CN115631985A - Liquid metal jet system and method for X-ray source anode target - Google Patents

Abstract

The invention discloses a liquid metal jet system and a liquid metal jet method for an X-ray source anode target, and relates to the technical field of X-ray sources. The device comprises an electron beam system, a jet system, a supply system, a driving system and a pressurization system, wherein the supply system and the pressurization 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 provides stable liquid metal for the liquid metal piston cylinders, the driving system provides hydraulic oil for the hydraulic piston cylinders, the pressurizing system pressurizes and conveys the liquid metal to the jet system, the jet system sprays liquid metal jet flow in the vacuum cavity, the electron beams bombard the liquid metal jet flow to generate X rays, and the liquid metal in the vacuum cavity is collected, cooled and then flows back to the supply system; the auxiliary vacuum system stabilizes the vacuum condition of the vacuum chamber. Compact structure, high luminous brightness, X-ray flux and test efficiency of the X-ray source, strong liquid metal pressure and fast emission speed.

Description

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

Technical Field

The invention relates to the technical field of X-ray sources, in particular to a liquid metal jet system and a liquid metal jet method for an anode target of an X-ray source.

Background

X-ray imaging is an effective nondestructive testing means, and plays an important role in the fields of material science, industrial manufacturing, aerospace, modern medicine and the like. Among them, the X-ray micro tomography (CT) system is generally used to characterize the microscopic structure inside the engineering material (such as metal/alloy/ceramic/composite material, etc.), and further identify, extract and quantitatively analyze the microscopic structure characteristics inside the material, such as different components of fiber bundle, composite material matrix, etc., or defects of holes, microcracks, etc. One of the core components which play a decisive role in the efficiency and the precision of the characterization test in the X-ray micro-CT system is an X-ray source, and the rapid characterization of the micro-structure in the material is realized, so that the X-ray source with compact and stable structure and micro-focus is generally required to be adopted, and the higher power density and the high-brightness light emission are formed.

During operation of the X-ray source, electrons escaping from the cathode bombard the surface of the anode target material after acceleration by a high voltage electric field and focusing by electron optical systems (e.g. electromagnetic lenses, electrostatic lenses, etc.), and after striking the anode, the electrons release their energy in the form of heat (about 99% of the energy) and X-rays (mainly bremsstrahlung and characteristic radiation). The continuous bombardment of the metal target by the high-power electron beam can cause the temperature of the target surface to be sharply increased, so that the target surface is ablated or melted, and further the X-ray source is damaged. On one hand, the selection of the anode target of the X-ray source needs to consider the wavelength of the characteristic X-ray, and the different wavelengths of the characteristic X-ray generated by different targets need to be selected according to different experimental conditions and experimental purposes; on the other hand, the properties of the metal are considered, and solid metal tungsten with high melting point, low expansion coefficient, good resistivity and thermal stability is generally selected as an anode target in a high-power X-ray micro-CT system.

Chinese patent publication No. CN113728410A discloses an X-ray source with a rotating liquid metal target, the X-ray beam being generated in the region of interaction of the electron beam and the target, which is an annular layer of molten fusible metal in the annular channel of the rotating anode assembly. The patent adopts the centrifugal force that the rotor rotation produced to drive liquid metal and attach to the ring channel lateral wall, produces the X ray and makes the X ray shoot through specific angle through the mode of electron beam side impact. It has the following problems: (1) The electron beam system and the liquid metal anode target action area cavity are large, so that the whole volume of the ray source is overlarge, and the X-ray micro-CT system requires the compact structure of the ray source; (2) Because the rotor is rigidly connected with the electron beam action area, vibration generated by the rotation of the rotor can be directly transmitted to the electron beam action area, so that the stability of a focal spot position is deteriorated, the resolution of an X-ray micro-CT system is directly influenced, and the resolution is poor; (3) In the course of the work, the mobility of liquid metal is relatively poor, receives heat transfer system work efficiency's restriction, and long-time work can lead to liquid metal operating temperature too high, and the liquid metal of evaporation can solidify at X ray window department and block X ray and jet out, and liquid metal steam or piece diffusion can influence the electron beam quality on the electron beam passageway simultaneously to influence X ray micro-CT system test quality and measuring accuracy.

