.

A multisource volumetric spectral computed tomography imaging device includes an x-ray source array with multiple spatially distributed x-ray focal spots, an x-ray beam collimator with an array of apertures, each confining the radiation from a corresponding x-ray focal spot to illuminate a corresponding segment of an object, a digital area x-ray detector, and a gantry to rotate the x-ray source array and the detector around the object. An electronic control unit activates the radiations from the x-ray focal spots to scan the object multiple times as the gantry rotates around the object. The images are used to reconstruct a volumetric CT image of the object with reduced scattered radiation. For dual energy and multi energy imaging, radiation from each focal spot is filtered by a corresponding spectral filter to optimize its energy spectrum.

A power supply circuit and a field emission electron source are provided. The power supply circuit includes: field effect transistors S.sub.i coupled in series via drains and sources in sequence, 1≤i≤n, i and n are natural numbers, n≥2, and a source of S.sub.1 is coupled to a negative electrode of a voltage source, and a drain of S.sub.n is used as an output terminal of the power supply circuit to couple to a load; a first group of diodes D.sub.1i coupled in series; a first group of resistors R.sub.1j, 2≤j≤n, and i and j are natural numbers; and a voltage control module configured to adjust an output voltage of the voltage source to cause a current passing through the load to be constant; the field effect transistors S.sub.i, 1≤i≤n, operate in a resistive region.