Ultra-high-density submicron high-current electron beam generator

Abstract

A device for generating an ultra-high-density, submicron, high-current electron beam comprises a particle accelerator for providing a relativistic high-current electron beam, a vacuum target chamber for providing a vacuum environment for interaction between the electron beam and the target, and a target element. The target element is a hollow conical target that focuses the electron beam to less than one-tenth of its initial diameter, down to the submicron scale, thereby increasing its density by more than two orders of magnitude, reaching the density of a solid. Such an extremely high-density, submicron-sized electron beam is unattainable by other devices and will provide new research methods for many cutting-edge scientific fields. The device is also suitable for focusing other charged particle beams, such as positron beams. Therefore, the present invention has important research value and application prospects.

Description

Technical Field

[0001] The present invention mainly relates to the fields of high-intensity field physics, accelerator physics and high-energy radiation sources, and in particular to a device for generating ultra-high-density submicron high-current electron beams. Background Art

[0002] Tightly focused, relativistic, high-intensity electron beams hold significant research value and application prospects in accelerator physics, high-intensity field physics, laser plasma physics, and high-energy radiation sources. This not only reduces the growth of electron beam emittance in free space but also reduces the demand for downstream focusing devices. Furthermore, tightly focused, high-density electron beams will significantly enhance the brightness of particle colliders and high-energy radiation sources, and hold promise for studying unexplored new physical mechanisms, such as the acceleration and radiation of particle beam-driven solid-state dense plasmas and high-field QED physics.

[0003] Currently, focusing and collimating high-energy electron beams is typically achieved using conventional magnets. However, this technology suffers from drawbacks such as low magnetic field strength, large device size, slow switching times, and lateral asymmetry. Furthermore, it is unsuitable for focusing high-current electron beams with micron-scale dimensions and relatively large divergences. For example, laser plasma acceleration is a promising candidate for next-generation compact accelerators and high-brightness radiation sources. However, the resulting electron beams are typically only a few microns in size, have divergences of a few milliradians, and carry currents in the hundreds of kiloamperes, making them difficult to focus or collimate for transmission to applications. To address this challenge, over two decades of tireless research by researchers worldwide have led to the discovery of novel focusing elements, such as plasma lenses, that can provide magnetic fields several orders of magnitude higher than conventional quadrupole magnets. This is particularly important for the development and application of laser- or particle-beam-driven plasma accelerators. Numerous research and applications would greatly benefit from tightly focused relativistic electron beams, such as multistage plasma accelerators, compact free-electron lasers, high-brightness radiation sources, and nonlinear scattering processes. Although significant progress has been made in electron beam focusing in recent years, there is no method that can focus relativistic high-current electron beams to the submicron scale and increase their density by more than hundreds of times to reach near-solid density.

[0004] On the other hand, the interaction between ultra-high-density electron beams and plasmas holds a wealth of physical processes and novel phenomena. However, due to the lack of such electron beams, many physical processes and mechanisms remain unstudied and urgently require in-depth research and exploration. For example, the resulting dense electron beams could replace high-intensity laser pulses to trigger strong-field QED effects, potentially opening a new avenue for studying extreme-field physics. Alternatively, the interaction of a focused dense electron beam with scattered laser pulses could allow the study of physical processes such as high-order nonlinear scattering. Furthermore, the interaction of a focused dense electron beam with another high-energy particle beam (such as a positron beam) could allow the study of particle collision physics.

[0005] Therefore, it is urgent to develop a device that can focus relativistic high-current particle beams, which is expected to achieve submicron beam spots and extremely dense electron beams with near-solid density, thus opening up new areas of scientific research. Summary of the Invention

[0006] The purpose of the present invention is to provide a relativistic high-current particle beam focusing device for generating high-energy dense electron beams or other charged particle beams (such as positron beams) with diameters at the submicron level, thereby opening up new avenues for research in extreme strong field physics.