Chinese patent publication No. CN102369587B discloses a closed loop cycle for providing liquid metal to an interaction region where an electron beam impinges on the liquid metal to generate X-rays. It has the following problems: (1) The device adopts a diaphragm pump as a high-pressure pump, the pressure obtained by the liquid metal is only 10-50 bar, and the lower pressure causes that the jet velocity of the liquid metal jet is not high and the jet velocity adjusting range of the liquid metal is small; (2) The jet speed of the liquid metal jet can be controlled only by adjusting the input power of the high-pressure pump, and the adjustment precision is not high; (3) The liquid metal in the area bombarded by the electron beam in the vacuum cavity can generate the problems of chipping, evaporation and the like, and the problems have certain influence on the stability of the electron beam, the stability of the focal spot position and the beam outgoing of the X-ray, so that the test quality and the test precision of the X-ray micro CT system are influenced, and the test quality and the test precision are poor; (4) Only the vacuum assembly is arranged in the electron beam system, on one hand, liquid metal debris and steam are easy to be sucked into the electron beam system in the continuous working process of the vacuum pump in the electron beam system, and corrosion is caused to metal elements in the electron beam system; on the other hand, because the liquid metal jet system has a complex structure and many parts, some slight vacuum leakage is easily generated, only one set of vacuum system in the electron beam system is difficult to ensure the stability of the vacuum degree in the vacuum cavity under the action of the electron beam and the liquid metal jet, and the instability of the vacuum degree can greatly affect the quality of the electron beam, thereby affecting the testing quality and the testing precision of the X-ray micro CT system.

Disclosure of Invention

The invention provides a liquid metal jet system and a method for an X-ray source anode target, which have the following problems that the structure of a part directly connected with an electron beam system is large; the focal spot position stability is poor, and the resolution of an X-ray micro CT system is poor; the working temperature of the liquid metal is too high, so that the evaporated liquid metal is solidified at an X-ray window to block the emission of X-rays, and the quality of electron beams can be influenced by the diffusion of liquid metal steam or debris on electron beam paths, and the testing quality and the testing precision of an X-ray micro-CT system can be influenced; the jet speed of the liquid metal jet is not high, and the jet speed adjusting range of the liquid metal is small; the jet speed regulation precision of the liquid metal jet is not high; the test quality and the test precision are poor; only the vacuum assembly is arranged in the electron beam system, so that metal elements in the electron beam system are corroded, and the stability of the vacuum degree is poor, so that the test quality and the test precision are poor.

To solve the above technical problem, an embodiment of the present invention provides the following solutions:

on one hand, the embodiment of the invention provides a liquid metal jet system for an anode target of an X-ray source, which comprises an electron beam system and a jet system, wherein the jet system sprays liquid metal jet in a vacuum cavity, electron beams emitted by the electron beam system bombard the liquid metal jet to generate X rays, and the X rays are emitted from an X-ray window; the pressurizing system comprises two liquid metal piston cylinders and a hydraulic piston cylinder, the supply system provides the liquid metal with certain initial pressure to the liquid metal piston cylinders, the driving system provides hydraulic oil to the hydraulic piston cylinders, and the pressurizing system conveys the liquid metal to the jet system through pressurization; the liquid metal in the vacuum cavity is collected, cooled and then flows back to the supply system; the vacuum chamber is connected with an auxiliary vacuum system to stabilize the vacuum condition of the vacuum chamber.

Preferably, actuating system includes the hydraulic oil pump, and the oil tank does the hydraulic oil pump provides hydraulic oil, hydraulic oil pump, first check valve, switching-over valve and high-pressure pump among the turbocharging system connects in proper order and forms the fuel feeding oil circuit, high-pressure pump, second cooler with the oil tank connects in proper order and forms the oil return oil circuit, lie in on the fuel feeding oil circuit output, solenoid valve of first check valve the cold cooler of second with the oil tank connects in proper order, the solenoid valve is connected the oil tank.

