Liquid metal jet system and method for an x-ray source anode target

Abstract

The application discloses a liquid metal jet system and method for an X-ray source anode target, and relates to the technical field of X-ray sources.The system comprises an electron beam system, a jet system, a supply system, a driving system and a pressurizing system, wherein the supply system and the pressurizing system are flexibly connected with the jet system through pipelines, and the electron beam system is rigidly connected with the jet system.The pressurizing system comprises two liquid metal piston cylinders and a hydraulic piston cylinder, the supply system supplies stable liquid metal to the liquid metal piston cylinders, the driving system supplies hydraulic oil to the hydraulic piston cylinder, the pressurizing system pressurizes and delivers the liquid metal to the jet system, the jet system sprays a liquid metal jet in a vacuum chamber, an X-ray is generated by electron beam bombardment on the liquid metal jet, and the liquid metal in the vacuum chamber is collected and returned to the supply system after cooling; and an auxiliary vacuum system stabilizes the vacuum condition of the vacuum chamber.The application has the advantages of compact structure, high X-ray source light brightness, high X-ray flux, high test efficiency, high liquid metal pressure and high jet speed.

Description

Technical Field

[0001] This invention relates to the field of X-ray source technology, and in particular to a liquid metal jet system and method for an X-ray source anode target. Background Technology

[0002] X-ray imaging, as an effective non-destructive testing method, plays a vital role in materials science, industrial manufacturing, aerospace, and modern medicine. X-ray micro-computed tomography (CT) systems are commonly used to characterize the internal microstructure of engineering materials (such as metals, alloys, ceramics, and composite materials), enabling the identification, extraction, and quantitative analysis of microstructural features such as fiber bundles, different components in composite matrix, or defects like pores and microcracks. One of the core components that determines the efficiency and accuracy of characterization testing in an X-ray micro-CT system is the X-ray source. To achieve rapid characterization of the internal microstructure of materials, a compact, stable, micro-focused X-ray source is generally required to generate a high power density and achieve high-brightness light output.

[0003] During the operation of an X-ray source, electrons emitted from the cathode are accelerated by a high-voltage electric field and focused by an electron optical system (such as electromagnetic lenses and electrostatic lenses) before bombarding the surface of the anode target. After impacting the anode, the electrons release their energy as heat (approximately 99% of their energy) and X-rays (mainly bremsstrahlung and characteristic radiation). Continuous bombardment of the metal target by a high-power electron beam can cause a rapid increase in the target surface temperature, leading to ablation or melting, and consequently, damage to the X-ray source. The selection of the anode target for an X-ray source must consider two factors: firstly, the wavelength of the characteristic X-rays, as different targets produce different wavelengths, requiring selection based on experimental conditions and objectives; and secondly, the properties of the metal itself. In high-power X-ray micro-CT systems, tungsten, a solid metal with a high melting point, low coefficient of thermal expansion, and good resistivity and thermal stability, is typically chosen as the anode target.

[0004] Chinese invention patent CN113728410A discloses an X-ray source with a rotating liquid metal target. The X-ray beam is generated in the interaction region between the electron beam and the target, which is an annular layer of molten fusible metal in the annular channel of the rotating anode assembly. This patent uses the centrifugal force generated by the rotation of the rotor to drive the liquid metal to adhere to the sidewall of the annular groove, and generates X-rays by impacting the side of the electron beam and ejecting the X-rays at a specific angle. It has the following problems: (1) The cavity of the electron beam system and the liquid metal anode target interaction area is large, resulting in an excessively large overall volume of the X-ray source, while the X-ray micro-CT system requires a compact structure of the X-ray source; (2) Since the rotor and the electron beam interaction area are rigidly connected, the vibration generated by the rotor rotation will be directly transmitted to the electron beam interaction area, resulting in poor stability of the focal spot position, which will directly affect the resolution of the X-ray micro-CT system, resulting in poor resolution; (3) During operation, the liquid metal has poor fluidity and is limited by the working efficiency of the heat exchange system. Long-term operation will cause the working temperature of the liquid metal to be too high. The evaporated liquid metal will solidify at the X-ray window and block the X-rays from being emitted. At the same time, the liquid metal vapor or debris diffuses into the electron beam path, which will affect the quality of the electron beam, thereby affecting the test quality and test accuracy of the X-ray micro-CT system.

