X-ray source and method for manufacturing an X-ray source

Abstract

An X-ray source (10) for generating X-rays (11) is provided. The X-ray source (10) comprises an emitter arrangement (12) for generating electrons or for generating X-rays, at least one feedthrough (38) for supplying electrical power to the emitter arrangement (12), and an insulator (20) configured for isolating an electrical potential of the at least one feedthrough (38) from a ground potential. Therein, the at least one feedthrough (38) extends at least partly through the insulator (20), and at least a part of the insulator (20) is in thermal contact with at least a part of the emitter arrangement (12). Further, the insulator (20) comprises at least one cooling channel (28) formed completely in an interior volume (25) of the insulator (20) and configured to dissipate heat from the emitter arrangement (12), wherein a distance (29) between an outer surface (26) of the insulator (20) and the cooling channel (28) is at least as large as half of a thickness (27) of the cooling channel (20).

Claims

1. An X-ray source, comprising: an emitter arrangement for generating X-rays; at least one feedthrough for supplying electrical power to the emitter arrangement; and an insulator configured to isolate an electrical potential of the at least one feedthrough from a ground potential; wherein the at least one feedthrough extends at least partly through the insulator; wherein at least a part of the insulator is in thermal contact with at least a part of the emitter arrangement; wherein the insulator comprises at least one cooling channel formed completely in an interior volume of the insulator and configured to dissipate heat from the emitter arrangement; wherein a distance between an outer surface of the insulator and the cooling channel is at least as large as half of a thickness of the cooling channel; wherein the cooling channel at least partly surrounds the feedthrough along a circumferential direction of the insulator; wherein the distance between the outer surface of the insulator and the cooling channel is constant along the circumferential direction; and wherein the distance between the cooling channel and the outer surface of the insulator is constant along a longitudinal extension direction of the cooling channel.

2. The X-ray source according to claim 1, wherein the distance between the outer surface and the cooling channel is a smallest distance between the outer surface and the cooling channel measured parallel to a surface normal vector of the outer surface; and wherein the thickness of the cooling channel is measured parallel to the surface normal vector of the outer surface.

3. The X-ray source according to claim 1, wherein a cross-section of the cooling channel is rounded; and/or wherein the thickness of the cooling channel is a diameter of the cooling channel.

4. The X-ray source according to claim 1, wherein the cooling channel is configured to guide a coolant such that heat from the emitter arrangement is dissipated based on convection cooling via the coolant; and/or wherein the cooling channel comprises a fluid coolant.

5. The X-ray source according to claim 1, further comprising: an inlet fluidly coupled to the cooling channel and configured to supply a coolant to the cooling channel; and/or an outlet fluidly coupled to the cooling channel and configured for purging a coolant from the cooling channel.

6. The X-ray source according to claim 1, wherein at least a part of the insulator is manufactured by sintering, gluing and/or three-dimensional printing.

7. The X-ray source according to claim 1, wherein the insulator is a single homogenous block of isotropic material; and/or wherein the insulator comprises ceramics material and/or alumina.

8. The X-ray source according to claim 1, wherein the insulator comprises a first side facing the emitter arrangement and a second side opposite to the first side; wherein the insulator comprises a first ceramics material at the first side and a second ceramics material at the second side; and wherein the first material and the second material differ from each other in at least one of a chemical composition, a density and an electrical conductivity.

9. The X-ray source according to claim 1, wherein at least a part of a surface of the cooling channel is metallized; and/or wherein the cooling channel is comprised of at least one tube formed in the interior volume of the insulator.

10. The X-ray source according to claim 1, wherein the emitter arrangement comprises at least a part of at least one of an anode, a cathode, a deflection plate, a deflection coil, a rotor drive, and an electron beam gun.

11. The X-ray source according to claim 1, further comprising: an enclosure at least partly enclosing the emitter arrangement; wherein the insulator is arranged on a side of the enclosure; and wherein at least a part of the insulator and the enclosure form a vacuum compartment, in which the emitter arrangement is arranged.

