Medium laser acceleration system and method

Abstract

The application discloses a medium laser acceleration system and method, the medium laser acceleration system comprises a laser system for providing a high-power laser pulse; a particle injection source for providing a charged particle beam; a medium laser acceleration device for generating a high-gradient acceleration electric field; an information acquisition module for acquiring parameters of the particle beam; a diagnosis module for diagnosing a state of the particle beam and electromagnetic field transmission characteristics of the medium laser acceleration device; and a controller connected to an output end of the diagnosis module and a controlled end of the laser system, for acquiring a preset energy value of the high-energy particle beam and determining a target power and time sequence of the laser pulse according to the preset energy value. The application further provides a medium laser acceleration method based on the above medium laser acceleration system. Compared with prior art solutions, the application can provide a high-energy particle beam while reducing the size of a particle accelerator.

Description

[0001] Medium laser acceleration systems and methods Technical Field

[0002] This invention relates to the field of particle accelerator technology, and more particularly to a medium laser acceleration system and method. Background Technology

[0003] Particle accelerators are devices used to accelerate charged particles (such as electrons and protons) to extremely high energy levels. They have important applications in basic scientific research such as particle physics, astrophysics, materials science, and nanoscience, as well as in fields such as semiconductor integrated circuits and medicine.

[0004] Traditional particle accelerators include ring accelerators and linear accelerators. In a ring accelerator, accelerated particles move within a circular structure with a certain energy, and the circular trajectory of the particles is controlled by a dipole magnet. The structure of a ring accelerator can continuously accelerate particles, and the particles will repeatedly pass through the same position on the circular trajectory, but the energy of the particles is dissipated through synchrotron radiation. Modern radio frequency linear induction accelerators use one or more radio frequency cavities to accelerate charged particles. The energy from an external radio frequency power source is coupled through a coupler to generate electromagnetic waves in the radio frequency cavity, forming a standing wave. In the standing wave radio frequency cavity, charged particles are continuously accelerated precisely at the peak of the standing wave during the acceleration half-cycle. During the deceleration half-cycle, the charged particles are designed to be precisely at the metal waveguide baffle, which is the stagnation point of the standing wave, where the electric field strength is zero, and the charged particles are not decelerated. In this way, the charged particles are continuously accelerated in the radio frequency cavity.

[0005] However, due to the limitations of the acceleration gradient of traditional accelerators, particle accelerators are large in size and inefficient. There is an urgent need in the field for a more efficient and smaller particle accelerator solution. Summary of the Invention

[0006] The main objective of this invention is to provide a dielectric laser acceleration system and method, which aims to overcome the shortcomings of existing particle accelerator technology by utilizing the advantage of high acceleration gradient in dielectric laser acceleration.

[0007] To achieve the above objectives, the present invention proposes a dielectric laser acceleration system comprising:

[0008] A laser system, including a laser for providing high-power laser pulses;

[0009] Particle injection source, used to provide a beam of charged particles;

[0010] A dielectric laser accelerator is used to generate a high-gradient accelerating electric field under the drive of a laser pulse, so as to accelerate the charged particle beam over a short distance to obtain a high-energy particle beam.

[0011] an information acquisition module configured to acquire a parameter of a charged particle beam at an outlet position of the medium laser acceleration device;

[0012] a diagnosis module configured to diagnose a state of the charged particle beam and an electromagnetic field transmission characteristic of the medium laser acceleration device;

[0013] a controller connected to an output end of the diagnosis module and a controlled end of the laser system, the controller being configured to:

[0014] acquire a preset energy value of the high-energy particle beam;

[0015] determine a target power and time sequence of laser pulses provided by the laser system according to the preset energy value.

[0016] Optionally, the medium laser acceleration device comprises a plurality of cascaded medium laser acceleration structures, and a period of the medium laser acceleration structure is designed to match a change in energy of the charged particle beam.