[0007] The present invention provides a device for generating an ultra-high-density submicron high-current electron beam, comprising:

[0008] A vacuum target chamber, wherein the vacuum target chamber is used to provide a vacuum environment for interaction between the electron beam and the target;

[0009] A particle accelerator is placed outside the vacuum target chamber and is used to provide a relativistic high-current electron beam;

[0010] a target element, placed in the vacuum target chamber and in the shape of a hollow cone, for focusing the electron beam to less than one tenth of its initial diameter;

[0011] The electron beam provided by the particle accelerator is incident on the target element, and refluxes through the target wall of the target element to generate an ultra-strong self-generated magnetic field, thereby focusing the electron beam itself; after an interaction distance of hundreds of microns, the electron beam is compressed to less than one-tenth of its initial diameter, reaching a submicron beam spot, thereby increasing its density by more than two orders of magnitude, reaching a near-solid density.

[0012] The initial beam spot size of the electron beam is several micrometers to tens of micrometers, preferably, 4 to 20 micrometers.

[0013] The initial pulse length of the electron beam is several micrometers to tens of micrometers, preferably, 4 to 20 micrometers.

[0014] The initial current of the electron beam is greater than 10 kiloamperes, preferably greater than 100 kiloamperes.

[0015] The initial energy of the electron beam is above 100 mega-electronvolts, preferably above 100 mega-electronvolts.

[0016] The density of the target element is a solid density, preferably greater than 10 23 per cubic centimeter.

[0017] The diameter of the bottom of the target element (incident opening) is greater than or equal to the initial electron beam diameter and can be adjusted within a range from several microns to tens of microns.

[0018] The diameter of the top of the target element (the exit opening) is smaller than one quarter of the diameter of the initial electron beam and can be adjusted within the range of 0.1 to 10 microns, preferably 0.2 to 2 microns.

[0019] The longitudinal length of the target element can be adjusted within the range of 100 to 10,000 microns, preferably, 200 to 1,000 microns.

[0020] The thickness of the conversion target can be adjusted in the range of several microns to hundreds of microns, preferably 10 to 100 microns.

[0021] The conversion target density is close to solid density or equivalent to the density of the focused electron beam. Preferably, 10 22 ~10 24 per cubic centimeter.

[0022] The target element and the conversion target can be prepared by 3D printing technology or precision processing technology, but are not limited to these two technical methods.

[0023] In another preferred embodiment, the parameters of the focused electron beam can be controlled by adjusting the parameters of the target element.

[0024] In another preferred embodiment, different physical processes can be studied and radiation source parameters can be regulated by adjusting the conversion target parameters.

[0025] In another preferred embodiment, the focused dense particle beam has one or more characteristics selected from the following group:

[0026] (a) The beam spot size after focusing can be as small as one tenth of the initial beam spot size;

[0027] (b) The beam density after focusing can reach more than 100 times the initial density;

[0028] (c) The minimum spot radius after focusing is about 0.1 μm;

[0029] (d) The beam density after focusing can exceed 10 23 per cubic centimeter;

[0030] (e) The beam energy after focusing can retain more than 90% of its initial value.

[0031] The present invention provides a device for generating an ultra-high-density submicron high-current electron beam and a method for studying extreme strong-field physics, comprising the following steps:

[0032] (a) providing a focused high-density electron beam, wherein the focused high-density electron beam can be achieved by the relativistic high-current electron beam interacting with the target element;

[0033] (b) Using a focused high-density electron beam to interact with a conversion target to generate an ultra-strong quasi-static field, thereby stimulating the strong-field QED effect, making it possible to study extreme strong-field physics and obtain collimated high-brightness gamma-ray sources.

[0034] (c) Alternatively, the focused electron beam can be used to interact with scattered laser pulses to study physical processes such as high-order nonlinear scattering.

[0035] (d) Alternatively, the focused electron beam can be used to interact with another high-energy particle beam (such as a positron beam) to study fundamental physics such as particle collision processes.

