According to one embodiment, in an X-ray tube, an electron convergence cup has a first surface located closer to the anode, and an electron convergence groove opening on the first surface and housing a filament. The first surface has a first edge located on the opening, and a second edge located on the opening and opposite to the first edge in a first direction. The first edge is closer to an outer peripheral part than the second edge is. When the distance between the first edge and the filament in the first direction is defined as a first distance and the distance between the second edge and the filament in the first direction is defined as a second distance, the first distance is shorter than the second distance.

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.

Various methods and systems are provided for x-ray tube conditioning for a computed tomography imaging method. In one embodiment, x-ray may be generated in an x-ray tube of a radiation source prior to a diagnostic scan to warmup the x-ray tube to a desired temperature for the diagnostic scan. The power delivered to the x-ray tube during warmup may be adjusted in a closed loop system based on an initial temperature of the x-ray tube and the desired temperature for the diagnostic scan. During tube warmup, by placing a blocking plate coupled to a collimator blade in a path of the x-ray beam, the x-ray beam may be blocked from exiting a collimator.

Provided is a target assembly for an x-ray apparatus comprising a target housing and an entrance path formed in an entrance part of the target housing for accepting an incident electron beam, as well as a target member for generating x-rays under electron beam illumination through the entrance path and an exit path formed in an exit part of the target housing for allowing generated x-rays to exit the target assembly, the exit path being covered by an x-ray transmissive window. In the assembly, the exit path comprises an exit bore formed in the exit part which is configured to limit the generation of x-rays by impact of scattered electrons, which have been reflected from the target member, onto an inside of the bore. Also provided is a target assembly, an x-ray apparatus, a structure measurement apparatus, a structure measurement method, and a method of modifying a target assembly.

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.

An x-ray micro-beam radiation production system is provided having: a source of accelerated electrons, an electron focusing component configured to focus the electrons provided by the source, and a target which produces x-rays when electrons impinge thereon from the source. The electron focusing component is configured to focus the electrons provided by the source such that they impinge at a focal spot having a width δ formed on a surface of the target. The focusing component is configured to move the electron beam relative to the target such that the focal spot moves across the target surface in the width direction, and/or the target is movable relative to the focusing component such that the focal spot moves across the target surface in the width direction, the surface velocity of the focal spot across the target surface in the width direction being greater than v.sub.t where:formula (I), k, ρ and c denoting respectively the heat conductivity, the density and the heat capacity of the target material, and d denoting the electron penetration depth in the target material.

[00001]$v_t=\frac{\pi k}{4\rho c}.Math.\frac{\delta }{d^2},$

An x-ray micro-beam radiation production system is provided having: a source of accelerated electrons, an electron focusing component configured to focus the electrons provided by the source, and a target which produces x-rays when electrons impinge thereon from the source. The electron focusing component is configured to focus the electrons provided by the source such that they impinge at a focal spot having a width δ formed on a surface of the target. The focusing component is configured to move the electron beam relative to the target such that the focal spot moves across the target surface in the width direction, and/or the target is movable relative to the focusing component such that the focal spot moves across the target surface in the width direction, the surface velocity of the focal spot across the target surface in the width direction being greater than v.sub.t where:formula (I), k, ρ and c denoting respectively the heat conductivity, the density and the heat capacity of the target material, and d denoting the electron penetration depth in the target material.

[00001]$v_t=\frac{\pi k}{4\rho c}.Math.\frac{\delta }{d^2},$

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.

An x-ray micro-beam radiation production system is provided having: a source of accelerated electrons, an electron focusing component configured to focus the electrons provided by the source, and a target which produces x-rays when electrons impinge thereon from the source. The electron focusing component is configured to focus the electrons provided by the source such that they impinge at a focal spot having a width δ formed on a surface of the target. The focusing component is configured to move the electron beam relative to the target such that the focal spot moves across the target surface in the width direction, and/or the target is movable relative to the focusing component such that the focal spot moves across the target surface in the width direction, the surface velocity of the focal spot across the target surface in the width direction being greater than v.sub.t where: formula (I), k, ρ and c denoting respectively the heat conductivity, the density and the heat capacity of the target material, and d denoting the electron penetration depth in the target material. $\begin{array}{cc}{v}_t=\frac{\pi k}{4\rho c}.Math.\frac{\delta }{d^2},& \left(I\right)\end{array}$

An x-ray micro-beam radiation production system is provided having: a source of accelerated electrons, an electron focusing component configured to focus the electrons provided by the source, and a target which produces x-rays when electrons impinge thereon from the source. The electron focusing component is configured to focus the electrons provided by the source such that they impinge at a focal spot having a width δ formed on a surface of the target. The focusing component is configured to move the electron beam relative to the target such that the focal spot moves across the target surface in the width direction, and/or the target is movable relative to the focusing component such that the focal spot moves across the target surface in the width direction, the surface velocity of the focal spot across the target surface in the width direction being greater than v.sub.t where: formula (I), k, ρ and c denoting respectively the heat conductivity, the density and the heat capacity of the target material, and d denoting the electron penetration depth in the target material. $\begin{array}{cc}{v}_t=\frac{\pi k}{4\rho c}.Math.\frac{\delta }{d^2},& \left(I\right)\end{array}$