Methods for adjusting the electron beam divergence angle, methods and apparatus for adjusting the field of view of an all-optical inverse Compton scattering source
By adjusting the initial transverse phase space distribution and transverse phase space evolution of the electron beam, the problem of field-of-view adjustment of the all-optical inverse Compton scattering source was solved, realizing flexible adjustment and precise control of the field of view, and expanding its application boundaries.
Patent Information
- Application Number
- CN202510990282.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-17
- Publication Date
- 2026-03-06
- Estimated Expiration
- 2045-07-17
AI Technical Summary
Existing all-optical inverse Compton scattering sources have a small field of view and are difficult to adjust precisely, which limits their wide applicability and flexibility.
By adjusting the initial transverse phase space distribution and transverse phase space evolution of the electron beam, the divergence angle of the electron beam is controlled, and the field of view of the all-optical inverse Compton scattering source is adjusted using a two-stage gas target and plasma density distribution.
It achieves precise adjustment of the field of view of the all-optical inverse Compton scattering source, meets the sample size requirements of different application scenarios, and improves its practicality in fields such as medical imaging and materials analysis.
Smart Images
Figure CN121001251B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of laser wake accelerator and light source technology, and more specifically, to a method for adjusting the divergence angle of an electron beam, and a method and apparatus for adjusting the field of view of an all-optical inverse Compton scattering source. Background Technology
[0002] Laser wakewave accelerators, as a novel accelerator technology, possess an acceleration gradient far exceeding that of traditional radio frequency accelerators. This significantly reduces the size and cost of accelerator devices, forming a core foundation for the development of compact light sources and particle colliders. All-optical inverse Compton scattering sources driven by laser wakewave accelerators can generate high-brightness X-rays in desktop-scale devices, featuring micrometer-scale source dimensions and femtosecond-scale pulse lengths. This provides excellent spatiotemporal resolution for ultra-high-definition imaging, ultrafast dynamic diagnostics, and other fields, and holds immense application potential in medical diagnosis, materials analysis, and nuclear physics research.
[0003] However, the field of view of existing all-optical inverse Compton scattering sources is small and difficult to adjust precisely, which imposes strict limitations on sample size and severely restricts the breadth and flexibility of their practical applications. Summary of the Invention
[0004] To address at least one of the aforementioned problems, this application proposes a method for adjusting the divergence angle of an electron beam, a method for adjusting the field of view of an all-optical inverse Compton scattering source, and an apparatus.
[0005] According to a first aspect of this application, at least one embodiment of this application provides a method for adjusting the divergence angle of an electron beam, the method comprising: generating an electron beam and adjusting the initial transverse phase space distribution of the electron beam; adjusting the evolution of the transverse phase space of the electron beam to adjust the divergence angle of the electron beam.
[0006] For example, in some embodiments of this application, generating an electron beam and adjusting the initial transverse phase space distribution of the electron beam includes: controlling a driving laser to ionize a first gas target to generate plasma; controlling electrons to be injected into the wake field of the plasma using an ionization injection mechanism to form an initial electron beam; and adjusting the initial transverse phase space distribution of the initial electron beam to generate an electron beam with an initial transverse phase space distribution that is either elliptical unsaturated or elliptical saturated.
[0007] For example, in some embodiments of this application, adjusting the evolution of the transverse phase space of the electron beam to adjust the divergence angle of the electron beam includes: controlling the driving laser to ionize the second gas target to generate plasma with a uniform density distribution, a gradually increasing density distribution, a decreasing density distribution, or a rapidly increasing density distribution; and controlling the electron beam to travel through the plasma to adjust the evolution of the transverse phase space of the electron beam, thereby adjusting the divergence angle of the electron beam.
[0008] For example, in some embodiments of this application, the second gas target includes a supersonic nozzle or a low-flow-rate gas chamber. The control-driven laser ionization of the second gas target to generate plasma with a uniform density distribution, a gradually increasing density distribution, a decreasing density distribution, or a steeply increasing density distribution includes: horizontally placing the supersonic nozzle or using the low-flow-rate gas chamber with a uniform diameter to generate plasma with a uniform density distribution, so that the electron beam obtains a reference divergence angle; firstly, obliquely placing the supersonic nozzle or using the low-flow-rate gas chamber with a narrowed diameter to generate plasma with a gradually increasing density distribution, thereby increasing the divergence angle of the electron beam; secondly, obliquely placing the supersonic nozzle or using the low-flow-rate gas chamber with an expanded diameter to generate plasma with a decreasing density distribution, thereby decreasing the divergence angle of the electron beam; and placing a sheet-like or filamentous object above the supersonic nozzle to generate plasma with a steeply increasing density distribution, thereby increasing the divergence angle of the electron beam.