Preferably, the pressurization system comprises a high-pressure pump, two ends of the high-pressure pump are connected with second check valve sets, one of the second check valve sets is connected with the liquid metal delivery pipe, the other second check valve set is connected with an energy accumulator through a high-pressure pipe, and the energy accumulator is connected with the jet system.

Preferably, the high-pressure pump comprises a hydraulic piston cylinder and liquid metal piston cylinders positioned at two ends of the hydraulic piston cylinder, and the liquid metal piston cylinders are connected with the two second check valve groups.

Preferably, the feed system comprises a media container connected to a coarse filter, a media pump connected to said coarse filter, said coarse filter connected to a high pressure pump.

Preferably, the auxiliary vacuum system comprises a vacuum pump, a vacuum gauge and a second filter which are sequentially connected, and the second filter is connected with the vacuum cavity.

Preferably, the fluidic system comprises a vacuum chamber, one side of the vacuum chamber is provided with an X-ray window, or two opposite sides of the vacuum chamber are provided with X-ray windows; the top of the vacuum cavity is provided with a high-pressure nozzle, the bottom of the vacuum cavity is provided with a collection chamber, the check valve, the first cooler and the first filter are sequentially connected, and the first filter is connected with the supply system.

Preferably, the supply system, the drive system and the pressurization system are provided separately on a vibration isolation platform.

Preferably, the supply system, the drive system and the pressurization system are all disposed within a sound-proofing housing.

In another aspect, an embodiment of the present invention provides a liquid metal jet method for an anode target of an X-ray source, where the method includes:

starting a device, starting a hydraulic oil pump and a medium pump, and opening a control valve;

the medium pump conveys liquid metal in a medium container into the high-pressure pump through a coarse filter, the liquid metal is pressurized by the high-pressure pump and then flows into an energy accumulator through a high-pressure pipeline, the energy accumulator outputs stable liquid metal flow, the liquid metal flow passes through the control valve and then is ejected out of a vacuum cavity through a high-pressure nozzle, the liquid metal is recovered into a collecting chamber, and then flows back to the medium container after being cooled by a first cooler and filtered by a first filter; in the process, the electromagnetic valve is controlled to accurately control the jet speed of the liquid metal jet;

and after the jet flow system stably operates, starting the electron beam system, wherein electron beams emitted by the electron beam system vertically bombard the liquid metal jet flow to generate X rays, and the X rays are vertically emitted from the single-side X ray window or the double-side X ray windows.

The scheme of the invention at least comprises the following beneficial effects:

in the scheme, (1) the liquid metal jet flow is used for replacing the traditional solid anode target, and the heat of an electron beam bombardment area is quickly taken away in the form of jet flow, so that the defect of low emergent brightness of an X-ray source of the solid anode target is overcome, the power density of the target material is improved, the emergent brightness and X-ray flux of the X-ray source are further improved, the test efficiency is improved, and the test time is shortened; (2) The structure design is compact, only an electron beam system and a jet system rigidly connected with the electron beam system need to be placed in a shielding lead room of the X-ray micro CT system, and the rest flexible connecting parts are connected through a high-pressure pipeline and can be arranged on an independent vibration isolation platform; (3) By adopting a mode of combining two closed loop circulation loops, the high-pressure pump can provide the highest pressure of 400MPa for the liquid metal, so that the highest injection speed of the liquid metal in an electron beam action area can reach 500m/s, the injection speed is high, and the adjustable range is large. Compared with the existing product, the jet speed of the liquid metal jet flow is greatly improved, and the heat dissipation efficiency is higher; (4) The vacuum cavity of the electron beam action area is provided with the auxiliary vacuum system, so that the stability of vacuum conditions in the system is improved, meanwhile, the auxiliary vacuum system can solve the problems of liquid metal scraps, evaporated gas and the like in the vacuum cavity to a certain extent, and the working stability and the working life of the whole device are superior to those of the conventional product; (5) Accurately adjusting the jet velocity of the liquid metal jet according to specific test conditions by using an electromagnetic valve; and (6) the stability and the service life of the X-ray source are improved.

