3D printed tail stage cascade acceleration capillary and its clamping device

Abstract

The application provides a 3D-printed tail field cascade acceleration capillary and a clamping device thereof. The capillary is an integrated structure formed by 3D printing, and comprises a first structure and a second structure. The first structure comprises a linear acceleration section and a first light outlet. The linear acceleration section is provided with first to fourth gas filling holes on one side in sequence. The first and fourth gas filling holes are located at edge positions and are used for filling gas. The second gas filling hole is used for forming gas disturbance. The third gas filling hole is used for discharging to form plasma. The first light outlet is located on one side of the rear end of the linear acceleration section and is used for guiding out the first level remaining laser energy. A connecting channel is arranged between the first structure and the second structure, which is used for isolating the first level remaining laser and transmitting the first level electrons. The capillary curvature shape of the second structure is gradually curved. A gas filling hole is arranged on one side of the light inlet of the second structure. A gas filling hole is arranged on each side of the light outlet. The capillary of the application can realize cascade acceleration between two levels of tail fields.

Description

Technical Field

[0001] This application relates to the fields of discharge plasma physics and laser tail field accelerated electronics, specifically to a 3D-printed tail field cascaded accelerating capillary and its clamping device. Background Technology

[0002] The rapid development of femtosecond lasers, high-power lasers, and plasma accelerator physics has enabled continuous breakthroughs in the technological barriers of new accelerators. Cascade acceleration requires complex plasma channel structures and precise laser discharge synchronization to be achieved.

[0003] A search revealed Chinese invention patent application CN119212197A, which discloses a curved discharge capillary and its clamping device. The device includes a curved discharge capillary and a clamping device comprising a base, a capillary housing, a capillary positioning groove, an inflation channel positioning groove, an inflation channel, a copper electrode, a copper electrode cover plate, and a capillary cover plate. This patent is characterized by its compact structure, good stability, and convenient assembly. However, this device is primarily designed for accelerating a single laser beam and cannot achieve cascaded acceleration of two laser beams. Furthermore, it employs sapphire etching technology, which is insufficient for complex channel processing, and the separate printing and assembly of the upper and lower pieces poses a risk of air leakage, making it impossible to form a stable and ideal plasma channel.

[0004] Patent application CN104394642A discloses a laser-plasma resonance X-ray source, comprising a support, an accelerator capillary, a torsion capillary, gas, a high-voltage discharge system, a laser, and a seed electron beam. The accelerator capillary and the torsion capillary are connected in series within the support. The central axes of the through-holes of the accelerator capillary and the torsion capillary are parallel but not coincident. Gas is pre-filled into the accelerator capillary and the torsion capillary through gas filling channels. The high-voltage discharge system is applied to both ends of the accelerator capillary and the torsion capillary through positive and negative electrodes, generating a plasma channel by ionizing the gas. Laser pulses output from the laser are successively guided in the plasma channels within the accelerator capillary and the torsion capillary, generating cavitation. The seed electron beam, following the laser pulses, enters the cavitation and is accelerated and resonates to generate X-rays. This device can generate X-ray radiation output through laser-coupled plasma resonance. However, this device mainly accelerates and radiates a single laser beam, and cannot achieve cascaded acceleration of two laser beams. Furthermore, the device mainly outputs X-ray radiation, and cannot accelerate the electron beam energy in multiple stages to output a high-energy electron beam.

[0005] Currently, there are no capillaries or clamping devices for dual-beam cascade acceleration, and experimental progress has only been limited to bent tube optical guidance and acceleration, without achieving cascade acceleration between two stages of tail fields. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the purpose of this application is to provide a 3D printed tail field cascaded accelerating capillary and its clamping device.

[0007] In a first aspect of this application, a 3D-printed tail field cascaded accelerating capillary is provided, wherein the capillary is a monolithic structure formed by 3D printing, including a first-stage structure and a second-stage structure.