[0009] For example, in some embodiments of this application, the first oblique placement of the supersonic nozzle includes: placing the supersonic nozzle such that the height of its outlet from the driving laser gradually decreases along the transmission direction of the driving laser; the second oblique placement of the supersonic nozzle includes: placing the supersonic nozzle such that the height of its outlet from the driving laser gradually increases along the transmission direction of the driving laser.
[0010] For example, in some embodiments of this application, adjusting the evolution of the transverse phase space of the electron beam to adjust the divergence angle of the electron beam includes: controlling the driving laser to ionize the second gas target to generate a plasma with a uniform density distribution when the initial transverse phase space distribution of the electron beam is in an elliptical unsaturated state; controlling the electron beam to travel through the plasma with a uniform density distribution; and adjusting the length of the second gas target to adjust the divergence angle of the electron beam.
[0011] According to a second aspect of this application, at least one embodiment of this application provides a method for adjusting the field of view of an all-optical inverse Compton scattering source, comprising: acquiring an electron beam generated by the method described in any one of the first aspects; controlling the electron beam to undergo inverse Compton scattering with a scattered laser pulse to generate an all-optical inverse Compton scattering source; and changing the field of view of the all-optical inverse Compton scattering source by changing the divergence angle of the electron beam.
[0012] According to a third aspect of this application, at least one embodiment of this application provides an apparatus for adjusting the field of view of an all-optical inverse Compton scattering source. The apparatus is used to perform the method described in the second aspect. The apparatus includes: a plasma source comprising an electron injection stage gas target and an electron acceleration stage gas target; a driving laser system for outputting a driving laser to ionize the electron injection stage gas target, generating an electron beam whose initial transverse phase space distribution is an unsaturated ellipse or a saturated ellipse, and further for outputting the driving laser to ionize the electron acceleration stage gas target, generating a plasma with a uniform, slowly increasing, decreasing, or steeply increasing density distribution, such that the electron beam travels through the plasma to adjust the divergence angle of the electron beam; and a scattering laser system for outputting scattering laser pulses to interact with the electron beam after adjusting the divergence angle to generate an all-optical inverse Compton scattering source.
[0013] For example, in some embodiments of this application, the electron accelerator gas target includes a supersonic nozzle or a low-flow-rate gas chamber, wherein: when the supersonic nozzle is horizontally placed or the low-flow-rate gas chamber has a uniform diameter, the electron accelerator gas target generates plasma with a uniform density distribution; when the supersonic nozzle is first obliquely placed or the low-flow-rate gas chamber has a constricted diameter, the electron accelerator gas target generates plasma with a gradually increasing density distribution; when the supersonic nozzle is first obliquely placed, the distance from the outlet of the supersonic nozzle to the driving laser gradually decreases along the transmission direction of the driving laser; when the supersonic nozzle is second obliquely placed or the low-flow-rate gas chamber has an expanding diameter, the electron accelerator gas target generates plasma with a decreasing density distribution; when the supersonic nozzle is second obliquely placed, the distance from the outlet of the supersonic nozzle to the driving laser gradually increases along the transmission direction of the driving laser; when a sheet-like or filamentous object is placed above the supersonic nozzle, the electron accelerator gas target generates plasma with a steeply increasing density distribution.
[0014] For example, in some embodiments of this application, the electron accelerator gas target includes a control component for adjusting the length of the electron accelerator gas target to adjust the divergence angle of the electron beam when the initial transverse phase space distribution of the electron beam is in an elliptical unsaturated state.
[0015] Through the above exemplary embodiments, this application provides a method for adjusting the electron beam divergence angle, a method and apparatus for adjusting the field of view of an all-optical inverse Compton scattering source, which addresses the current field of view problem faced by all-optical inverse Compton scattering sources. Starting from the physical mechanism of ray generation, it adjusts the electron beam divergence angle at the ray generation point by adjusting the initial transverse phase space distribution and the evolution process of the transverse phase space of the electron beam generated by the laser wake accelerator, thereby realizing the field of view adjustment of the all-optical inverse Compton scattering source. The solution is simple, can be implemented based on existing laser wake accelerator technology, and has high engineering feasibility.