Drawings

FIG. 1 is a schematic diagram of a liquid metal jet system for an anode target of an X-ray source according to the present invention;

FIG. 2 is a schematic diagram of the driving system of the present invention;

FIG. 3 is a schematic diagram of the electron beam system, the fluidic system, and the auxiliary vacuum system according to the present invention;

FIG. 4 is a schematic diagram of the feed system and pressurization system of the present invention;

fig. 5 is a schematic view of the high pressure pump according to the present invention.

Reference numerals are as follows:

1. an electron beam system; 2. a fluidic system; 21. a control valve; 22. a high pressure nozzle; 23. a vacuum chamber; 24. a check valve; 25. a first cooler; 26. a first filter; 27. a collection chamber; 3. a supply system; 31. a media container; 32. a medium pump; 33. a coarse filter; 4. a drive system; 41. a hydraulic oil pump; 42. an oil tank; 43. a first check valve; 44. a second cooler; 45. an electromagnetic valve; 46. a diverter valve; 5. a pressurization system; 51. a high pressure pump; 511. a liquid metal piston cylinder; 512. a hydraulic piston cylinder; 52. a second check valve group; 53. a high pressure pipe; 54. an accumulator; 6. an auxiliary vacuum system; 61. a vacuum pump; 62. a vacuum gauge; 63. a second filter.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below 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 embodied 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.

Example one

As shown in fig. 1 to 4, the present embodiment provides a liquid metal jet system 2 for an anode target of an X-ray source, which employs an anode target in the form of liquid metal jet, and the power density of the anode target is several times that of the solid metal anode target, so that the anode target can bear the bombardment of an electron beam with higher power, and the X-ray source has higher light output brightness. The fluidic system 2 comprises a source vacuum cavity 23, wherein an X-ray window is arranged on one side of the vacuum cavity 23, or X-ray windows are arranged on two opposite sides of the vacuum cavity 23, a high-pressure nozzle 22 is arranged on the top of the vacuum cavity 23, a collection chamber 27 is arranged at the bottom of the vacuum cavity 23, and the collection chamber 27, a check valve 24, a first cooler 25 and a first filter 26 are sequentially connected. The vacuum chamber 23 is connected to the auxiliary vacuum system 6. The auxiliary vacuum system 6 includes a vacuum pump 61, a vacuum gauge 62 and a first filter 26 connected in this order, and the first filter 26 is connected to the vacuum chamber 23. The control valve 21 is communicated with the energy accumulator 54, the control valve 21 is connected with the high-pressure nozzle 22, the vacuum cavity 23 is in rigid connection with the electron beam system 1, and the vacuum cavity 23 is in flexible connection with the rest parts in the jet system 2, so that the influence of vibration generated by the medium pump 32, the hydraulic oil pump 41, the high-pressure pump 51 and other parts in the jet system 2 on the position of an electron beam focal spot is avoided. The high pressure nozzle 22 sprays liquid metal in the vacuum chamber 23 to form liquid metal jet flow, and the electron beam emitted by the electron beam system 1 vertically bombards the liquid metal jet flow to generate X rays, wherein the X rays are vertically emitted from a single-side X-ray window or a double-side X-ray window. The material of the X-ray window at least has lower absorptivity for X-rays and has certain strength; in a preferred embodiment, the material of the X-ray window is beryllium, and other alternative embodiments include but are not limited to diamond, lithium, boron nitride, silicon carbide, and other low atomic number materials or composite materials; in a preferred version the X-ray window has a thickness of 70 μm, in other alternative versions the thickness ranges between 30 μm and 1500 μm.