[0008] The first stage structure includes a linear acceleration section and a first stage light output port. The linear acceleration section has a first to a fourth gas filling hole arranged sequentially on one side. The first gas filling hole at the front end and the fourth gas filling hole at the rear end are located at the edge and are used to fill gas. The second gas filling hole is used to form gas disturbance and the third gas filling hole is used to discharge and form plasma. The first stage light output port is located on one side of the rear end of the linear acceleration section and is used to export the remaining laser energy of the first stage.

[0009] A connection channel is provided between the first-stage structure and the second-stage structure. The connection channel is used to isolate the remaining laser light in the first stage and allow the electrons in the first stage to pass through.

[0010] The capillary curvature of the second-stage structure gradually changes, with an air inlet on one side of the light inlet and an air inlet on each side of the light outlet.

[0011] Optionally, a reinforcing rib is provided on one side of the first-level structure, the reinforcing rib being used to improve the strength of the first-level structure.

[0012] Optionally, the first-stage light outlet has a curved structure with a gradually increasing cross-section.

[0013] Optionally, the two ends of the connection channel are respectively connected to the rear end of the first structure and the position after the light enters the second stage structure.

[0014] A second aspect of this application provides a clamping device for the 3D-printed tail-field cascaded accelerating capillary, comprising:

[0015] The fixture includes a base and a support. The base is fixed on a displacement stage, and the support is fixed on the base. The upper surface of the support is provided with a main groove for fixing the capillary body, an air inlet groove corresponding to each air inlet hole of the capillary, and a light guide groove corresponding to the first-stage light outlet. The support is provided with copper electrode grooves for connecting copper electrodes at the light inlet and light outlet of the first-stage structure and the light inlet and light outlet of the second-stage structure.

[0016] A top cover, located above the capillary, is used to encapsulate the capillary.

[0017] The first inflation tube is used to connect the first inflation port, the second inflation port, the fourth inflation port of the first-level structure, and the three inflation ports of the second-level structure.

[0018] The second inflation tube is used to connect to the third inflation port of the first-stage structure; the length of the second inflation tube is less than the length of the first inflation tube.

[0019] A copper electrode is connected in the copper electrode groove;

[0020] A discharge needle is inserted into the copper electrode at the first-stage light outlet to cooperate with the copper electrode and the second gas filling tube to discharge the first-stage light outlet.

[0021] Optionally, the copper electrode includes a hollow cylindrical structure and a sheet structure. One end of the sheet structure is sleeved on the outside of the hollow cylindrical structure, and the other end of the sheet structure is provided with a groove for light transmission or for the insertion of a discharge needle. The middle part is provided with a copper electrode through hole for fixing the copper electrode on the base. The hollow cylindrical structure is provided with an electrode connection hole for connecting a discharge electrode.

[0022] The copper electrode groove is provided with a threaded hole and an insertion hole. The threaded hole cooperates with the copper electrode through hole to press the copper electrode, and the copper electrode is inserted and connected to the insertion hole.

[0023] Optionally, the discharge needle is in a 90-degree L-shape, with one end fixed to the copper electrode and the other end extending into the capillary through the second gas tube to discharge at the first-stage light outlet.

[0024] Optionally, the first inflation tube is a hollow cylinder.

[0025] Optionally, the second inflation tube is a hollow cylinder.

[0026] Optionally, the top cover has a raised structure below it that matches the shape of the capillary tube. The raised structure is used to increase the pressure after the capillary tube is assembled, pressing the capillary tube onto the clamp.

[0027] The 3D-printed tail field cascaded accelerating capillary provided in this application is manufactured by 3D printing, forming a seamless, leak-proof structure. The first-stage capillary can be inflated through the first and fourth inflation holes, while the second inflation hole can achieve density perturbation to control the injection of the first stage. The first laser beam gradually dissipates through the first-stage outlet, thus not affecting the plasma inside the second stage. The three inflation holes of the second-stage capillary can achieve uniform inflation, so that the second laser beam forms a tail field cavitation after turning. The electron beam of the first stage can be transmitted to the second stage through the connection channel between the two stages and injected into the accelerating cavitation of the second beam to achieve relay acceleration, thereby realizing cascaded acceleration between the two tail fields.