[0016] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description
[0017] The above and other objects, features, and advantages of this application will become more apparent from the detailed description of exemplary embodiments with reference to the accompanying drawings. The drawings described below are merely some embodiments of this application and are not intended to limit the scope of this application.
[0018] Figure 1 A flowchart illustrating a method for adjusting the divergence angle of an electron beam, as shown in an exemplary embodiment;
[0019] Figure 2 The diagram shows different states of the initial transverse phase space distribution after electron beam injection.
[0020] Figure 3 A schematic diagram of a plasma generation method with uniform density distribution is shown.
[0021] Figure 4 A schematic diagram of a plasma generation mode with a gradually increasing density distribution is shown.
[0022] Figure 5 A schematic diagram showing the generation mode of density-decreasing distribution plasma is shown;
[0023] Figure 6 A schematic diagram showing the generation mode of plasma with a sharp increase in density distribution is shown;
[0024] Figure 7 A schematic diagram illustrating the evolution of the electron beam's transverse phase space in the initial unsaturated elliptical transverse phase space state;
[0025] Figure 8 A flowchart of a method for adjusting the field of view of an all-optical inverse Compton scattering source is shown.
[0026] Figure 9 A schematic diagram of the plasma source is shown;
[0027] Figure 10The transverse phase space of the electron beam and the beam spot of the scattering source are shown in a plasma with uniform density distribution.
[0028] Figure 11 The transverse phase space of the electron beam and the beam spot of the scattering source are shown in a plasma with a gradually increasing density distribution.
[0029] Figure 12 The transverse phase space of the electron beam and the beam spot of the scattering source are shown in a plasma with a decreasing density distribution. Detailed Implementation
[0030] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted.
[0031] The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced without one or more of these specific details, or other methods, components, materials, devices, etc. In these cases, well-known structures, methods, devices, implementations, materials, or operations will not be shown or described in detail.
[0032] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.
[0033] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.
[0034] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of exemplary embodiments, and the modules or processes in the drawings are not necessarily essential for implementing this application, and therefore cannot be used to limit the scope of protection of this application.
[0035] An all-optical inverse Compton scattering source is generated by the inverse Compton scattering of a high-energy electron beam produced by a laser wake accelerator and a scattered laser pulse. Its field-of-view performance directly depends on the electron beam parameters. Specifically, the field of view can be approximated as the convolution of the electron beam divergence angle and the field of view of a single electron beam. Therefore, adjusting the electron beam divergence angle is the core approach to achieving field-of-view adjustment.
[0036] The divergence angle of the electron beam is determined by both the initial transverse phase space distribution during its injection process and the transverse phase space evolution during acceleration.
[0037] During the injection process, the initial transverse phase space distribution of the electron beam is controlled by the ionization injection mechanism. Due to the mixing phenomenon of transverse phase space, the change of injection distance will cause the phase space ellipse to be saturated or unsaturated.
[0038] During acceleration, the lateral focusing force on the electron beam is proportional to the plasma density, and the lateral phase space evolution can be adjusted by constructing different plasma density distributions.
[0039] Based on the above principles, this application proposes a method for precisely adjusting the field of view of an all-optical inverse Compton scattering source by adjusting the initial transverse phase space distribution of the electron beam and the evolution of the acceleration process.
[0040] Figure 1 A flowchart illustrating a method for adjusting the divergence angle of an electron beam, as shown in an exemplary embodiment.
[0041] like Figure 1 As shown, the method for adjusting the divergence angle of the electron beam generated by the laser wake accelerator includes steps S1 and S2.
[0042] Step S1: Generate an electron beam and adjust the initial transverse phase space distribution of the electron beam.
[0043] Specifically, it includes:
[0044] S1.1, control the driving laser to ionize the first gas target to generate plasma.
[0045] S1.2, control electrons are injected into the wake field of the plasma using an ionization injection mechanism to form an initial electron beam.
[0046] S1.3, Adjusting the initial transverse phase space distribution of the initial electron beam. By adjusting the length of this stage, two states of the electron beam can be achieved: an initial transverse phase space distribution that is either an unsaturated ellipse or a saturated ellipse. Figure 2 As shown.
