X-ray generating device

Abstract

The present application relates to the field of X-ray rotating target, and discloses an X-ray generating device, comprising: a shell; a fixed seat, which is sealingly installed in the shell; an anode target, which is arranged in the shell and has a target surface formed around a central axis; a rotating driving member, which is arranged along the central axis direction in the fixed seat and is slidingly matched with the fixed seat along the central axis direction, the rotating driving member has a rotating shaft, and the rotating shaft is connected with the anode target; a sealing member, which is annularly arranged around the rotating shaft; an extension tube, which is telescopic along the central axis direction, one end of the extension tube is connected with the fixed seat and the other end is connected with the sealing member; and an axial driving member, which is located outside the shell and is connected with the rotating driving member.The axial driving member can control the axial displacement of the anode target, and after the local area of the target surface is etched or damaged by the electron beam, the device can be switched to the new area which is not etched or damaged to focus the electron beam and excite X-rays, thereby prolonging the service life of the target material.

Description

Technical Field

[0001] This invention relates to the field of X-ray rotating target technology, and more particularly to an X-ray generating device. Background Technology

[0002] In related technologies, rotating anode X-ray generators are currently the core light source for high-performance X-ray diffractometers (XRD), X-ray fluorescence spectrometers (XRF), X-ray absorption spectroscopy (XAFS), and small-angle X-ray scattering spectrometers (SAXS). The working principle of a rotating anode X-ray generator is to emit an electron beam from a cathode filament, which is accelerated under a high-voltage electric field and bombards the anode target. To withstand the high heat generated by the electron beam bombardment (typically less than 1% of the energy is converted into X-rays, with the remaining 99% converted into heat), the anode target is usually rotated at high speed (e.g., 6000-9000 rpm, or even higher, reaching or exceeding 12000 rpm), distributing the heat along a ring-shaped focal spot trajectory, thereby significantly improving the power load capacity and brightness of the light source.

[0003] However, the rotating anode structure of an X-ray generator has the following problems:

[0004] First, the target material utilization rate is low, and its lifespan is limited. In traditional rotating anodes, the electron beam position relative to the target axis is fixed during operation. This means the electron beam consistently bombards the same fixed annular region on the target surface. Prolonged high-energy bombardment leads to severe physical damage to the target surface in this region, such as surface roughening, microcracks, and target erosion. Once the surface quality of this specific trajectory deteriorates, the X-ray output intensity decreases significantly (the rough surface absorbs some X-rays), and the metal particles generated by erosion can cause high-voltage arcing or contaminate the cathode filament. At this point, although other areas on either side of this trajectory on the cylindrical target remain pristine and intact, structural limitations prevent their utilization, forcing the entire expensive target disk to be scrapped.

[0005] Secondly, target replacement is costly and involves long downtime. When the fixed trajectory of the target surface wears out, the user must replace the target. This process is extremely cumbersome: it requires shutting down and cooling the entire system; disrupting the vacuum environment; disassembling the complex sealing structure to remove the old target; and after installing the new target, re-evacuating to a high vacuum (typically 10⁻⁵ Pa or higher) for a lengthy baking, degassing, and high-pressure aging process. The entire process often takes several days, severely impacting the research and production efficiency of laboratories or factories. Although theoretically the bombardment position can be changed by deflecting the electron beam, in X-ray diffraction applications, especially in Bragg-Brentano geometry, the spatial position of the X-ray source must remain absolutely fixed to coordinate with subsequent precision optical components (such as multilayer mirrors, monochromators), and the center of the goniometer. If the electron beam is moved, the source position changes, and the entire optical path needs to be recalibrated, which is unacceptable in practical applications.

[0006] Based on the above analysis, how to extend the service life of the target material in X-ray generators and reduce the cost of using the target material has become one of the urgent problems to be solved. Summary of the Invention

[0007] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes an X-ray generating device that can extend the service life of the anode target and reduce the cost of use.

[0008] An X-ray generating apparatus according to an embodiment of the present invention includes: a housing; a fixed base, the fixed base being sealed and installed in the housing; an anode target, the anode target being disposed within the housing, the anode target having a central axis, and a target surface formed around the central axis, the target surface being used for electron beam bombardment to generate X-rays; a rotary drive member, the rotary drive member being disposed through the fixed base along the central axis and slidingly engaged with the fixed base along the central axis, the rotary drive member having a rotation shaft located within the housing, the rotation shaft being connected to the anode target to drive the anode target to rotate around the central axis; a sealing member, the sealing member being circumferentially disposed around the rotation shaft to dynamically seal the rotation shaft in a vacuum environment; a telescopic tube, the telescopic tube being telescopic along the central axis, the telescopic tube being circumferentially disposed around the rotary drive member, one end of the telescopic tube being connected to the fixed base and the other end being connected to the sealing member; and an axial drive member, the axial drive member being located outside the housing and connected to the rotary drive member to drive the rotary drive member to move on the fixed base along the central axis.