[0017] Optionally, the laser system further comprises a light splitting component configured to split the laser pulses into a plurality of secondary laser pulses corresponding to the medium laser acceleration structures one by one, and the secondary laser pulses are used to drive the corresponding medium laser acceleration structures to generate acceleration electric fields.

[0018] Optionally, the light splitting component is a tree-shaped dielectric waveguide.

[0019] Optionally, the medium laser acceleration structure is a planar symmetric double-column structure, and a structure period of the planar symmetric double-column structure is configured to match a change in energy of the charged particle beam.

[0020] Optionally, a dielectric material of the medium laser acceleration structure is at least one of fused quartz, quartz and diamond.

[0021] The application further provides a medium laser acceleration method applied to the medium laser acceleration system, and the medium laser acceleration method comprises the following steps of:

[0022] providing laser pulses by a single laser;

[0023] providing a charged particle beam by a particle injection source;

[0024] configuring a medium laser acceleration device to generate an acceleration electric field with a preset period and intensity under the driving of the laser pulses;

[0025] introducing the charged particle beam into the medium laser acceleration device, and accelerating the charged particle beam in the acceleration electric field into a high-energy particle beam with a preset energy value.

[0026] Optionally, the step of providing the laser pulse by the single laser further comprises:

[0027] obtaining a preset energy value of the high-energy particle beam;

[0028] determining a length, a target power and a time sequence of the laser pulse provided by the laser system according to the preset energy value.

[0029] Optionally, the step of configuring the medium laser acceleration device to generate an acceleration electric field with a preset period and intensity under the driving of the laser pulse further comprises:

[0030] determining the period of the medium laser acceleration structure according to the wavelength of the laser pulse.

[0031] Optionally, the medium laser acceleration method further comprises:

[0032] obtaining a charged particle beam parameter in the cavity of the laser acceleration device;

[0033] diagnosing a state of the charged particle beam and an electromagnetic field transmission characteristic of the medium laser acceleration device according to the charged particle beam parameter to obtain a diagnosis signal;

[0034] adjusting the length, the power and the time sequence of the laser pulse according to the diagnosis signal.

[0035] Compared with the prior art, the present application has the following beneficial effects:

[0036] The medium laser acceleration device generates an acceleration electric field under the driving of a high-power laser to accelerate a charged particle beam, which has the advantages of high efficiency and small size compared with a traditional linear accelerator. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from the structures shown in the drawings without creative labor.

[0038] Figure 1 a principle block diagram of a first embodiment of the medium laser acceleration system of the present application;

[0039] Figure 2 a principle block diagram of a second embodiment of the medium laser acceleration system of the present application;

[0040] Figure 3 a principle block diagram of a third embodiment of the medium laser acceleration system of the present application;

[0041] Figure 4 A schematic diagram of an electric field distribution and structure of a medium laser acceleration device of the present application;

[0042] Figure 5 A schematic diagram of a flow of a medium laser acceleration method of the present application.

[0043] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0045] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture (as shown in the drawings). If the certain posture changes, the directional indications also change accordingly.

[0046] In addition, if the embodiments of the present application involve descriptions of “first”, “second”, etc., the descriptions of “first”, “second”, etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by “first” and “second” can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it. When the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the scope of protection claimed by the present application.

[0047] Traditional particle accelerators are limited by small acceleration gradient and other problems, and have large device size and high cost.

[0048] The present application provides a medium laser acceleration system and method, which aims to solve the above problems.

[0049] To achieve the above-mentioned purpose, in an embodiment, the present application provides a medium laser acceleration system, which comprises:

[0050] A laser system comprising a laser 11 for providing high-power laser pulses;

[0051] A particle injection source 12 for providing a charged particle beam;

[0052] a medium laser acceleration device 13 for generating a high gradient acceleration electric field under the driving of the laser pulse to accelerate the charged particle beam in a short distance to obtain a high energy particle beam;

[0053] an information acquisition module 14 for acquiring a charged particle beam parameter at an outlet position of the medium laser acceleration device;

[0054] a diagnosis module 15 for diagnosing a state of the charged particle beam and electromagnetic field transmission characteristics of the medium laser acceleration device;

[0055] a controller 16 connected to an output end of the diagnosis module and a controlled end of the laser system, the controller being configured to:

[0056] acquire a preset energy value of the high energy particle beam;

[0057] determine a target power and time sequence of the laser pulse provided by the laser system according to the preset energy value.

