Abstract
An anode with a linear main direction of extent for an x-ray device, has an anode body and a focal track layer, which is connected to the anode body in a material-bonding manner on a focal track layer volume portion of the anode body. At least one cooling channel for the cooling of the anode body and the focal track layer is arranged in the interior of the anode body and at least the focal track layer volume portion is formed of a material with at least a basic matrix of refractory metal. The focal track layer volume portion extends as far as to the cooling channel.
Claims
1. An anode with a linear main direction of extent for an x-ray device, the anode comprising: an anode body having a focal track layer volume portion formed of a material with at least a basic matrix of a refractory metal; a focal track layer connected to said anode body in a material-bonding manner on said focal track layer volume portion of said anode body, said focal track layer having a length being greater than five times a width of said focal track layer; at least one cooling channel for cooling said anode body and said focal track layer, said cooling channel being disposed in an interior of said anode body, said focal track layer volume portion extending as far as to said cooling channel; and said anode body having at least in a region of said focal track layer volume portion a side face adjusted at an acute angle, on which said focal track layer is at least partially disposed.
2. The anode according to claim 1, wherein said anode body is monolithically formed.
3. The anode according to claim 1, wherein said focal track layer and said focal track layer volume portion are formed of a same material.
4. The anode according to claim 1, wherein said anode body is formed of a single material.
5. The anode according to claim 1, wherein said focal track layer and said anode body are monolithically formed.
6. The anode according to claim 1, wherein said anode body is configured in at least two parts, said two parts extending along a main direction of extent of said focal track layer and being connected to one another in a material-bonding manner.
7. The anode according to claim 6, wherein said cooling channel is defined by at least said two parts of said anode body.
8. The anode according to claim 1, wherein said cooling channel is formed in said anode body in a vacuum-tight manner.
9. The anode according to claim 1, wherein said material of said focal track layer volume portion is selected from the group consisting of tungsten, molybdenum, a tungsten-based alloy with more than 50 percent by weight of tungsten, a molybdenum-based alloy with more than 50 percent by weight of molybdenum, a tungsten-based composite with more than 50 percent by weight of tungsten, and a molybdenum-based composite with more than 50 percent by weight of molybdenum.
10. The anode according to claim 1, further comprising one interlayer disposed to create a material-bonding connection between said focal track layer and said focal track layer volume portion.
11. The anode according to claim 1, wherein said cooling channel having a wall and at least one portion of said wall is aligned parallel or generally parallel to said focal track layer.
12. The anode according to claim 1, wherein said cooling channel is formed for directly carrying a cooling fluid.
13. The anode according to claim 1, wherein said anode body is formed of a single material being said material with at least said basic matrix of said refractory metal.
14. A method for producing an anode with a linear main direction of extent for an x-ray device, which comprises the steps of: forming a cooling channel in an interior of an anode body having a focal track layer volume portion formed of a material with at least a basic matrix of a refractory metal; placing a focal track layer on a side face of the focal track layer volume portion of the anode body and the focal track layer volume portion extending as far as to the cooling channel, the cooling channel provided for cooling the anode body and the focal track layer, the anode body having at least in a region of the focal track layer volume portion a side face adjusted at an acute angle, on the side face the focal track layer is at least partially disposed; forming the focal track layer to have a length being greater than five times a width of the focal track layer; and connecting at least the focal track layer to the focal track layer volume portion in a material-bonding manner.
Description
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
(1) FIG. 1 shows a first embodiment of an anode according to the invention in a schematic cross section,
(2) FIG. 2a shows an embodiment of an anode according to the invention in a schematic cross section,
(3) FIG. 2b shows a further embodiment of an anode according to the invention in a schematic cross section,
(4) FIG. 2c shows a further embodiment of an anode according to the invention in a schematic cross section,
(5) FIG. 3 shows a further embodiment of an anode according to the invention in a schematic cross section,
(6) FIG. 4a shows an anode according to the invention during a first production step,
(7) FIG. 4b shows the anode according to the invention according to FIG. 4a in a second production step,
(8) FIG. 4c shows the anode according to the invention according to FIG. 4a in a third production step,
(9) FIG. 4d shows an anode according to the invention according to FIG. 4a in a fourth production step,
(10) FIG. 5a shows a further embodiment of an anode according to the invention in a first production step,
(11) FIG. 5b shows the embodiment of the anode according to FIG. 5a in a second production step,
(12) FIG. 5c shows the embodiment of the anode according to FIG. 5a in a third production step.