[0009] According to the embodiments of the present invention, the X-ray generating apparatus can control the axial displacement of the anode target through the axial drive component. After a local area of ​​the target surface is etched or damaged by the electron beam, it can switch to a new un-etched or un-damaged area to continue electron beam focusing and X-ray excitation. It can make full use of the undamaged area of ​​the target surface and achieve the switching of the working area of ​​the target surface without changing the X-ray emission spatial position or destroying the vacuum environment. This is beneficial to extending the service life of the target material. Moreover, since it is not necessary to disassemble the anode target or destroy the vacuum environment, it can also reduce the operating cost of the X-ray generating apparatus.

[0010] In some embodiments of the present invention, the telescopic tube is a metal bellows, one end of which is welded to the fixed base and the other end is connected to the sealing element.

[0011] In some embodiments of the present invention, the seal is a magnetic fluid sealing assembly, which includes a main shaft and a magnetic fluid sealing component. The main shaft is fitted onto the rotating shaft through the magnetic fluid sealing component, and the main shaft is welded to the metal bellows.

[0012] In some embodiments of the present invention, the rotary drive component includes a motor stator, a motor mover, and a bearing. The motor stator passes through the fixed base and is slidably engaged with the fixed base. The motor mover is disposed inside the motor stator. The rotating shaft is disposed on the motor mover and is mounted on the motor stator through the bearing.

[0013] In some embodiments of the present invention, the rotary drive includes a base component disposed at one end of the motor stator away from the anode target and connected to the axial drive.

[0014] In some embodiments of the present invention, the anode target is provided with a cooling channel, and the rotating shaft is provided with a first channel and a second channel. The first channel and the second channel extend along the axial direction of the rotating shaft. The first channel is connected to the inlet of the cooling channel, and the second channel is connected to the outlet of the cooling channel.

[0015] In some embodiments of the present invention, a dynamic rotary joint is provided at the end of the rotating shaft away from the anode target, and the X-ray generating device further includes a cooling medium inlet pipe, a cooling medium outlet pipe, and a cable chain. The cooling medium inlet pipe and the cooling medium outlet pipe are both flexible hoses. The cooling medium inlet pipe is connected to the first flow channel through the dynamic rotary joint, and the cooling medium outlet pipe is connected to the second flow channel through the dynamic rotary joint. The cooling medium inlet pipe and the cooling medium outlet pipe are disposed on the cable chain.

[0016] In some embodiments of the present invention, the axial drive is configured to drive the anode target to multiple working positions so that the target surface can form multiple independent working areas, each of which can be used for electron beam bombardment to generate X-rays.

[0017] In some embodiments of the present invention, the axial drive member includes a pneumatic drive component and a plurality of limiting components. The pneumatic drive component has a drive rod that extends and retracts along the central axis direction. The drive rod is connected to the rotary drive member. The plurality of limiting components are arranged sequentially along the central axis direction and configured to be movable to limit and cooperate with the rotary drive member.

[0018] In some embodiments of the present invention, the width of each working area in the direction of the central axis is greater than or equal to 5 mm.

[0019] In some embodiments of the present invention, the anode target is made entirely of a thermally conductive metal.

[0020] In some embodiments of the present invention, the anode target includes a base layer and a functional layer, the base layer is connected to the rotation axis, the functional layer covers the base layer, or the functional layer covers part of the base layer, the base layer is a thermally conductive metal component, and the functional layer is an elemental substance that excites X-rays, wherein the elemental substance has an atomic number greater than or equal to 24 in the periodic table.

[0021] In some embodiments of the present invention, the thickness of the functional layer is 1 mm to 2 mm.

[0022] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0024] Figure 1 This is a schematic diagram of the structure of an X-ray generating device provided in some embodiments of the present invention.

[0025] Figure label:

[0026] 100. X-ray generator; 10. Mounting base; 20. Anode target; 201. Target surface; 30. Rotary drive component; 301. Rotary shaft; 3011. First flow channel; 3012. Second flow channel; 302. Motor stator; 303. Motor mover; 304. Bearing; 305. Base component; 40. Seal; 401. Main shaft; 50. Telescopic tube; 60. Axial drive component; 601. Pneumatic drive component; 602. Limiting component. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] The following is for reference. Figure 1 The present invention describes an X-ray generating apparatus 100 according to an embodiment of the present invention.

[0031] like Figure 1As shown, an X-ray generating device 100 according to an embodiment of the present invention includes: a housing (not shown), a fixed base 10, an anode target 20, a rotary drive 30, a sealing member 40, a telescopic tube 50, and an axial drive 60. The fixed base 10 is sealed and installed in the housing; the anode target 20 is disposed inside the housing, the anode target 20 has a central axis, and a target surface 201 is formed around the central axis of the anode target 20. The target surface 201 is used to generate X-rays by electron beam bombardment; the rotary drive 30 passes through the fixed base 10 along the central axis and slides with the fixed base 10 along the central axis. The rotary drive 30 has a rotary shaft 301 located inside the housing. The rotary shaft 301 is connected to the anode target 20 to drive the anode target 20 to rotate around the central axis; the sealing member 40 is arranged around the rotary shaft 301 to dynamically seal the rotary shaft 301 in a vacuum environment; the telescopic tube 50 is telescopic along the central axis and is arranged around the rotary drive 30. One end of the telescopic tube 50 is connected to the fixed base 10 and the other end is connected to the sealing member 40; the axial drive 60 is located outside the housing and is connected to the rotary drive 30 to drive the rotary drive 30 to move along the central axis on the fixed base 10.