[0005] Chinese invention patent CN102369587B discloses a closed-loop circulation for providing liquid metal to an interaction region, where an electron beam strikes the liquid metal to generate X-rays. It has the following problems: (1) The device uses a diaphragm pump as a high-pressure pump, and the pressure obtained by the liquid metal is only 10-50 bar. The low pressure results in a low jet velocity of the liquid metal and a small range for adjusting the jet velocity; (2) The jet velocity of the liquid metal can only be controlled by adjusting the input power of the high-pressure pump, resulting in low adjustment accuracy; (3) The liquid metal in the electron beam-bombarded region of the vacuum chamber will also produce debris and evaporate, which will have a certain impact on the stability of the electron beam, the stability of the focal spot position, and the X-ray beam exit, thus affecting the test quality and accuracy of the X-ray micro-CT system, leading to poor test quality. (4) There is only a vacuum component in the electron beam system. On the one hand, the vacuum pump in the electron beam system is prone to sucking liquid metal debris and vapor into the electron beam system during continuous operation, which will cause corrosion to the metal components in the electron beam system. On the other hand, due to the complex structure and many parts of the liquid metal jet system, some minor vacuum leaks are easy to occur. It is difficult to ensure the stability of the vacuum degree in the vacuum cavity where the electron beam interacts with the liquid metal jet if there is only one vacuum system in the electron beam system. The instability of the vacuum degree will have a significant impact on the quality of the electron beam, which will in turn affect the test quality and test accuracy of the X-ray micro-CT system. Summary of the Invention

[0006] This invention provides a liquid metal jet system and method for an X-ray source anode target. Existing systems suffer from the following problems: large structure directly connected to the electron beam system; poor focal spot position stability, resulting in poor resolution of the X-ray micro-CT system; excessively high liquid metal operating temperature, causing evaporated liquid metal to solidify at the X-ray window, blocking X-ray emission; liquid metal vapor or debris diffuses into the electron beam path, affecting electron beam quality and thus the test quality and accuracy of the X-ray micro-CT system; low jet velocity and limited jet velocity adjustment range; low jet velocity adjustment accuracy; poor test quality and accuracy; and the presence of a vacuum component only in the electron beam system, leading to corrosion of metal components within the electron beam system and poor vacuum stability, resulting in poor test quality and accuracy.

[0007] To address the aforementioned technical problems, embodiments of the present invention provide the following solutions:

[0008] On one hand, embodiments of the present invention provide a liquid metal jet system for an X-ray source anode target, comprising an electron beam system and a jet system. The jet system ejects a liquid metal jet within a vacuum chamber. An electron beam emitted by the electron beam system bombards the liquid metal jet to generate X-rays, which exit through an X-ray window. The system is characterized by further comprising a supply system, a drive system, and a pressurization system. The supply system and the pressurization system are flexibly connected to the jet system via pipelines, while the electron beam system is rigidly connected to the jet system. The pressurization system includes two liquid metal piston cylinders and a hydraulic piston cylinder. The supply system provides the liquid metal with a certain initial pressure to the liquid metal piston cylinders, and the drive system provides hydraulic oil to the hydraulic piston cylinders. The pressurization system delivers the liquid metal to the jet system by pressurization. The liquid metal within the vacuum chamber is collected, cooled, and then returned to the supply system. An auxiliary vacuum system is connected to the vacuum chamber to stabilize the vacuum conditions within it.