12. An X-ray imaging system, comprising: an X-ray source, comprising: an emitter arrangement for generating X-rays; at least one feedthrough for supplying electrical power to the emitter arrangement; and an insulator configured to isolate an electrical potential of the at least one feedthrough from a ground potential; wherein the at least one feedthrough extends at least partly through the insulator; wherein at least a part of the insulator is in thermal contact with at least a part of the emitter arrangement; wherein the insulator comprises at least one cooling channel formed completely in an interior volume of the insulator and configured to dissipate heat from the emitter arrangement; wherein a distance between an outer surface of the insulator and the cooling channel is at least as large as half of a thickness of the cooling channel; wherein the cooling channel at least partly surrounds the feedthrough along a circumferential direction of the insulator; wherein the distance between the outer surface of the insulator and the cooling channel is constant along the circumferential direction; and wherein the distance between the cooling channel and the outer surface of the insulator is constant along a longitudinal extension direction of the cooling channel; and an X-ray detector for detecting the X-rays.

13. A method for manufacturing an X-ray source, comprising: providing an emitter arrangement for emitting electrons or X-rays; providing at least one feedthrough for supplying electrical power to the emitter arrangement; providing an insulator configured to isolate an electrical potential of the at least one feedthrough from a ground potential; forming at least one cooling channel in an interior volume of the insulator, such that the cooling channel is completely arranged in the interior volume of the insulator; and arranging the insulator on a side of the emitter arrangement, such that at least a part of the insulator is in thermal contact with at least a part of the emitter arrangement; wherein the cooling channel is formed at a distance between an outer surface of the insulator and the cooling channel, the distance being at least as large as half of a thickness of the cooling channel; wherein the cooling channel at least partly surrounds the feedthrough along a circumferential direction of the insulator; wherein the distance between the outer surface of the insulator and the cooling channel is constant along the circumferential direction; and wherein the distance between the cooling channel and the outer surface of the insulator is constant along a longitudinal extension direction of the cooling channel.

14. The method according to claim 13, wherein at least a part of the insulator and the cooling channel are formed by three-dimensional printing, sintering and/or gluing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The subject-matter of the invention will be explained in more detail in the following with reference to exemplary embodiments which are illustrated in the attached drawings.

(2) FIG. 1 shows schematically an X-ray imaging system according to exemplary embodiment.

(3) FIG. 2A shows schematically a cross-sectional view of an X-ray source according to an exemplary embodiment.

(4) FIG. 2B shows schematically a top view of a part of the X-ray source of FIG. 2A.

(5) FIG. 2C shows schematically a top view of a part of the X-ray source of FIG. 2A.

(6) FIG. 3 shows schematically a cross-sectional view of an X-ray source according to an exemplary embodiment.

(7) FIG. 4 shows a flow chart illustrating steps of a method for manufacturing an X-ray source according to an exemplary embodiment.

(8) In principle, identical and/or similar parts are provided with the same reference symbols in the figures.

DETAILED DESCRIPTION OF EMBODIMENTS

(9) FIG. 1 shows an X-ray imaging system 100 according to exemplary embodiment.

(10) The X-ray imaging system 100 comprises an X-ray source 10 for generating and/or emitting X-rays 11. Further, the X-ray imaging system 100 comprises an X-ray detector 102 for detecting X-rays 11. The X-ray source 10 may emit X-rays 11 in direction of an object of interest 104, which may be e.g. a patient and/or any other object to be examined, and the X-ray detector 102 may detect X-rays 11 passing through and/or traversing the object of interest 104 to generate an X-ray image of at least a part of the object of interest 104.

(11) Further, the X-ray imaging system 100 comprises a controller 106 coupled to the X-ray source 10 and/or to the X-ray detector 102. The controller 106 may be configured for controlling the X-ray source 10 and/or the X-ray detector 102. Also, the controller 106 may be configured to process detector signals of the X-ray detector 102 to generate the X-ray image.

(12) Further, the X-ray imaging system 100 comprises a power supply 108 for supplying electrical power to the X-ray source 10 and/or to the X-ray detector 102. The power supply 108 may be coupled to the controller 106, wherein the controller 106 may be configured to control and/or adjust a power level, such as e.g. a voltage value and/or a current value, supplied to the X-ray source 10.