[0036] Compared to traditional magnet technology, this method offers numerous unique advantages and can provide an ultra-strong focusing magnetic field several orders of magnitude higher than that of conventional quadrupole magnets. The magnetic field strength generated by this method can reach over gigagauss, enabling the focusing of relativistic high-current electron beams to within one-tenth of their initial diameter within a hundred-micrometer scale, reaching the submicrometer scale. The corresponding beam density will increase by more than two orders of magnitude, reaching near-solid-state density. This device boasts the advantages of high efficiency, compact size, and the ability to focus relativistic high-current particle beams. The resulting submicrometer-scale beam spot and ultra-high-density particle beam with near-solid-state density are currently unattainable with conventional accelerator devices, breaking through the bottleneck of particle beam focusing technology. This tightly focused, dense electron beam has important research and application value for fundamental physics and other scientific research. For example, it can replace high-intensity laser pulses to stimulate strong-field QED effects and study extreme-field physics. Furthermore, the conditions required for this method are relatively simple, easy to implement, and practical, promising application in a wider range of fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of the structure of the device for generating ultra-high-density submicron high-current electron beam according to the present invention;

[0038] Figure 2 It is a schematic diagram of the ultra-strong magnetic field and electron beam focusing generated in the hollow cone target of the present invention;

[0039] Figure 3 is a distribution diagram of the effective focusing field generated in the cone target of the present invention;

[0040] Figure 4 It is the energy spectrum distribution diagram of the electron beam before and after focusing in the present invention;

[0041] Figure 5 It is the density distribution diagram of the electron beam before and after focusing in the present invention;

[0042] Figure 6 is a trajectory diagram of electron beam focusing in the present invention;

[0043] Figure 7 It is a trajectory diagram of the positron beam focusing in the present invention.

[0044] In the accompanying drawings, the symbols are as follows:

[0045] 1-Accelerator / Particle Accelerator

[0046] 2-Vacuum target chamber

[0047] 3-driven particle beam / relativistic high-current electron beam, 31-electron beam injected into hollow conical target

[0048] 4-Target element / hollow cone target

[0049] 5-focused high-density electron beam

[0050] 6-Super strong magnetic field generated on the target surface DETAILED DESCRIPTION

[0051] Through extensive research, the inventors have developed, for the first time, a device for generating ultra-high-density, submicron, high-current electron beams. This device achieves a submicron beam spot and a tightly focused, dense electron beam with near-solid-state density. This device is based on the interaction of a relativistic, high-current electron beam with energies exceeding hundreds of megaelectronvolts and currents exceeding tens of kiloamperes with a hollow conical target element, focusing the electron beam through a self-induced, ultra-strong angular magnetic field. The electron beam is compressed to less than one-tenth of its initial diameter, reaching submicron dimensions, thereby increasing its density by more than two orders of magnitude, reaching near-solid-state density. Such high-density electron beams could replace ultra-intense lasers to stimulate strong-field QED effects, thus opening up new avenues for studying extreme-field physics.

[0052] The specific implementation of the present invention requires a particle accelerator and a vacuum target chamber, wherein the vacuum target chamber contains a hollow conical target element for focusing a relativistic high-current particle beam; the accelerator can be a radio frequency accelerator or a plasma accelerator. The relativistic high-current electron beam is incident on the target element, and the beam self-focusing is achieved by inducing an ultra-strong magnetic field on the inner wall surface of the target. After sufficient interaction, the electron beam can be focused to less than one-tenth of its initial diameter, reaching a submicron beam spot, thereby increasing its density by more than two orders of magnitude, reaching a near-solid density. The parameters of the focused electron beam, such as the beam spot size and density, can be controlled by changing parameters such as the longitudinal length and outlet size of the target element.

