Method and system for an X-ray tube assembly

Abstract

The present invention is entitled "Methods and Systems for X-ray Tube Assemblies". The present invention provides various systems for an X-ray system. In one example, the X-ray system includes a high voltage connector that is physically coupled to a cathode of an X-ray tube via a plurality of pins, wherein the pins include niobium.

Description

Technical Field

[0001] Embodiments of the subject matter disclosed herein relate to the facilitation of medical imaging and X-ray scanning.

[0002] Discussion in this area

[0003] In an X-ray tube, ionizing radiation is produced by accelerating electrons from a cathode to an anode via an electric field in a vacuum. The electrons originate from a filament of a cathode assembly having an electric current flowing through it. The filament may be driven by a high frequency generator to release electrons from the cathode and accelerate the electrons toward the anode. Summary of the invention

[0004] In one embodiment, an X-ray system includes an interface configured to couple a high voltage connector to an X-ray tube via pins including a refractory material.

[0005] It should be understood that the above brief description is provided to introduce in a simplified form selected concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is solely defined by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The present disclosure will be better understood by reading the following description of non-limiting embodiments with reference to the accompanying drawings, in which:

[0007] Figure 1 A block diagram of an X-ray system is shown.

[0008] Figure 2A and Figure 2B A high voltage connector having a plurality of pins for coupling the high voltage connector to an X-ray tube of an X-ray system is shown.

[0009] Figure 2C An exemplary arrangement of pins for physically coupling a high voltage connector to a secondary insulator assembly is shown.

[0010] Figure 3A The skin depth of a previous example including Kovar's pins is shown.

[0011] Figure 3B The skin depth of this example of a pin comprising a refractory material is shown.

[0012] Figure 4A and Figure 4B The X-ray tube assembly and detailed flat emitter assembly are shown separately.

[0013] FIG. 5A to FIG. 5D Examples of soldering included in various embodiments of pins are shown. DETAILED DESCRIPTION

[0014] The following description relates to embodiments of a secondary insulator for an X-ray tube. Figure 1 An exemplary block diagram of an X-ray system is shown. Figure 2A and Figure 2B An exemplary pin and socket arrangement is shown. Figure 2C Exemplary pin orientations for the secondary insulator assembly are shown. Figure 3A The skin depth of the previous example used to physically couple the high voltage connector to the pins of the cathode is shown. Figure 3B The skin depth of this example for physically coupling the high voltage connector to the pins of the cathode is shown. Figure 4A A detailed view of the X-ray tube is shown. Figure 4B Shown is a detailed path of a flat emitter arranged in an X-ray tube. Figure 5A , Figure 5B , Figure 5C and Figure 5D Different pin materials and brazing techniques for reducing heat transfer to the pin and components surrounding the pin are shown.

[0015] FIG. 2A to FIG. 5DAn exemplary configuration of relative positioning of various components is shown. In at least one example, if it is shown as directly contacting or directly coupling each other, such elements may be referred to as directly contacting or directly coupling, respectively. Similarly, in at least one example, elements adjacent to or adjacent to each other may be adjacent to or adjacent to each other, respectively. For example, components arranged to coplanarly contact each other may be referred to as coplanar contact. For another example, in at least one example, elements positioned to be spaced apart from each other and having only space therebetween without other components may be described and cited as such. For another example, elements shown to be located above / below each other, located on opposite sides of each other, or located between the left / right sides of each other may be described and cited as such relative to each other. In addition, as shown in the figure, in at least one example, the topmost element or point of an element may be referred to as the "top" of a component, and the bottommost element or point of an element may be referred to as the "bottom" of a component. As used herein, top / bottom, upper / lower, upper / lower may be relative to the vertical axis of the figure, and may be used to describe the positioning of elements relative to each other in the figure. Thus, in one example, an element shown to be located above other elements is vertically positioned above other elements. As another example, the shapes of elements shown in the figures may be referred to as having these shapes (e.g., such as being rounded, straight, planar, curved, rounded, chamfered, angled, etc.). In addition, in at least one example, elements shown as intersecting each other may be referred to as intersecting elements or intersecting each other. In addition, in one example, an element shown as being within another element or shown as being outside another element may be described and referred to as such.

[0016] Go to Figure 1 , which shows an X-ray CT system 1 including a gantry 2, a radiography table 4, and an operation console 6. The gantry 2 includes an X-ray tube 20. X-rays radiated from the X-ray tube 20 are reconstructed or collimated into a cone-shaped X-ray beam or cone-beam X-ray radiation by a collimator 22, and then irradiated to an X-ray detector 24. The assembly of the X-ray tube 20 and the collimator 22 is one example of an X-ray generating device included in the present disclosure.