DESCRIPTION OF THE INVENTION
(13) In FIG. 1, a first embodiment of an anode -10- according to the invention is represented in a schematic cross section. Here it can be seen well that this embodiment concerns an anode body -20- with two parts -20a- and -20b-. The first part -20a- of the anode body -20- has in this case the focal track layer volume portion -22-. Connected to this focal track layer volume portion -22- in a material-bonding manner is the focal track layer -30-. Between the focal track layer -30- and the focal track layer volume portion -22-, a single interlayer -50- is provided. This single interlayer -50- is configured as a brazed layer and is connected both to the focal track layer -30- and to the focal track layer volume portion -22- in a material-bonding manner.
(14) It can also be seen in FIG. 1 that both the interlayer -50- and the focal track layer -30- are recessed in the anode body -20-, in particular the first part -20a- of the anode body -20-. Since the focal track layer -30- is under a very high electrical voltage, the recessed arrangement prevents a voltage flashover, that is to say an arc, at the edges of the focal track layer -30-.
(15) In the case of the embodiment of FIG. 1, the cooling channel -40- is formed between the two parts -20a- and -20b- of the anode body -20-. Such a form is explained in still more detail later with reference to FIGS. 2a, 2b and 2c. In addition, the cooling channel -40- is provided with a connection -60- for the connection to an external coolant supply. This connection -60- is an inserted bush, which is, for example, connected by a material-bonding connecting method to at least one or both parts -20a- and -20b- of the anode body -20-. This material-bonding connection in particular likewise is achieved by a brazing method. It goes without saying that, in other geometries, the connection -60- may also protrude in other directions, for example may lead into the cooling channel -40- from below. An application-specific alignment is performed in particular here, so that the connection -60- is set with respect to the space requirement during the operation of the anode -10- according to the invention.
(16) FIGS. 2a to 2c show three different variants of how the anode body -20- can be put together to form the cooling channel -40-. A common feature of all of these variants is that, as in the case of the embodiment of FIG. 1, the focal track layer -30- is connected to the focal track layer volume portion -22- in a material-bonding manner by way of a single interlayer -50-. In the case of all three of these variants, the anode body -20- is respectively formed in a multi-part manner, in particular a two-part manner, from a first part -20a- and a second part -20b-.
(17) In the case of FIG. 2a, the cooling channel is formed by both parts -20a- and -20b- of the anode body -20-. In the case of this embodiment, the cooling channel -40- has a round flow cross section, so that a half-round free cross section is formed in each case in the respective part -20a- and -20b- of the anode body -20-. In the case of this embodiment, the first part -20a- is preferably produced completely from the material of the focal track layer volume portion, that is to say in particular a tungsten- or molybdenum-based alloy. The second part -20b- of the anode body -20-, which terminates underneath the cooling channel, may also be produced from a low-cost material, for example high-grade steel or copper.
(18) Also in FIG. 2b, a two-part embodiment of the anode body -20- is shown. Here, however, the cooling channel -40- is only formed in the lower part -20b- of the anode body -20-. This has the advantage that machining or other formation of the cooling channel -40- only has to be performed in one of the two parts -20a- and -20b- of the anode body -20-. This reduces the depth of production for such an anode -10- according to the invention. In order to cover the cooling channel -40-, the first part -20a- is placed onto the second part -20b-. As also in the case of the embodiment of FIG. 2a, the two parts -20a- and -20b- of the anode body -20- are connected to one another in a material-bonding manner, for example by a brazing method. In this way, the cooling channel -40- is configured in an essentially completely vacuum-tight form, so that it can in particular be used directly, that is to say without further introduction of an additional pipe as a wall, for the transporting of cooling fluid.
