Cathode assemblies for X-ray imaging

Abstract

A cathode assembly component (CC) for X-ray imaging comprises an integral outer shell (OS) having an electron optical function, and an insulator structure (INS) for two or more electrodes that can be inserted into the shell.

Description

Technical Field

[0001] The invention relates to a cathode assembly component, an X-ray source, an X-ray device, a method for producing a cathode assembly component, a computer program element and a computer-readable medium. Background Art

[0002] An X-ray source (sometimes simply referred to as an X-ray "tube") includes as basic components an anode and a cathode head for generating X-rays for medical or non-medical purposes. During the use of an X-ray tube, these components are exposed to harsh conditions. For example, the cathode operates under high voltage (HV) and high temperature conditions. In this case, "HV" means that the cathode is maintained at a potential of up to 150 kV or even higher relative to ground, while "high temperature" means that the cathode head may be subjected to a temperature of about 800°C, with the cathode's emitter exposed to even higher temperatures (about 2400°C).

[0003] Thermal management and efficient manufacturing of the cathode head remain a challenge. Summary of the invention

[0004] In order to meet at least some of the above needs, according to a first aspect, there is provided a cathode assembly component for X-ray imaging, comprising:

[0005] An integral (i.e., one-piece) outer housing having an electro-optical function and an insulating member structure for two or more electrodes that can be inserted into the outer housing. The outer housing is formed from a single piece, which ensures ease of manufacture and provides flexibility in design changes, as will be described in more detail below.

[0006] The electron optical function helps to shape the electron beam emitted from the emitter of the cathode assembly, which helps to achieve the desired focal spot size at the anode of the cathode assembly. The electron optical function can be achieved because the housing is made of metal and / or by extending the outer housing to at least partially surround the emitter. In an embodiment, the housing has a portion for mounting the cathode assembly into an X-ray source of an X-ray imaging device.

[0007] In one embodiment, it is also an integral insulator. In other words, the insulator is formed of a single piece of suitable insulator material, such as ceramic or other. The insulator is configured to thermally and / or electrically insulate the electrical components of the cathode assembly. Preferably, there is such an insulator in the outer shell. Preferably, the insulator is configured to further retain one or more such electrical components. Examples of such components include electrodes / pins for one or more emitters or other emitters or integrated electron beam forming components ("EBF"). Such an EBF is configured to shape the length or width or both of the electron beam, or to adjust the intensity of the electron beam from maximum intensity to zero. To this end, the insulator includes one or more through holes for mounting the components.

[0008] Having a single one-piece insulator in a single one-piece housing allows for greater flexibility in mounting the above-mentioned components (eg, additional transmitters or additional EBFs).

[0009] The proposed housing design provides easy assembly when additional parts are fixed (e.g. by brazing) to the insulation inside the outer housing. When multiple (e.g. hundreds or thousands) cathode assemblies are produced in the same brazing furnace, the additional parts can all be installed in one step.

[0010] In particular, if necessary, the pins / electrodes of the EBF can be easily added, such as two, three, four or more. If necessary, multiple (flat or coiled type) emitters can also be accommodated in the design, and the manufacturing process can be adjusted in a cost-effective and easy way. In other words, a simpler assembly with higher precision and reproducibility can be achieved.

[0011] In an embodiment, the housing has an integrated thermal barrier to prevent heat from flowing from the emitter of the assembly to the insulation. This allows for better heat management.

[0012] In one embodiment, the thermal barrier comprises one or more holes. This allows for good thermal management and additionally mechanical rigidity. In an alternative embodiment of the integrated thermal barrier, the outer housing is locally thinned, ie comprises one or more portions of reduced thickness.

[0013] In one embodiment, the housing is metallic. This includes pure metals, such as nickel, molybdenum or iron, or alloys thereof, such as Ni 42 or NiloK (nickel-cobalt-iron), or other metals and alloys. Preferably, the housing is formed from a bulk metal, but a metal coating may be used instead.

[0014] Since in one embodiment the housing is (entirely) made of metal, this allows in particular using spark erosion to adjust the height of the emitter relative to the edge of the outer housing, which allows cost-effective manufacturing.

[0015] In one embodiment, the insulation has a relief structure. This allows for better high potential ("withstand voltage") compliance and mechanical stiffness.

[0016] The proposed cathode assembly is suitable for different designs including planar emitters or helical filaments.

