ROTATING X-RAY ANODE

Abstract

A rotating X-ray anode for generating X-radiation has an annular main body made of carbon-based material, an annular focal track covering, which is arranged on a focal track side of the main body, and a metal connection component, which is arranged radially inside relative to the main body. A radially outer portion of the connection component is formed by a tubular metal adapter. The radial outside surface of the adapter is at least partly joined, face to face and integrally, to at least a portion of the radial inside surface of the main body. An integral joining zone between the main body and the adapter extends over at least 75 percent of the area of the radial inside surface of the main body.

Claims

1-15. (canceled)

16. A rotary x-ray anode for generating x-radiation, the x-ray anode comprising: an annular basic body of carbon-based material, said basic body having, with reference to an axis of rotation of the rotary x-ray anode, a radially inner opening with a radial inner surface; an annular focal track coating arranged on a focal track side of said basic body; a metallic connecting component arranged radially on an inside relative to said basic body and configured to connect said basic body to a drive shaft; said metallic connecting component having a radially outer portion formed by a tubular metallic adapter, said adapter having a radial outer surface connected by a material bond to at least a portion of said radial inner surface of said basic body, and wherein a materially bonded connecting zone formed between said basic body and said adapter extends over at least 75 area percent along said radial inner surface of said basic body.

17. The rotary x-ray anode according to claim 16, wherein an outer circumference of said adapter decreases in an axial direction.

18. The rotary x-ray anode according to claim 16, wherein said adapter is rotationally symmetrical.

19. The rotary x-ray anode according to claim 16, wherein said adapter has a frustoconical basic shape with a cone angle between 155° and 205°.

20. The rotary x-ray anode according to claim 16, wherein a radially inner portion of said metallic connecting component is formed by a shaft connection component, wherein said shaft connection component is connected on a radially outer circumference to said radial inner surface of said tubular adapter and said radially inner portion of said shaft connection component is configured for a connection to the drive shaft.

21. The rotary x-ray anode according to claim 20, wherein said shaft connection component has a circular-disk-shaped basic shape and is arranged in a plane perpendicular to an axial direction.

22. The rotary x-ray anode according to claim 20, wherein said shaft connection component has a frustoconical basic shape with a cone angle between 90° and 100° or between 260° and 270°.

23. The rotary x-ray anode according to claim 20, wherein said shaft connection component is connected to said radial inner surface of said adapter in a range of 40% to 60% of a height of said adapter in an axial direction.

24. The rotary x-ray anode according to claim 20, wherein said shaft connection component has a thin-walled configuration with a thickness in an axial direction of less than 10 mm.

25. The rotary x-ray anode according to claim 20, wherein a maximum thickness of said shaft connection component in an axial direction is less than 20% of a height of said adapter in the axial direction.

26. The rotary x-ray anode according to claim 16, wherein said adapter has a thin-walled configuration with a thickness in a radial direction of less than 5 mm.

27. The rotary x-ray anode according to claim 16, wherein said adapter and said annular basic body are soldered to one another.

28. The rotary x-ray anode according to claim 16, wherein said metallic connecting component includes a heat restrictor being an intermediate component or an intermediate layer of a material with low thermal conductivity.

29. The rotary x-ray anode according to claim 16, wherein said metallic connecting component comprises at least one metal selected from the group consisting of tungsten, molybdenum, and copper, an alloy based on tungsten, molybdenum or copper, a tungsten-copper, a molybdenum-copper, or a copper composite material.

30. The rotary x-ray anode according to claim 16, wherein the focal track side carrying said focal track coating in a radially outer region of said annular basic body is beveled.

Description

[0042] The invention is described in more detail on the basis of the following description of three exemplary embodiments with reference to the appended figures. In the figures, in a not-to-scale illustration:

[0043] FIG. 1a: shows a perspective sectional illustration of a first embodiment variant of the rotary x-ray anode;

[0044] FIG. 1b: shows a plan view of the rotary x-ray anode of FIG. 1a;

[0045] FIG. 1c: shows a radial sectional illustration of the rotary x-ray anode of FIG. 1a through the sectional plane A-A;

[0046] FIG. 1d: shows a temperature profile of the rotary x-ray anode from FIG. 1a in a perspective sectional illustration;

[0047] FIG. 2a: shows a perspective sectional illustration of a second embodiment variant of the rotary x-ray anode;

[0048] FIG. 2b: shows a plan view of the rotary x-ray anode of FIG. 2a;

[0049] FIG. 2c: shows a radial sectional illustration of the rotary x-ray anode of FIG. 2a through the sectional plane A-A;

[0050] FIG. 3a: shows a perspective sectional illustration of a third embodiment variant of the rotary x-ray anode;

[0051] FIG. 3b: shows a plan view of the rotary x-ray anode of FIG. 3a; and

[0052] FIG. 3c: shows a radial sectional illustration of the rotary x-ray anode of FIG. 3a through the sectional plane A-A.