[0032] The shell can refer to an outer shell structure with a high internal vacuum, also known as a target chamber. The shell material can be, but is not limited to, 304 or 316L stainless steel, etc. The interior of the shell can be maintained at 10... -5 Pa to 10 -7 Even higher levels of ultra-high vacuum, such as Pa.

[0033] The mounting base 10 can refer to a component used to provide a mounting position for the rotary drive 30. For example, the mounting base 10 can refer to a fixed flange, and one end of the housing can be provided with an opening. The mounting base 10 can be sealed and installed at the opening position of the housing.

[0034] The anode target 20 can refer to a target body, a device used to provide the position for electron beam bombardment, and the anode target 20 can be a cylindrical component. For example, in this embodiment of the invention, the anode target 20 can be a cylindrical component with a diameter of 100 mm.

[0035] The rotary drive component 30 can refer to a device used to drive the anode target 20 to rotate at high speed (up to 3000~12000 rpm), and can be, but is not limited to, a single-phase asynchronous induction motor, an electromagnetic levitation drive motor, a pulse inertial induction motor, a piezoelectric ultrasonic friction drive device, an electrostatic field rotary drive device, a flywheel passive inertial rotation device, etc. The axial drive component 60 can refer to a device that provides movement along the central axis, and can be, but is not limited to, a cylinder, a hydraulic cylinder, a linear motor, etc.

[0036] Seal 40 can refer to a component that can dynamically seal the rotating shaft 301 in a vacuum environment. Seal 40 can be, but is not limited to, a magnetohydrodynamic seal assembly, a labyrinth gap seal assembly, a dry gas film seal assembly, a metal end face mechanical seal assembly, etc.

[0037] The telescopic tube 50 can refer to a tubular component capable of telescopic movement, and can be, but is not limited to, a metal corrugated pipe, a metal sleeve telescopic tube assembly (a sleeve assembly with multi-stage sliding telescopic movement), a thin-walled cylindrical elastic straight tube (which achieves telescopic compensation by relying on the elasticity of the tube material itself through micro-compression and micro-stretching), etc. The telescopic tube 50 enables an airtight connection between the fixed seat 10 and the sealing element 40, isolating the rotating drive element 30 from the vacuum environment inside the housing.

[0038] During the operation of the X-ray generator 100, after the electron beam bombards the target surface 201 to generate X-rays, over a long period of operation, some surfaces of the target surface 201, which are the working areas, will be etched or damaged by the electron beam and become unusable. In this case, there is no need to replace the anode target 20 or disrupt the high vacuum environment inside the housing. The axial drive component 60 can move the rotary drive component 30 and the anode target 20 together along the central axis, thereby adjusting the position of the target surface 201 relative to the electron beam. This allows undamaged surfaces of the target surface 201 to move to the corresponding electron beam positions, thus fully utilizing the remaining surface areas of the target surface 201. Throughout the entire process of switching the target surface 201 position, the telescopic tube 50 provides vacuum isolation of the rotary drive component 30 within the housing and compensates for the axial displacement of the rotary drive component 30 and the anode target 20, ensuring the stability and reliability between the rotary drive component 30 and the anode target 20 during the target surface 201 switching operation.

[0039] It should be noted that the X-ray generating device 100 of the present invention can be applied to analytical instruments that have extremely high requirements for the power density, focal spot stability and spectral purity of the X-ray source, including but not limited to X-ray diffractometer (XRD), X-ray fluorescence spectrometer (XRF), X-ray absorption spectrometer (XAFS) and small angle X-ray scatterer (SAXS).

[0040] According to the embodiment of the present invention, the X-ray generating device 100 can control the anode target 20 to generate axial displacement through the axial drive member 60. After a local area of ​​the target surface 201 is etched or damaged by the electron beam, it can switch to a new un-etched or un-damaged area to continue electron beam focusing and X-ray excitation. It can make full use of the undamaged area of ​​the target surface 201 and achieve the switching of the working area of ​​the target surface 201 without changing the X-ray emission spatial position or destroying the vacuum environment. This is beneficial to extending the service life of the target material. Moreover, since it is not necessary to disassemble the anode target 20 or destroy the vacuum environment, it can also reduce the operating cost of the X-ray generating device 100.

[0041] In some embodiments of the present invention, such as Figure 1 As shown, the telescopic tube 50 is a metal bellows, with one end of the metal bellows welded to the fixed seat 10 and the other end connected to the sealing element 40.