[0017] The proposed cathode assembly is particularly contemplated for use with multi-shaped electrodes. That is, the design provides improved isolation possibilities, especially for the addition of an integrated electron beam forming component ("EBF"). Such an EBF is configured to shape the length or width or both of the electron beam, or to adjust the intensity of the electron beam from maximum intensity to zero. The EBF can be made of wires, plates, metal sheets, and other subcomponents.

[0018] The proposed design integrates the possibility to optimize the design in terms of heat storage, thermal expansion and creepage.

[0019] According to a second aspect, an X-ray source (tube) is provided, comprising a cathode assembly component according to any one of the above embodiments.

[0020] According to a third aspect, an X-ray imager is provided, comprising the cathode assembly as described above or the X-ray source as described above.

[0021] According to a fourth aspect, there is provided a method of manufacturing comprising the step of forming a unitary casing for a cathode assembly.

[0022] The method may further include installing an insulator into the housing.

[0023] The step of forming the monolithic housing is preferably completed from a single block of material. The forming step can be achieved by subtractive machining (e.g., CNC milling, laser cutting, or electrospark erosion (EDM)) or other methods. Alternatively or in addition, an additive material forming technique such as 3D printing is used. Any of these techniques can also be used to form the insulating member.

[0024] In another optional step, one or more components (eg, transmitters, electrodes, electrical connections, etc.) are mounted on the insulation within the housing.

[0025] According to a fifth aspect, a computer program element is provided, which, when executed by at least one processing unit, is adapted to cause a material forming apparatus to form at least a part of a cathode assembly as described above.

[0026] According to a sixth aspect, a computer program element as described above is provided, wherein the program element is a CAD file for 3D printing.

[0027] According to a seventh aspect, a computer-readable storage medium is provided, on which the program element as described above is stored. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which:

[0029] Figure 1A schematic diagram showing components of an X-ray imaging apparatus;

[0030] Figure 2 is a schematic cross-sectional view of an X-ray source;

[0031] Figure 3A shows a perspective view of a cathode cup for an X-ray source according to one embodiment;

[0032] Figure 3B is a partial cross-sectional view of a cathode cup for an X-ray source according to a second embodiment;

[0033] Figure 4 shows a perspective view of a cathode cup for an X-ray source according to a third embodiment;

[0034] Figure 5 shows a cross-sectional view of an insulator for insertion into a cathode cup according to one embodiment;

[0035] Figure 6 A flow chart showing a method for making a cathode cup; and

[0036] Figure 7 A schematic diagram of the workflow for fabricating the cathode cup is shown. DETAILED DESCRIPTION

[0037] refer to Figure 1 , which is a schematic diagram of an X-ray imaging device XI. Embodiments thereof include a C-arm imaging device, a CT scanner, a mammography device, or a radiography device or other device configured to acquire X-ray images of an object OB. Although the main application of the X-ray imager envisioned herein is in the medical field, non-medical situations such as non-destructive material testing or baggage inspection are not excluded herein. Therefore, as used herein, the term "object OB" includes inanimate objects in a general sense, but also includes living objects such as human or animal patients or their anatomical parts. Therefore, we will use "object OB" or "patient OB" where appropriate in this document.

[0038] Broadly, the X-ray imaging apparatus XI includes an X-ray source XS and an X-ray sensitive detector XD. In use, an object OB is located in an examination region within the X-ray source XS and the X-ray detector XD. To facilitate this, an examination table T is sometimes provided on which the patient OB is located during imaging, but this is not necessary in all embodiments. For example, in an alternative embodiment, the patient OB is in the examination region during the X-ray examination.

[0039] In use, the X-ray source XS is excited to generate an X-ray beam XB, which passes through the inspection area and therefore passes through at least the area of ​​interest of the object OB. The X-ray interacts with the material (e.g., tissue, bone, etc.) of the object OB. After the interaction, the radiation hits the X-ray detector XD. The detector XD detects the impacted X-rays in the form of electrical signals. The electrical signals are converted into image values ​​by suitable conversion circuits, which can then be processed into X-ray images. The X-ray image can show the internal details of the imaging object OB. This can help the diagnosis and treatment of the imaging object OB or other inspections. The display of the image can then be realized on one or more display devices (e.g., monitors, etc.) using suitable drawing software. The image can also be stored or otherwise processed.