[0009] Preferably, the drive system includes a hydraulic oil pump, an oil tank provides hydraulic oil to the hydraulic oil pump, the hydraulic oil pump, a first check valve, a reversing valve and a high-pressure pump in the booster system are sequentially connected to form an oil supply circuit, the high-pressure pump, a second cooler and the oil tank are sequentially connected to form a return oil circuit, the oil supply circuit is located at the output end of the first check valve, a solenoid valve, the second cooler and the oil tank are sequentially connected, and the solenoid valve is connected to the oil tank.

[0010] Preferably, the pressurization system includes a high-pressure pump, with a second check valve assembly connected to both ends of the high-pressure pump. One of the second check valve assemblies is connected to a liquid metal delivery pipe, and the other second check valve assembly is connected to an accumulator via a high-pressure pipe. The accumulator is connected to the jet system.

[0011] Preferably, the high-pressure pump includes a hydraulic piston cylinder and liquid metal piston cylinders located at both ends of the hydraulic piston cylinder, the liquid metal piston cylinders being connected to two second one-way valve groups.

[0012] Preferably, the supply system includes a medium container connected to a medium pump, the medium pump connected to the coarse filter, and the coarse filter connected to a high-pressure pump.

[0013] Preferably, the auxiliary vacuum system includes a vacuum pump, a vacuum gauge, and a second filter connected in sequence, with the second filter connected to the vacuum chamber.

[0014] Preferably, the jet system includes a vacuum chamber with an X-ray window on one side, or with X-ray windows on both opposite sides of the vacuum chamber; a high-pressure nozzle is provided at the top of the vacuum chamber and a collection chamber is provided at the bottom; the collection chamber, check valve, first cooler and first filter are connected in sequence, and the first filter is connected to the supply system.

[0015] Preferably, the supply system, the drive system, and the booster system are each separately mounted on the vibration isolation platform.

[0016] Preferably, the supply system, the drive system, and the pressurization system are all housed within a soundproof enclosure.

[0017] On the other hand, embodiments of the present invention provide a liquid metal jet method for an X-ray source anode target, utilizing the aforementioned system, the method comprising:

[0018] The starting device activates the hydraulic oil pump and medium pump, and the control valve opens.

[0019] The medium pump delivers the liquid metal in the medium container through a coarse filter to a high-pressure pump. The liquid metal is pressurized by the high-pressure pump and then flows into an accumulator through a high-pressure pipeline. The accumulator outputs a stable stream of liquid metal. After passing through the control valve, the liquid metal stream is ejected from the vacuum chamber through a high-pressure nozzle. The liquid metal is then recovered into a collection chamber, cooled by a first cooler, filtered by a first filter, and flows back to the medium container. During the above process, the control solenoid valve precisely controls the injection speed of the liquid metal jet.

[0020] After the jet system is running stably, the electron beam system is turned on. The electron beam emitted by the electron beam system bombards the liquid metal jet vertically to generate X-rays, which are emitted vertically from a single-sided or double-sided X-ray window.

[0021] The above-described solution of the present invention has at least the following beneficial effects:

[0022] In the above scheme, (1) liquid metal jet replaces the traditional solid anode target, and the heat of the electron beam bombardment area is quickly removed in the form of jet, which overcomes the defect of low X-ray source brightness of solid anode target, improves the power density of target material, and thus improves the X-ray source brightness and X-ray flux, improves test efficiency and shortens test time; (2) the structure is compact. Only the electron beam system and the jet system rigidly connected to the electron beam system need to be placed in the shielded lead room of the X-ray micro-CT system. The remaining flexible connection parts are connected by high-pressure pipelines and can be set on a separate vibration isolation platform; (3) the two closed-loop circulation loops are combined. The high-pressure pump can provide the liquid metal with a pressure of up to 400MPa, which can make the liquid metal jet speed in the electron beam action area up to 500m / s. The jet speed is high and the adjustable range is large. Compared with existing products, the jet speed of liquid metal jet is greatly improved and the heat dissipation efficiency is higher; (4) An auxiliary vacuum system is set on the upper part of the vacuum cavity of the electron beam action area, which improves the stability of the vacuum conditions in the system. At the same time, the auxiliary vacuum system can deal with problems such as liquid metal debris and evaporated gas in the vacuum cavity to a certain extent. The working stability and working life of the whole device are better than existing products; (5) The jet speed of liquid metal jet is precisely adjusted according to specific test conditions using electromagnetic valves; (6) The stability and working life of X-ray source are improved. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the liquid metal jet system for an X-ray source anode target according to the present invention;