[0042] The metal bellows possesses good rigidity, preventing deformation in a vacuum environment, and allows for axial expansion and contraction along its central axis to compensate for the axial displacement of the anode target 20 and the rotary drive component 30. Secondly, the lower axial stiffness of the metal bellows helps reduce the driving force requirements of the axial drive component 60, thus reducing its load and lowering costs. The metal bellows also exhibits high radial stiffness to suppress vibration and misalignment, and boasts a high cyclic fatigue life, making it suitable for long-term reciprocating motion. Specifically, the compression of the telescopic tube 50 along its central axis is greater than or equal to the target displacement of the anode target 20.

[0043] Optionally, the metal bellows is made of 316L stainless steel, which has extremely high fatigue life (greater than 100,000 cycles) and good vacuum compatibility.

[0044] In some embodiments of the present invention, the seal 40 is a magnetic fluid sealing assembly, which includes a main shaft 401 and a magnetic fluid sealing component. The main shaft 401 is fitted onto the rotating shaft 301 through the magnetic fluid sealing component, and the main shaft 401 is welded to a metal bellows.

[0045] In the above technical solution, the magnetic fluid sealing component can refer to other structures in the magnetic fluid sealing assembly besides the main shaft 401, such as the magnetic circuit, bearing components, and magnetic fluid, etc. Other components of the magnetic fluid sealing assembly are known to the art and will not be described in detail here. It is understood that by setting the seal 40 as a magnetic fluid sealing assembly, better dynamic sealing of the rotating shaft 301 can be achieved in a vacuum environment. The two peripheral edges of the metal bellows are connected to the main shaft 401 and the fixed seat 10 by welding, which can improve the connection reliability between the metal bellows and the main shaft 401 and the fixed seat 10, ensure airtightness, and reduce the risk of leakage.

[0046] In some embodiments of the present invention, such as Figure 1 As shown, the rotary drive component 30 includes a motor stator 302, a motor mover 303, and a bearing 304. The motor stator 302 passes through and slides with the fixed base 10. The motor mover 303 is disposed inside the motor stator 302. The rotating shaft 301 is disposed on the motor mover 303 and is mounted on the motor stator 302 via the bearing 304. In the above technical solution, by configuring the rotary drive component 30 as the aforementioned induction motor structure, it can be applied to harsh working environments, avoiding the impact of the rotary drive component 30 on the vacuum environment.

[0047] Furthermore, a guide structure may be provided between the motor stator 302 and the fixed base 10 to achieve high-precision axial movement of the rotary drive component 30 on the fixed base 10, and to prevent radial runout when the anode target 20 moves along the central axis.

[0048] Optionally, the guide structure can be a guide key and a guide groove that slide against each other, with one of the guide key and guide groove located on the motor stator 302 and the other located in the through hole of the fixed seat 10. Optionally, the guide structure can also be a linear bearing.

[0049] In some embodiments of the present invention, such as Figure 1 As shown, the rotary drive 30 includes a base component 305, which is located at the end of the motor stator 302 away from the anode target 20 and is connected to the axial drive component 60. The base component 305 may refer to the end cap assembly structure at the tail of the motor.

[0050] In some embodiments of the present invention, such as Figure 1 As shown, the anode target 20 has a cooling channel 202 inside, and the rotating shaft 301 has a first channel 3011 and a second channel 3012 inside. The first channel 3011 and the second channel 3012 extend along the axial direction of the rotating shaft 301. The first channel 3011 is connected to the inlet of the cooling channel 202, and the second channel 3012 is connected to the outlet of the cooling channel 202. Since the anode target 20 rotates at high speed and generates a huge amount of heat (e.g., 1.2kW~9kW heat load), in this technical solution, the first channel 3011, the second channel 3012, and the cooling channel 202 work together to form a circulating cooling system to cool the anode target 20. The cooling medium in the cooling channel 202 can be, but is not limited to, gaseous or liquid, for example, water.

[0051] In some embodiments of the present invention, a dynamic rotary joint is provided at the end of the rotating shaft 301 away from the anode target 20. The X-ray generating device 100 also includes a cooling medium inlet pipe, a cooling medium outlet pipe, and a cable chain. Both the cooling medium inlet pipe and the cooling medium outlet pipe are flexible hoses. The cooling medium inlet pipe is connected to the first flow channel 3011 through the dynamic rotary joint, and the cooling medium outlet pipe is connected to the second flow channel 3012 through the dynamic rotary joint. The cooling medium inlet pipe and the cooling medium outlet pipe are located on the cable chain.