[0028] Other technical effects resulting from the additional features will be further illustrated in the corresponding embodiments. Attached Figure Description

[0029] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0030] Figure 1 This is a schematic diagram of the structure of a 3D-printed tail field cascaded accelerating capillary according to an exemplary embodiment;

[0031] Figure 2 This is a schematic diagram of the structure of a clamping device for a 3D-printed tail-field cascaded accelerating capillary, according to an exemplary embodiment. Figure 1 ;

[0032] Figure 3 This is a schematic diagram of the structure of a clamping device for a 3D-printed tail-field cascaded accelerating capillary, according to an exemplary embodiment. Figure 2 ;

[0033] Figure 4 This is a schematic diagram of the structure of a clamp according to an exemplary embodiment;

[0034] Figure 5 This is a schematic diagram of the structure of a cover plate according to an exemplary embodiment;

[0035] Figure 6 This is a schematic diagram of the structure of a first inflation tube according to an exemplary embodiment;

[0036] Figure 7 This is a schematic diagram of the structure of a second inflation tube according to an exemplary embodiment;

[0037] Figure 8 This is a schematic diagram of the structure of a copper electrode according to an exemplary embodiment;

[0038] Figure 9 This is a schematic diagram of the structure of a discharge needle according to an exemplary embodiment;

[0039] In the diagram: 1-Capillary body, 2-Top cover, 3-Base, 4-Copper electrode, 5-First gas filling tube, 6-Second gas filling tube, 7-Discharge needle, 11-First stage light inlet, 12-Second stage light inlet, 13-First gas filling hole, 15-Third gas filling hole, 16-Fourth gas filling hole, 17-First stage light outlet, 18-Connecting channel, 19-Second stage pre-stage gas filling hole, 21-Through hole, 22-Protruding structure, 3 1-Clamping through hole, 32-Copper electrode groove, 33-Inflation tube groove, 34-Main groove, 35-Light guide groove, 36-Screw hole, 41-Groove, 42-Copper electrode through hole, 43-Copper electrode protrusion, 44-Electrode connection hole, 51-First inflation tube inflation hole, 52-First inflation tube body, 61-Second inflation tube inflation hole, 62-Second inflation tube body, 71-Extension end, 72-Fixed end. Detailed Implementation

[0040] The present application will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any way. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, and these all fall within the protection scope of the present application. Parts not described in detail in the following embodiments can be implemented using existing technology.

[0041] In existing technologies, capillary tubes do not achieve cascaded acceleration between tail fields, which is detrimental to the miniaturization design of future novel accelerators. To address these issues, this application provides a 3D-printed tail-field cascaded acceleration capillary to solve these problems.

[0042] Reference Figure 1As shown, in one embodiment of this application, a 3D-printed tail-field cascaded accelerating capillary is provided. This capillary is a 3D-printed integral structure, including a first-stage structure and a second-stage structure. The first-stage structure includes a linear acceleration section and a first-stage light outlet 17. A first to a fourth gas filling hole are sequentially provided on one side of the linear acceleration section. The first gas filling hole 13 at the front end and the fourth gas filling hole 16 at the rear end are located at the outermost edge and are used to fill gas. The second gas filling hole is used to create gas disturbance, and the third gas filling hole 15 is used to discharge and form plasma. The first-stage light outlet 17 (i.e., the first-stage light guide port) is located at... On one side of the rear end of the linear acceleration section, it is used to extract the remaining laser energy of the first stage; a connecting channel 18 is provided between the first stage structure and the second stage structure. The connecting channel 18 is located at the coupling point of the first stage structure and the second stage structure, and is used to isolate the remaining laser energy of the first stage after acceleration and allow the first stage electrons to pass through; the capillary curvature shape of the second stage structure gradually bends. This geometry can effectively make the second stage high laser bend under the guidance state and coaxial with the electrons accelerated by the first stage. A gas filling hole (second stage pre-stage gas filling hole 19) is provided on one side of its light inlet, and a gas filling hole is provided on each side of the light outlet.