[0053] Compared with traditional focusing technology, the main advantages of the present invention are as follows:

[0054] Traditional magnet focusing technology is limited by low magnetic field strength, large device size, slow switching time, and lateral asymmetry, making it difficult to focus high-current, small-sized, and relatively large-divergence relativistic electron beams. Currently, electron beams focused using traditional quadrupole magnets are typically larger than tens of microns in size, and currents are generally limited to fewer than a few thousand amperes. Plasma-based focusing methods can generate even greater magnetic field strengths, making them more suitable for focusing and collimating these high-current, small-sized, high-energy electron beams.

[0055] Compared with other plasma focusing methods, the main advantages of the present invention are as follows:

[0056] After more than 20 years of unremitting efforts, researchers around the world have found that plasma focusing methods can generate magnetic fields several orders of magnitude stronger than traditional magnets. For example, plasma lens technology is suitable for focusing high-energy electron beams with large currents and small sizes. However, this technology can generally only focus to a beam spot of several microns, and the corresponding particle beam density generally does not exceed 10 21 per cubic centimeter, which limits its application and research scope. The present invention aims to break through the bottleneck of current particle beam focusing technology to achieve submicron beam spot and density exceeding 10 23 This extremely high-density electron beam can generate a tightly focused, dense electron beam with a density of 100,000 electrons per cubic centimeter. This extremely high-density electron beam will drive new research directions, for example, by replacing ultra-intense laser pulses in the study of high-intensity field physics. By varying the parameters of the target element, the parameters of the focused, relativistic, high-current, dense electron beam can be easily controlled. Furthermore, the focusing element of the present invention measures only a few hundred microns to a few millimeters, making it a highly efficient, compact focusing device that is both miniaturized and economical.

[0057] Therefore, the present invention can focus relativistic high-current electron beams to achieve a submicron beam spot and an extremely dense electron beam with near-solid density. This invention is superior to and different from other particle beam focusing devices, and it also breaks through the bottleneck of current particle beam focusing technology. This will provide a cost-effective, practical, stable, reliable, and compact particle beam focusing device for the scientific community.

[0058] In the following description, many technical details are provided to help readers better understand this application. However, those skilled in the art will understand that even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in this application can be implemented.

[0059] the term

[0060] As used herein, the terms "device for generating ultra-high-density submicron high-current electron beams" and "device for focusing high-energy particle beams" may be used interchangeably.

[0061] The terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a" does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0062] In the present invention, all directional indications (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0063] Ultra-high-density submicron high-current electron beam generator / high-energy particle beam focusing device

[0064] In the present invention, a high-energy particle beam focusing device includes an accelerator, a vacuum target chamber and a target element;

[0065] The accelerator is used to provide a relativistic high-current electron beam;

[0066] The vacuum target chamber can provide a vacuum environment for the interaction between the electron beam and the target;

[0067] The target element is placed within the vacuum target chamber. It is a hollow conical target with openings at both the bottom (inlet) and top (exit). A relativistic high-current electron beam is incident upon the target element, inducing backflow through the target wall to generate an extremely strong self-generated magnetic field, thereby focusing the electron beam. After an interaction distance of several hundred microns, the electron beam is compressed to less than one-tenth of its initial diameter, achieving a submicron beam spot size. This increases its density by more than two orders of magnitude, reaching near-solid density.

[0068] The focused, high-density electron beam can replace high-intensity laser pulses to stimulate the strong-field QED effect. This will open up new avenues for the study of extreme-field physics and is expected to surpass the brightness and conversion efficiency of existing gamma-ray sources, thereby realizing an unprecedentedly efficient, ultra-bright gamma radiation source.

[0069] particle accelerator

[0070] In the present invention, the particle accelerator may be a radio frequency accelerator or a laser plasma accelerator, which is used to generate a relativistic high current driven electron beam with appropriate parameters.

[0071] Driving electron beam

[0072] In the present invention, the driving electron beam is of a commonly used Gaussian distribution, and the beam current parameters are adjustable.