[0052] Because the rotary drive 30 drives the anode target 20 to rotate at high speed, the dynamic rotary joint enables the delivery of the cooling medium to the first flow channel 3011 and its discharge from the second flow channel 3012. Secondly, since the anode target 20 and the rotary drive 30 need to move axially, the cooling medium inlet and outlet pipes are made of flexible hoses to prevent them from being torn. When the axial drive 60 pushes the anode target 20 and the rotary drive 30 to translate, the cooling medium inlet and outlet pipes undergo slight bending deformation within the cable chain. This allows the axial displacement of the anode target 20 to be accommodated without affecting the high-flow-rate cooling cycle of several liters per minute (L / min). In other words, the cable chain guides the cooling medium inlet and outlet pipes to bend within a preset radius, avoiding stress concentration at the joints. The cooling medium inlet and outlet pipes can be connected to an external chiller.

[0053] In the above technical solution, the dynamic rotary joint is provided with a coaxial circulating cooling flow path. The cooling medium enters the inner wall of the anode target 20 through the first flow channel 3011 of the rotating shaft 301 for heat exchange, and then flows out through the second flow channel 3012.

[0054] The dynamic rotary joint employs a balanced mechanical seal assembly instead of a standard rubber oil seal. This mechanical seal assembly includes a rotating ring, a stationary ring, and an elastic compensating element. The rotating ring rotates at high speed with the rotating shaft 301 and is preferably made of silicon carbide (SiC) or tungsten carbide (WC), possessing extremely high hardness and wear resistance. The stationary ring is fixed to the outer shell of the dynamic rotary joint and does not rotate; it is preferably made of impregnated graphite. The elastic compensating element has a wave spring behind the stationary ring, providing a constant end-face pressure. Even when the rotating shaft 301 rotates at high speed, generating micro-vibrations or thermal expansion, the end faces of the rotating and stationary rings remain tightly fitted, forming a "zero-leakage" liquid barrier. Optionally, the outer shell of the dynamic rotary joint in this embodiment is designed to be floating and includes an anti-rotation pin.

[0055] Furthermore, an isolation chamber and a leakage guide hole are provided between the mechanical seal assembly of the dynamic rotary joint and the external bearing. In the event of a minor leak in the mechanical seal assembly, the cooling medium will be discharged directly to the water collection pan through the guide hole and trigger the humidity alarm sensor, and will never enter the bearing or flow back into the vacuum chamber, thus completely eliminating the catastrophic failure of "water vapor destroying the vacuum".

[0056] Optionally, the cooling medium inlet and outlet pipes can be highly flexible polyurethane or Teflon braided hoses. Optionally, the cable chain can be a nylon cable chain.

[0057] In some embodiments of the present invention, the axial drive 60 is configured to drive the anode target 20 to multiple working positions so that the target surface 201 can form multiple independent working areas, each of which can be used for electron beam bombardment to generate X-rays.

[0058] It is understood that the axial drive 60 can drive the anode target 20 to stay at multiple working positions, thus forming multiple working areas on the target surface 201, each of which can be bombarded with an electron beam to generate X-rays. Any two adjacent working areas are independent and do not overlap. The number of working positions can be, but is not limited to, two, three, four, etc., and correspondingly, the number of working areas can also be, but is not limited to, two, three, four, etc. For example, the axial drive 60 can drive the anode target 20 to three working positions, forming three working areas on the target surface 201. Therefore, compared to anode targets of related technologies, the lifetime of the anode target 20 of this embodiment can be extended by three times.

[0059] In some embodiments of the present invention, such as Figure 1 As shown, the axial drive component 60 includes a pneumatic drive component 601 and multiple limiting components 602. The pneumatic drive component 601 has a drive rod that extends and retracts along the central axis. The drive rod is connected to the rotary drive component 30. The multiple limiting components 602 are arranged sequentially along the central axis and configured to be movable to limit and engage with the rotary drive component 30. That is, by limiting and engaging the rotary drive component 30 with the multiple limiting components 602, the anode target 20 can be stopped between multiple working positions. The number of multiple limiting components 602 and the number of multiple working positions are equal and correspond one-to-one. The limiting components 602 can be, but are not limited to, limiting blocks, limiting pins, etc., and the movement of the limiting components 602 can be, but is not limited to, electric control, manual control, etc.

[0060] The pneumatic drive component 601 can refer to a pneumatic drive device, such as a cylinder assembly, which may include a cylinder and a solenoid valve assembly, etc. The drive rod can refer to the piston rod of the cylinder, which is connected to the rotary drive component 30. When the cylinder is in the exhaust state (or negative pressure state), under the elastic restoring force of the telescopic tube 50 or the action of an external return spring, the rotary drive component 30 touches the first limiting component 602, and the anode target 20 is in the initial position, defined as position A (original track). When the control system commands a track switching, compressed air (e.g., the pressure range can be 0.4-0.6 MPa) is injected into the cylinder, pushing the rotary drive component 30 to compress the telescopic tube 50. The multiple limiting components 602 ensure absolute accuracy of displacement. For example, there are three limiting components 602, working positions, and working areas. The cylinder's extension and retraction stroke is 10mm each time. After the first limiting component 602 is removed, when the telescopic tube 50 is compressed by 10mm, the rotary drive 30 touches the second limiting component 602, and the anode target 20 shifts inward by 10mm, precisely switching the electron beam bombardment position to position B. When the second limiting component 602 is removed and pressure continues to be applied, when the telescopic tube 50 is compressed by 20mm, the anode target 20 continues to shift, and the rotary drive 30 touches the third limiting component 602, switching the electron beam bombardment position to position C.