(13) The X-ray source 10 of FIG. 1 will be explained in more detail with reference to the following figures.

(14) FIG. 2A shows schematically a cross-sectional view of an X-ray source 10 according to an exemplary embodiment. FIGS. 2B and 2C each show schematically a top view of a part of the X-ray source 10 of FIG. 2A.

(15) The X-ray source 10 comprises an emitter arrangement 12 for emitting electrons and/or X-rays 11. For this purpose, the emitter arrangement 12 comprises a first emitter element 14 and a second emitter element 16 arranged opposite to the first emitter element 14. The emitter arrangement 12, the first emitter element 14 and/or the second emitter element 16 comprises at least a part of at least one of an anode, a cathode, a deflection plate, a deflection coil, a rotor drive, and an electron beam gun. By way of example the first emitter element 14 may be and/or may comprise a cathode 14 and/or an electron beam gun 14, wherein in this case emitter element 16 may be an anode 16. Electrons emitted by the first emitter element 14 may be accelerated by an acceleration potential between the first emitter element 14 and the second emitter element 16 in direction of the second emitter element 16, wherein X-rays 11 may be generated by electrons impinging onto the second emitter element 16. Alternatively, the first emitter element 14 may be an anode 14 and the second emitter element 16 may be an electron beam gun 16 and/or a cathode 16. Likewise, electrons emitted by the second emitter element 16 may be accelerated by an acceleration potential between the first emitter element 14 and the second emitter element 16 in direction of the first emitter element 14, wherein X-rays 11 may be generated by electrons impinging onto the first emitter element 14.

(16) The X-ray source 10 further comprises an enclosure 18 and an insulator 20 arranged on a side of the enclosure 18. At least a part of the insulator 20 and the enclosure 18 form a vacuum compartment 19, in which the emitter arrangement 12 is arranged.

(17) The insulator 20 comprises a first side 22 facing the vacuum compartment 19, wherein the first side 22 may also be referred to as vacuum side 22. FIG. 2B shows a top view onto the first side 22 of the insulator 20. The insulator 20 further comprises a second side 24 opposite to the first side 14, wherein the second side 24 faces an ambient, a surrounding, an outside and/or an environment of the X-ray source 10. FIG. 2C shows a top view onto the second side 24 of the insulator 20. The second side 24 of the insulator 20 may also be referred to as ambient side 24 of the insulator 20. Accordingly, the insulator 20 may form an interface between the vacuum in the vacuum compartment 19 and an ambient pressure in the surrounding of and/or around the X-ray source 10.

(18) In the example shown in FIGS. 2A-2C, the insulator 20 is cylindrically shaped and/or the insulator 20 is an axisymmetric insulator 20. Such insulators 20 may be referred to as pancake insulators 20 and/or as flat insulators 20. However, the insulator 20 may have any other shape, such as e.g. a conical shape. An axis of symmetry of the insulator 20 illustrated in FIGS. 2A-2C may be arranged substantially perpendicular to the plane of projection of FIGS. 2B and 2C.

(19) The X-ray source 10 further comprises a first insulating element 30 and a second insulating element 32 arranged on the second side of the insulator 20. The first insulating element 30 may e.g. be a silicone slab 30, e.g. a silicone rubber slab 30, and/or the second insulating element 32 may e.g. be a plastic insulator 32. The first insulating element 30 may provide an electrically stable interface. It is to be noted that the X-ray source 10 may comprise further components arranged on the ambient side 24 of the insulator 20.

(20) The insulator 20 is at least partly surrounded, encased and/or encompassed by a metal element 34 and/or a metal ring 34, wherein the metal element 34 may be kept at an electrical ground potential.