[0058] Specifically, referring to Figure 1 The present application employs a single high power laser 11 to provide a laser pulse required for driving the medium laser acceleration device, the laser pulse acting on a medium acceleration structure of the medium laser acceleration device 13, an optical field of the laser exciting an intrinsic mode in an acceleration cavity, the generated main mode being a TM01-like mode, a main electric field direction of which being an axial direction (the size of the medium acceleration structure can be configured to have a wide aspect ratio), the axial direction electric field being available for accelerating the charged particle beam.

[0059] It can be understood that the charged particle beam includes electrons, protons and other charged particles, and the particle injection source 12 is used to generate a low-emittance charged particle beam.

[0060] Since the medium laser acceleration device needs to work under the condition of extremely high power and ultra-short pulse length, it is extremely important to diagnose the parameters of the particle beam and the electromagnetic field transmission characteristics.

[0061] Therefore, the embodiment is provided with the information acquisition module 14 for acquiring the particle beam parameters in the cavity of the medium laser acceleration device, the particle beam parameters including a particle beam length and position, and the nanometer-level resolution can be achieved by configuring a medium grating structure having a linear response to the length and position of the charged particle beam in the medium laser acceleration device in combination with an external spectrum analyzer. Further, the diagnosis module 15 is used to diagnose the state of the particle beam and the electromagnetic field transmission characteristics of the medium laser acceleration device.

[0062] Obviously, the embodiment also includes the controller 16 for determining the target power and time sequence of the laser system according to the preset energy value required to be reached by the high-energy particle beam, and the frequency comb technology can be used to achieve the precise synchronization of the pulse timing of the laser system.

[0063] Therefore, the embodiment uses the high-power laser pulse to excite the medium acceleration structure of the medium laser acceleration device, so as to generate an acceleration electric field for accelerating the charged particle beam, and uses the advantage of large laser acceleration gradient to achieve the beneficial effect of reducing the size of the particle accelerator.

[0064] In an embodiment, the medium laser acceleration device 13 includes a plurality of cascaded medium laser acceleration structures, and the medium laser acceleration structures are configured to periodically change to match the energy change of the charged particle beam.

[0065] Referring to Figure 2 Since the medium laser acceleration device 13 requires a very high-power laser pulse, in order to reduce the design difficulty of the medium laser acceleration device, the medium laser acceleration device 13 can be designed to be composed of a plurality of cascaded medium laser acceleration structures, the period of the medium laser acceleration structure changes to match the energy change of the charged particle beam in the acceleration electric field, and a single high-power laser is used to accurately drive the medium acceleration structure according to the correct time sequence.

[0066] In an embodiment, the laser system further includes a light splitting component 17, and the light splitting component 17 is used to split the laser pulse into a plurality of secondary laser pulses corresponding to the medium laser acceleration structures one by one, and the secondary laser pulses are used to drive the corresponding medium laser acceleration structures to generate a high-gradient acceleration electric field.

[0067] Referring to Figure 2 The setting of the light splitting component only needs to use a single laser 11 to provide a laser pulse, and the control of the laser is relatively simple.

[0068] In an embodiment, the light splitting component is a tree-shaped dielectric waveguide.

[0069] The tree-shaped dielectric waveguide provides a branch structure of the light splitting component, which can not only split the light path but also distribute the laser power. The delay between the particle beam and the input laser power can be preset by the length of the dielectric waveguide, and can also be finely controlled by an additional optical phase shifter to adjust the manufacturing error or thermal expansion.