[0040] Figure 2 is a schematic cross-sectional view of an X-ray source XS. Broadly, the X-ray source XS includes an anode AN assembly (referred to herein as the "anode") and a cathode CAT assembly (referred to herein as the "cathode"). A high voltage potential is established between the cathode CAT and the anode AN. Figure 2 As shown, this is achieved by applying a negative voltage to the cathode CAT and a positive voltage to the anode AN by connecting the cathode and anode to a suitable power supply PS. For this purpose, suitable electrical connections CON are provided at the source XS. In use, the anode AN and cathode CAT are maintained at a high voltage potential of about 150KV relative to ground (referred to herein as "tube voltage" or "working voltage").

[0041] The cathode assembly CAT (also referred to as "cathode head") and the anode AN are spatially arranged in a relative relationship in the housing H to define a drift path between the cathode CAT and the anode AN. The anode AN and the cathode assembly CAT and the drift path are encapsulated in a vacuum glass tube (not shown) inside the housing H. The housing provides protection against mechanical shocks and enables it to be installed in the X-ray imager XI. The housing may also include cooling lines and may provide other functions. Suitable materials for the outer housing include ceramics, glass, metal or others.

[0042] Preferably, but not necessarily, the X-ray source XS is of a rotating type, wherein the anode is arranged as a disk (in Figure 2 ), the disk is rotatably supported in a suitable bearing B and is electrically driven by a suitably powered electric motor. X-ray sources with a fixed anode are also envisaged.

[0043] The cathode assembly CAT includes an emitter 330 (at Figure 23 and 4). A current (referred to herein as a "transmitter current") is generated by a power supply PSH. The transmitter current flows through the transmitter 330 during use. It should be understood that the three power supplies PSH, PS - , PS+ is drawn as a separate, independent entity, which is indeed envisaged in some embodiments. However, this does not exclude alternative embodiments in which some or all of the mentioned power supplies are integrated into a single power supply.

[0044] The cathode assembly CAT includes a cathode cup CC as a component, the structure of which will be described in more detail below. The cathode cup CC is arranged to hold the emitter 330 in a position opposite to the anode AN. The cathode cup CC is connected to the housing H and / or to the housing H by a suitable fixing device FX. The cathode cup CC is arranged to hold the emitter at a certain distance from the edge portion (especially the bevel) of the anode AN in the case of a rotating anode, such as Figure 2 as shown in .

[0045] When the emitter current is applied, the emitter 330 heats to about 2400 0 temperature, and electrons boil away from the surface 330 of the emitter in thermal emission.

[0046] Due to the high potential difference between the cathode and the anode, the boiling of electrons forms an electron beam which is accelerated towards the anode and impinges on a focal spot FS on the anode surface. In the case of a rotating anode, the focal spot is located on the inclined edge of the anode disk. It will be appreciated that due to the rotation, the focal spot FS describes a track around the edge of the anode disk AN. The anode AN is formed of a high density material such as molybdenum, tungsten or other high Z metal / material. When impinging on the focal spot FS, the electron beam XB is decelerated, the energy drop is partly converted into heat and partly (about 1%) into an X-radiation beam XB which radiates from the focal spot FS. The housing H is radiation blocking, for example by having a layer of lead (or other suitable high Z material) to prevent the X-radiation from escaping to the outside of the housing, safe for the exit window E of the housing formed of a non-radiation opaque material such as glass. The X-ray beam XR generated inside the X-ray source XS then exits through the exit window EW essentially undisturbed, propagating towards the detector XD (whose relative position is in Figure 2 Indicated by "x" in the figure).

[0047] The heating current in the emitter and the impinging electron beam at the focal spot on the anode surface generate a lot of heat, so good thermal management is required. This is achieved by rotating the anode AN to provide better heat dissipation (and increase the life of the anode AN) and / or by various cooling circuits (not shown). In addition to this, thermal management is achieved here by the novel structure of the cathode cup CC, which will now be described below. Figure 3A, B and 4 are described in more detail.

[0048] First go to Figure 3A , which is a perspective view of a cathode cup CC according to one embodiment. In this embodiment, the cathode cup CC is generally cylindrical, but other shapes, such as prismatic, are also conceivable. Broadly speaking, the cathode cup comprises a proximal portion PP and a distal portion DP. When the cathode cup is mounted inside the housing of an X-ray tube XS by a suitable fixture FX, the proximal portion PP is closer to the anode than the distal portion DP.