[0043] Specifically, the capillary has an inlet (light inlet) at the front and an outlet (light outlet) at the rear. The capillary and fixture are placed together in a vacuum chamber. The first inflation port 13 and the fourth inflation port 16 are connected to a controller to control the inflation pressure and time. The first stage structure is inflated through the first and fourth inflation ports 13 and 16, while the second inflation port is suspended and connected to the atmosphere. Simultaneous inflation through the first and fourth inflation ports 13 and 16 fills the entire capillary. Since the second inflation port is connected to a vacuum, gas leakage from it creates density disturbances, thus controlling the first-stage injection. The three inflation ports of the second stage structure can be set to have the same injection time and pressure via a controller, achieving uniform inflation and causing the second laser beam to form a tail field cavitation bubble after turning.

[0044] The 3D printing material used in this embodiment is pure alumina, which possesses excellent physical properties such as heat resistance, insulation, high strength, and ablation resistance. When gas is injected into the capillary through the inflation channel, the gas is ionized by high voltage, and under the action of the Ohmic heating effect, a plasma density distribution that gradually increases radially is formed inside the capillary. The plasma density inside the tube is low in the center and high around the edges, forming a plasma optical lens similar to a convex lens, balancing the optical diffraction divergence effect after the ultra-intense laser is focused. Adjusting the inflation density and discharge voltage inside the tube allows the plasma channel to match the laser spot. At this time, the ultra-intense laser can be transmitted over long distances inside the tube without defocusing, thereby achieving the purpose of the first-stage laser accelerating the electron beam over long distances, and the second-stage laser accelerating the electron beam after being guided by the curved channel.

[0045] This application embodiment combines 3D printing technology to realize the complex configuration of a laser accelerator tail field cascaded capillary, which can generate two plasma stages in conjunction with high-voltage discharge. This configuration ensures that the two plasma stages do not interfere with each other, enabling two laser beams to achieve seamless tail field relay cascade acceleration. This dual-beam tail field cascaded capillary has a key impact and broad applications in the future application of new accelerators and accelerator miniaturization.

[0046] The embodiments described above are manufactured using 3D printing, resulting in a seamless, leak-proof, one-piece molding. The first-stage capillary can be inflated through the first and fourth inflation holes 16, while the second inflation hole can achieve density perturbation to control the injection in the first stage. The first laser beam gradually dissipates through the first-stage outlet, thus not affecting the plasma inside the second stage. The three inflation holes of the second-stage capillary can achieve uniform inflation, causing the second laser beam to form a tail field cavitation after turning. The electron beam of the first stage can be transmitted to the second stage through the connection channel 18 between the two stages and injected into the accelerating cavitation of the second beam to achieve relay acceleration, thereby realizing cascade acceleration between the tail fields of the two stages.

[0047] In order to improve the structural strength of the capillary, in some specific embodiments of this application, a reinforcing rib is provided on one side of the first-stage structure, and the reinforcing rib is used to improve the strength of the first-stage structure.

[0048] In order not to affect the internal plasma of the second stage, in some specific embodiments of this application, the first stage light outlet 17 is a curved structure with a gradually increasing cross-section.

[0049] In the above embodiments of this application, through the structural arrangement of the first-stage light-emitting port 17, the first laser beam is gradually dissipated through the first-stage light-emitting port 17, thereby not affecting the plasma inside the second-stage structure.

[0050] In order to achieve dual-light cascade acceleration, in some specific embodiments of this application, the two ends of the connecting channel 18 are respectively connected to the rear end of the first structure and the position after the light enters the second stage structure.