Specifically, the liquid metal material is selected from a gallium indium alloy or a gallium indium tin alloy, it should be understood that the liquid metal has a certain corrosivity to other metals, aluminum and copper materials should be prevented from being in direct contact with the liquid metal in each element in the system as much as possible, the part in direct contact with the liquid metal is preferably selected from a metal material or a non-metal material which is not easily corroded by the liquid metal, such as stainless steel and titanium, and in addition, the temperature of the liquid metal in each component of the system should not be too high, the corrosion in the system is accelerated by the too high temperature, and the temperature of the liquid metal should be optimally slightly higher than the melting point of the selected liquid metal.

In the vacuum chamber 23, the electron beam hits the liquid metal jet, which, after leaving the high-pressure nozzle 22, maintains a uniform circular cross-section at a distance, this section being called the linear region, in which the central axis of the liquid metal jet coincides with the direction of gravity; after the jet of liquid metal has exited the linear zone, the liquid metal will assume an irregular cross-section until it reaches the collection chamber 27. The area of the collection chamber 27 that is subjected to the liquid metal jet is a plate that is arcuate or angled relative to the jet tangent, preferably diamond, but alternatively sapphire, ruby or other relatively hard metallic/non-metallic material.

In this embodiment, the control valve 21 is used to control the flow rate of the jet flow and to stop the liquid metal spraying immediately after the device is closed, so as to keep the pressure in the system stable.

The material of the high pressure nozzle 22 of the present embodiment is preferably diamond, and in other alternatives, ruby or sapphire may be used; the preferred diameter of the high pressure nozzle 22 is 100 μm, and in the alternative, the diameter of the high pressure nozzle 22 may be 10-1000 μm.

The check valve 24 of this embodiment enables the liquid metal in the collection chamber 27 to uniformly and smoothly flow through the first cooler 25 and return to the medium container 31 of the supply system 3, thereby preventing the liquid backflow phenomenon caused by the difference in vacuum degree between the vacuum chamber and the medium container, and enabling the liquid metal to be uniformly and sufficiently cooled.

The first cooler 25 of this embodiment includes the refrigeration coil and the coolant circulation, and liquid metal flows in the refrigeration coil, utilizes the cold heat transfer of circulation, realizes liquid metal cooling. The first cooler 25 should cool the liquid metal to a moderate set point temperature, for example a temperature slightly above the melting point, to reduce corrosion and other types of degradation of the system. Since the liquid metal temperature may be different in different regions of the whole apparatus, and the liquid metal temperature in some components may be lower than the melting point, the solidified liquid metal may affect the stability of the operation of the apparatus, in a preferred embodiment, the apparatus is equipped with a temperature control system, a comb heater may be selected to ensure that the liquid metal temperature in all components is above the melting point, and in other alternative embodiments, the selection of the heater includes, but is not limited to, an air conditioner, a tubular heater, and the like.

In this embodiment, the second filter 63 is a stainless steel filter element, and the second filter 63 in the auxiliary vacuum system 6 also has a function of preventing liquid metal from entering the vacuum assembly to corrode the vacuum assembly, so that a paper filter element or a chemical fiber filter element with high filtering precision can be selected. The auxiliary vacuum system 6 maintains a vacuum level in the vacuum chamber 23 higher than 1X 10-5Pa, and in an alternative embodiment the auxiliary vacuum system 6 maintains a vacuum level in the vacuum chamber 23 between 1X 10-3Pa and 1X 10-7 Pa.

The working process of the fluidic system 2 of the present embodiment is as follows: the control valve 21 controls the high-pressure nozzle 22, the high-pressure nozzle 22 sprays liquid metal jet flow in the vacuum cavity 23, the electron beam emitted by the electron beam system 1 vertically bombards the liquid metal jet flow, the generated X-ray vertically shoots out from a single-side X-ray window or a double-side X-ray window, the bombarded liquid metal jet flow vertically falls 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.