(21) The X-ray source 10 further comprises at least one feedthrough 38 extending at least partly through the insulator 20, e.g. through an opening 39 and/or a through hole 39. The at least one feedthrough 38 may be arranged in a center region 23 of the insulator 20 and/or it may be at least partly embedded in the insulator 20. The feedthrough 38 may be a pin-like conductive element 38 and/or a pin 38 coupled to a power supply 108 and coupled to at least a part of the emitter arrangement 12 such that at least a part of the emitter arrangement 12 is supplied with electrical power via the feedthrough 38. The X-ray source 10 may comprise a plurality of feedthroughs 38. As illustrated in FIG. 2C, the X-ray source 10 may comprise four feedthroughs 38 which may be arranged parallel to each other, wherein each feedthrough 38 may be arranged in an opening 39 and/or a through hole 39. The feedthroughs 38 may generally be configured for supplying voltage and/or current to at least a part of the emitter arrangement 12 and/or for conducting sensor signals.

(22) Generally, the insulator 20 is configured for isolating an electrical potential of the at least one feedthrough 38 from ground potential, on which the metal element 34 is kept. Therein, the electrical potential of the feedthrough 38 may be above about 1000 V, particularly above about 100 kV. Accordingly, the insulator 20 may be a high voltage insulator 20, e.g. a high voltage ceramics insulator 20. To sufficiently isolate the feedthrough 38 from the ground potential and/or from the metal element 34, at least one ridge 21a, 21b and/or rib 21a, 21b is arranged and/or formed on the first side 22 of the insulator 20. As illustrated in FIGS. 2A and 2B, the insulator 20 comprises a first ridge 21a surrounding the feedthrough 38 and/or the center region 23 of the insulator 20 along a circumferential direction 40 of the insulator 20. Further, the insulator 20 comprises a second ridge 21b also surrounding the center region 23 and/or the feedthrough 38 along the circumferential direction 40. Accordingly, the first ridge 21a and the second ridge 21b are arranged concentrically with respect to each other and are spaced apart from each other in a radial direction 41 of the insulator 20. The ridges 21a, 21b may serve to increase a creep distance between the metal element 34 and the emitter arrangement 12 and/or the first emitter element 14 in order to avoid an electrical flashover and/or spark over. It is to be noted that in case the first emitter element 14 is a cathode 14, the electrical potential of the feedthrough 38 is negative and in case the first emitter element 14 is an anode 14, the electrical potential of the feedthrough 38 may be positive.

(23) The X-ray source 10 and/or the insulator 20 further comprises a cooling channel 28, which is completely and/or entirely integrated, formed and/or arranged in an interior volume 25 and/or an inner volume 25 of the insulator 20, such that the cooling channel 28 is substantially completely surrounded by insulator material of the insulator 20. The cooling channel 28 surrounds the feedthrough 38 and/or the center region 23 of the insulator 20 along the circumferential direction 40. Further, the cooling channel 28 is arranged at a distance 29 to an outer surface 26 and/or an outer periphery 26 of the insulator 20, on which outer surface 26 the metal element 34 is arranged. The distance 29 between the cooling channel 28 and the outer surface 26 of the insulator may be measured from an outer surface of the cooling channel 28 to the outer surface 26 of insulator, which outer surface of the cooling channel 28 may face and/or may be arranged opposite to the outer surface 26 of the insulator 20. Accordingly, the distance 29 may be measured along and/or parallel to the radial direction 41 of the insulator 20. Accordingly, the distance 29 may be a radial distance 29. Alternatively, or additionally, the distance 29 may be measured parallel and/or along a surface normal vector 42 of the insulator 20, wherein the surface normal vector 42 may be parallel to the radial direction 41 of the insulator 20 in the example illustrated in FIGS. 2A-2C. The distance 29 may be a smallest distance 29 between the outer surface 26 and the cooling channel 28 along a periphery of the insulator 20 in circumferential direction 41.