[0047] Due to the transverse phase mixing phenomenon during ionization injection, the transverse phase space ellipse is gradually filled with injected electrons as the electron injection distance increases. In ionization injection, electrons originate from atoms with high ionization potential energy. Therefore, by controlling the distribution region of high ionization potential energy atoms, the injection distance can be adjusted, thereby regulating the initial transverse phase space distribution of the electron beam.
[0048] Step S2: Adjust the evolution of the transverse phase space of the electron beam to adjust the divergence angle of the electron beam.
[0049] Specifically, it includes:
[0050] S2.1 controls the laser to ionize the second gas target to generate plasma with a uniform density distribution, a gradually increasing density distribution, a decreasing density distribution, or a rapidly increasing density distribution.
[0051] S2.2, controlling the electron beam to travel through the plasma to adjust the evolution of the transverse phase space of the electron beam, thereby adjusting the divergence angle of the electron beam.
[0052] During electron beam acceleration, since the lateral focusing force on the electron beam is proportional to the plasma density at its location, the lateral phase space evolution process can be manipulated by constructing different plasma density distributions.
[0053]
[0054] Among them, F r The lateral focusing force is g, which is a constant, and n is n. e Let be the plasma density, e be the charge of a single electron, ∈ be the vacuum permittivity, and r be the distance between the transverse oscillation of the electron and its equilibrium position.
[0055] The second gas target includes a supersonic nozzle or a low-flow-rate gas chamber. For electron beams with an initial transverse phase space distribution that is either elliptic unsaturated or elliptic saturated, this application employs four types of plasma density distributions (uniform density distribution, gradually increasing density distribution, decreasing density distribution, and abruptly increasing density distribution) to manipulate the transverse phase space evolution of the electron beam:
[0056] (1) Uniform density distribution type: A horizontally placed supersonic nozzle or a low-velocity gas chamber with a uniform pipe diameter, such as... Figure 3 As shown, a plasma with a uniform density distribution is generated. In a plasma with a uniform density distribution, the final divergence angle of the electron beam in the initial transverse phase space elliptic saturation state (i.e., the divergence angle of the electron beam at the point of ray generation) is obtained, which is the reference divergence angle of the electron beam; combined with the scattered laser, the field of view of the all-optical inverse Compton scattering source is obtained, which is the reference field of view.
[0057] (2) Gradually varying density distribution: A first obliquely placed supersonic nozzle or a low-velocity gas chamber with a narrowed tube diameter is used to generate plasma with a gradually varying density distribution to increase the divergence angle of the electron beam. The first obliquely placed supersonic nozzle is positioned such that the distance between its outlet and the height of the driving laser gradually decreases along the direction of laser propagation. Figure 4 As shown. In plasmas with a gradually increasing density distribution, the divergence angle of the electron beam increases compared to the reference electron beam due to the increased lateral focusing force, which in turn increases the field of view of the all-optical inverse Compton scattering source.
[0058] (3) Density Decreasing Distribution Type: A second obliquely placed supersonic nozzle or a low-velocity gas chamber with expanded pipe diameter is used to generate plasma with a decreasing density distribution to reduce the divergence angle of the electron beam. The second obliquely placed supersonic nozzle includes: positioning the supersonic nozzle such that the height of its outlet from the driving laser gradually increases along the transmission direction of the driving laser, such as... Figure 5 As shown. In plasmas with decreasing density distribution, the divergence angle of the electron beam is reduced compared to the reference divergence angle due to the reduced lateral focusing force on the electron beam, thereby reducing the field of view of the all-optical inverse Compton scattering source.
[0059] (4) Abrupt Density Increase Distribution Type: A thin sheet or filamentous object is placed above the supersonic nozzle, such as... Figure 6 As shown, a plasma with a steeply increasing density distribution is generated to increase the divergence angle of the electron beam. In a plasma with a steeply increasing density distribution, the divergence angle of the electron beam increases compared to the reference electron beam divergence angle due to the increased lateral focusing force on the electron beam, thereby increasing the field of view of the all-optical inverse Compton scattering source.