[0017] The X-ray detector 24 comprises a plurality of detector elements arranged in a two-dimensional array along the propagation of the cone beam X-ray radiation. When a radiographic subject lies on the radiographic table 4 , he or she is transported into the space between the X-ray tube 20 and the X-ray detector 24 .

[0018] The X-ray tube 20 has a plurality of focal spots and generates X-ray beams from the focal spots. The collimator 22 collimates the plurality of X-ray radiations. The X-ray tube 20, the collimator 22 and the X-ray detector 24 constitute an X-ray radiation / detection device.

[0019] The data acquisition unit 26 is connected to the X-ray detector 24. The data acquisition unit 26 acquires detection signals, which are sent in the form of digital data from the corresponding detector elements included in the X-ray detector 24. The X-ray detector 24 and the data acquisition unit 26 constitute an example of an acquisition device included in the present disclosure. The detection signals sent from the detector elements serve as signals representing projections of the subject produced with X-rays.

[0020] X-ray radiation from the X-ray tube 20 is controlled by an X-ray controller 28. The description of the coupling between the X-ray tube 20 and the X-ray controller 28 will be described in more detail below. The X-ray controller 28 may include a high-frequency current drive circuit. Additionally or alternatively, a high-voltage generator (which may be included in the X-ray controller 28) may include a high-frequency current drive circuit. The high-voltage connector may carry the voltage and emitter current generated by the high-voltage generator to the X-ray tube 20. The voltage and emitter current may release electrons from an electron emission source of the cathode of the X-ray tube 20, wherein the electron source may be a coiled filament or a flat emitter having a larger emission area in order to increase the emission current. However, in order to utilize the larger emission area of ​​the flat emitter, the X-ray tube may require a higher voltage and emitter current, resulting in increased heat dissipated to components of the X-ray tube 20, the X-ray controller 28, and the interaction device / coupling between the high-voltage connector and the X-ray tube 20. An embodiment of an interaction device / coupling for more efficient heat dissipation is described below. The collimator 22 is controlled by a collimator controller 30. Description of the coupling between the collimator 22 and the collimator controller 30 will be omitted.

[0021] The aforementioned components starting with the X-ray tube 20 and ending with the collimator controller 30 may be incorporated in a rotating drum 34 included in the scanner gantry 2 and may be rotated around a radiographic subject. The rotation of the rotating drum 34 is controlled by a rotation controller 36. The description of the coupling between the rotating drum 34 and the rotation controller 36 will be omitted.

[0022] The operator console 6 includes a data processing unit 60. The data processing unit 60 is implemented by, for example, a computer. A control interface 62 is connected to the data processing unit 60. The scanning gantry 2 and the radiography table 4 are connected to the control interface 62. The data processing unit 60 controls the scanning gantry 2 and the radiography table 4 via the control interface 62.

[0023] The data acquisition unit 26, the X-ray controller 28, the collimator controller 30, and the rotation controller 36 incorporated in the gantry 2 are controlled via the control interface 62, thereby scanning a radiographic subject. The description of the connection of these components to the control interface 62 will be omitted. In one example, the data processing unit 60 includes a non-transitory memory having instructions stored thereon, which enable the data processing unit 60 to signal the X-ray controller 28 to activate the X-ray tube 20 by delivering a voltage to it.

[0024] The data acquisition buffer 64 is connected to the data processing unit 60. The data acquisition unit 26 incorporated in the scanner frame 2 is connected to the data acquisition buffer 64. The data acquired by the data acquisition unit 26 is transmitted to the data processing unit 60 via the data acquisition buffer 64.

[0025] The storage device 66 is connected to the data processing unit 60. The projection data transmitted to the data processing unit 60 via the data acquisition buffer 64 and the control interface 62 is stored in the storage device 66. In addition, programs for providing instructions to the data processing unit 60 are stored in the storage device 66. The data processing unit 60 runs any one of these programs, thereby performing actions in the X-ray system 1.

[0026] The data processing unit 60 reconstructs an image using a plurality of views of the projection data stored in the storage device 66 via the data acquisition buffer 64. The data processing unit 60 is an example of a reconstruction device included in the present disclosure.

[0027] A display device 68 and an operating device 70 are connected to the data processing unit 60. The display device 68 is implemented by a graphic display, etc. The operating device 70 is implemented by a keyboard with a pointing device.