(24) Moreover, the cooling channel 28 has a thickness 27, which may be measured parallel to and/or along the radial direction 41 and/or the surface normal vector 42. Therein, the distance 29 between the outer surface 26 of the insulator 20 and the cooling channel 28 is at least as large as half of the thickness 27 of the cooling channel 28. As at least a part of the insulator 20, particularly the center region 25, is in thermal contact with at least a part of the emitter arrangement 12, particularly the first emitter element 14, heat generated during operation of the X-ray source 10 may be conducted from the emitter arrangement 12 to the center region 23 of the insulator 20 and then spread over substantially the entire inner volume 25 of the insulator 20. As the distance 29 is at least as large as half of the thickness 27 of the cooling channel 28, heat may also be conducted to an outer region 31 of the insulator 20, which outer region 31 is arranged between the outer surface 26 of the insulator 20 and the cooling channel 28. Accordingly, heat may be spread in the interior volume 25 of the insulator 20 such that the heat may be spread and/or distributed around the cooling channel 28. Due to the arrangement of the cooling channel 28 at the distance 29, a cooling efficiency and/or a cooling rate may be significantly increased. Particularly, by arranging the cooling channel 28 in the insulator 20 heat may be dissipated such that a thermal integrity of the further components of the X-ray source 10 arranged at the ambient side 24 of the insulator 20, such as e.g. the first insulator elements 30 and/or the second insulator element 32, is maintained. Also, this may increase a lifetime of the X-ray source 10.

(25) The cooling channel 28 may generally have an arbitrarily shaped cross section and/or an arbitrarily shaped cross-sectional area, such as e.g. a polygon-like, a rectangular, a round, a rounded, an oval, a triangular, or an elliptical shape. In the example illustrated in FIGS. 2A-2C the cooling channel 28 has a round shape. Accordingly, the thickness 27 of the cooling channel 28 refers to a diameter 28 of the cooling channel 28 and the distance 29 may be at least as large as half of a radius of the cooling channel 28. However, generally the thickness 27 of the cooling channel 28 may refer to a characteristic dimension of the cooling channel 28 measured along and/or parallel to the radial direction 41 and/or the surface normal vector 42. Accordingly, in case the cross-section of the cooling channel 28 is rectangular, the thickness 27 may refer to an edge length 27 of the cooling channel 28.

(26) In the example shown in FIGS. 2A-2C, the cooling channel 28 surrounds the center region 23 along the circumferential direction 40, wherein the distance 29 between the cooling channel 28 and the outer surface 26 is constant. Accordingly, the first ridge 21a, the second ridge 21b and the cooling channel 28 may be arranged concentrically with respect to each other. However, the distance 29 may also vary along the circumferential direction 41. By way of example, the cooling channel 28 may be arranged in the outer region 31 of the insulator 20, wherein the cooling channel 28 may at least partly overlap with a region of the insulator 20, in which the first ridge 21a is arranged. Alternatively or additionally, the cooling channel 28 may be arranged in a region of the insulator 28 between the first ridge 21a and the second ridge 21b, wherein the cooling channel 28 may at least partly overlap with the first ridge 21a and/or the second ridge 21b. Alternatively or additionally, the cooling channel 28 may be arranged between the center region 23 and a region of the insulator 20, in which the second ridge 21b is arranged, wherein the cooling channel 28 may also at least partly overlap with the second ridge 21b. Further, the cooling channel may also at least partly be arranged in the first ridge 21a and/or the second ridge 21b. However, it is to be noted that the cooling channel 28 may be arranged at a certain minimum distance to the feedthrough 38 to avoid a flashover and/or spark over via the cooling channel 28.

(27) Optionally, the cooling channel 28 is configured to guide a coolant 44, which may comprise, water, alcohol, ester and/or any other suitable coolant material. To supply coolant 44 to the cooling channel 28, the X-ray source 10 and/or the insulator 20 may comprise an inlet 46 in fluid communication with the cooling channel 28, as illustrated in FIGS. 2B and 2C. To purge coolant 44 from the cooling channel 28 the X-ray source 10 and/or the insulator 20 may also comprise an outlet 48 in fluid communication with the cooling channel 28. The inlet 46 and/or the outlet 48 may be arranged in the outer region 31 of the insulator 20 and may extend parallel or transverse to the radial direction 41 and/or the surface normal vector 42. Further, a pump device (not shown) may be arranged between inlet 46 and outlet 48 to provide a flow of coolant 44 through the cooling channel 28, thereby increasing a cooling rate.