[0060] According to the example embodiment, for an electron beam whose initial transverse phase space is in an elliptical unsaturated state, during acceleration, as the transverse phase space of the electron beam rotates, the divergence angle of the electron beam exhibits periodic oscillation characteristics, such as... Figure 7 As shown. This application utilizes this feature to control the driving laser to ionize the second gas target to generate a plasma with a uniform density distribution, and to control the electron beam to travel through the plasma with a uniform density distribution; by adjusting the length of the second gas target to adjust the divergence angle of the electron beam, i.e., the length of the electron accelerator stage gas target, the final divergence angle of the electron beam can be manipulated, and then combined with the scattered laser, the field of view of the all-optical inverse Compton scattering source can be adjusted.
[0061] This application also provides a method for adjusting the field of view of a phantom optical inverse Compton scattering source, the flowchart of which is shown below. Figure 8 As shown.
[0062] The method for adjusting the field of view of an all-optical inverse Compton scattering source includes: S8.1, obtaining an electron beam generated by the method described above for adjusting the electron beam divergence angle, i.e., an electron beam obtained through an electron injection stage and an electron acceleration stage. S8.2, controlling the electron beam to undergo inverse Compton scattering with the scattered laser pulse to generate an all-optical inverse Compton scattering source, and changing the field of view of the all-optical inverse Compton scattering source by changing the divergence angle of the electron beam.
[0063] This application also provides an apparatus for adjusting the field of view of an all-optical inverse Compton scattering source, for performing a method for adjusting the field of view of an all-optical inverse Compton scattering source. The apparatus includes: a plasma source, a driving laser system, and a scattering laser system.
[0064] The plasma source includes an electron injection stage gas target and an electron acceleration stage gas target, such as... Figure 9 As shown.
[0065] In the two-stage gas target structure, the core function of the first stage (electron injection stage) is to inject electrons into the plasma wake field through the ionization injection mechanism, focusing on controlling the initial transverse phase space distribution (saturated or unsaturated state) of the electron beam; while the core task of the second stage (electron acceleration stage) is to use the plasma wake field to continuously accelerate the injected electrons to a high-energy state, and at the same time, by adjusting the plasma density distribution or length of this stage, the evolution process of the transverse phase space of the electron beam can be further manipulated.
[0066] The driving laser system is used to output a driving laser to ionize an electron injection stage gas target, generating an electron beam. The initial transverse phase space distribution of the electron beam is an ellipse in an unsaturated state or an ellipse in a saturated state. The driving laser system is also used to output a driving laser to ionize an electron acceleration stage gas target, generating plasma with a uniform, slowly varying, falling, or steeply varying density distribution, allowing the electron beam to travel through the plasma and thus adjusting the divergence angle of the electron beam.
[0067] According to an example embodiment, the electron accelerator gas target includes a supersonic nozzle or a low-flow-rate gas chamber.
[0068] When the supersonic nozzle is horizontally positioned or the low-flow-rate gas chamber has a uniform diameter, the electron accelerator gas target produces plasma with a uniform density distribution. When the supersonic nozzle is positioned at a first angle or the low-flow-rate gas chamber has a converging diameter, it produces plasma with a gradually increasing density distribution. The first angled placement means that the distance from the supersonic nozzle's exit to the driving laser gradually decreases along the laser's propagation direction. When the supersonic nozzle is positioned at a second angle or the low-flow-rate gas chamber has an expanding diameter, the electron accelerator gas target produces plasma with a decreasing density distribution. The second angled placement means that the distance from the supersonic nozzle's exit to the driving laser gradually increases along the laser's propagation direction. When a sheet-like or filamentous object is placed above the supersonic nozzle, the electron accelerator gas target produces plasma with a steeply increasing density distribution.
[0069] According to some embodiments, the flow rate of the low-flow-rate gas chamber needs to balance gas distribution stability, plasma density control, and electron beam acceleration efficiency, with a recommended range of 50–300 m / s. However, in practical applications, optimization is required based on specific experimental conditions. Therefore, this application uses this as an example only, but is not limited thereto.
[0070] According to an example embodiment, the electron accelerator stage gas target may also include control components.
[0071] The control unit is used to adjust the plasma length in the electron accelerator stage gas target to adjust the divergence angle of the electron beam when the initial transverse phase space distribution of the electron beam is an ellipse in an unsaturated state.
[0072] The scattered laser system is used to output scattered laser pulses to interact with the electron beam after adjusting the divergence angle to generate an all-optical inverse Compton scattering source.