[0049] Broadly speaking and as will be explained in more detail below, the cathode cup CC not only holds the emitter 330 in position relative to the anode AN, but it also provides the electron optical function by focusing the outgoing electron beam onto the anode's focal spot FS with suitable spatial definition of the approximately 1mm-2mm focal spot size.

[0050] The size and shape of the cathode cup generally depends on the requirements of the cathode ray tube XS to be used. In one embodiment, the maximum diameter at the distal portion DP is of the order of tens of millimeters, which tapers to a smaller diameter at the proximal portion DP. The overall height / length of the cup CC, i.e., the distance between the distal portion DP and the proximal portion PP, is of the order of tens of millimeters. In alternative embodiments, the taper is reversed, so that the proximal portion is larger than the distal portion. In other designs, the cup CC has a constant cross-section and does not taper. The variations in shape and size described in this paragraph are consistent with Figure 3B and Figure 4 The other embodiments in have the same application.

[0051] As proposed herein, the cathode cup CC has an outer shell OS. The outer shell OS is formed integrally, ie, in one piece. The shell OS comprises a heat barrier HB ( Figure 3B ). At the proximal end, the emitter, in this case a flat emitter, is fixed in a position opposite to the anode surface. The one-piece outer shell OS is formed of metal, in particular a single piece, and preferably a metal block. Suitable metal materials include Ni, iron, molybdenum or their alloys or others. Depending on requirements, the outer shell is a few millimeters thick in the radial direction (e.g. 5 mm).

[0052] Inside and surrounded by the outer shell OS, an insulating member INS is arranged. Preferably, each single shell OS has a single integral insulating member. In other words, the proposed cathode cup uses a single metal shell (or outer shell) OS forming the exterior, and this shell fully or partially covers the single insulating member INS.

[0053] The insulating member is preferably formed of ceramic, but other electrically insulating materials are also contemplated herein. The shape of the insulator conforms to the cross-sectional shape of the outer shell to ensure a tight fit. In the following, the insulating member is referred to as a ceramic disc, with the understanding that other polygonal shapes are not excluded herein, depending on the cross-section of the outer shell OS.

[0054] The functions of the insulation INS include electrically and thermally insulating various electrical components and their electrical connections (eg, the emitter 330 or other components of the EBF or X-ray source XS).

[0055] More specifically, and as Figure 3B As shown in the cross-sectional view of , the ceramic disk INS includes a plurality of holes, in particular through holes 410a, 410b. Wires 415a, b (also referred to as pins) pass through the through holes and connect the power supply PSH with the transmitter 330. The pins are formed as rigid metal wires with a diameter of about 2 mm, but other diameters are also envisioned. Flexible cable wiring can also be used. Preferably, the transmitter pins 415a, 415b are fixed to the inner surface of the through holes 410a, 410b by soldering or other means. Alternatively, these pins are not so fixed inside the through holes, but are held in the through holes by friction or are freely held in the through holes to better accommodate thermal expansion.

[0056] Figure 3B The example in is similar to Figure 3A The embodiment shown in , but the individual transmitters are different. Figure 3B The emitter 330 shown in cross section is of the filament or coiled type, and in Figure 3A What is shown in the figure is a flat emitter. In other words, if various emitters are used, the two types of emitters are envisioned alternatively or in combination. In the flat emitter, unlike the spiral filament type, the filament is deposited on a flat surface in a zigzag layout instead. As described above, the thermal current flows through the pins 415a, 415b to heat the emitter 330. If the cathode cup includes more than one emitter, such as shown in Figure 3, where two flat emitters are arranged side by side, the insulating disk INS includes more holes for the corresponding pair of pins to provide the corresponding thermal current to the additional (one or more) emitters 330. Typically, the number of holes passing through the insulating member INS is twice the number of emitters.

[0057] like Figure 3A As shown in FIG. 2B , for coiled filament emitters and flat emitters, the cathode cup CC is essentially the same, but may differ in the nature and location of the thermal insulation layer and the location of the insulating member INS. Figure 3A In the embodiment, the thermal insulation layer is formed by through holes in the outer shell. This embodiment with holes will be described in the following Figure 4 On the other hand, in Figure 3BIn the embodiment, the proximal end PP has one or more portions of TP with reduced thickness (only one portion is shown in the figure), and this forms an integrated heat barrier HB to reduce the heat flow out of the emitter in the distal direction. Figure 3B No holes are required in the design.