(28) In order to further increase a cooling effect and/or a cooling efficiency, at least a part of a surface 50 of the cooling channel 28 may be metallized, e.g. with copper. The surface 50 of the cooling channel 28 may be an inner surface 50 or an outer surface 50 of the cooling channel 28. Accordingly, the cooling channel 28 may comprise a layer 52 of metal arranged on the surface 50 of the cooling channel 28. Alternatively, or additionally, the cooling channel 28 may be comprised of at least one tube 52 formed in the interior volume 25 of the insulator 20.

(29) Further, at least a part of the insulator 20 may be manufactured by sintering, gluing and/or three-dimensional printing, which may allow to cost-efficiently produce a homogenous insulator 20 conducting heat homogenously in the interior volume 25. The insulator 20 may be a single homogenous block of isotropic material, such as e.g. alumina, SiC, doped alumina, glass, ceramics material and/or any other suitable material. Alternatively, the insulator 20 may comprise a first material, particularly a first ceramics material, on the first side 22 facing the emitter arrangement 12 and a second material, particularly a second ceramics material, on the second side 24 opposite to the first side 22, wherein the first material and the second material may differ from each other in at least one of a chemical composition, a density and an electrical conductivity.

(30) FIG. 3 shows schematically a cross-sectional view of an X-ray source 10 according to an exemplary embodiment. If not stated otherwise, the X-ray source 10 of FIG. 3 comprises the same features, functions, characteristics and/or elements as the X-ray source 10 described with reference to previous figs, particularly FIGS. 2A-2C.

(31) The Insulator 20 of the X-ray source 10 depicted in FIG. 3 comprises a first cooling channel 28a and a second cooling channel 28b, which may be arranged concentrically to each other. To allow a coolant 44 to be guided by both cooling channels 28a, 28b, the cooling channels 28a, 28b may be interconnected with each other by one or more connecting channels 54, which may extend parallel and/or transverse to the radial direction 41 and/or the surface normal vector 42. Therein, a radial distance between the first cooling channel 28a and the second cooling channel 28 may be smaller than a radial distance between the feedthrough 38 and the second cooling channel 28b to prevent any flashover. Further, the cooling channels 28a, 28b may have the same thickness 27 or they may have different thicknesses 27. Particularly, a thickness 27 of the second cooling channel 28b, which is arranged closer to the feedthrough 38 than the first cooling channel 28a, may be smaller than a thickness 27 of the first cooling channel 28a to avoid any flashover. However, the distance 29 between the outer surface 26 and the first cooling channel 28a, which is arranged closer to the outer surface 26 than the second cooling channel 28b, may in either arrangement be at least as large as the thickness 27 of the first cooling channel 28a. Further, it is to be noted that the X-ray source 10 and/or the insulator 20 may also comprise more than two cooling channels 28a, 28b.

(32) FIG. 4 shows a flow chart illustrating steps of a method for manufacturing an X-ray source 10 according to an exemplary embodiment, wherein the X-ray source 10 may be an X-ray source 10 as described with reference to FIGS. 1-3.

(33) Particularly the X-ray source 10 comprises an emitter arrangement 12 for emitting electrons or X-rays, at least one feedthrough 38 for supplying electrical power to the emitter arrangement 12, and an insulator 20 configured for isolating an electrical potential of the at least one feedthrough 38 from a ground potential.

(34) In a first step S1 at least one cooling channel 28 is formed in an interior volume 25 of the insulator 20, such that the cooling channel 28 is completely arranged in the interior volume 25 of the insulator 20. In step S1, the entire insulator 20 with the cooling channel 28 may be formed in a single process step, e.g. by three-dimensional printing, sintering and/or gluing of insulator sub-components, such as e.g. particles and/or granules of insulator material. Therein, the cooling channel 20 is formed at a distance 29 between an outer surface 26 of the insulator 20 and the cooling channel 28, which distance 29 is at least as large as half of a thickness 27 of the cooling channel 28.

(35) In a second step S2 the insulator 20 is arranged on a side of the emitter arrangement 12, such that at least a part of the insulator 20 is in thermal contact with at least a part of the emitter arrangement 12.

(36) While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art and practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

(37) In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.