[0024] Figure 2 This is a schematic diagram of the drive system of the present invention;

[0025] Figure 3 This is a schematic diagram of the electron beam system, jet system, and auxiliary vacuum system of the present invention;

[0026] Figure 4 This is a schematic diagram of the supply system and booster system of the present invention;

[0027] Figure 5 This is a schematic diagram of the high-pressure pump of the present invention.

[0028] Figure label:

[0029] 1. Electron beam system; 2. Jet system; 21. Control valve; 22. High-pressure nozzle; 23. Vacuum chamber; 24. Check valve; 25. First cooler; 26. First filter; 27. Collection chamber; 3. Supply system; 31. Medium container; 32. Medium pump; 33. Coarse filter; 4. Drive system; 41. Hydraulic oil pump; 42. Oil tank; 43. First check valve; 44. Second cooler; 45. Solenoid valve; 46. Directional valve; 5. Pressurization system; 51. High-pressure pump; 511. Liquid metal piston cylinder; 512. Hydraulic piston cylinder; 52. Second check valve assembly; 53. High-pressure pipe; 54. Accumulator; 6. Auxiliary vacuum system; 61. Vacuum pump; 62. Vacuum gauge; 63. Second filter. Detailed Implementation

[0030] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0031] Example 1

[0032] like Figures 1-4As shown, this embodiment provides a liquid metal jet system 2 for an X-ray source anode target. The anode target using a liquid metal jet has a power density several times higher than that of a solid metal anode target, allowing it to withstand higher power electron beam bombardment and resulting in higher brightness of the X-ray source. The jet system 2 includes a source vacuum chamber 23, with an X-ray window on one side or on both opposite sides. A high-pressure nozzle 22 is located at the top of the vacuum chamber 23, and a collection chamber 27 is located at the bottom. The collection chamber 27, check valve 24, first cooler 25, and first filter 26 are sequentially connected. The vacuum chamber 23 is connected to an auxiliary vacuum system 6. The auxiliary vacuum system 6 includes a vacuum pump 61, a vacuum gauge 62, and a second filter 63 connected sequentially. The second filter 63 is connected to the vacuum chamber 23. The accumulator 54 is connected to the control valve 21, which is connected to the high-pressure nozzle 22. The vacuum chamber 23 is rigidly connected to the electron beam system 1, while the vacuum chamber 23 is flexibly connected to the rest of the jet system 2. This avoids the vibrations generated by components such as the medium pump 32, hydraulic oil pump 41, and high-pressure pump 51 in the jet system 2 from affecting the position of the electron beam focal spot. The high-pressure nozzle 22 ejects liquid metal into the vacuum chamber 23, forming a liquid metal jet. The electron beam emitted by the electron beam system 1 bombards the liquid metal jet perpendicularly to generate X-rays, which are emitted perpendicularly from a single-sided or double-sided X-ray window. The material of the X-ray window should have a low absorption rate for X-rays and a certain strength. In a preferred embodiment, the material of the X-ray window is beryllium. Other alternative materials include, but are not limited to, low atomic number materials or composite materials such as diamond, lithium, boron nitride, and silicon carbide. In a preferred embodiment, the thickness of the X-ray window is 70 μm. In other alternative embodiments, the thickness ranges from 30 μm to 1500 μm.