[0051] In the embodiments described above, the electron beam of the first-stage structure can be transmitted to the second-stage structure through the connecting channel 18 between the two stages and injected into the accelerating cavitation of the second beam to achieve relay acceleration. The connecting channel between the first and second stages has a circular cross-section, with an aperture smaller than that of a capillary channel, and is coaxial with the straight channels of the first and second stages. The connecting channel 18 between the first and second stages does not have a plasma channel formed by discharge, creating a suitable plasma structure for cascade acceleration, thereby allowing the first-stage electrons to pass through while blocking the remaining energy of the first stage. The second-stage laser can then continue to accelerate the electrons that have passed through the first stage.

[0052] In the embodiments described above, the two-stage structure inside the capillary can generate two plasma stages without mutual interference, and guide the laser to achieve dual-beam cascade acceleration. Using 3D printing technology, all the geometric features inside the capillary can be obtained, resulting in a seamless, airtight structure that also enables bending light guidance.

[0053] Based on the same concept, another embodiment of this application provides a clamping device for the above-mentioned 3D-printed tail-field cascaded accelerating capillary, referring to... Figures 2 to 5 As shown, the device includes a clamp, a top cover 2, a first inflation tube 5, a second inflation tube 6, a copper electrode 4, and a discharge needle 7, etc. The clamp includes a base 3 and a support. The base 3 is fixed to the displacement stage, and the support is fixed to the base 3. The upper surface of the support is provided with a main groove 34 for fixing the capillary body 1, inflation tube grooves 33 corresponding to each inflation hole of the capillary, and a light guide groove 35 corresponding to the first-stage light outlet 17. The remaining energy of the first stage is discharged from the light guide groove 35 through the light guide. The support is provided with a copper electrode for connecting the light inlet (i.e., the first-stage light inlet 11) and light outlet of the first-stage structure, and a light inlet (i.e., the second-stage light inlet 12) and light outlet of the second-stage structure. The copper electrode groove 32 of electrode 4; the top cover 2 is located above the capillary tube and is used to encapsulate the capillary tube; the first inflation tube 5 is used to connect the first inflation hole 13, the second inflation hole, the fourth inflation hole 16 of the first stage structure and the three inflation holes of the second stage structure; the second inflation tube 6 is used to connect the third inflation hole 15 of the first stage structure; the length of the second inflation tube 6 is less than the length of the first inflation tube 5, and this length is flush with the side of the fixture after assembly, which is just right to cooperate with the copper electrode 4 to press the third inflation hole and the internal discharge needle 7 after fixing; the copper electrode 4 is connected in the copper electrode groove 32; the discharge needle is inserted into the copper electrode at the first stage light outlet and is used to cooperate with the copper electrode 4 and the second inflation tube 6 to discharge the first stage light outlet 17.

[0054] Specifically, the base 3 has four rectangularly arranged clamping through holes 31 for fixing the device on the displacement stage. The shape of the main groove 34 matches the shape of the capillary tube for assembly. The gas filling tube grooves 33 correspond to the four gas filling holes of the first-stage structure and the three gas filling holes of the second-stage structure, allowing the gas filling tube connected to the capillary tube to be connected to an external gas cylinder after assembly. The copper electrode 4 is used to connect to the external electrode to discharge and break down the gas in the capillary tube, thereby forming plasma for laser cascade tail field acceleration. The first stage of plasma is formed by the discharge of the copper electrode at the entrance of the first-stage structure in conjunction with the discharge needle at the fourth gas filling hole of the first stage, and the second stage of plasma is formed by the discharge of the copper electrode at the entrance of the second-stage structure in conjunction with the copper electrode at the exit of the second stage.

[0055] It should be noted that since the copper electrodes at the first-stage light inlet and the light inlet and outlet of the second-stage structure can directly contact the gas, a discharge needle is not required for discharge. However, the discharge at the first-stage light outlet is through a pipe, so a discharge needle needs to be inserted into the pipe to contact the gas for discharge.