[0073] This application provides a method for adjusting the divergence angle of an electron beam, a method and apparatus for adjusting the field of view of an all-optical inverse Compton scattering source, which realizes flexible adjustment of the field of view of the all-optical inverse Compton scattering source, solving the problem of fixed and limited field of view in the prior art. Through precise adjustment of the two-stage gas target structure and plasma density distribution, continuous or stepwise adjustment of the field of view can be achieved to meet the sample size requirements of different application scenarios. The adjustment mechanism is based on the physical evolution law of the transverse phase space of the electron beam, with a clear principle and high controllability, making it suitable for engineering applications. It improves the practicality of the all-optical inverse Compton scattering source in medical imaging, materials analysis and other fields, and expands its application boundaries.
[0074] This application further elaborates on the case of an electron beam in an initial transverse phase space elliptic saturation state, with reference to specific embodiments.
[0075] In a specific embodiment, the divergence angle of the electron beam is obtained using OSIRIS, an authoritative and commonly used numerical simulation software in the field of laser wake acceleration, and the field of view of the all-optical inverse Compton scattering source is obtained using CAIN, an authoritative Monte Carlo simulation software for the inverse Compton scattering process.
[0076] In the simulation, the driving laser parameters were: pulse energy 1 joule, pulse length 35 femtoseconds, and focal size 15 micrometers; the scattering laser parameters were: pulse energy 0.5 joules, pulse length 500 femtoseconds, and focal size 10 micrometers. Figure 10-12 The electron beams in the initial transverse phase space elliptic saturation state are shown in the electron injection stage with a uniform density distribution (e.g., ...). Figure 10 As shown), density gradually increasing distribution pattern (such as...) Figure 11 As shown) and density decreasing distribution type (such as Figure 12 (As shown) In the plasma, when the center energy of the electron beam reaches 100MeV, the final transverse phase space distribution of the electron beam and the beam spot of the obtained all-optical inverse Compton scattering source are shown.
[0077] exist Figure 10-12 In the experiment, the final divergence angles of the electron beam were 13 milliradians (uniform density distribution), 18 milliradians (gradually increasing density distribution), and 8 milliradians (decreasing density distribution), respectively, while the field of view of the all-optical inverse Compton scattering source were 32 milliradians (uniform density distribution), 44 milliradians (gradually increasing density distribution), and 22 milliradians (decreasing density distribution), respectively. Therefore, the field of view of the all-optical inverse Compton scattering source was effectively adjusted.
[0078] It should be clearly understood that this application describes how specific examples are formed and used, but this application is not limited to any details of these examples. Rather, based on the teachings of the disclosure of this application, these principles can be applied to many other embodiments.
[0079] Furthermore, it should be noted that the above figures are merely illustrative representations of the processes included in the method according to exemplary embodiments of this application, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.
[0080] Exemplary embodiments of this application have been specifically shown and described above. It should be understood that this application is not limited to the detailed structures, arrangements, or implementation methods described herein; rather, this application is intended to cover various modifications and equivalent arrangements that fall within the objectives and scope of the appended claims.
Claims
1. A method of adjusting an electron beam divergence angle, characterized by, The method comprises: generating an electron beam and adjusting an initial transverse phase space distribution of the electron beam, comprising: controlling a driving laser to ionize a first gas target to generate a plasma; controlling electrons to be injected into a wakefield of the plasma by an ionization injection mechanism to form an initial electron beam; adjusting the initial transverse phase space distribution of the initial electron beam to generate an electron beam with an initial transverse phase space distribution in an elliptical unsaturated state or an elliptical saturated state; adjusting an evolution of a transverse phase space of the electron beam to adjust a divergence angle of the electron beam, comprising: in a case where the initial transverse phase space distribution of the electron beam is in an elliptical unsaturated state, controlling a driving laser to ionize a second gas target to generate a plasma with a uniform density distribution; controlling the electron beam to pass through the plasma with the uniform density distribution; adjusting a length of the second gas target to adjust the divergence angle of the electron beam.
2. The method of claim 1, wherein, The adjusting of the evolution of the transverse phase space of the electron beam to adjust the divergence angle of the electron beam comprises: controlling a driving laser to ionize a second gas target to generate a plasma with a uniform density distribution, a slowly-rising distribution, a falling distribution or a steeply-rising distribution; controlling the electron beam to pass through the plasma to adjust the evolution of the transverse phase space of the electron beam, thereby adjusting the divergence angle of the electron beam.