[0033] Specifically, the liquid metal material should be selected as gallium-indium alloy or gallium-indium-tin alloy. It should be noted that liquid metal has a certain degree of corrosivity to other metals. Direct contact between aluminum and copper materials and liquid metal should be avoided as much as possible in the components of the system. For parts that come into direct contact with liquid metal, stainless steel, titanium, or other metal or non-metal materials that are not easily corroded by liquid metal should be preferred. In addition, the temperature of liquid metal in each component of the system should not be too high, as excessively high temperatures will accelerate corrosion in the system. The optimal temperature for liquid metal is slightly higher than the melting point of the selected liquid metal.

[0034] In vacuum chamber 23, an electron beam impacts the liquid metal jet. After leaving high-pressure nozzle 22, the liquid metal jet maintains a uniform circular cross-section for a certain distance; this region is called the linear region. Within the linear region, the central axis of the liquid metal jet coincides with the direction of gravity. After leaving the linear region, the liquid metal jet will have an irregular cross-section until it reaches collection chamber 27. The area in collection chamber 27 that is impacted by the liquid metal jet is an arc-shaped plate or a flat plate at a certain angle to the tangent of the jet. Diamond is the preferred material for this plate, but sapphire, ruby, or other metal / non-metal materials with high hardness can be selected from other alternatives.

[0035] In this embodiment, control valve 21 is used to control the jet flow rate and to immediately stop the liquid metal from being sprayed after the equipment is shut down, so as to maintain the pressure stability in the system.

[0036] In this embodiment, the high-pressure nozzle 22 is preferably made of diamond, but ruby ​​or sapphire can be used in other alternatives; the orifice diameter of the high-pressure nozzle 22 is preferably 100 μm, but 10-1000 μm can be used in other alternatives.

[0037] In this embodiment, the check valve 24 enables the liquid metal in the collection chamber 27 to flow evenly and smoothly through the first cooler 25 back into the medium container 31 of the supply system 3, preventing liquid backflow caused by the difference in vacuum degree between the vacuum chamber and the medium container, so that the liquid metal can be cooled evenly and fully.

[0038] The first cooler 25 in this embodiment includes a cooling coil and a circulating coolant. Liquid metal flows within the cooling coil, and cooling is achieved through circulating heat exchange. The first cooler 25 should cool the liquid metal to a suitable setpoint temperature, such as slightly above the melting point, to reduce system corrosion and other types of degradation. Since the liquid metal temperature may vary in different areas of the entire device, and the liquid metal temperature in some components may be below the melting point, solidified liquid metal can affect the stability of the device's operation. In a preferred embodiment, the device needs to be equipped with a temperature control system. A comb-shaped heater can be used to ensure that the liquid metal temperature in all components is above the melting point. In other alternative embodiments, the heater selection should include, but is not limited to, air conditioners, tubular heaters, etc.

[0039] In this embodiment, the second filter 63 is made of stainless steel. The second filter 63 in the auxiliary vacuum system 6 also serves to prevent liquid metal from entering the vacuum assembly and causing corrosion. Therefore, a paper filter or a synthetic fiber filter with high filtration accuracy can be selected. In other optional embodiments, the selection of the filter element should include, but is not limited to, microporous filter elements, PP filter elements, ceramic filter elements, and resin filter elements. The auxiliary vacuum system 6 maintains a vacuum level in the vacuum chamber 23 higher than 1×10⁻⁶.-5 Pa, in an optional alternative, the auxiliary vacuum system 6 maintains the vacuum level within the vacuum chamber 23 at a range of 1 × 10⁻⁶. -3 Pa and 1×10 -7 Between Pa.

