Patent ID: 7085353

Claim:
An X-ray source comprising: an X-ray tube comprising: a vacuum envelope comprising a first tubular part having an X-ray exit window in an opening on a leading end side, a second tubular part communicating with the inside of the first tubular part and projecting from a peripheral part of the first tubular part, and a bulb part attached to the first tubular part, said X-ray tube comprising an attachment flange positioned at a base end side of the first tubular part, the first tubular part extending away from the attachment flange direction away from the bulb part; and an electron gun and a target both contained in the vacuum envelope; wherein the electron gun emits an electron beam to the target, the target generates an X-ray in response, and the generated X-ray exits through the X-ray exit window; and wherein an exhaust pipe for evacuating the vacuum envelope projects from the peripheral face of the first tubular part; and a metallic tubular member attached to the X-ray tube with the attachment flange, wherein the metallic tubular member is located within a space covering the periphery of the first tubular part and defined by translation of a virtual line bridging a periphery of a leading end portion of the first tubular part and a periphery of the attachment flange around the entirety of the peripheries of the leading end portion of the first tubular part and the attachment flange, and at least one part of the metallic tubular member surrounds at least one part of the vacuum envelope without the metallic tubular member being in physical contact with the at least one part of the vacuum envelope.