[0073] The initial beam spot diameter of the electron beam is 2 to 100 microns, preferably 4 to 20 microns. The pulse length of the electron beam is 2 to 100 microns, preferably 4 to 20 microns.

[0074] The peak current of the electron beam is greater than 10 kiloamperes, preferably greater than 100 kiloamperes.

[0075] The electron beam energy is above 100 MeV, preferably above 100 MeV.

[0076] Target element

[0077] In the present invention, the target element can be produced by 3D printing technology or precision machining technology, but is not limited to the above two technical methods. The inlet and outlet of the target element are both openings, and parameters such as the diameter and length of the inlet and outlet can be changed as needed.

[0078] The target element has a solid density and can be a conductor target such as aluminum, copper, or gold.

[0079] The length of the target element along the propagation direction of the electron beam is 100 to 10,000 microns, preferably 200 to 1,000 microns.

[0080] The inner diameter of the entrance port of the target element is 2 to 200 microns, preferably 5 to 50 microns.

[0081] The inner diameter of the exit port of the target element is 0.1 to 10 microns, preferably 0.2 to 2 microns.

[0082] The target element has a wall thickness of any dimension greater than 1 micron.

[0083] Characteristics of a tightly focused dense electron beam

[0084] In the present invention, the focused relativistic high current dense electron beam has the following characteristics:

[0085] (a) The beam spot size after focusing can be as small as one tenth of the initial beam spot size;

[0086] (b) The beam density after focusing can reach more than 100 times the initial density;

[0087] (c) The minimum spot radius after focusing is about 0.1 μm;

[0088] (d) The beam density after focusing can exceed 10 23per cubic centimeter;

[0089] (e) More than 90% of the beam energy can be retained after focusing.

[0090] Methods for studying extreme strong field physics

[0091] In the present invention, a method for studying extreme strong field physics comprises the following steps:

[0092] (a) providing a focused high-density electron beam, wherein the focused high-density electron beam can be obtained by the relativistic high-current electron beam interacting with the target element;

[0093] (b) Using a focused high-density electron beam to interact with a conversion target to generate an ultra-strong quasi-static field, thereby stimulating the strong-field QED effect, enabling the study of extreme strong-field physics and generating a large number of collimated high-energy gamma photons.

[0094] (c) Alternatively, the focused electron beam can be used to interact with scattered laser pulses to study physical processes such as high-order nonlinear scattering.

[0095] (d) Alternatively, the focused electron beam can be used to interact with another high-energy particle beam (such as a positron beam) to study fundamental physics such as particle collision processes.

[0096] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the present invention is not limited to the embodiments shown in the accompanying drawings, and those skilled in the art can understand the present invention from the essential spirit embodied in the following scheme description.

[0097] Figure 1 This is a schematic diagram of the structure of the device for generating ultra-high density submicron high current electron beams according to the present invention, which is used to focus high energy and high current electron beams. Figure 1 As shown, the device includes a particle accelerator 1 , a vacuum target chamber 2 and a target element 4 .

[0098] The particle accelerator 1 is used to output a relativistic high-current electron beam 3. The accelerator can be a radio frequency accelerator or a laser plasma accelerator. The electron beam 3 has a Gaussian distribution; a beam spot diameter of 2 to 100 microns, preferably 4 to 20 microns; a pulse length of 2 to 100 microns, preferably 4 to 20 microns; a peak current of at least 10 kiloamperes, preferably at least 100 kiloamperes; and a peak energy of at least 100 megaelectronvolts, preferably at least 10 gigaelectronvolts.

[0099] The vacuum target chamber 2 is used to provide a vacuum environment for the interaction between the electron beam and the target.

[0100] Among them, the target element 4 is placed inside the vacuum target chamber 2 and is used to focus the relativistic high-current electron beam 3, thereby generating a sub-micron-sized beam spot and an ultra-high-density electron beam 5 with near-solid density. Parameters such as the length and the inlet and outlet diameters of the target element are adjustable.