The driving system 4 provides pressure required by high injection speed for the liquid metal, the hydraulic oil transfers the driving force of the hydraulic oil pump 41 to the high-pressure pump 51, and the working medium is hydraulic oil. The driving system 4 comprises a hydraulic oil pump 41, an oil tank 42 supplies hydraulic oil to the hydraulic oil pump 41, a first check valve 43, a reversing valve 46 and a hydraulic piston cylinder 512 of a high-pressure pump 51 in the pressurization system 5 are sequentially connected to form an oil supply path, the hydraulic piston cylinder 512 of the high-pressure pump 51, a second cooler 44 and the oil tank 42 are sequentially connected to form an oil return path, an electromagnetic valve 45, the second cooler 44 and the oil tank 42 are sequentially connected at the output end of the first check valve 43 on the oil supply path, and the electromagnetic valve 45 is connected with the oil tank 42. The directional valve 46 is preferably a solenoid directional valve 46. The hydraulic oil pump 41 is a plunger pump, vane pump, diaphragm pump or other high pressure pump 51. The electromagnetic directional valve 46 of the present embodiment controls the piston reciprocation of the high-pressure pump 51. The electromagnetic valve 45 can perform the functions of pressure compensation and pressure relief, and the pressure of hydraulic oil in the driving system 4 can be accurately controlled by controlling the electromagnetic valve 45, so as to control the output pressure of the high-pressure pump 51. In a preferred embodiment, the liquid metal is at a pressure of about 50MPa at the nozzle, and the drive system 4 of the apparatus is capable of providing pressures up to 400MPa.

The working process of the driving system 4 of the embodiment is as follows:

starting the hydraulic oil pump 41, allowing hydraulic oil to flow into a right cylinder body of a hydraulic piston cylinder 512 of the high-pressure pump 51 through the first check valve 43 and the electromagnetic directional valve 46, increasing oil pressure in the cylinder body to push the piston to move to the left, discharging the hydraulic oil in the left cylinder body, starting the electromagnetic directional valve 46 after the piston moves for a certain distance, allowing the hydraulic oil pump 41 to enter the left cylinder body and push the piston to move to the right, and repeating the steps in such a circulating manner, wherein a piston rod is used for continuously sucking and pumping liquid metal in first cavities at two sides of the high-pressure pump 51 in the process; the returned hydraulic oil is cooled to the set point temperature by the second cooler 44 and then flows back to the hydraulic oil tank 42, forming a closed loop. The electromagnetic valve 45 can be used for supplementing or discharging hydraulic oil, and the functions of pressure compensation and pressure relief are achieved.

As shown in fig. 3 to 4, the pressurization system 5 includes a high-pressure pump 51, two ends of the high-pressure pump 51 are connected to second check valve sets 52, specifically, the high-pressure pump 51 includes a hydraulic piston cylinder 512 and liquid metal piston cylinders located at two ends of the hydraulic piston cylinder 512, the liquid metal piston cylinders are connected to the second check valve sets 52, one of the second check valve sets 52 is connected to a liquid metal delivery pipe, the other second check valve set 52 is connected to an energy accumulator 54 through a high-pressure pipe 53, and the energy accumulator 54 is connected to the fluidic system 2. The booster pump drives the piston to reciprocate through hydraulic oil to pump liquid metal, meanwhile, the liquid metal pumped by the high-pressure pump 51 flows through the second check valve group 52 and the energy accumulator 54 and then enters the incident flow and collection system, the second check valve group 52 is installed at two ends of the high-pressure pump 51 simultaneously, backflow of the liquid metal in the working process of the high-pressure pump 51 or at the moment of starting and stopping of the device is avoided, the energy accumulator 54 plays a role in attenuating pressure pulse brought by the high-pressure pump 51 in the pumping process of the liquid metal, and the liquid metal can stably reach the nozzle and has spatial continuity after being sprayed out. In a preferred embodiment, the accumulator 54 is a piston type accumulator 54 with a strong damping effect on the pressure pulses, and other alternatives include, but are not limited to, a diaphragm type accumulator 54 or a bladder type accumulator 54.