[0056] The clamping device in the above embodiments of this application can effectively fix the capillary, the air tube, and the copper electrode 4 through the cooperation of the air tube, the copper electrode 4, the top cover 2, etc., thereby achieving tight clamping of the cascaded accelerating capillary.

[0057] To achieve the fixed encapsulation of the capillary, in some specific embodiments of this application, reference is made to... Figure 5 The top cover 2 has a raised structure 22 below it that matches the shape of the capillary tube. The raised structure 22 is used to increase the pressure after the capillary tube is assembled and press the capillary tube onto the clamp.

[0058] Specifically, the shape of the protruding structure 22 below the cover plate is the outer contour of the capillary, which is used to increase the pressure after the capillary is assembled, so that the capillary can be firmly fixed. The top cover 2 covers the top of the discharge capillary and presses it tightly. The top of the bracket has three screw holes 36, and the top cover 2 has three corresponding through holes 21, so as to realize the assembly and fixation of the top cover 2 and fix the capillary to the fixture.

[0059] In order to achieve the purpose of discharge, in some specific embodiments of this application, reference is made to... Figure 8 The copper electrode 4 includes a hollow cylindrical structure and a sheet structure. One end of the sheet structure is fitted onto the outside of the hollow cylindrical structure, and the other end of the sheet structure has a groove 41 for light transmission or the insertion of a discharge needle. The middle part has a copper electrode through hole 42 for fixing the copper electrode 4 to the base 3, which can be connected with a screw. The hollow cylindrical structure is used for insertion and fixing of the bracket, and has an electrode connection hole 44 for connecting a smaller discharge electrode (i.e., discharge terminal). The copper electrode groove 32 has a threaded hole and an insertion hole. The threaded hole and the copper electrode through hole 42 cooperate to press the copper electrode 4, and the copper electrode 4 is inserted and connected in the insertion hole.

[0060] Specifically, the base 3 has four copper electrode grooves 32, located at the light inlet and outlet ports of the first and second stage structures, respectively. Correspondingly, copper electrodes 4 are assembled at the first-stage light inlet port, the first-stage light outlet port, and the second-stage light inlet and outlet ports. The groove at the other end of the sheet-like structure, in conjunction with the two light inlets of the capillary, guides the laser into the capillary. Simultaneously, when this groove is assembled at the second-stage outlet of the capillary, it can extract the accelerated electrons. The copper electrode through-hole 42 in the middle is used to fix the copper electrode 4 onto the capillary clamp. The end of the hollow cylindrical structure (i.e., the copper electrode protrusion 43) is used to connect to external electrodes. This copper electrode 4 can realize functions such as electrode discharge, light introduction and electron extraction, fitting the clamp, and adapting to different electrodes.

[0061] In order to discharge the first-stage light-emitting port 17, a discharge needle is installed at the first-stage light-emitting port (i.e., near the first-stage third air-filling hole). In some specific embodiments of this application, refer to... Figure 9 The discharge needle 7 is L-shaped at 90 degrees. One end of the discharge needle 7 is fixed on the copper electrode at the first light outlet, and the other end extends into the capillary through the second gas tube to discharge the first light outlet.

[0062] Specifically, the discharge needle 7 is used to discharge to the downstream stage of the first stage of the capillary. One end of the needle (i.e., the fixed end 72) is used to cooperate with the copper electrode 4 to contact and conduct the external circuit and fix the discharge needle 7; the other end (i.e., the insertion end 71) extends into the hollow tube of the short gas-filled tube to discharge the plasma corresponding to the position of the capillary.

[0063] For example, the discharge needle 7 is a steel needle.

[0064] In the above embodiments of this application, through the cooperation of the discharge needle 7 and the copper electrode 4, the second gas filling tube 6 extends into the third gas filling hole 15 of the first stage structure to discharge the first stage light outlet 17.