[0028] The reconstructed image and other information sent from the data processing unit 60 are displayed on the display device 68. The user manipulates the operation unit 70 to input various instructions or pieces of information transmitted to the data processing unit 60. The user uses the display device 68 and the operation device 70 to interactively operate the X-ray CT system.

[0029] In an example of the present disclosure, a flat emitter is used in an X-ray tube to utilize a greater amount of current from a high voltage connector. By doing so, Joule heating of various components arranged near the cathode and the high voltage connector may be increased relative to previous examples where the generator used provides a lower current (which may have been in a configuration to send a DC current to the spiral emitter). An exemplary component that may be heated includes at least one pin for physically coupling the high voltage connector to the cathode. The pin may be configured to conduct current from the high voltage connector to the cathode, and may be heated when doing so. The heat may be dissipated through a secondary insulator, wherein components adjacent to the pin may also be heated. As will be described herein, Joule heating may be reduced by adjusting the material of the pin while still providing the flat emitter with the amount of current required for high quality X-ray imaging via the X-ray assembly.

[0030] Now go to Figure 2A and 2B , which respectively show exemplary embodiments 200 and 250 of the interaction arrangement between the high voltage connector 204 and the cathode 202. In one example, the cathode 202 includes Figure 1 The X-ray tube 20 and the high voltage connector 204 are Figure 1 The X-ray tube 20 and the X-ray controller 28 are connected.

[0031] In one example, the high voltage connector 204 drives the filaments arranged in the cathode 202 via a relatively high frequency. For example, the relatively high frequency may be about 20kHz-8050kHz. Due to the fact that a flat emitter is used, a high current is required. The combination of high frequency current and high drive current may result in a high resistive heat load. As these technologies develop, the heat generated by the high voltage connector 204 may increase as the frequency delivered to the cathode 202 increases. Components used to couple the HV connector 204 and the cathode 202 in the interactive device may be susceptible to heating, which may result in undesirable heat transfer to other areas of the X-ray system and / or degradation of components.

[0032] Figure 2A The embodiment 200 shows a plurality of pins 206 inserted through corresponding sockets in the plurality of sockets 208. Each pin in the plurality of pins 206 can extend through a portion of a corresponding socket in the plurality of sockets 208. Figure 2B Embodiment 250 shows a plurality of sockets 256 physically coupled to a plurality of pins 258, wherein the plurality of pins 258 extend from the high voltage connector 204 toward the cathode 202. Thus, the plurality of sockets 256 are disposed in the vacuum-filled portion of the cathode 202, and the plurality of pins 258 extend from the air side corresponding to the high voltage connector 204 to the vacuum-filled portion including the plurality of sockets 256.

[0033] In any case, in each of the embodiments 200 and 250, the interactive device including one or more of the plurality of pins 206, the plurality of sockets 208, the first plurality of pins 256 and the second plurality of pins 258 may include a refractory material. In one example, the refractory material may have a larger skin depth. By utilizing a refractory material with a larger skin depth at high frequencies, when current flows through a larger portion of the pin cross-sectional area, lower AC resistance heating may be generated. In this way, the plurality of pins 206 of the present disclosure together with the plurality of sockets 208 provide an arrangement configured to allow a higher current to be delivered to the cathode 202 while reducing the possibility of degradation of the high voltage connector 204.

[0034] Now go to Figure 2C , which shows a secondary insulator assembly 275 including a plurality of pins 280. The plurality of pins 280 may include Figure 2A and Figure 2B The plurality of pins 280 includes exactly four pins, including a first pair of pins 282 and a second pair of pins 284. The first pair of pins 282 is aligned along a first axis 283, and the second pair of pins 284 is aligned along a second axis 285, wherein the second axis 285 is perpendicular to the first axis 283. It should be understood that the plurality of pins 280 may include other numbers and arrangements of pins.

[0035] The secondary insulator assembly 275 may house the cathode assembly and the anode assembly, such as Figure 4A As described above, the combination of high frequency AC current from the high voltage connector to meet the current demand of the flat emitter assembly to release electrons can exacerbate heating of the pins and other proximal components. Although this higher frequency can provide improved image quality of an X-ray system including the secondary insulator assembly 275, the heating can reduce the durability of the pins used in previous X-ray systems that used lower currents. Thus, refractory materials can at least partially address this problem because refractory materials can conduct higher amounts of current while reducing Joule heating.

