A transmission-target x-ray tube can include an x-ray window mounted on a window-housing. The window-housing can be made of a high density material (e.g. 12 g/cm.sup.3) with a high atomic number (e.g. 45), and can include an aperture with an increasing-inner-diameter region, with a smaller diameter closer to the electron-emitter and a larger diameter closer to the window-mount, for blocking x-rays and electrons. An example angle in the increasing-inner-diameter region is between 15 degrees and 35 degrees. The x-ray tube can further comprise a window-cap. The x-ray window can be sandwiched between the window-housing and the window-cap. The window-cap can be made of a high density material (e.g. 12 g/cm.sup.3) with a high atomic number (e.g. 45) for blocking x-rays in undesirable directions, and can include an aperture for allowing x-rays to transmit in desirable directions.

An X-ray tube includes a metal portion in which an X-ray emission window is provided, an insulation valve which is joined to the metal portion and forms a vacuum region in cooperation with the metal portion, and a target and an electron gun which are accommodated in the vacuum region. The insulation valve has a low resistivity glass portion joined to the metal portion, and a high resistivity glass portion for fixing an anode including the target. A volume resistivity of a material forming the low resistivity glass portion is lower than a volume resistivity of a material forming the high resistivity glass portion. According to this configuration, electrification of the insulation valve is curbed, so that deterioration in withstand voltage ability of the insulation valve is curbed, and electric discharge caused by electrification is curbed.

An X-ray tube includes an electron gun, a target that generates X-rays, and a vacuum housing that accommodates the electron gun and the target. The vacuum housing has a metal portion having an X-ray emission window, and an insulation valve connected to the metal portion. The metal portion has a cylinder portion in which the X-ray emission window is provided and which surrounds a tube axis of the vacuum housing, and a tapered portion which is connected to an end portion of the cylinder portion, surrounds the tube axis, and protrudes such that a connection part between the metal portion and an insulation valve is covered. The tapered portion has a shape increased in diameter such that a separation distance between a distal end portion and the tube axis is longer than a separation distance between a base end portion and the tube axis.

An X-ray tube includes a rod-shaped anode which includes a target receiving electrons and generating X-rays and has a main body portion extending in a direction of a tube axis; a vacuum housing which accommodates a distal end side of the anode having the target disposed therein and in which a proximal end side of the anode is fixed by a housing coupling portion; and a cover electrode which is disposed inside the vacuum housing, is coupled to the anode by a cover coupling portion, and surrounds the housing coupling portion. The anode has a third diameter increasing portion protruding from a front surface of the main body portion in a direction intersecting the tube axis. The cover coupling portion is disposed closer to the proximal end side of the anode than the third diameter increasing portion.

An X-ray tube includes: an envelope that is a case; a cathode assembly that emits electrons in the envelope; and an anode including a first member of which at least a portion extends to the outside of the envelope, a second member that is provided in a direction perpendicular to a central axis of the first member, comes into contact with the first member, and has a higher X-ray shielding performance than the first member, and a target that receives the electrons emitted from the cathode assembly and generates X-rays.

Some embodiments include a structure, comprising: an insulator forming at least a part of a wall of a vacuum chamber, the insulator having a first end and a second end wider than the first end; a first conductive structure disposed at the first end of the insulator; and a second conductive structure disposed at the second end of the insulator, contacting the insulator, and including at least a portion surrounded by the insulator; wherein: a portion of an outer surface of the insulator extends radially outward from a triple junction between the insulator, the second conductive structure, and a medium contacting the outer surface of the insulator.

An XRF analyzer can include an x-ray source and an x-ray detector; an x-ray source heat-sink adjacent a side of the x-ray source; and an x-ray detector heat-sink adjacent a side of the x-ray detector. In one embodiment, the x-ray source heat-sink can be separated from the x-ray detector heat sink by a material having a thermal conductivity of less than 20 W/(m*K). In another embodiment, the x-ray source heat-sink can be separated from the x-ray detector heat sink by at least 3 millimeters of a thermally insulating material. In one embodiment, the x-ray source heat-sink can be separated from the x-ray detector heat sink by a segment of the engine component casing. Separation of the heat sinks can help avoid heat from the x-ray source adversely affecting resolution of the x-ray detector.

An X-ray generating tube including a transmission target having a minute focal spot. The X-ray generating tube includes a transmission target having a first surface configured to be irradiated with an electron beam; an electron emitting source configured to irradiate the transmission target with the electron beam obliquely; and a tubular forward shield member to define an extraction angle of an extracted X-ray beam. The forward shield member is disposed such that a central axis of the electron beam and a central axis of the X-ray beam whose extraction angle is defined are located at the same side with respect to a virtual normal plane perpendicular to the surface and a projection of the central axis of the electron beam to the surface.

An XRF analyzer can include an x-ray source and an x-ray detector; an x-ray source heat-sink adjacent a side of the x-ray source; and an x-ray detector heat-sink adjacent a side of the x-ray detector. In one embodiment, the x-ray source heat-sink can be separated from the x-ray detector heat sink by a material having a thermal conductivity of less than 20 W/(m*K). In another embodiment, the x-ray source heat-sink can be separated from the x-ray detector heat sink by at least 3 millimeters of a thermally insulating material. In one embodiment, the x-ray source heat-sink can be separated from the x-ray detector heat sink by a segment of the engine component casing. Separation of the heat sinks can help avoid heat from the x-ray source adversely affecting resolution of the x-ray detector.

A portable XRF analyzer includes a hand shield and a handle. In one embodiment, the XRF analyzer further comprises a power component spaced-apart from an engine component. The handle and the hand shield extend in parallel between the engine component and the power component, attaching the engine component to the power component. In another embodiment, the XRF analyzer further comprises two housing portions, each integrally formed in a single, monolithic body formed together at the same time. The two housing portions are joined together to form an XRF analyzer housing. In another embodiment, the hand shield is shorter than the handle.