[0070] In an embodiment, the medium laser acceleration structure is a planar symmetric double-column structure, and the structure period of the planar symmetric double-column structure is configured to match the energy change of the charged particle beam.

[0071] Referring to Figure 4, the planar symmetric structure is easy to manufacture, the working mode of the dielectric laser acceleration structure has the strongest electric field component in the propagation direction of the charged particle beam (i.e. the axial direction in Figure 4

[0072] In an embodiment, the dielectric material of the dielectric laser acceleration structure is at least one of fused silica, quartz and diamond.

[0073] Fused silica is relatively easy to process, and can be processed by photolithography or ion etching; the electromagnetic properties of diamond and quartz are better than those of fused silica, and the damage threshold is also higher, but the processing is more difficult.

[0074] Based on the above embodiments, in another embodiment, the dielectric laser acceleration system proposed in the present application can also be used as an electron acceleration system for free electron laser radiation (X-ray to extreme ultraviolet wavelength).

[0075] Referring to Figure 3 , the laser pulses provided by the laser 11 are split and can act on the electron injection source 18 (such as a photocathode device) to generate an electron beam, and can act on the dielectric laser acceleration structure to generate an acceleration electric field. The high-energy electron beam is accelerated by the acceleration electric field to obtain a high-energy electron beam. The undulator 19 is designed to generate a transverse electric field perpendicular to the propagation direction of the electron beam, and the high-energy electron beam generates high-energy coherent electromagnetic radiation by the action of the transverse electric field of the undulator 19. In this embodiment, the high gradient advantage of dielectric laser acceleration is used to realize the advantage of reducing the size of the free electron laser radiation system.

[0076] The present application also proposes a dielectric laser acceleration method applied to the dielectric laser acceleration system described above. In an embodiment, referring to Figure 5 , the dielectric laser acceleration method comprises the following steps:

[0077] S1, providing laser pulses by a single laser;

[0078] S2, providing a charged particle beam by a particle injection source;

[0079] S3, configuring a dielectric laser acceleration device to generate an acceleration electric field with a preset period and intensity under the driving of the laser pulses;

[0080] S4, introducing the charged particle beam into the dielectric laser acceleration device, and accelerating the charged particle beam in the acceleration electric field to a high-energy particle beam with a preset energy value.

[0081] The method is based on the dielectric laser acceleration system described above, and the acceleration step of the charged particle beam is illustrated.

[0082] It should be understood that, although​Figure 5 The steps in the flowchart are displayed in sequence according to the arrows, but the steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, the execution of the steps is not strictly limited in sequence, and the steps can be executed in other orders. Moreover, Figure 5 At least part of the steps in the flowchart can include multiple steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution sequence of the steps or stages is not necessarily sequential, but can be alternately executed with other steps or steps or stages in other steps.

[0083] In an embodiment, the step of providing a laser pulse by a laser further comprises:

[0084] Obtaining a preset energy value of the high-energy particle beam;

[0085] According to the preset energy value, the length, target power and time sequence of the laser pulse provided by the laser system are determined.

[0086] In an embodiment, the step of configuring a medium laser acceleration device to generate an acceleration electric field with a preset period and intensity under the driving of the laser pulse further comprises:

[0087] According to the wavelength and length of the laser pulse, the structural period of the medium laser acceleration device is determined.

[0088] In an embodiment, the medium laser acceleration method further comprises:

[0089] Obtaining the particle beam parameters at the outlet of the medium laser acceleration device;

[0090] According to the particle beam parameters, the state of the particle beam and the electromagnetic field transmission characteristics of the medium laser acceleration device are diagnosed to obtain a diagnosis signal;

[0091] According to the diagnosis signal, the length, power and time sequence of the laser pulse are adjusted.