The feed system 3 includes a medium container 31, the medium container 31 is connected to a coarse filter 33, a medium pump 32 is connected to the coarse filter 33, the coarse filter 33 is connected to a high-pressure pump 51, and the medium pump 32 transports the metal solution in the medium container 31 to the coarse filter 33, and the metal solution is filtered by the coarse filter 33 and then transported to the high-pressure pump 51. The medium pump 32 gives a certain initial pressure to the liquid metal to ensure that the liquid metal in piston cylinders (liquid metal cavities) at two ends of the high-pressure pump 51 is sufficiently supplied when the device works, and prevent the formation of cavities to damage the high-pressure pump 51 or other components. The type of media pump 32 may be selected from diaphragm pumps, and in other alternative embodiments, the selection of media pump 32 includes a vane pump, plunger pump, or other pump.

Example two

As shown in fig. 1 to fig. 4, the present embodiment provides a liquid metal jet method for an anode target of an X-ray source, which employs the liquid metal jet apparatus of the first embodiment, and the method includes:

starting the device, starting the hydraulic oil pump 41 and the medium pump 32, and opening the control valve 21;

the medium pump 32 conveys the liquid metal in the medium container 31 into the high-pressure pump 51 through the coarse filter 33, the liquid metal is pressurized by the high-pressure pump 51 and then flows into the energy accumulator 54 through the high-pressure pipeline 53, the energy accumulator 54 outputs a stable liquid metal flow, the liquid metal flow passes through the control valve 21 and then is ejected out of the vacuum cavity 23 through the high-pressure nozzle 22, the liquid metal is recovered into the collection chamber 27 and then flows back to the medium container 31 after being cooled by the first cooler 25 and filtered by the first filter 26; in the above process, the control solenoid valve 45 precisely controls the jet speed of the liquid metal jet;

and after the jet system 2 operates stably, the electron beam system 1 is started, the electron beams emitted by the electron beam system 1 vertically bombard the liquid metal jet to generate X rays, and the X rays are vertically emitted from the single-side X-ray window or the double-side X-ray windows.

The liquid metal jet system 2 and the method for the X-ray source anode target of the invention (1) replace the traditional solid anode target with the liquid metal jet, and quickly take away the heat of an electron beam bombardment area in the form of jet, thereby overcoming the defect of low light brightness of the X-ray source of the solid anode target, improving the power density of a target material, further improving the light brightness and X-ray flux of the X-ray source, improving the testing efficiency and shortening the testing time; (2) The structure design is compact, only the electron beam system 1 and the jet system 2 rigidly connected with the electron beam system 1 need to be placed in the X-ray micro-CT system shielding lead room, and the other flexible connecting parts are connected through a 53-way high-pressure pipe and can be arranged on an independent vibration isolation platform; (3) By adopting a mode of combining two closed loop circulation loops, the high-pressure pump 51 can provide the highest pressure of 400MPa for the liquid metal, and compared with the existing product, the jet speed of the liquid metal jet flow is greatly improved, and the heat dissipation efficiency is higher; (4) The auxiliary vacuum system 6 is arranged in the vacuum cavity 23 of the electron beam action area, so that the stability of the vacuum condition in the system is improved, meanwhile, the auxiliary vacuum system 6 can solve the problems of liquid metal scraps, evaporated gas and the like in the vacuum cavity 23 to a certain extent, and the working stability and the service life of the whole set of device are superior to those of the conventional product; and (5) the stability of the X-ray source is improved.

While the foregoing is directed to the preferred embodiment of the present invention, it will be appreciated by those skilled in the art that various changes and modifications may be made therein without departing from the principles of the invention as set forth in the appended claims.