[0065] In order to inflate the capillary, in some specific embodiments of this application, reference is made to... Figure 6 The first inflation tube 5 is a hollow cylinder.

[0066] Specifically, six first inflation tubes 5 are assembled with inflation tube grooves, respectively connecting to the first, second, and fourth inflation holes of the first stage structure of the capillary and the three inflation holes of the second stage structure to achieve inflation, used to fill gas into the capillary. The hollow pipe of the first inflation tube body 52 is a gas channel, with the first inflation tube inflation hole 51 on one side of the outer wall connecting to an external gas cylinder, and the other side cooperating with the inflation tube groove to achieve inflation.

[0067] In order to discharge the first-stage light output port, in some specific embodiments of this application, refer to Figure 7The second inflation tube 6 is a hollow cylinder, assembled with the third inflation hole 15 of the first-stage structure, and works with the discharge needle 7 and copper electrode 4 to achieve discharge at the first-stage light outlet 17. The hollow tube of the second inflation tube body 62 guides the discharge needle 7 into the rear end of the first stage. The inflation hole 61 of the second inflation tube at one end of the outer wall is connected to the capillary inflation port to achieve discharge, while the other end, along with the discharge needle 7, is fixed in the fixture by the copper electrode 4 to discharge to the rear stage of the first stage of the capillary.

[0068] It should be noted that, to ensure the generation of two plasma stages within the capillary, the discharge electrodes are connected in a manner where the anode and cathode of the first-stage outlet and the second-stage inlet are identical electrodes. For example, the first-stage inlet and the second-stage outlet can be connected to the anode, and the remaining first-stage outlet and second-stage inlet can be connected to the cathode, thus forming an anode-cathode-anode-cathode discharge pattern. Optionally, an anode-cathode-anode-cathode discharge pattern can also form the desired plasma channel. In the above embodiments of this application, the four copper electrode discharge modes provide the ability to achieve independent high-voltage breakdown of the first-stage and second-stage structures without mutual interference.

[0069] The cascaded capillary and clamping device in the above embodiments of this application achieve precise clamping of the cascaded capillary through devices such as a cover plate, clamps, copper electrodes, long gas inlet tubes, short gas inlet tubes, and discharge needles. This enables the generation of two plasma segments within the capillary for seamless laser tail field cascading. This technology has significant application value in laser plasma physics, particularly in the direction of laser tail field cascading, and is expected to enable the miniaturization and everyday applications of novel accelerators and radiation sources in the future.

[0070] The dual-beam cascade experimental method provided in the above embodiments of this application can solve problems such as gas filling, laser guidance, electron transfer, formation of discharge plasma channels, first-stage electron injection, and second-stage laser injection suppression in seamless cascading. The above embodiments of this application have important applications in the field of laser plasma physics, especially in experiments involving laser tailfield electron acceleration; furthermore, they have potential significant applications in particle beam acceleration, novel particle accelerators, and other fields of physics.

[0071] The preferred features in the above embodiments can be used individually in any embodiment, or in any combination thereof, provided they do not conflict with each other. Furthermore, parts not described in detail in the embodiments can be implemented using existing technologies.

[0072] In the description of the embodiments of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this application 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. Therefore, they should not be construed as limitations on this application.

[0073] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0074] In the description of the embodiments in this application, "multiple" means two or more, unless otherwise explicitly specified. In this application, unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," "fixed," etc., 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 application according to the specific circumstances.

[0075] The terms "comprising" and "having," and any variations thereof, in the embodiments of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or devices.

[0076] The foregoing has described some specific embodiments of this application. It should be understood that this application is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this application. The above-described preferred features can be used in any combination without conflict.