[0058] As another variation of the above design, Figure 3B The design may include a thermal barrier as a hole, while Figure 3A and Figure 4 The thermal barrier in is formed by having one or more thinned portions TP. However, it will be appreciated that, as another variation, holes and ducts having portions of reduced thickness may be used in combination in alternative embodiments.

[0059] exist Figure 3B In the design, the insulation is larger than that in Figure 3 and Figure 4 Closer, but the opposite is also conceivable.

[0060] In any embodiments presented herein, the shell OS of the cathode cup CC is configured to provide a passive electron-optical function. In other words, the cup CC allows the electron beam to be guided or focused on its drift path towards the anode AN to achieve a better spatial definition of the focal spot FS, down to 1 or 2 mm. This electron-optical function is achieved by the metal outer shell and the proximal part PP extending sufficiently close to the (one or more) emitters 330. In other words, the proximal part PP of the metal outer shell at least partially surrounds the emitter in cross section. In other words again, and geometrically speaking, an imaginary section SP can be made to pass through the proximal part PP of the outer shell so that the plane intersects the emitter 330. The plane is orthogonal to the longitudinal axis X of the shell OS, as shown in FIG. Figure 3B As shown in the X, Y, and Z coordinate system. Figure 3B As shown, the imaginary cross-sectional plane SP is orthogonal to the cross-sectional plane of the view. The Y and Z axes of the imaginary plane SP are substantially perpendicular to the primary propagation of the electron beam in the -X direction. Figure 3B The geometry of the section SP is described, but for Figure 3A and Figure 4 For other embodiments of the invention, the same geometry still applies. In other words, such cross-sectional planes can be defined for all embodiments, and each plane will preferably pass through the corresponding emitter.

[0061] As required, the electron optical function can be enhanced by installing one or more EBFs on its electrodes as required. To this end, the cathode cup CC can also include additional pins 415a, b (i.e., in addition to the pins of the emitter 330), which also pass through additional holes 410a, b in the ceramic disk INS to support and / or supply other components, especially one or more EBFs. The EBF is positioned between the emitter 330 and the anode AN by means of pins 415a, 415b. If a negative control voltage is applied to it, the electron beam from the emitter to the anode AN may be weakened or even completely interrupted. On the contrary, if a positive voltage is applied, the electron beam can be accelerated. The EBF provides better imaging control, for which the imaging safe patient dose is turned on and off. For example, in some imaging modalities (such as fluoroscopy) or gated imaging protocols, when imaging moving anatomical structures (such as cardiac imaging or other imaging), for example, it is necessary to quickly turn on / off imaging. Preferably, the cup CC is configured for multiple EBFs, each EBF having its own supply pair and / or support pins 415a, 415b. Likewise, the number of through holes (not shown in FIG. 3 ) for supporting and / or supplying the EBFs is twice the number of EBFs required. The EBFs may be arranged in different spatial directions from each other.

[0062] Reference now Figure 4 , which is similar to Figure 3A , which shows in more detail the pins 415a, b for EBF. The pins 415a, b pass through the insulating disk INS inside the outer shell and through the through holes 325a, b in the top CP of the proximal portion PP of the outer shell OS. If there are more than one pair of such through holes 325a, 325b (such as Figure 4 As shown), the through holes are preferably grouped around one or more emitters 330.

[0063] Figure 4 The above shows Figure 3B , 3B More details are mentioned of the perforated embodiment of the heat barrier HB integrated into the outer shell OS of the cathode cup CC. Figure 4 The embodiments in correspond to Figure 3A . In this embodiment, the heat barrier HB is arranged as a series of holes 320a, b extending around the circumference of the outer housing. The holes 320a, 320b prevent heat from flowing from the emitter 330 to the distal portion DP of the cathode cup CC, thereby providing heat management. The series of holes 320a, 320b are equidistantly placed relative to each other with a defined inter-hole distance, so that only relatively narrow strip elements 315a, b are left between any two adjacent holes 320a, 320b to allow heat to spread. In alternative embodiments, non-equidistant placement of the holes 320a, 320b is also envisioned.

[0064] One or more additional series of thermal barrier holes 310a,b may be placed distal to the first series. Figure 4 One such additional series is shown. Figure 4 As shown, the distance between holes in each series (and therefore the width of the strip elements) can be the same or can be different, such as Figure 4 As shown, wherein the distance between holes in the second more distal series 310a,b is greater than the distance between holes in the first more proximal series 320a,b. In the embodiment shown, insulation is arranged between the two series of thermal barrier holes 310a,b and 320a,b.