[0040] The working process of the jet system 2 in this embodiment is as follows: the control valve 21 controls the high-pressure nozzle 22, the high-pressure nozzle 22 ejects liquid metal jet in the vacuum chamber 23, the electron beam emitted by the electron beam system 1 bombards the liquid metal jet vertically, and the generated X-rays are ejected vertically from the single-sided X-ray window or the double-sided X-ray window. The bombarded liquid metal jet falls vertically into the collection chamber 27, and then returns to the supply system 3 through the check valve 24, the first cooler 25, and the first filter 26.

[0041] The drive system 4 provides the pressure required for high-speed injection of liquid metal. Hydraulic oil transmits the driving force of the hydraulic pump 41 to the high-pressure pump 51. The working medium is hydraulic oil. The drive system 4 includes a hydraulic pump 41, and an oil tank 42 supplies hydraulic oil to the hydraulic pump 41. The hydraulic pump 41, the first check valve 43, the reversing valve 46, and the hydraulic piston cylinder 512 of the high-pressure pump 51 in the booster system 5 are sequentially connected to form a supply oil circuit. The hydraulic piston cylinder 512 of the high-pressure pump 51, the second cooler 44, and the oil tank 42 are sequentially connected to form a return oil circuit. On the supply oil circuit, at the output end of the first check valve 43, the solenoid valve 45, the second cooler 44, and the oil tank 42 are sequentially connected. The solenoid valve 45 is connected to the oil tank 42. The reversing valve 46 is preferably an electromagnetic reversing valve 46. The hydraulic pump 41 is a piston pump, vane pump, diaphragm pump, or other high-pressure pump 51. In this embodiment, the electromagnetic reversing valve 46 controls the reciprocating motion of the piston of the high-pressure pump 51. The solenoid valve 45 can perform pressure compensation and pressure relief functions. By controlling the solenoid valve 45, the pressure of the hydraulic oil in the drive system 4 can be precisely controlled, thereby controlling the output pressure of the high-pressure pump 51. In a preferred embodiment, the pressure of the liquid metal at the nozzle is approximately 50 MPa, and the drive system 4 in this device can provide a maximum pressure of up to 400 MPa.

[0042] The working process of the drive system 4 in this embodiment is as follows:

[0043] When the hydraulic oil pump 41 is started, hydraulic oil flows through the first check valve 43 and the solenoid directional valve 46 into the right cylinder of the hydraulic piston cylinder 512 of the high-pressure pump 51. The oil pressure in the cylinder increases, pushing the piston to the left. Hydraulic oil in the left cylinder is discharged. After the piston moves a certain distance, the solenoid directional valve 46 is activated, and the hydraulic oil pump 41 enters the left cylinder and pushes the piston to the right. This cycle repeats continuously. During this process, the piston rod continuously draws in and pumps liquid metal into the first chambers on both sides of the high-pressure pump 51. The returning hydraulic oil is cooled to the set temperature by the second cooler 44 and then flows back to the hydraulic oil tank 42, forming a closed loop. The solenoid valve 45 can be used to replenish or unload hydraulic oil, serving as a pressure compensation and pressure relief function.

[0044] like Figures 3-4 As shown, the booster system 5 includes a high-pressure pump 51, and a second check valve assembly 52 is connected to both ends of the high-pressure pump 51. Specifically, the high-pressure pump 51 includes a hydraulic piston cylinder 512 and a liquid metal piston cylinder located at both ends of the hydraulic piston cylinder 512. The liquid metal piston cylinder is connected to the second check valve assembly 52. ​​One of the second check valve assemblies 52 is connected to a liquid metal delivery pipe, and the other second check valve assembly 52 is connected to an accumulator 54 through a high-pressure pipe 53. The accumulator 54 is connected to the jet system 2. The booster pump drives a piston to reciprocate via hydraulic oil to pump liquid metal, simultaneously applying a set pressure to the liquid metal. The liquid metal pumped by the high-pressure pump 51 flows through the second one-way valve group 52 and the accumulator 54 before entering the jet and collection system. The second one-way valve group 52 is installed at both ends of the high-pressure pump 51 to prevent backflow of the liquid metal during operation or at the start / stop of the device. The accumulator 54 attenuates the pressure pulses generated by the high-pressure pump 51 during the pumping process, ensuring the liquid metal reaches the nozzle smoothly and maintains spatial continuity after ejection. In a preferred embodiment, the accumulator 54 is a piston-type accumulator 54, which has a strong attenuation effect on pressure pulses. Other alternative solutions include, but are not limited to, diaphragm-type accumulators 54 or pneumatic accumulators 54.