Claims

1. A 3D-printed tail-field cascaded accelerating capillary, characterized in that, The capillary is a 3D-printed integral structure, including a first-level structure and a second-level structure; The first stage structure includes a linear acceleration section and a first stage light output port. The linear acceleration section has a first to a fourth gas filling hole arranged sequentially on one side. The first gas filling hole at the front end and the fourth gas filling hole at the rear end are located at the edge and are used to fill gas. The second gas filling hole is used to form gas disturbance and the third gas filling hole is used to discharge and form plasma. The first stage light output port is located on one side of the rear end of the linear acceleration section and is used to export the remaining laser energy of the first stage. A connection channel is provided between the first-stage structure and the second-stage structure. The connection channel is used to isolate the remaining laser light in the first stage and allow the electrons in the first stage to pass through. The capillary curvature of the second-stage structure gradually changes, and an air inlet is provided on one side of the light inlet and an air inlet is provided on each side of the light outlet. The two ends of the connection channel are respectively connected to the rear end of the first-level structure and the position after the light inlet of the second-level structure.

2. The 3D-printed tail-field cascaded accelerating capillary according to claim 1, characterized in that, A reinforcing rib is provided on one side of the first-level structure, and the reinforcing rib is used to improve the strength of the first-level structure.

3. The 3D-printed tail-field cascaded accelerating capillary according to claim 1, characterized in that, The first-stage light outlet has a curved structure with a gradually increasing cross-section.

4. A clamping device for a 3D-printed tail-field cascaded accelerating capillary as described in any one of claims 1-3, characterized in that, include: The fixture includes a base and a support, wherein the base is fixed to a displacement stage and the support is fixed to the base; The upper surface of the bracket is provided with a main groove for fixing the capillary body, an air inlet groove corresponding to each air inlet hole of the capillary, and a light guide groove corresponding to the first stage light outlet; the bracket is provided with copper electrode grooves for connecting copper electrodes at the light inlet and light outlet of the first stage structure and the light inlet and light outlet of the second stage structure. A top cover, located above the capillary, is used to encapsulate the capillary. The first inflation tube is used to connect the first inflation port, the second inflation port, the fourth inflation port of the first-level structure, and the three inflation ports of the second-level structure. The second inflation tube is used to connect to the third inflation port of the first-stage structure; the length of the second inflation tube is less than the length of the first inflation tube. A copper electrode is connected in the copper electrode groove; A discharge needle is inserted into the copper electrode at the first-stage light outlet to cooperate with the copper electrode and the second gas filling tube to discharge the first-stage light outlet.

5. The clamping device for the 3D-printed tail-field cascaded accelerating capillary according to claim 4, characterized in that, The copper electrode includes a hollow cylindrical structure and a sheet structure. One end of the sheet structure is sleeved on the outside of the hollow cylindrical structure, and the other end of the sheet structure is provided with a groove for light transmission or for the insertion of a discharge needle. The middle part is provided with a copper electrode through hole for fixing the copper electrode on the base. The hollow cylindrical structure is provided with an electrode connection hole for connecting a discharge electrode. The copper electrode groove is provided with a threaded hole and an insertion hole. The threaded hole cooperates with the copper electrode through hole to press the copper electrode, and the copper electrode is inserted and connected to the insertion hole.

6. The clamping device for the 3D-printed tail-field cascaded accelerating capillary according to claim 4, characterized in that, The discharge needle is L-shaped at 90 degrees. One end of the discharge needle is fixed to the copper electrode, and the other end extends into the capillary through the second gas tube to discharge the first-stage light outlet.

7. The clamping device for the 3D-printed tail-field cascaded accelerating capillary according to claim 4, characterized in that, The first inflation tube is a hollow cylinder.

8. The clamping device for the 3D-printed tail-field cascaded accelerating capillary according to claim 4, characterized in that, The second inflation tube is a hollow cylinder.

9. The clamping device for the 3D-printed tail-field cascaded accelerating capillary according to claim 4, characterized in that, The top cover has a raised structure below it that matches the shape of the capillary tube. The raised structure is used to increase the pressure after the capillary tube is assembled, pressing the capillary tube tightly onto the clamp.

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