[0036] Now go to Figure 3A and Figure 3B , which respectively show a previous example 300 and a current example 350 of pins arranged in a high voltage connector. Figure 3A It is shown that previously with X-ray systems (such as Figure 1 The skin depth of the material used in the pin 302 of the X-ray system 1 of FIG. 2A . The pin 302 may include Kovar, which is a nickel-cobalt-iron alloy. The combination of the material of the pin 302 and the high frequency from the high voltage connector (such as the high voltage connector 204 of FIG. 2A ) causes the pin and socket temperature to exceed the threshold degradation temperature.

[0037] A pin 302 having a Kovar material with a diameter between 1.5 mm and 3 mm has a skin depth 306 of approximately 55 μm. Kovar is a highly conductive material with a relatively low resistivity (e.g., 49E-8). This can cause Kovar to have a relatively low skin depth at high AC frequencies (e.g., 50 kHz). As a result, Joule heating during use of the X-ray system can cause the pin and socket temperatures to rise to a temperature above a threshold degradation temperature. In one example, the threshold degradation temperature is equal to approximately 180°C. However, due to the pin material and the high frequency delivered to the cathode as required in the prior art, the temperature of the pin and socket can reach a temperature above 240°C, which is above the threshold degradation temperature. This can shorten the life of the X-ray system, resulting in increased maintenance costs and reduced reliability.

[0038] Now go to Figure 3B , which shows the size and Figure 3A Pin 302 is identical to pin 352, so that diameter 354 is exactly equal to Figure 3A The pin 352 may be used similarly to the pin 302, such that the pin 352 is one of a plurality of pins used to physically couple the high voltage connector to the cathode. The pin 352 includes a different material than the material of the pin 302 in the previous example. In one example, the pin 352 includes a refractory material such as niobium. The refractory material of the pin 352 may provide several benefits, including reducing the pin and socket temperature while delivering a high current to the cathode.

[0039] In one example, the skin depth 356 of pin 352 is greater than the skin depth 306 of pin 302. For a 50 kHz current, the skin depth 356 can be close to (e.g., equal to) or greater than about 1 mm, which is more than 18 times the skin depth 306 of pin 302. In one example, the ratio of the skin depth of pin 352 to the pin radius is equal to or greater than 1. Thus, the Joule heating (e.g., AC resistive heating) associated with the 50 kHz AC current is reduced relative to pin 302 because the skin depth 356 is greater than the skin depth 306 of pin 302. Figure 3A Less current is forced to the exterior of pin 352 than pin 302 of the refractory material. That is, pin 352 (which may include niobium or another refractory material such as molybdenum and / or tungsten) has a greater skin depth than Kovar at high frequencies, resulting in lower AC resistive heating because current is allowed to flow through a larger portion of the cross-sectional area of ​​pin 352 than pin 302. In one example, the temperature of pin 352 and the socket is about 120° C. to 140° C., which is less than the threshold degradation temperature.

[0040] In one example, refractory materials may not be widely used due to their relatively high cost and difficulty in brazing and / or coating. In addition, these materials may be low strength relative to previously used materials such as those used in pin 302. For example, niobium may be an expensive material that is difficult to weld. Niobium may also include a stable oxide layer, which may make it difficult to braze and coat the niobium.

[0041] Now go to Figure 4A , which shows a cross-sectional view of an X-ray tube 400 according to an embodiment of the present specification. The X-ray tube 400 can be used for medical diagnostic examinations and can be Figure 1 In the presently contemplated configuration, the X-ray tube 400 includes a cathode assembly 402 and an anode assembly 404 disposed within an evacuated housing 406. That is, the housing may be under a vacuum (e.g., low pressure). Note that the X-ray tube 400 may include other components and is not limited to Figure 4A 406 can be a vacuum chamber positioned within the housing of the X-ray tube 400. In addition, the cathode assembly 402 includes a cathode cup 408 that is configured to emit electrons toward the anode assembly 404. Specifically, current is applied to an electron source (e.g., a flat emitter 410 in the cathode cup 408), which causes electrons to be generated by thermionic emission. The current can be supplied by a high voltage connector (such as Figure 2A and Figure 2B A high voltage connector 204 is applied, which is electrically coupled to a voltage source (such as Figure 1 between the X-ray controller 28) and the cathode assembly 402.