Claims (10)

1. A liquid metal jet system for an anode target of an X-ray source comprises an electron beam system and a jet system, wherein the jet system sprays liquid metal jet in a vacuum cavity, electron beams emitted by the electron beam system bombard the liquid metal jet to generate X rays, and the X rays are emitted from an X-ray window; the pressurizing system comprises two liquid metal piston cylinders and a hydraulic piston cylinder, the supply system supplies the liquid metal with certain initial pressure to the liquid metal piston cylinders, the driving system supplies hydraulic oil to the hydraulic piston cylinders, and the pressurizing system conveys the liquid metal to the jet system through pressurization; the liquid metal in the vacuum cavity is collected, cooled and then flows back to the supply system; the vacuum chamber is connected with an auxiliary vacuum system to stabilize the vacuum condition of the vacuum chamber.

2. The system of claim 1, wherein the driving system comprises a hydraulic oil pump, an oil tank provides hydraulic oil for the hydraulic oil pump, the first check valve, the reversing valve and a high-pressure pump in the pressurizing system are sequentially connected to form an oil supply path, the high-pressure pump, the second cooler and the oil tank are sequentially connected to form an oil return path, the oil supply path is located at an output end of the first check valve, the electromagnetic valve, the second cooler and the oil tank are sequentially connected, and the electromagnetic valve is connected to the oil tank.

3. The liquid metal jet system for an anode target of an X-ray source as claimed in claim 1, wherein the pressurizing system comprises a high-pressure pump, and second check valve sets are connected to two ends of the high-pressure pump, wherein one of the second check valve sets is connected to a liquid metal delivery pipe, and the other second check valve set is connected to an accumulator through a high-pressure pipe, and the accumulator is connected to the jet system.

4. A liquid metal jet system for an X-ray source anode target according to claim 3, wherein the high pressure pump comprises a hydraulic piston cylinder and liquid metal piston cylinders located at both ends of the hydraulic piston cylinder, the liquid metal piston cylinders connecting the two second check valve sets.

5. The liquid metal fluidic system for an X-ray source anode target according to claim 1, characterized in that the feed system comprises a media container, said media container is connected with a coarse filter, a media pump is connected with said coarse filter, said coarse filter is connected with a high pressure pump.

6. The system of claim 1, wherein the auxiliary vacuum system comprises a vacuum pump, a vacuum gauge and a second filter, the vacuum pump, the vacuum gauge and the second filter are connected in sequence, and the second filter is connected with the vacuum chamber.

7. The liquid metal fluidic system for an X-ray source anode target according to claim 1, characterized in that said fluidic system comprises a vacuum chamber provided with an X-ray window at one side of said vacuum chamber or at both opposite sides of said vacuum chamber; the top of vacuum cavity is provided with high-pressure nozzle, the bottom is provided with the collection room, check valve, first cooler and first filter are connected gradually, first filter is connected feed system.

8. The liquid metal fluidic system for an X-ray source anode target of claim 1, wherein said supply system, said drive system, and said pressurization system are individually disposed on a vibration isolation platform.

9. The liquid metal fluidic system for an X-ray source anode target according to claim 1, wherein said supply system, said drive system and said pressurization system are all disposed within a sound-proof enclosure.

10. A liquid metal jet method for an X-ray source anode target, characterized in that with a system according to any one of claims 1-9, the method comprises:

the starting device, the hydraulic oil pump and the medium pump start to work, and the control valve is opened;

the medium pump conveys liquid metal in a medium container into the high-pressure pump through a coarse filter, the liquid metal is pressurized by the high-pressure pump and then flows into an energy accumulator through a high-pressure pipeline, the energy accumulator outputs stable liquid metal flow, the liquid metal flow passes through the control valve and then is ejected out of a vacuum cavity through a high-pressure nozzle, the liquid metal is recovered into a collecting chamber, and then flows back to the medium container after being cooled by a first cooler and filtered by a first filter; in the process, the electromagnetic valve is controlled to accurately control the jet speed of the liquid metal jet;

and after the jet system stably operates, starting the electron beam system, wherein electron beams emitted by the electron beam system vertically bombard the liquid metal jet to generate X rays, and the X rays are vertically emitted from the single-side X-ray window or the double-side X-ray windows.

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