(19) FIG. 2c shows an embodiment of an anode -10- according to the invention, in which the cooling channel -40- has a semicircular cross section. In the case of this embodiment, the focal track layer volume portion -22- is essentially the same as the first part -20a- of the anode body -20-. Here, too, the two parts -20a- and -20b- are connected to one another in a material-bonding manner, so that a vacuum-tight termination of the cooling channel -40- is achieved. In the case of this embodiment, the refractory metal is reduced to a minimum, at least as a basic matrix for the focal track layer volume portion -22-, with regard to the extent over the volume. This accordingly also reduces the correspondingly necessary costs for the anode -10- as a whole, since, for example, a lower-cost material can be used for the second part -20b-.
(20) In FIG. 3, a further embodiment of an anode -10- according to the invention is represented. This embodiment differs from FIG. 1 in that the cooling channel -40- is not only made narrower but also in addition formed with respect to the focal track layer -30- such that it comes closer to this focal track layer -30-. Cooling fluid that enters the cooling channel -40- through the connection -60- will therefore minimize the distance from the focal track layer -30- to be cooled as it passes over the course of the cooling channel -40-. Thus, at the beginning a poorer removal of heat will take place and at the end of the cooling channel -40- an improved removal of heat will take place. Since the cooling fluid heats up over the course of the cooling channel -40-, a constant or essentially constant temperature of the focal track layer -30- can be achieved by this form.
(21) FIGS. 4a to 4d and 5a to 5c describe two variants of the production of an anode according to the invention. In both cases, the respective focal track layer -30- and the interlayer -50- have been applied to a side face of the anode body -20-. For the sake of better overall clarity, it is not shown here that both the interlayer -50- and the focal track layer -30- are in a recess, so that, in the case of the actual product, the edges of the focal track layer -30- and of the interlayer -50- are not visible, in order to avoid an undesired arc.
(22) FIGS. 4a to 4d show a variant of the production of an anode body -20- that has an essentially monolithic embodiment. The anode body -20- is produced from a piece of refractory metal essentially in the form of a bar. In a first step, the corresponding side faces are machined and one side face, which also at least partially forms the focal track layer volume portion -22-, is adjusted to an acute angle by milling. In the next step, as represented in FIG. 4b, the cooling channel -40- is created, for example by machining in the form of the use of a drilling method. Subsequently, the interlayer -50- in the form of a brazing metal and the focal track layer -30- may be placed on the focal track layer volume portion -22-, so that the material-bonding connection is established in the way according to the invention by the material-bonding connecting method, for example a brazing method. Depending on the operating situation, a curvature may subsequently be additionally created. As a result, a curved side face of the anode body -20- can be seen, with the consequence also of a curved embodiment of the focal track layer -30- and of the interlayer -50-. Consequently, even the formation of fully circumferential images of an x-ray device, such as for example in the case of a computed tomography scanner or a baggage scanning tube, can be made possible by an anode -10- according to the invention.
(23) FIGS. 5a to 5c show a variant in which a multi-part embodiment of the anode body -20- is used for the production of the anode -10-. Here, the respective part -20a- and -20b- of the anode body -20- may be separately prefabricated, so that the cooling channel -40- can be formed in the individual parts -20a- and -20b- of the anode body -20-, for example by milling as the machining operation. Subsequently, the individual parts are put together, so that the anode body -20- is produced by a material-bonding connection of the parts -20a- and -20b-. In the case of this variant, it is additionally possible particularly easily also to introduce an inner pipe into the cooling channel -40-, since it only has to be inserted before the two parts -20a- and -20b- are connected to one another. FIG. 5c shows the final step, in which, in a way similar to in FIG. 4c, the focal track layer -30- and the interlayer -50- are placed on and formed for the material-bonding connection.
(24) The foregoing descriptions of the individual embodiments only explain the present invention within the scope of examples. It goes without saying that, to the extent to which it is technically meaningful, features of the individual embodiments can be freely combined with one another without departing from the scope of the present invention.
LIST OF REFERENCE NUMERALS
(25) 10 Anode 20 Anode body 20a First part of the anode body 20b Second part of the anode body 22 Focal track layer volume portion 30 Focal track layer 40 Cooling channel 50 Interlayer 60 Connection