[0042] In addition, the anode assembly 404 includes a rotating anode disk 412 and a stator (not shown). The stator is provided with a magnetic field to rotate the rotating anode disk 412. In addition, the rotating anode disk 412 is positioned in the direction of emitting electrons to receive electrons from the cathode cup 408. In one example, a copper base having a target surface including a material having a high atomic number ("Z" number) such as rhodium, palladium and / or tungsten is used in the rotating anode disk 412. It should be noted that a fixed anode may also be used instead of the rotating anode disk 412 in the X-ray tube 400.

[0043] During operation, a flat emitter 410 in the cathode cup 408 emits a beam of electrons, which are accelerated toward a rotating anode disk 412 of the anode assembly 404 by applying a high voltage potential between the cathode assembly 402 and the anode assembly 404. These electrons impact at a focal point on the rotating anode disk and release kinetic energy in the form of extremely high frequency electromagnetic radiation (i.e., X-rays). Specifically, the electrons decelerate rapidly when they impact the rotating anode disk 412, and X-rays are generated from the process. These X-rays are emitted from the rotating anode disk 412 in all directions. Some of these X-rays may exit the X-ray tube 400 through a window or X-ray port 414 of the evacuated housing 406 and may be used to interact in or on a material sample, patient, or other object.

[0044] Now go to Figure 4B , which shows a detailed view of the filament. Figure 4B In the example of the filament 410, the filament is shown as a flat emitter 410. In one example, the filament is configured only as a flat emitter 410 to achieve a higher radiant flux via a higher emitter drive current that may not be achieved in a spiral filament. However, it should be understood by a person of ordinary skill in the art that the filament 410 may include other configurations to achieve a higher radiant flux without departing from the scope of the present disclosure.

[0045] The flat emitter 410 may be disposed in the cathode cup 408 and may be configured to direct the electron beam toward the rotating anode disk 412. The flat emitter 410 may be a conductive strip divided into three parts, including a first part 452, a second part 454 identical to the first part, and a third part 456. The first part 452 and the second part 454 are disposed at opposite ends of the flat emitter 410, and the third part is disposed therebetween. The third part 456 may include a plurality of slits or cutouts 466 defining a winding track 468.

[0046] The first portion 452 and the second portion 454 can be welded to the cathode cup 408. The first portion 452 can include a first plurality of welds 453, and the second portion 454 can include a second plurality of welds 455. In some examples, additionally or alternatively, the first portion 452 and the second portion 454 can be attached via brazing or other similar techniques without departing from the scope of the present disclosure.

[0047] Now go to Figure 5A , which shows a cross-section of a first embodiment 500 of a solder pin feedthrough. The first embodiment 500 includes a pin 502, wherein the pin 502 can be used Figure 2A and Figure 2B , and similar to Figure 3B Pin 352.

[0048] The pin 502 includes a first braze 504 disposed between the pin 502 and a cap 506. A second braze 508 may be disposed between the cap 506 and a metallization 510, wherein the metallization separates the second braze 506 from a ceramic material 512. In one example, the ceramic material 512 may correspond to the material of a socket in which the pin is disposed.

[0049] Due to the mismatch in thermal expansion values ​​between metal components (such as the pin 502) and the ceramic 512, the pin 502 may include a cap 506. Each of the first braze 504, the cap 506, the second braze 508, the metallization 510, and the ceramic material 512 extends around the entire circumference of the pin 502. The cap 506 may include a reduced wall thickness at the interface between the cap 506 and the second braze 508, where the thickness is measured along an axis perpendicular to the central axis 599 of the pin 502. In one example, due to the stable oxide layer of the niobium pin 502, the first braze 504 and / or the second braze 508 may be a higher temperature braze alloy relative to previously used brazes.

[0050] exist Figure 5A In the example of the first embodiment 500, the first embodiment 500 is symmetrical. When moving in a direction away from the pin 502, the first braze 504 and the cap 506 include the same width at the interface therebetween, wherein the width is measured along an axis parallel to the central axis 599. Thus, the cap 506 does not directly contact the pin 502. The cap 506 increases in width and decreases in thickness adjacent to the interface between it and the second braze 508, wherein the second braze 508 does not contact the pin 502 due to the cap 506 and the first braze 504. The width of the metallization 510 is greater than the width of the second braze 508. Additionally or alternatively, the wall thickness of the metallization 510 may be greater than the wall thickness of the second braze 508. The ceramic material 512 may be the radially outermost portion of the first embodiment 500, wherein the width and wall thickness of the ceramic material are greater than the width and wall thickness of each of the first braze 504, the cap 506, the second braze 508, and the metallization 510.