[0061] For example, the limiting component 602 can be a limiting screw and can be configured as three. State 1 (Initial): The cylinder exhausts air, and the telescopic tube 50 uses its own elasticity or an external return spring to push the anode target 20 to the zero position. State 2 (First Switch): The control system opens the first-stage solenoid valve, charging the cylinder with 0.4MPa compressed air. The cylinder pushes the anode target 20 forward until the rotary drive 30 touches the "first-stage limiting screw". At this time, the displacement is physically locked to a precise 10.0mm. State 3 (Second Switch): The cylinder continues to pressurize or, through the action of the second-stage piston, pushes the anode target 20 past the first limit until it touches the "second-stage limiting screw", and the displacement is locked to 20.0mm. This purely mechanical pneumatic limiting method can achieve a repeatability accuracy of ±0.05mm, which is more than sufficient for a working area with a width of 10mm, and completely avoids the complexity of electronic control systems and the potential risk of radiation failure.

[0062] In the above technical solution, the axial drive component 60 can achieve pneumatic and mechanical limiting by adopting the structure of pneumatic drive component 601 and multiple limiting components 602. This can ensure the displacement accuracy of the axial movement of the anode target 20, with a repeatability accuracy better than ±0.05mm. It can also prevent the electron beam from hitting the boundary between the two working areas due to the anode target 20 moving too much or too little each time, thus ensuring the consistency of the optical path.

[0063] In some embodiments of the present invention, the width of each working area in the central axis direction is greater than or equal to 5 mm. It can be understood that the widths of multiple working areas in the central axis direction may be equal or unequal, and may be, but are not limited to, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, etc. Similarly, it can be understood that the distance between any two adjacent working positions of the anode target 20 is greater than or equal to 5 mm, and the travel distance of the pneumatic drive component 601 each time is also greater than or equal to 5 mm.

[0064] Optionally, the width of each working area in the central axis direction is greater than or equal to 10 mm. Since the projected width of the standard electron beam focal spot on the target surface 201 is generally about 1 mm, but considering thermal diffusion and the Gaussian distribution of the electron beam, the actual width of the bombardment heat mark is about 8 mm to 10 mm. Therefore, by making the width of each working area in the central axis direction greater than or equal to 10 mm, a wider working area can be formed on the target surface 201, which can match the size of the electron beam heat mark and avoid the influence of the previous electron beam heat mark on the X-rays generated by the next electron beam. For example, the target surface 201 can have three working areas, each with a width of 10 mm, and the width of the anode target 20 in the central axis direction is 30 mm.

[0065] In some embodiments of the present invention, the anode target 20 is entirely made of a thermally conductive metal. For example, the anode target 20 is made of pure copper, specifically high-purity oxygen-free copper, with the copper substrate surface serving not only as a heat conductor but also as an X-ray excitation layer. An anode target 20 using this material can be used for the analysis of biomacromolecules or organic materials. Exemplarily, in this embodiment, the target surface 201 is virtually divided along the axial direction into three regions of equal width: Zone A (0-10 mm) is the initial working area; Zone B (10-20 mm) is the first backup area; and Zone C (20-30 mm) is the second backup area. Since pure copper is relatively soft and easily eroded by an electron beam, the pneumatic displacement of the present invention can directly extend the service life of the pure copper target to three times its original value.

[0066] In some embodiments of the present invention, the anode target 20 includes a base layer and a functional layer. The base layer is connected to the rotation shaft 301, and the functional layer covers the base layer, or the functional layer covers part of the base layer. The base layer is a thermally conductive metal component, and the functional layer is an elemental substance that excites X-rays. The elemental substance has an atomic number greater than or equal to 24 in the periodic table.

[0067] Understandably, the anode target 20 can be a composite target structure, applicable to a wider range of scenarios, and employs a high atomic number metal as the functional layer. The base layer is made of a metallic element with excellent thermal conductivity, such as copper (Cu), to ensure efficient heat dissipation under high-speed rotation. The functional layer is made of an element with high X-ray excitation efficiency, whose atomic number Z in the periodic table satisfies Z ≥ 24. For example, the functional layer material could include molybdenum (Mo, Z=42), tungsten (W, Z=74), silver (Ag, Z=47), chromium (Cr, Z=24), or gold (Au, Z=79), etc.