[0045] The supply system 3 includes a medium container 31, which is connected to a medium pump 32. The medium pump 32 is connected to a coarse filter 33, which is connected to a high-pressure pump 51. The medium pump 32 transports the molten metal from the medium container 31 to the coarse filter 33, where it is filtered and then delivered to the high-pressure pump 51. The medium pump 32 provides a certain initial pressure to the liquid metal to ensure that the liquid metal in the piston cylinders (liquid metal chambers) at both ends of the high-pressure pump 51 is adequately supplied during operation, preventing cavitation and damage to the high-pressure pump 51 or other components. The medium pump 32 can be a diaphragm pump; in other alternative embodiments, the medium pump 32 can be a vane pump, a plunger pump, or other pumps.

[0046] Example 2

[0047] like Figures 1-4 As shown, this embodiment provides a liquid metal jetting method for an X-ray source anode target, using the liquid metal jetting device of Embodiment 1. The method includes:

[0048] When the device is started, the hydraulic oil pump 41 and the medium pump 32 begin to work, and the control valve 21 opens.

[0049] The medium pump 32 delivers the liquid metal in the medium container 31 through the coarse filter 33 to the high-pressure pump 51. After being pressurized by the high-pressure pump 51, the liquid metal flows into the accumulator 54 through the high-pressure pipe 53. The accumulator 54 outputs a stable liquid metal stream. After passing through the control valve 21, the liquid metal stream is ejected from the high-pressure nozzle 22 into the vacuum chamber 23. The liquid metal is recovered into the collection chamber 27, cooled by the first cooler 25, filtered by the first filter 26, and then flows back to the medium container 31. In the above process, the control solenoid valve 45 precisely controls the injection speed of the liquid metal jet.

[0050] After the jet system 2 is running stably, the electron beam system 1 is turned on. The electron beam emitted by the electron beam system 1 bombards the liquid metal jet vertically to generate X-rays. The X-rays are emitted vertically from a single-sided or double-sided X-ray window.

[0051] The liquid metal jet system 2 and method for X-ray source anode targets of the present invention (1) replaces the traditional solid anode target with liquid metal jet, which rapidly removes the heat from the electron beam bombardment area in the form of jet, overcoming the defect of low X-ray source brightness of solid anode targets, improving the target power density, thereby improving the X-ray source brightness and X-ray flux, improving testing efficiency, and shortening testing time; (2) has a compact structural design. In the lead shielding room of the X-ray micro-CT system, only the electron beam system 1 and the jet system 2 rigidly connected to the electron beam system 1 need to be placed. The remaining flexible connection parts are connected through high-pressure pipes 53. (3) It adopts a combination of two closed-loop circulation circuits, and the high-pressure pump 51 can provide liquid metal with a pressure of up to 400MPa. Compared with existing products, it greatly improves the jet speed of liquid metal and has higher heat dissipation efficiency. (4) An auxiliary vacuum system 6 is set in the vacuum chamber 23 of the electron beam action area, which improves the stability of the vacuum conditions in the system. At the same time, the auxiliary vacuum system 6 can deal with problems such as liquid metal debris and evaporated gas in the vacuum chamber 23 to a certain extent. The working stability and working life of the whole device are better than existing products. (5) The stability of the X-ray source is improved.