[0065] It will be appreciated that the holes 310a,b, 320a,b need not necessarily be as Figure 4 The circular through holes shown are not shown, but other shapes are also contemplated herein, such as polygons, etc. In yet another embodiment, the holes 310a, b, 320a, b of the heat barrier HB can be elongated to form a lattice pattern or a truss pattern in the shell OS. By arranging the insulation wall HB holes 320a, b or 310a, b into the outer shell OS to form a lattice pattern or a truss pattern, not only better thermal management can be achieved, but also the mechanical rigidity of the outer shell can be improved. In particular, this enhanced rigidity allows the emitter 330 to be more accurately aligned with the focal spot FS, resulting in an enhanced image.

[0066] As mentioned above, Figure 4 As shown, the distal portion DP comprises a mounting portion 305, such as a threaded portion, which allows the cathode cup CC to be mounted in the fixture FX of the source XS. Other types of mounting options are also envisaged, such as snap fit or others.

[0067] The tapering from the distal portion to the proximal portion of the cathode cup CC may be continuous (not shown) or may be in steps as shown.

[0068] As in Figure 3A and Figure 4 As seen in the embodiment of the flat emitter 330 of FIG. 1 and similar designs, the emitter is arranged in a recess or depression in the cup top CP. In the described embodiment, the shape of the recess is consistent with the shape of the emitter 330, and is therefore rectangular, but other polygonal shapes such as triangles, pentagons, or non-polygonal shapes such as circles are also contemplated in different embodiments.

[0069] exist Figure 3BIn an alternative design, in which the transmitter 330 is not flat but coiled, there is an exemplary embodiment 340 of an electrode insert for EBF, which is sunken into the outer shell, essentially flush with the proximal edge of the proximal part PP. The electrodes are supplied with current via pins 415a, 415b. In this embodiment, the transmitter 330 coil is held in a cutout in the central part of the cylindrical insert 340. The sunken insert is not necessarily semi-cylindrical. In particular, the electrode 340 preferably conforms to the cross-section of the outer shell OS, so that, for example, a prismatic design is also conceivable depending on the cross-section of the outer shell OS. Similar electrodes can be used for Figure 3A and 4 In the design of planar transmitters. Figure 4 The EBFs are not shown in FIG. 4 , but only their supply pins 415 a , 415 b are shown. Figure 3A A design without EBF is shown.

[0070] Reference now Figure 5 , which shows Figure 3A and Figure 4 A close-up of a partial section of a Figure 5 The insulating disc INS is shown in more detail, which is preferably made entirely of ceramic. As mentioned above, the shape and size of the insulating piece conform to the internal cross-section of the external shell OS holding the insulating piece. Preferably, the insulating disc INS is mounted to rest on a shoulder 505 in the inner periphery of the external shell OS and to bear against it. Preferably, the insulating piece INS is fixed to the inner surface of the external shell OS and / or to said shoulder 505. Fixing can preferably be achieved by brazing or alternatively by sintering or gluing.

[0071] According to one embodiment, the insulating disc INS is reactivated, ie it has an integrated relief structure RS (relieved structure) formed in one or both surfaces of the disc. Figure 5 In the embodiment shown, both faces have relief. The relief structure RS is defined by one or more wall portions 550a, b, 560a, b, which protrude from the upper surface and / or the lower surface to protrude in the proximal or distal direction, respectively. The relief structure RS allows for better mechanical rigidity and high voltage adaptability (also referred to as "withstand voltage" characteristics). The insulating member is configured to provide insulation against voltages up to several kilovolts.

[0072] Preferably, but not necessarily, the wall portions 560a,b, 550a,b simultaneously form the walls of through holes 410a,b and 450a,b through the ceramic disk INS to accommodate the pins 415a, 415b for the EBF and / or the feed pins 405a,b of the emitter 330, respectively. In other words, the through holes 450a,b, 410a,b are embossed relative to the corresponding face (in this case the proximal face) of the disk INS.