[0101] The length L of the target element 4 along the electron beam propagation direction is from hundreds of micrometers to several millimeters, the inlet diameter D is from several micrometers to dozens of micrometers, and the outlet diameter d is in the range of 0.1 - 10 micrometers. In order to better focus the electron beam, the opening angle of the target element should satisfy the following relational expression: (D - d) / 2L < f[2I b ln(d b / d f ) / I A 1 / 2 , where I A ≈17γ b [kiloampere] is the Alfvén current limit, γ b is the relativistic Lorentz factor of the electron beam, I b is the peak current of the electron beam, d b is the initial electron beam diameter, d f is the diameter of the focused electron beam, and 0 < f < 1 is a correction factor. Taking a GeV electron beam with a current of hundreds of kiloamperes as an example, if it is desired to focus it to less than one-tenth of the initial diameter, the opening angle of the target element should preferably satisfy (D - d) / 2L < 0.05; the outlet size of the target element is set to be comparable to one-tenth of the initial electron beam size. The target element can be prepared by 3D printing technology or precision machining technology.

[0102] For the sake of easy understanding, Figure 2 a schematic diagram of the focusing magnetic field 6, the injected electron beam 31, and the focused high-density electron beam 5 in the target element is given. By using the focused high-density electron beam to interact with the conversion target, the strong-field QED effect can be excited, thereby generating a tightly focused high-brightness dense gamma-ray beam. It should be noted here that the target element 4 is mainly used to focus the relativistic high-current electron beam, and the strong magnetic field generated mainly exists on the inner wall surface of the cone. Therefore, the electron beam will not lose a large amount of beam current energy due to radiation during the focusing process. However, when the high-density electron beam interacts with the solid conversion target, a stronger quasi-static field will be excited; since the electron beam is completely in the high-field-strength region, a large amount of electron beam energy will be effectively converted into high-energy photon radiation.

[0103] ​Furthermore, the present invention can achieve focusing of different types of particle beams (e.g., a focused positron beam) by varying the output of different types of charged particle beams from the accelerator 1. By varying the parameters of the target element 4, the parameters of the focused particle beam, such as the beam spot size and number density, can be controlled, thereby achieving an adjustable tightly focused, high-density particle beam. When the focused, high-density electron beam interacts with a conversion target, the excited static field can be manipulated by varying the conversion target parameters (e.g., target density, thickness, etc.), thereby controlling the associated physical processes and the resulting high-brightness gamma-ray pulses.

[0104] The present invention will be further described below in conjunction with Specific Example 1. It should be understood that this example is intended only to illustrate the present invention and is not intended to limit the scope of the present invention. The experimental methods in the following examples, for which specific conditions are not specified, are generally carried out under conventional conditions or under conditions recommended by the manufacturer.

[0105] Example 1

[0106] This embodiment adopts Figure 1 The embodiment includes an accelerator, a vacuum target chamber and a target element.

[0107] The accelerator is used to provide a relativistic high-current drive electron beam. The relativistic high-current electron beam has a commonly used Gaussian distribution, a beam length of 4 microns, a beam spot radius of 2 microns, a peak current of approximately 500 kiloamperes, a peak energy of 5 GeV, an energy spread of 5%, and an emittance of 4 milliradians.

[0108] The vacuum target chamber is used to provide a vacuum environment for the interaction between the electron beam and the target.

[0109] The target element has a bottom (inlet) diameter D of 4 microns, a top (exit) diameter d of 0.6 microns, and a longitudinal length L along the electron beam propagation direction of approximately 200 microns. The target element density is the solid density. Taking the current electron beam parameters as an example, the target element's entrance and exit diameters and length can be varied proportionally according to (Dd) / 2L to 0.01. To effectively focus the electron beam, the target element entrance dimension should be greater than or equal to the initial beam spot size, while the exit dimension should be less than or equal to one-tenth of the initial beam spot size.