[0052] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A liquid metal jet system for an X-ray source anode target, comprising an electron beam system and a jet system, wherein the jet system ejects a liquid metal jet within a vacuum cavity, and an electron beam emitted by the electron beam system bombards the liquid metal jet to generate X-rays, the X-rays exiting from an X-ray window, characterized in that, It also includes a supply system, a drive system, and a pressurization system. The supply system and the pressurization system are flexibly connected to the jet system via pipelines, and the electron beam system is rigidly connected to the jet system. The pressurization system includes a high-pressure pump, which includes a hydraulic piston cylinder and liquid metal piston cylinders located at both ends of the hydraulic piston cylinder. The liquid metal piston cylinders are connected to a second one-way valve group, one of which is connected to a liquid metal delivery pipe, and the other is connected to an accumulator via a high-pressure pipe. The accumulator is connected to the jet system. The supply system provides liquid metal with a certain initial pressure to the liquid metal piston cylinders, the drive system provides hydraulic oil to the hydraulic piston cylinders, and the pressurization system delivers the liquid metal to the jet system by pressurization. The liquid metal in the vacuum chamber is collected and cooled before flowing back to the supply system. The vacuum chamber is connected to an auxiliary vacuum system to stabilize the vacuum conditions of the vacuum chamber. The drive system provides the pressure required for high-speed injection of liquid metal, and the hydraulic oil transmits the driving force of the hydraulic oil pump to the high-pressure pump. The working medium is hydraulic oil. The drive system includes a hydraulic oil pump, an oil tank that supplies hydraulic oil to the hydraulic oil pump, the hydraulic oil pump, a first check valve, a reversing valve and a high-pressure pump in the booster system are sequentially connected to form an oil supply circuit, the high-pressure pump, a second cooler and an oil tank are sequentially connected to form a return oil circuit, the oil supply circuit is located at the output end of the first check valve, a solenoid valve, the second cooler and the oil tank are sequentially connected, and the solenoid valve is connected to the oil tank; The supply system includes a medium container connected to a medium pump, which is connected to a coarse filter, which is connected to a high-pressure pump.

2. The liquid metal jet system for an X-ray source anode target according to claim 1, characterized in that, The auxiliary vacuum system consists of a vacuum pump, a vacuum gauge, and a second filter connected in sequence, with the second filter connected to the vacuum chamber.

3. The liquid metal jet system for an X-ray source anode target according to claim 2, characterized in that, The jet system includes a vacuum chamber with an X-ray window on one side or on both sides of the vacuum chamber. A high-pressure nozzle is provided at the top of the vacuum chamber and a collection chamber is provided at the bottom. The collection chamber, check valve, first cooler and first filter are connected in sequence. The first filter is connected to the supply system.

4. The liquid metal jet system for an X-ray source anode target according to claim 1, characterized in that, The supply system, the drive system, and the booster system are each separately mounted on the vibration isolation platform.

5. The liquid metal jet system for an X-ray source anode target according to claim 1, characterized in that, The supply system, the drive system, and the booster system are all housed within a soundproof enclosure.

6. A liquid metal jetting method for an X-ray source anode target, characterized in that, Using the system of claim 3, the method comprises: The starting device activates the hydraulic oil pump and medium pump, and the control valve opens. The medium pump delivers the liquid metal in the medium container through a coarse filter to a high-pressure pump. The liquid metal is pressurized by the high-pressure pump and then flows into an accumulator through a high-pressure pipeline. The accumulator outputs a stable stream of liquid metal. After passing through the control valve, the liquid metal stream is ejected from the vacuum chamber through a high-pressure nozzle. The liquid metal is then recovered into a collection chamber, cooled by a first cooler, filtered by a first filter, and flows back to the medium container. During the above process, the control solenoid valve precisely controls the injection speed of the liquid metal jet. After the jet system is operating stably, the electron beam system is activated. The electron beam emitted by the electron beam system bombards the liquid metal jet vertically to generate X-rays. The X-rays are emitted vertically from a single-sided or double-sided X-ray window.

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