[0073] In one embodiment, one or more additional holes 510 are formed in the body of the ceramic insulator INS. These additional through holes may be referred to as drain holes. Figure 5 In the embodiment of FIG. 5 , a single central discharge hole 510 is shown. Preferably, the discharge hole is funnel-shaped so that the discharge hole opens to the two faces with different diameters. Preferably, as Figure 5 As shown, the larger diameter opens in the distal direction. The drain holes are useful when manufacturing the outer shell into which the ceramic disc INS is inserted. According to one embodiment, spark erosion is used in the manufacture of the outer shell or when adjusting the height of the emitter 330 relative to the outer shell OS. Then, when flushing the dielectric liquid during the spark erosion process, one or more drain holes 510 help to drain quickly. As an alternative to the relief structure of the disc, it can be completely flat on one or both faces.

[0074] It will be appreciated that the various through holes 410a, b and 450a, b through the single-sided insulator INS allow for the respective supply pins 405, 415 to be safely insulated collectively, rather than individually insulating each pin 405, 415 by installing their own respective insulating sleeves. This can save manufacturing costs and allow for more compact packaging per area per component (e.g., multiple emitters and / or multiple EBFs and / or other components).

[0075] As proposed herein, the insulating member INS, in particular ceramic, is integrally formed from a single ceramic block, like the outer shell OS, or may be integrally formed from a block of other suitable high temperature resistant insulating material as appropriate. Any one or a combination of various processing techniques, such as CNC milling or laser cutting, is also contemplated, and additive manufacturing processes, such as 3D printing, are also contemplated.

[0076] In summary, the cathode assembly proposed above comprises a cathode cup having a single housing as described above, said housing having electron beam optics for focusing the electron beam on the anode of the source XS when mounted. The proposed cathode cup design comprises two parts: an integral outer housing in which an integral monolithic ceramic insulator is housed. The insulator is configured to accommodate and insulate various components, such as electrical conductors or components, from each other. As described above, such conductors / components include pins for feeding power to the heating element or pins for one or more EBFs for controlling the propagation of the electron beam. The EBF is optional. If the design comprises more than one emitter, such as two or three or more, each emitter has a pair of dedicated feed pins that pass through the required number of through holes in the disc and / or through the proximal portion PP of the cathode cup CC.

[0077] As can be seen in the above-described embodiments, the proximal portion terminates in the top portion CP to close the housing OS, but proximal open designs of the housing are also contemplated. For example, in one embodiment for such an open design, the top portion CP may be formed as a grid or lattice structure, or even more simply, there may be no top portion at all, but rather one or more crossbars extending across the cylindrical opening of the cathode cup OS to provide rigidity.

[0078] The exact form of the ceramic insulation can be adjusted to the requirements of the specific tube transmitter. The creepage distance can be adjusted by other wall elements.

[0079] Reference now Figure 6 , where the fabrication methods are discussed in more detail.

[0080] In step S610, a monolithic outer shell OS of the cathode assembly is formed. This can be accomplished by an additive manufacturing process such as 3D printing, or by more traditional subtractive machining such as CNC milling, laser cutting, spark erosion (also known as electrical discharge machining "EDM"). Preferably, the outer shell OS is monolithic in that it is formed from a single block of metal material. The metal can be a pure metal or can be an alloy. Suitable metals include nickel, molybdenum, iron or others. Suitable alloys include Ni 42 or NiloK or others. The outer shell is preferably formed from bulk metal, but metal coating / lamination or sputtering of non-metallic substrates is also contemplated. The various through-holes previously described can be formed in a second process step by machining (e.g., milling or laser cutting) in an earlier formed shell, or can be formed by additive formation in an additive manufacturing (e.g., 3D printing) manner, line-by-line, or layer-by-layer manner as the entire shell is constructed.

[0081] In step S620, the integral insulating member is mounted into the housing by brazing, welding, or other fixing methods. In an alternative, fixing with pure friction fit is also conceivable. Preferably, the insulating member is formed from a block such as ceramic by any of the above-mentioned techniques, such as machining, including CNC milling or (laser) cutting, boring, broaching, etc. Alternatively, additive formation such as 3D printing is also contemplated. The manufacture of the ceramic insulating member may also include press molding and sintering of ceramic clay.

[0082] A single one-piece metal outer shell OS in combination with a single one-piece insulator allows for efficient mounting of the pin / electrode structure of the emitter or EBF or other device. This mounting can be accomplished in a single step S630 by using a suitable brazing furnace. Once the electrode is in place in the insulator INS within the outer shell OS, mounting can be accomplished in another step by spark erosion or other means to adjust the electrode to the outer shell with the desired accuracy by using spark erosion or similar techniques. The emitter can then be included in the next step and appropriately adjusted by a further step of spark erosion or other techniques.