[0110] The relativistic high current drives the electron beam to be incident on the target element, causing the electrons to flow back on the inner wall surface of the target, generating an ultra-strong self-generated angular magnetic field, such as Figure 2 As shown in the figure, the electron beam converges towards the center under the force of the magnetic field; as the diameter of the cone target decreases, the beam focusing becomes more significant. After sufficient focusing, the driven electron beam will be focused to less than one tenth of the initial diameter (i.e., less than 0.4 microns), thereby increasing its density by more than 2 orders of magnitude (reaching 10 23per cubic centimeter, which is close to the density of solids). Such high-density electron beams can replace high-intensity lasers to study extreme strong field physics. For example, when combined with solid conversion targets, they can induce up to 10 14 Ultra-strong quasi-static fields above volts / meter (equivalent to light intensity exceeding 10 22 Watts / square centimeter of laser pulse electric field strength), thereby triggering the strong-field QED effect and radiating a large number of collimated gamma photons. This is expected to break through the existing radiation mechanism and efficiently produce tightly focused ultra-bright gamma-ray sources.

[0111] Figure 3 The effective focusing field (E eff =E+v×B) and the direction of the focusing force on the electron beam. Figure 4 The energy spectrum distribution of the electron beam before and after focusing is given. Figure 5 The lateral density distribution of the electron beam before and after focusing is given. Figure 6 The trajectory diagram of the electron beam focusing in the cone target is given, and the results clearly show that the beam spot can be reduced to less than one tenth of the initial size after the electron beam interacts with the target element. Such a high-density electron beam will be able to stimulate extreme strong field physics research and efficiently produce a large number of collimated gamma photons with submicron beam spots and a high conversion efficiency of more than 60%. In addition, the parameters of the focused electron beam can be adjusted by changing the parameters of the target element; the parameters of the radiated gamma-ray beam can be adjusted by changing the parameters of the conversion target. It is worth mentioning that the device is also suitable for focusing other charged particle beams, such as positively charged positron beams, such as Figure 7 The focusing trajectory of the positron beam is shown. It should be noted that the direction of the electromagnetic field excited by the positively charged particle beam will change accordingly.

[0112] The device for generating ultra-high-density submicron high-current electron beams of the present invention has the following advantages:

[0113] (a) Simple, compact, and low-cost device: The hollow conical target element and conversion target required by the present invention can be manufactured using mature technologies such as 3D printing or precision machining. These technologies are already well-established and can be used to manufacture the required target elements. Vacuum target chamber equipment technology is also highly mature and can be ordered directly from manufacturers.

[0114] (b) Generating a high-energy relativistic electron beam with a submicron spot and near-solid-state density: Using conventional quadrupole magnets or plasma lenses, it is difficult to focus a high-current, small-sized relativistic particle beam to a submicron spot and increase its density to near-solid-state density. The method of the present invention can produce a high-energy electron beam with a submicron spot and near-solid-state density, overcoming the limitations of conventional particle beam focusing techniques. Furthermore, the device of the present invention is also suitable for focusing other charged particle beams, such as positron beams. Therefore, this method is expected to have broad application prospects and research value.

[0115] (c) Opening up new avenues for physics research: Extreme-field physics research typically relies on high-intensity laser fields, but the high-density electron beams obtained using the method of the present invention are expected to replace high-intensity lasers to study extreme-field physics. For example, the use of a focused high-density electron beam interacting with a solid conversion target can produce an ultra-strong quasi-static field and stimulate a strong-field QED effect, making it possible to conduct extreme-field physics research without a laser field. In addition, over 60 percent of the electron beam energy can be efficiently converted into high-energy gamma rays, and the resulting spot size is only about 0.2 microns, thereby increasing the brightness of the gamma-ray source by several orders of magnitude. Therefore, this will not only open up new avenues for high-intensity field physics research, but also has the potential to achieve an unprecedentedly efficient and extremely bright gamma-ray source.