[0068] In the above technical solution, the functional layers can be composed of a single material. Referring to the previous embodiment, Zone A, Zone B, and Zone C of the target surface 201 are all made of the same material (e.g., all are Cu). Alternatively, the functional layers can be composed of multiple materials. For example, Zone A may be a copper (Cu) substrate, with Zones B and C as functional layers, or Zone B may be copper (Cu), with Zones A and C as functional layers. By designing the combination of functional layers, the lifespan of a single wavelength can be maximized, thus forming a coincident target with the copper (Cu) substrate anode target 20 for different characteristic wavelengths. In this case, switching the position via the axial drive 60 not only extends the lifespan but also enables online switching of two different X-ray wavelengths on a single instrument to meet different crystallographic research needs.

[0069] In some embodiments of the present invention, the functional layer may be coated or bonded to the cylindrical side surface of the substrate by one of electroplating, vacuum sputtering or diffusion bonding.

[0070] Optionally, for the anode target 20 that forms a composite target material after coating (especially in the case of Mo or W coating), embodiments of the present invention further include a post-treatment step for the anode target 20. Specifically, the post-treatment step is vacuum annealing, thereby forming an atomic diffusion bonding layer between the functional layer and the substrate layer, improving the bonding strength. More specifically, during vacuum annealing, the vacuum degree is 10. -5 Pa~10 -6 Pa; the annealing temperature is set at 800°C~950°C, and the holding time is 2-4 hours. This process can eliminate internal stress and prevent the target material from falling off under high-speed rotation and electron beam thermal shock.

[0071] In some embodiments of the present invention, the thickness of the functional layer is 1 mm to 2 mm. That is, the thickness of the functional layer can be, but is not limited to, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, or 2.0 mm. By setting the thickness of the functional layer within the above range, it is ensured that the functional layer will not be broken down even after long-term electron beam etching, and the waste of precious metal materials is avoided.

[0072] The following is in conjunction with the appendix Figure 1 This describes a specific embodiment of the X-ray generating apparatus 100 of the present invention.

[0073] The X-ray generating device 100 includes a housing, a fixed base 10, an anode target 20, a rotary drive 30, a seal 40, a telescopic tube 50, and an axial drive 60.

[0074] The shell is a vacuum enclosure made of stainless steel, and its interior maintains a vacuum level of 10⁻⁵ Pa or even higher.

[0075] The fixed seat 10 is a fixed flange, which is sealed and installed on the housing.

[0076] The anode target 20 is housed within the casing and is a cylindrical copper (Cu) target drum with a diameter of 100 mm. The surface of the target drum is plated with a 1-2 mm thick layer of high-purity metal such as molybdenum (Mo), tungsten (W), silver (Ag), cadmium (Cr), or gold (Au) as the X-ray excitation material, thereby forming the target surface 201. The anode target 20 has a central axis, and its axial width along the central axis is 30 mm. It is divided into three independent, non-overlapping working zones: Zone A, Zone B, and Zone C. The width of each zone is 10 mm.

[0077] The rotary drive component 30 is a motor, and includes a motor stator 302, a motor mover 303, and a bearing 304. The motor stator 302 is mounted on the fixed base 10 along the central axis. The motor stator 302 and the fixed base 10 are slidably engaged along the central axis via a guide key and a guide groove. The motor mover 303 is located inside the motor stator 302. The rotating shaft 301 is located on the motor mover 303 and is mounted on the motor stator 302 via the bearing 304. The motor stator 302 has a rotating shaft 301 located within a housing. The rotating shaft 301 is connected to the anode target 20 to drive the anode target 20 to rotate around the central axis.

[0078] The seal 40 is a magnetohydrodynamic sealing assembly and is arranged around the rotating shaft 301 to dynamically seal the rotating shaft 301 in a vacuum environment. The telescopic tube 50 is a metal bellows made of 316L stainless steel and is arranged around the rotating drive 30. One end of the metal bellows is welded to the fixing seat 10, and the other end is welded to the main shaft 401 of the magnetohydrodynamic sealing assembly.

[0079] The axial drive member 60 is located on the outside of the housing and connected to the rotary drive member 30 to drive the rotary drive member 30 to move along the central axis on the fixed base 10. The axial drive member 60 includes a pneumatic drive component 601 and three limiting components 602. The pneumatic drive component 601 has a drive rod that extends and retracts along the central axis. The drive rod is connected to the rotary drive member 30. The three limiting components 602 are limiting pins and are arranged sequentially along the central axis. The three limiting components 602 can be movable to limit and cooperate with the rotary drive member 30.

[0080] When the metal bellows is in its naturally elongated state, the anode target 20 is at position A (original orbit). When the metal bellows is compressed by 10 mm, the anode target 20 shifts inward by 10 mm, and the electron beam bombardment position changes to position B. When the metal bellows is compressed by 20 mm, the anode target 20 continues to shift, and the electron beam bombardment position changes to position C.