[0053] FIG. 1a shows a schematic perspective sectional illustration of a first embodiment variant of the rotary x-ray anode. The rotary x-ray anode 10 is rotationally symmetrical with respect to the axis of rotation R and consists of an annular basic body 11 of graphite, on the beveled end face of which an annular focal track coating 12 is arranged. Graphite has a comparatively low density and is distinguished by a comparatively high specific heat capacity. During operation, high-energy electrons are accelerated onto the focal track coating 12 in order to generate x-radiation. The focal track coating 12 consists of a tungsten-rhenium alloy with a rhenium proportion of approx. 10% by weight and is applied to the annular basic body 11 in the form of a spray layer. Optionally, for better adhesion and as a diffusion barrier against carbon diffusion, it is possible to arrange one or more intermediate layer(s) (not illustrated in FIG. 1a), in particular of rhenium, between the basic body 11 and the focal track coating 12. The annular basic body 11 can be connected to a drive shaft (not illustrated) via the radially inner metallic connecting component 13. In this respect, the openings 16 serve to accommodate screw connections for fastening on the drive shaft. The metallic connecting component 13 is composed of the tubular adapter 14 and the circular disk-shaped shaft connection component 15 and is located completely within the contour spanned by the basic body 11 both in a radial direction and in an axial direction. The tubular adapter 14 has a frustoconical basic shape with a cone angle 17 of approx. 160°, and its outer diameter decreases in the direction of the focal track side. The tubular adapter 14 is materially bonded on its radial outer surface to the radial inner surface of the annular basic body 11 by means of a soldered connection. Here, the materially bonded connecting zone between the annular basic body 11 and the tubular adapter 14 extends over the entire radial inner surface of the annular basic body 11. The tapering of the tubular adapter in the direction of the focal track side obtains a more uniform, approximately isothermal temperature distribution along the connecting zone between the tubular adapter 14 and the basic body 11. The temperature profile can be seen in FIG. 1d, which illustrates the temperature profile determined by means of a computer simulation. Lighter regions correspond to higher temperatures, while the temperature decreases as the shade of gray becomes darker. The temperature profile along the connecting zone between the tubular adapter 14 and the basic body 11 is approximately isothermal for typical operating parameters. The shaft connection component 15 meets the radial inner surface of the tubular adapter 14 centrally in a slightly rounded transition region. The metallic connecting component 13 (both the tubular adapter 14 and the circular disk-shaped shaft connection component 15) have a thin-walled configuration and are manufactured from a refractory metal, such as molybdenum or tungsten or an alloy on the basis of these metals (e.g. TZM, MHC), in terms of lowest possible thermal expansion.

[0054] The rotary x-ray anode 10′ illustrated in FIG. 2a to FIG. 2c has a somewhat wider focal track coating 12′ and differs from the embodiment in FIG. 1a to FIG. 1c in terms of the shape of the annular basic body 11′ (corners rounded to a greater extent). In comparison with the first embodiment, the annular adapter 14′ has a slightly larger cone angle 17′ (approx. 170°) and the shaft connection component 15′ does not engage the adapter 14′ centrally, but is offset in the direction of the focal track side.

[0055] The rotary x-ray anode 10″ illustrated in FIG. 3a to FIG. 3c has an adapter 14″ with a toroidal basic shape, the contact surface of which with the basic body 11″ opens out concavely to the outside. Overall, the adapter 14″ tapers in the direction of the focal track side, analogously to the two previous embodiments.

[0056] All three rotary x-ray anodes 10, 10′, 10″ have a compact shape with a low mass and are distinguished by good thermomechanical properties. They have an advantageously high proportion by mass of the basic body serving as heat store. In addition, there is no metallic connection between the focal track coating and the radially inner region of the rotary x-ray anode.