[0051] In one example, the cap 506 is a low expansion iron-nickel-cobalt alloy or an iron-nickel alloy, wherein the pin 502 is uncoated (e.g., bare) and brazed directly to the cap 506 via the first braze 504. Since the niobium pin 502 is uncoated, a braze alloy with a liquidus greater than about 900° C. may be required to achieve wetting and braze flow. Thus, the material of the first braze 504 may be selected to achieve the desired wetting and braze flow. In one example, the first braze includes an alloy including one or more of a mixture of Au / Cu in a ratio of 50 / 50, a mixture of Au / Cu in a ratio of 81.5 / 16.5 (Nicoro- 80), and a mixture of Au / Cu in a ratio of 82 / 18 (Nioro).

[0052] In one example, the first braze 504 and the second braze 508 can include the same material. In another example, the first braze 504 and the second braze 508 can include different materials.

[0053] Additionally or alternatively, Figure 5A In an example, the pin 502 and the cap 506 may include different materials. In one example, the pin 502 includes one or more of niobium, tungsten, and molybdenum, and the cap 506 includes a nickel-cobalt-iron alloy (e.g., Kovar). In one example, the first braze 504 may be disposed between the pin 502 and the cap 506 to prevent the formation of intermetallic compounds due to the reaction of niobium within one or more components of the Kovar.

[0054] Now go to Figure 5B , which shows a second embodiment 525, which is substantially similar to the first embodiment 500, except that the pin 502 and the cap 506 are formed as a single machined component (e.g., a single piece). Figure 5A soldering 504), the pins 502 may be uncoated. Figure 5B The second braze portion 508 in the example includes a braze alloy of one or more of a mixture of Au / Cu with a ratio of 50 / 50, a mixture of Au / Cu with a ratio of 81.5 / 16.5 (Nicoro-80), and a mixture of Au / Cu with a ratio of 82 / 18 (Nioro).

[0055] Now go to Figure 5C, which shows a third embodiment 550, which can be substantially similar to the first embodiment 500, except that the pin 502 is coated with a coating 552 along its entire surface. The coating 552 can separate the material of the pin 502 (e.g., niobium) from the material of the cap 506 (e.g., Kovar). In one example, the pin 502 can react with the Kovar via the transport of material across the brazing interface between the pin 502 and the cap 506. The transport can result in the formation of a brittle intermetallic compound by reaction of niobium (Nb) with one or more of iron (Fe), nickel (Ni), and cobalt (Co) in the Kovar. In order to prevent the formation of intermetallic compound materials, the pin 502 can be coated with a coating 552, which includes one or more of gold (Au) or platinum (Pt) and has a coating thickness of about 1 micron to 10 meters. In Figure 5C In the example of , coating 552 is gold. Coating 552 can enhance wetting of pin 502, thereby allowing the incorporation of lower temperature, lower cost brazing materials, such as a mixture of Ag / Cu (Cusil) in a ratio of 72 / 28. Thus, second brazing portion 508 can include Cusil. Figure 5C In the example of FIG. 5 , coating 552 has a width equal to the width of pin 502, so that the entire surface of pin 502 is coated with coating 552. In some examples, additionally or alternatively, coating 552 may only coat the portion of pin 502 that would otherwise directly contact cap 506. By doing so, manufacturing costs may be reduced.

[0056] Now go to Figure 5D , which shows a fourth embodiment 575, which is substantially similar to Figure 5B The second embodiment 525 is different in that the pin 502 and the cap 506 are machined as separate pieces. Thus, the first braze 504 is arranged between the pin 502 and the cap 506, even if each of the pin 502 and the cap 506 includes niobium. The first braze 504 may include one or more of a mixture of Au / Cu with a ratio of 50 / 50, a mixture of Au / Cu with a ratio of 81.5 / 16.5 (Nicoro-80), and a mixture of Au / Cu with a ratio of 82 / 18 (Nioro).

[0057] In one aspect, the high voltage connector may include a plurality of pins configured to physically couple the high voltage connector to the X-ray tube. The plurality of pins are configured to conduct a high current from the high voltage connector to the flat emitter, so that the image quality of the X-ray system is improved. The plurality of pins may include a refractory material such as niobium. The technical effect of the plurality of pins including the refractory material is to reduce Joule heating caused by an increase in the amount of current delivered to the flat emitter. By reducing Joule heating, the temperature of the pins and surrounding components can be reduced, thereby increasing their lifespan and durability.

[0058] In one embodiment, an X-ray system includes an interface configured to couple a high voltage connector to an X-ray tube via pins including a refractory material.