[0081] For example, a user can use the X-ray generator 100 of the above embodiment to conduct long-term protein crystal diffraction experiments: During normal operation, the anode target 20 is in position A (original orbit), Zone A of the target surface 201 corresponds to the electron beam, the electron beam bombards Zone A, and the power of the X-ray generator 100 is 1.2kW. After 2000 hours of operation, the user finds that the X-ray intensity has decreased by 20%, indicating that the surface of Zone A has become rough. The following is a switchover preparation: the user clicks "Change Target Track" on the control software. The system automatically cuts off the high voltage, but keeps the filament preheated and the vacuum pump running. At this time, there is no need to break the vacuum or open the target chamber. Pneumatic execution: the system controls the solenoid valve to operate, the cylinder is filled with air, and with a "click", the anode target 20 is pushed inward by 10mm, precisely locking into the second position. The whole process takes only 5 seconds. Resumption of operation: the system automatically turns on the high voltage. Since the electron beam is now bombarding a brand new Zone B with extremely high surface smoothness, the X-ray intensity instantly recovers to the factory specification (100%). Result: The entire maintenance process took only 1 minute, and the experiment could continue immediately without having to find the optical path again.

[0082] Other configurations and operations of the X-ray generating apparatus 100 according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0083] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0084] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An X-ray generating device, characterized in that, include: case; A mounting base is sealed and installed on the housing; An anode target is disposed within the housing. The anode target has a central axis and a target surface is formed around the central axis. The target surface is used to generate X-rays by electron beam bombardment. A rotary drive component is provided, which passes through the fixed base along the central axis and slides with the fixed base along the central axis. The rotary drive component has a rotary shaft located inside the housing, and the rotary shaft is connected to the anode target to drive the anode target to rotate around the central axis. A sealing element, which is arranged around the rotating shaft to dynamically seal the rotating shaft in a vacuum environment; A telescopic tube, which is telescopic along the central axis, is arranged around the rotating drive member, with one end of the telescopic tube connected to the fixed base and the other end connected to the sealing member; An axial drive member is located outside the housing and connected to the rotary drive member to drive the rotary drive member to move along the central axis on the fixed base. The axial drive member is configured to drive the anode target to multiple working positions so that the target surface can form multiple independent working areas, each of which can be used for electron beam bombardment to generate X-rays.

2. The X-ray generating apparatus according to claim 1, characterized in that, The telescopic tube is a metal bellows, with one end of the metal bellows welded to the fixed base and the other end connected to the sealing element.

3. The X-ray generating apparatus according to claim 2, characterized in that, The seal is a magnetic fluid sealing assembly, which includes a main shaft and a magnetic fluid sealing component. The main shaft is fitted onto the rotating shaft through the magnetic fluid sealing component, and the main shaft is welded to the metal bellows.

4. The X-ray generating apparatus according to claim 1, characterized in that, The rotary drive component includes a motor stator, a motor mover, and a bearing. The motor stator passes through the fixed base and slides with the fixed base. The motor mover is located inside the motor stator. The rotating shaft is located on the motor mover and is mounted to the motor stator through the bearing.

5. The X-ray generating apparatus according to claim 4, characterized in that, The rotary drive includes a base component located at the end of the motor stator away from the anode target and connected to the axial drive.

6. The X-ray generating apparatus according to claim 1, characterized in that, The anode target has a cooling channel inside, and the rotating shaft has a first channel and a second channel inside. The first channel and the second channel extend along the axial direction of the rotating shaft. The first channel is connected to the inlet of the cooling channel, and the second channel is connected to the outlet of the cooling channel.

7. The X-ray generating apparatus according to claim 6, characterized in that, The rotating shaft is provided with a dynamic rotary joint at the end away from the anode target. The X-ray generating device also includes a cooling medium inlet pipe, a cooling medium outlet pipe, and a cable chain. The cooling medium inlet pipe and the cooling medium outlet pipe are both flexible hoses. The cooling medium inlet pipe is connected to the first flow channel through the dynamic rotary joint, and the cooling medium outlet pipe is connected to the second flow channel through the dynamic rotary joint. The cooling medium inlet pipe and the cooling medium outlet pipe are located on the cable chain.

8. The X-ray generating apparatus according to claim 1, characterized in that, The axial drive component includes a pneumatic drive component and multiple limiting components. The pneumatic drive component has a drive rod that extends and retracts along the central axis. The drive rod is connected to the rotary drive component. The multiple limiting components are arranged sequentially along the central axis and configured to be movable to engage with the rotary drive component in a limiting manner.

9. The X-ray generating apparatus according to claim 1, characterized in that, The width of each working area in the direction of the central axis is greater than or equal to 5 mm.

10. The X-ray generating apparatus according to any one of claims 1, 8, and 9, characterized in that, The anode target is made entirely of thermally conductive metal.

11. The X-ray generating apparatus according to any one of claims 1, 8, and 9, characterized in that, The anode target includes a base layer and a functional layer. The base layer is connected to the rotation axis. The functional layer covers the base layer, or the functional layer covers part of the base layer. The base layer is a thermally conductive metal component. The functional layer is an elemental substance that excites X-rays. The elemental substance has an atomic number greater than or equal to 24 in the periodic table.

12. The X-ray generating apparatus according to claim 11, characterized in that, The thickness of the functional layer is 1 mm to 2 mm.

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