3. The method of claim 2, wherein, The second gas target comprises a supersonic nozzle or a low-flow-rate gas chamber, and the controlling of the driving laser to ionize the second gas target to generate the plasma with the uniform density distribution, the slowly-rising distribution, the falling distribution or the steeply-rising distribution comprises: horizontally placing the supersonic nozzle or using the low-flow-rate gas chamber with a uniform tube diameter to generate the plasma with the uniform density distribution, so that the electron beam obtains a reference divergence angle; first obliquely placing the supersonic nozzle or using the low-flow-rate gas chamber with a tube diameter contraction to generate the plasma with the slowly-rising distribution, so that the divergence angle of the electron beam is increased; second obliquely placing the supersonic nozzle or using the low-flow-rate gas chamber with a tube diameter expansion to generate the plasma with the falling distribution, so that the divergence angle of the electron beam is decreased; placing a sheet-shaped or filament-shaped object above the supersonic nozzle to generate the plasma with the steeply-rising distribution, so that the divergence angle of the electron beam is increased.
4. The method of claim 3, wherein the first oblique placement of the supersonic nozzle comprises placing the supersonic nozzle such that a height of an outlet of the supersonic nozzle from the driving laser gradually decreases along a transmission direction of the driving laser; the second oblique placement of the supersonic nozzle comprises placing the supersonic nozzle such that the height of the outlet of the supersonic nozzle from the driving laser gradually increases along the transmission direction of the driving laser.
5. A method for adjusting the field of view of a plenoptic inverse Compton scattering source, characterized in that, comprising: obtaining an electron beam generated by the method of any one of claims 1-4; controlling the electron beam to undergo inverse Compton scattering with a scattering laser pulse to generate a full-optical inverse Compton scattering source, and changing a field of view of the full-optical inverse Compton scattering source by changing the divergence angle of the electron beam.
6. An apparatus for adjusting the field of view of a plenoptic inverse Compton scattering source, characterized in that, The device is used to perform the method of claim 5, and the device comprises: a plasma source comprising an electron injection stage gas target and an electron acceleration stage gas target; a driving laser system for outputting driving laser to ionize the electron injection stage gas target to generate an electron beam, the initial transverse phase space distribution of the electron beam being an unsaturated ellipse or a saturated ellipse, and further for outputting driving laser to ionize the electron acceleration stage gas target to generate plasma with a density distribution of uniform distribution, slowly rising distribution, falling distribution or steep rising distribution, so that the electron beam passes through the plasma to adjust the divergence angle of the electron beam; a scattering laser system for outputting scattering laser pulses to undergo inverse Compton scattering with the electron beam after the divergence angle is adjusted to generate a full-optical inverse Compton scattering source.
7. The apparatus of claim 6, wherein, The electron acceleration stage gas target comprises: a supersonic nozzle or a low flow rate gas chamber, wherein: in the case of horizontally placing the supersonic nozzle or the tube diameter of the low flow rate gas chamber being uniform structure, the electron acceleration stage gas target generates plasma with a density distribution of uniform distribution; in the case of first obliquely placing the supersonic nozzle or the tube diameter of the low flow rate gas chamber being contraction structure, the electron acceleration stage gas target generates plasma with a density distribution of slowly rising distribution, and in the case of first obliquely placing the supersonic nozzle, the height of the outlet of the supersonic nozzle from the driving laser gradually decreases along the transmission direction of the driving laser; in the case of second obliquely placing the supersonic nozzle or the tube diameter of the low flow rate gas chamber being expansion structure, the electron acceleration stage gas target generates plasma with a density distribution of falling distribution, and in the case of second obliquely placing the supersonic nozzle, the height of the outlet of the supersonic nozzle from the driving laser gradually increases along the transmission direction of the driving laser; in the case of placing a sheet-shaped or filament-shaped object above the supersonic nozzle, the electron acceleration stage gas target generates plasma with a density distribution of steep rising distribution.
8. The apparatus of claim 6, wherein, The electron acceleration stage gas target comprises: a control component for adjusting the length of the electron acceleration stage gas target to adjust the divergence angle of the electron beam in the case of the initial transverse phase space distribution of the electron beam being an unsaturated ellipse.