[0083] Figure 7 A basic workflow diagram for 3D printing an external housing or internal insulation INS is shown.

[0084] The information about the geometry and shape of the outer shell or insulation is described by an appropriate CAD language in an appropriate format (e.g. STL, OBJ, PLY or other). This information is stored in a computer file FL. In one embodiment, this is a CAD file. The geometry in the geometry file FL is described by a set of surfaces. Each surface is given by its normal and vertex orientation. The shell and shape of the outer shell or insulation are then defined as a surface model established by a collection of these surface elements.

[0085] The geometry describing the file FL may be stored in a suitable memory MEM, for example in a permanent memory of a computing unit, or in a removable storage medium, such as a memory stick, a CD memory card or other.

[0086] In an embodiment, a data processing unit PU, such as a laptop or desktop computer or tablet or one or more servers (with or without cloud architecture), or other suitable computing units, runs a 3D slicer software that reads the geometry information from the geometry file FL and converts it into slices and associated commands suitable for controlling the operation of the 3D printer MFD through an appropriate interface. Specifically, the 3D slicer converts the geometry information into codes such as G-code and C programming language.

[0087] 3D printing in particular allows for more complex insulation structures to be formed in the outer shell, such as more complex grids or truss work that not only impede heat flow but also impart greater rigidity.

[0088] A similar workflow applies, for example, if the material forming device MFD is a CNC milling device.

Claims

1. A cathode assembly component (CC) for an X-ray imaging device (XI), comprising: An integral outer shell (OS) with electro-optical functions, and an insulator structure (INS) for two or more electrodes insertable into the housing, wherein the integral outer shell is cylindrical, the integral outer shell (OS) having an integrated thermal barrier to interfere with heat flow from the emitter (330) of the cathode assembly component towards the insulator structure (INS), And wherein the integrated heat barrier (HB) comprises at least one of the following: One or more holes (320a, b, 310a, b) formed at the outer surface of the cylinder; and One or more thinned portions (TP) are formed at the cylindrical shape, the cylindrical shape including a convex portion convexed from the thinned portion toward an exterior of the cylindrical shape, wherein a thickness of the thinned portion is smaller than a thickness of the convex portion.

2. The cathode assembly component according to claim 1, wherein: The insulating member structure (INS) is monolithic.

3. The cathode assembly component according to any one of claims 1 to 2, wherein: The housing (OS) is metal.

4. The cathode assembly component according to any one of claims 1 to 2, wherein: The insulator structure (INS) has a relief structure (RS).

5. The cathode assembly component according to any one of claims 1 to 2, wherein: The monolithic outer shell (OS) is formed from a single piece of material by any one or more of the following methods: i) 3D printing, ii) CNC milling, iii) laser cutting.

6. An X-ray source (XS) comprising a cathode assembly component according to any one of the preceding claims.

7. X-ray source (XS) according to claim 6, comprising: Cathode assembly (CAT) comprising the cathode assembly component according to any of the preceding claims, the cathode assembly (CAT) further comprising an emitter (330), wherein the emitter is flat or coiled.

8. An X-ray imaging device (XI) comprising a cathode assembly component (CC) according to any of the preceding claims or an X-ray source (XS) according to claim 7.

9. A method of manufacturing at least a portion of a cathode assembly component for an X-ray imaging device, comprising the steps of: forming ( S610 ) an integral outer shell; installing (S620) an insulator structure (INS) into the integral outer housing (OS), wherein the integral outer shell is cylindrical, the integral outer shell (OS) having an integrated thermal barrier to interfere with heat flow from the emitter (330) of the cathode assembly component towards the insulator structure (INS), And wherein the integrated heat barrier (HB) comprises at least one of the following: One or more holes (320a, b, 310a, b) formed at the outer surface of the cylinder; and One or more thinned portions (TP) are formed at the cylindrical shape, the cylindrical shape including a convex portion convexed from the thinned portion toward an exterior of the cylindrical shape, wherein a thickness of the thinned portion is smaller than a thickness of the convex portion.

10. A computer program element, which, when run by at least one processing unit (PU), is adapted to cause a material forming device (MFD) to form at least part of a cathode assembly component (CC) according to any of claims 1-6.

11. The computer program element according to claim 10, wherein: The program unit is a CAD file for 3D printing.

12. A computer-readable storage medium (MEM) on which a program element according to claim 10 or 11 is stored.

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