Patent ID: 9431206
Filing Date: 2016-08-30
CPC Classification: G21K,H01J

Claim Text:
1. An X-ray generation tube comprising: a target for generating an X-ray through irradiation with an electron beam; an electron source provided opposed to the target; and a grid electrode having multiple electron passage apertures, wherein the grid electrode is disposed between the target and the electron source so that a part of a source-side electron beam emitted from the electron source passes through the multiple electron passage apertures and irradiates the target, wherein the source-side electron beam shows a current density distribution, wherein the grid electrode has an aperture ratio distribution, wherein a region of the source-side electron beam, in which a current density is largest, is aligned with a region of the grid electrode, in which an aperture ratio is smallest, wherein the grid electrode causes the part of the source-side electron beam to pass through the multiple electron passage apertures so as to form a target-side electron beam on the target side of the grid electrode, and wherein a current density at a beam center of the target-side electron beam is lower than a current density at a beam center of the source-side electron beam.