[0116] (d) Simple operation: The method of the present invention only requires that the driving electron beam be incident into the target element in a set direction. The electron beam self-focusing is achieved through the strong surface magnetic field induced by the interaction between the electron beam and the target element, without the need for other additional equipment, so it is a simple and efficient method. The focused high-density electron beam can directly interact with the conversion target to study high-intensity field physics and generate high-brightness gamma-ray sources, or be used for other research, such as high-order nonlinear scattering processes of strong lasers and electrons, particle beam and particle beam collision processes, and the excitation of high-density plasma acceleration and radiation. Therefore, the method of the present invention has the advantages and characteristics of being small and compact, low cost, high simplicity, high stability and strong practicality.

[0117] All documents mentioned in this application are considered to be included in their entirety in the disclosure of this application so that they can be used as a basis for modification when necessary. In addition, it should be understood that after reading the above disclosure of this application, those skilled in the art may make various changes or modifications to this application, and these equivalent forms also fall within the scope of protection claimed in this application.

Claims

1. A device for generating ultra-high density submicron high current electron beam, characterized in that: include A vacuum target chamber, wherein the vacuum target chamber is used to provide a vacuum environment for interaction between the electron beam and the target; A particle accelerator is placed outside the vacuum target chamber and is used to provide a relativistic high-current electron beam; a target element, placed in the vacuum target chamber and in the shape of a hollow cone, for focusing the electron beam to less than one tenth of its initial diameter; The electron beam provided by the particle accelerator is incident on the target element, and refluxes through the target wall of the target element to generate an ultra-strong self-generated magnetic field, thereby focusing the electron beam itself; after an interaction distance of hundreds of microns, the electron beam is compressed to less than one-tenth of its initial diameter, reaching a submicron beam spot, thereby increasing its density by more than two orders of magnitude, reaching a near-solid density.

2. The device for generating ultra-high density submicron high current electron beam according to claim 1, characterized in that: The interior of the target element is hollow, the central axis is parallel to the propagation direction of the electron beam, and the length L along the central axis is adjustable within the range of 100 to 10,000 microns; The diameter D of the target element at the entrance opening is greater than or equal to the initial electron beam spot size and is adjusted within the range of 2 microns to 200 microns; The diameter d of the exit opening of the target element is smaller than a quarter of the initial electron beam spot size and is adjusted within the range of 0.1 to 10 microns.

3. The device for generating ultra-high density submicron high current electron beam according to claim 1, characterized in that: The energy of the relativistic high-current electron beam is above 100 mega-electron-volts, the current intensity is above 10 kiloamperes, the beam spot size of the relativistic high-current electron beam is in the range of 2 microns to 100 microns, and the pulse length of the relativistic high-current electron beam is in the range of 2 microns to 100 microns.

4. The device for generating ultra-high density submicron high current electron beam according to any one of claims 1 to 3, characterized in that: Also includes: a conversion target, placed in the vacuum target chamber and located behind the target element; The electron beam focused by the target element interacts with the conversion target to generate an ultra-strong quasi-static field, thereby stimulating a strong-field QED effect and generating a collimated ultra-high brightness gamma-ray source; or scattered laser pulses, provided by another laser; The scattered laser pulse is incident on a vacuum target chamber and interacts with the focused electron beam to study the high-order nonlinear scattering physical process; or another high-energy particle beam, provided by another particle accelerator; The other high-energy particle beam is incident into the vacuum target chamber and interacts with the focused electron beam to study the basic physics of the particle collision process.

5. The device for generating ultra-high density submicron high current electron beam according to claim 4, characterized in that: The thickness of the conversion target is adjusted within a range of 10 μm to 100 μm.

6. The device for generating ultra-high density submicron high current electron beam according to claim 4, characterized in that: The number density of the conversion targets is comparable to the density of the focused electron beam.

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