[0059] The first embodiment of the X-ray system also includes wherein the refractory material is one or more of niobium, molybdenum, and tungsten.

[0060] A second embodiment of the X-ray system optionally includes the first embodiment, further comprising wherein the pin is arranged in a brazed vacuum feedthrough, wherein the pin includes a cap formed as a single piece with the pin, wherein the pin and the cap include a refractory material.

[0061] A third embodiment of the X-ray system optionally includes one or more of the preceding embodiments, further comprising wherein the pins are coated with a coating comprising gold or platinum, and wherein the coating separates the pins from a cap, wherein the cap comprises a nickel-cobalt-iron alloy or a nickel-iron alloy.

[0062] A fourth embodiment of the X-ray system optionally includes one or more of the preceding embodiments, further comprising wherein a ratio of the skin depth of the pin to the pin radius is equal to or greater than 1.

[0063] A fifth embodiment of the X-ray system optionally includes one or more of the preceding embodiments, further comprising wherein the pin includes a first braze separating the pin from the cap, and further comprising a second braze separating the cap from the metallization.

[0064] A sixth embodiment of the X-ray system optionally includes one or more of the preceding embodiments, further comprising wherein the high voltage connector provides current at 20 kHz-80 kHz AC.

[0065] A seventh embodiment of the X-ray system optionally includes one or more of the preceding embodiments, further comprising wherein the refractory material includes a stabilized oxide layer.

[0066] An eighth embodiment of the X-ray system optionally includes one or more of the preceding embodiments, further comprising wherein the diameter of the pin is between 1.5 mm and 3.0 mm.

[0067] A ninth embodiment of the X-ray system optionally includes one or more of the preceding embodiments, further comprising wherein the pin is a single pin of a plurality of pins, wherein the plurality of pins includes three or more pins.

[0068] One embodiment of a system includes an X-ray system including an X-ray tube physically coupled to a high voltage connector via a plurality of pins, wherein pins of the plurality of pins include niobium.

[0069] The first embodiment of the system also includes wherein the pins or other pins in the plurality of pins include tungsten, molybdenum, or tantalum.

[0070] A second embodiment of the system optionally includes the first embodiment, further comprising wherein the pin is coated with a coating comprising one of gold or platinum, and wherein the coating extends along the entire circumference and width of the pin and prevents a cap comprising nickel-cobalt-iron or nickel-iron from directly contacting the pin.

[0071] A third embodiment of the system optionally includes one or more of the preceding embodiments, further comprising wherein the pins are configured to supply a high frequency alternating current from the high voltage connector to a cathode of the X-ray tube, wherein the cathode includes a flat emitter.

[0072] A fourth embodiment of the system optionally includes one or more of the preceding embodiments, further comprising wherein the high frequency AC current is 20kHz-80kHz AC, and wherein when the high frequency AC current is conducted from the high voltage connector to the flat emitter of the X-ray tube, the ratio of the skin depth of the pin to the pin radius is close to or greater than 1a.

[0073] A fifth embodiment of the system optionally includes one or more of the preceding embodiments, further comprising wherein the pin comprises a first braze portion and a second braze portion with a cap sandwiched therebetween, and wherein the metallization portion is arranged between the second braze portion and the ceramic material, wherein the ceramic material corresponds to a socket in which the pin is arranged.

[0074] An embodiment of the connection device includes a plurality of conductive pins that secure a high voltage connector to an X-ray tube, wherein the pins are configured to conduct current from the high voltage connector to a flat emitter of a cathode of the X-ray tube, wherein the pins include a refractory material including one or more of niobium, molybdenum, tungsten, and tantalum.

[0075] A first embodiment of the connection device also includes one in which the pins are brazed directly to the alumina insulator.

[0076] A second embodiment of the connection device optionally includes the first embodiment, further comprising wherein the planar emitter is configured to release electrons in response to receiving an electric current.

[0077] A third embodiment of the connection device optionally includes any of the preceding embodiments, further including wherein the pins include only one refractory material.

[0078] As used herein, the elements or steps listed in the singular and beginning with the word "one" or "a kind of" should be understood as not excluding a plurality of said elements or steps, unless such exclusion is explicitly stated. In addition, the reference to "an embodiment" of the present invention does not exclude the existence of additional embodiments that also include the cited features. In addition, unless explicitly stated to the contrary, the embodiment of "including", "comprising" or "having" an element or multiple elements with a specific characteristic may include additional such elements without the characteristic. The terms "including" and "in..." are used as the concise language equivalents of the corresponding terms "including" and "wherein". In addition, the terms "first", "second" and "third" etc. are only used as marks, and are not intended to impose numerical requirements or specific positional order on their objects.