[0092] In summary, the present application constructs a medium laser acceleration system, which uses a high-power laser pulse to excite the medium acceleration structure of the medium laser acceleration device, thereby generating a high-gradient acceleration electric field for accelerating a charged particle beam. The advantage of large gradient of medium laser acceleration is used to achieve the beneficial effect of reducing the size of the particle accelerator. The medium laser acceleration system realized based on the present application can be applied to high-energy electron acceleration, proton acceleration, free electron laser and other technical devices, covering basic scientific research, semiconductor integrated circuits, medical applications and other application fields.

[0093] The above merely describes preferred embodiments of the present application, and is not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process conversion, or direct or indirect application in other related technical fields, which is made according to the content of the present application specification and drawings, and is under the inventive concept of the present application, is included in the patent protection scope of the present application.

Claims

1. A dielectric laser acceleration system, characterized in that, The dielectric laser acceleration system includes: A laser system includes a laser for providing high-power laser pulses; the laser system also includes a beam splitter, which is a dendritic dielectric waveguide. Particle injection source, used to provide a beam of charged particles with low emission; A dielectric laser accelerator is provided, which generates a high-gradient accelerating electric field under the drive of a laser pulse to accelerate a charged particle beam into a high-energy particle beam over a short distance. The dielectric laser accelerator includes multiple cascaded dielectric laser accelerator structures, each a planar symmetric double-column structure, with its period designed to match the energy variation of the charged particle beam. A beam splitting component is used to split the laser pulse into multiple secondary laser pulses corresponding one-to-one with each dielectric laser accelerator structure. These secondary laser pulses drive the corresponding dielectric laser accelerator structures to generate an accelerating electric field. The information acquisition module is used to acquire the particle beam parameters inside the cavity of the dielectric laser accelerator. The particle beam parameters include the particle beam length and position. The resolution at the nanometer level can be achieved by setting a dielectric laser accelerator structure in the dielectric laser accelerator that has a linear response to the length and position of the charged particle beam, combined with an external spectrometer. The diagnostic module is used to diagnose the state of the charged particle beam and the electromagnetic field transmission characteristics of the dielectric laser acceleration device. A controller, connected to the output of the diagnostic module and the controlled end of the laser system, is used for: Obtain the preset energy value of the high-energy particle beam; Based on the preset energy value, the target power and time sequence of the laser pulses provided by the laser system are determined, and the pulse timing of the laser system is synchronized using frequency comb technology.

2. The dielectric laser acceleration system as described in claim 1, characterized in that, The dielectric material of the dielectric laser acceleration structure is at least one of fused silica, quartz, and diamond.

3. A dielectric laser acceleration method, characterized in that, Based on the dielectric laser acceleration system according to any one of claims 1-2, the dielectric laser acceleration method includes: Laser pulses are provided by a single laser; A beam of charged particles is provided by a single particle injection source; A dielectric laser accelerator is configured to generate an accelerating electric field of a preset period and intensity under the drive of the laser pulse. The charged particle beam is introduced into the dielectric laser acceleration device, and the charged particle beam is accelerated into a high-energy particle beam with a preset energy value in the accelerating electric field.

4. The dielectric laser acceleration method as described in claim 3, characterized in that, The step of providing laser pulses from a single laser further includes: Obtain the preset energy value of the high-energy particle beam; Based on the preset energy value, the length, target power, and time sequence of the laser pulse provided by the laser system are determined.

5. The dielectric laser acceleration method as described in claim 4, characterized in that, The step of configuring a dielectric laser acceleration device to generate an accelerating electric field of a preset period and intensity under the drive of the laser pulse further includes: The period of the dielectric laser acceleration structure is determined based on the wavelength of the laser pulse.

6. The dielectric laser acceleration method as described in claim 3, characterized in that, The medium laser acceleration method further includes: Obtain the parameters of the charged particle beam inside the cavity of the medium laser accelerator; Based on the charged particle beam parameters, the state of the charged particle beam and the electromagnetic field transmission characteristics of the dielectric laser acceleration device are diagnosed to obtain a diagnostic signal. Based on the diagnostic signal, the length, power, and timing sequence of the laser pulse are adjusted.

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