A rotatable anode target for an X-ray tube (1) of the present invention includes a metallic disc (2) which includes a first crystal structure; a metallic cylinder (3) which is joined with the metallic disc and includes a second crystal structure, where a first average aspect ratio of first crystal grains positioning at a first region within 2 mm from an interface between the metallic disc and the metallic cylinder is less than 2, and a second average aspect ratio of second crystal grains positioning at a second region within 2 mm from the interface is 2 or more and 8 or less. It is thereby possible to provide an X-ray tube target which has high heat release performance and where thermal deformation is difficult to occur.

An X-ray assembly may include a vacuum wall, an anode, and a cathode. The vacuum wall may define a vacuum enclosure and may include an X-ray window. The anode may be located within the vacuum enclosure. The anode may include a target area. The cathode may be located within the vacuum enclosure. The cathode may generate an electron stream to travel to a focus area located at the target area of the anode. The cathode may be positioned such that the electron stream travels along an oblique path relative a virtual line positioned so as to intersect a center of the focus area and a center of the X-ray window.

A structure and associated method for forming a liquid metal or spiral groove bearing assembly for an x-ray tube is illustrated that utilizes a unitary sleeve and a thrust ring or seal each formed of a weldable, non-refractory material. The sleeve and the thrust seal are welded to one another to provide an improved construction for minimizing leaks of the liquid metal bearing fluid. The structure of the sleeve and the thrust seal are formed with deformation restricting features that maintain the integrity of the bearing surfaces of the assembly when the thrust seal is secured within the sleeve and welded thereto to form the bearing assembly.

According to one embodiment, a rotating anode X-ray tube includes a fixed shaft, a rotor, a lubricant, target, and a supporting member. The fixed shaft includes a small-diameter portion provided with a first radial bearing surface including first grooved surfaces, and a large-diameter portion provided with a second radial bearing surface including second grooved surfaces. The rotor includes a third radial bearing surface. The lubricant is filled in a gap between the fixed shaft and the rotor, and drawn by the first and second grooved surfaces.

Technology is described for an antiwetting coating attached to a substrate (e.g., metal substate) on a liquid metal container. In one example, the liquid metal container includes a first enclosure member, a second enclosure member, liquid metal, and an antiwetting coating. The first enclosure member includes a first substrate with a first surface. The second enclosure member includes a second substrate with a second surface. The first enclosure member is positioned proximate to the second enclosure member such that a gap is formed between the first surface and the second surface. The liquid metal positioned within the gap. An antiwetting coating attached to the first surface and/or the second surface. The antiwetting coating includes chromium nitride (CrN), dichromium nitride (Cr.sub.2N), chromium (III) oxide (Cr.sub.2O.sub.3), and/or titanium aluminum nitride (TiAlN) attached to the first surface and/or the second surface.

A liquid metal bearing includes at least one first bearing part and at least one second bearing part that have a non-positive fit connection to one another. At least one first ductile sealing layer is disposed at least partly between at least a first bearing part of the at least one bearing and a second bearing part of the at least one second bearing part.

Liquid metal bearing assemblies and methods for operation of said assemblies are provided. One example liquid metal bearing assembly includes a channel fluidly coupling a liquid metal reservoir to a gap between a sleeve and a shaft, and the channel comprising a first section sloped at a first angle and a second section sloped at a second angle, wherein the first angle is different from the second angle, and a curved transition section is positioned between the first section and the second section.

Technology is described for an antiwetting coating attached to a substrate (e.g., metal substate) on a liquid metal container. In one example, the liquid metal container includes a first enclosure member, a second enclosure member, liquid metal, and an antiwetting coating. The first enclosure member includes a first substrate with a first surface. The second enclosure member includes a second substrate with a second surface. The first enclosure member is positioned proximate to the second enclosure member such that a gap is formed between the first surface and the second surface. The liquid metal positioned within the gap. An antiwetting coating attached to the first surface and/or the second surface. The antiwetting coating includes chromium nitride (CrN), dichromium nitride (Cr.sub.2N), chromium (III) oxide (Cr.sub.2O.sub.3), and/or titanium aluminum nitride (TiAlN) attached to the first surface and/or the second surface.

A rotatable anode target for an X-ray tube (1) of the present invention includes a metallic disc (2) which includes a first crystal structure; a metallic cylinder (3) which is joined with the metallic disc and includes a second crystal structure, where a first average aspect ratio of first crystal grains positioning at a first region within 2 mm from a interface between the metallic disc and the metallic cylinder is less than 2, and a second average aspect ratio of second crystal grains positioning at a second region within 2 mm from the interface is 2 or more and 8 or less. It is thereby possible to provide an X-ray tube target which has high heat release performance and where thermal deformation is difficult to occur.

A control method of a radiation tomographic imaging apparatus having a gantry rotating section equipped with a radiation tube including a liquid bearing and a rotor configured to support an anode and configured to rotate is provided. The control method includes a control step that is configured to start a rotation of the gantry rotating section at a second velocity slower than a first velocity, start control for stopping the rotation of the rotor, and control the gantry rotating section and the radiation tube so as to stop the gantry rotating section at a home position. The control method further includes a setting step configured to set at least one of the second velocity and the delay time such that a rotational angular position of the gantry rotating section at a time that the rotor stops rotation averagely varies when a shutdown is performed plural times.