[0079] The control methods and routines disclosed herein may be stored as executable instructions in a non-transitory memory and may be implemented by a control system (including a combination of a controller and various sensors, actuators, and other engine hardware). The specific routines described herein may represent one or more of any number of processing strategies (such as event-driven, interrupt-driven, multi-tasking, multi-threading, etc.). Therefore, the various actions, operations, and / or functions shown may be executed in the sequence shown, executed in parallel, or omitted in some cases. Similarly, the order of processing is not necessarily required to achieve the features and advantages of the exemplary embodiments described herein, but is provided for ease of illustration and description. One or more of the actions, operations, and / or functions shown may be repeatedly performed according to the specific strategy used. In addition, the actions, operations, and / or functions may be graphically represented as codes in a non-transitory memory of a computer-readable storage medium to be programmed into an engine control system, wherein the actions are implemented by executing instructions in a system including a combination of various engine hardware components and an electronic controller.

[0080] This written description uses examples to disclose the invention, including the best mode, and also to enable a person of ordinary skill in the relevant art to practice the invention, including making and using any devices or systems and performing any included methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to a person of ordinary skill in the art. Such other examples are intended to fall within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with minor differences from the literal language of the claims.

Claims

1. An X-ray system comprising: an interaction device configured to couple the high voltage connector to the X-ray tube via a pin and a cap comprising a refractory material, Wherein the cap has a decreasing thickness in a direction along the axis of the pin. 2 . The X-ray system of claim 1 , wherein the refractory material is one or more of niobium, molybdenum, and tungsten.

3. The X-ray system of claim 1, wherein the pins are arranged in a brazed vacuum feedthrough, wherein the pins are formed as an integral single piece with the cap, wherein the pins and the cap comprise the refractory material.

4. The X-ray system of claim 1, wherein the pins are coated with a coating comprising gold or platinum, and wherein the coating separates the pins from a cap, wherein the cap comprises a nickel-cobalt-iron alloy or a nickel-iron alloy.

5. The X-ray system of claim 4, wherein a ratio of the skin depth of the pin to the pin radius is equal to or greater than 1.

6. The X-ray system of claim 1, wherein the pin comprises a first soldering portion separating the pin from a cap, and further comprising a second soldering portion separating the cap from a metallization portion.

7. The X-ray system of claim 1, wherein the refractory material comprises a stabilized oxide layer.

8. The X-ray system of claim 7, wherein the diameter of the pin is between 1.5 mm and 3.0 mm.

9. The X-ray system of claim 1, wherein the pin is a single pin of a plurality of pins, wherein the plurality of pins comprises three or more pins.

10. A system for medical imaging, comprising: An X-ray system comprising an X-ray tube physically coupled to a high voltage connector via a plurality of pins and a cap, wherein the pins of the plurality of pins comprise niobium, Wherein the cap has a decreasing thickness in a direction along the axis of the pin.

11. The system of claim 10, wherein the pin is coated with a coating comprising one of gold or platinum, and wherein the coating extends along the entire circumference and width of the pin and prevents a cap comprising nickel-cobalt-iron or nickel-iron from directly contacting the pin.

12. The system of claim 10, wherein the pins are configured to supply a high frequency alternating current from the high voltage connector to a cathode of the X-ray tube, wherein the cathode comprises a flat emitter.

13. The system of claim 12, wherein the high frequency AC current is 20kHz-80kHz AC, and wherein when the high frequency AC current is conducted from the high voltage connector to the flat emitter of the X-ray tube, a ratio of the skin depth of the pin to the pin radius is close to or greater than 1.

14. The system of claim 10, wherein the pin includes a first braze portion and a second braze portion sandwiching a cap therebetween, and wherein a metallization is disposed between the second braze portion and a ceramic material, wherein the ceramic material corresponds to a socket in which the pin is disposed.

15. A connection device, comprising: A plurality of conductive pins; as well as cap, wherein the plurality of conductive pins and the cap secure a high voltage connector to an X-ray tube, wherein the plurality of conductive pins and the cap are configured to conduct current from the high voltage connector to a flat emitter of a cathode of the X-ray tube, wherein the plurality of conductive pins comprise a refractory material comprising at least one of niobium, molybdenum, tungsten and tantalum, and wherein the cap has a decreasing thickness in a direction along an axis of the pins.

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