Resolution measurement tool convenient for improving size of beam cross section in accelerating tube

Abstract

The invention discloses a resolution measurement tool convenient for improving the size of the beam cross section in an accelerating tube, and relates to the technical field of accelerating tube measurement, the resolution measurement tool comprises a vacuum chamber, a target frame and a linear electric driving device, the vacuum chamber is internally provided with an independent adjustable supporting base, and the independent adjustable supporting base is internally provided with an intra-cavity reflector; two groups of observation windows are arranged on one side, far away from the independent adjustable supporting base, in the vacuum chamber, a fluorescent target is arranged in the target frame, and fluorescence emitted by the fluorescent target is reflected by the reflector in the cavity, is led out from the observation window on the right side, passes through the light path assembly and is imaged by the CCD camera at the observation window. According to the structure, the shape of a beam spot can be observed through the CCD camera, and the in-cavity reflecting mirror is arranged in the vacuum chamber, so that the resolution during light beam viewing can be improved.

Description

Technical Field

[0001] This invention relates to the field of accelerator tube measurement technology, specifically to a resolution measurement fixture that facilitates improving the size of the beam cross-section inside an accelerator tube. Background Technology

[0002] The Hard X-ray Free Electron Laser (FEL) facility is one of the world's most efficient and advanced FEL user facilities, providing cutting-edge research tools for multiple disciplines, including physics, chemistry, life sciences, materials science, and energy science, such as high-resolution imaging, ultrafast process exploration, and advanced structure analysis. For hard X-ray projects, the beam diagnostic system is a crucial component, allowing researchers to measure various beam parameters and understand the beam's operational status. Transverse beam profiling has always been a key element in the design and optimization of free electron lasers (FELs) and is widely used in FEL facilities.

[0003] However, for the SHINE project, some profile targets will be used for precise beam size measurement under conditions of small beam spots and ultra-short beam lengths; the optimal measurement resolution requirement will be as low as 5 μm. Under these operating parameters, the measurement resolution of traditional profile measurement systems is mainly affected by coherent OTR radiation (COTR) and the excessively large system point spread function caused by the target thickness. Several experiments have already reported the adverse effects of COTR on measurements; the lateral beam spot size of the SHINE device will be compressed to the order of 10 μm, and the excessively large point spread function caused by the target thickness will amplify the final measurement error. To address this, the SHINE project plans to develop some novel, COTR-resistant, precise profile measurement systems. Summary of the Invention

[0004] The purpose of this invention is to provide a resolution measurement fixture that facilitates improving the beam cross-sectional area within an accelerating tube, thereby addressing the related problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a resolution measurement fixture for improving the cross-sectional size of the beam inside an accelerating tube, comprising a vacuum chamber, a target frame and a linear electric drive device, wherein an independent adjustable support base is provided inside the vacuum chamber, and an internal reflector is provided inside the independent adjustable support base, and two sets of observation windows are provided on the side of the vacuum chamber away from the independent adjustable support base, and a fluorescent target is provided inside the target frame.

[0006] As a preferred embodiment of the present invention, which facilitates the resolution measurement of the beam cross-section size in an accelerating tube, the output end of the linear electric drive device is connected to the vacuum chamber via a target frame.

[0007] As a preferred embodiment of the present invention, which facilitates the resolution measurement of the beam cross-section size in an accelerating tube, the independent adjustable support base includes a support frame and a fixed shaft. The fixed shaft is installed inside the support frame, and a ratchet is installed on the outer wall of the fixed shaft. An annular groove is installed on the outer wall of the support frame through a bearing, and a connecting frame connected to the cavity reflector is installed on the outer wall of the annular groove.

[0008] As a preferred embodiment of the present invention, which facilitates the resolution measurement of the beam cross-section size inside the accelerating tube, the annular groove is provided with a movable groove inside, and a T-shaped tie rod is provided inside the movable groove. The bottom end of the T-shaped tie rod is fitted with a spring piece that matches the outer wall of the ratchet.

[0009] As a preferred embodiment of the present invention, which facilitates the resolution measurement of the beam cross-section size inside the accelerating tube, the outer wall of the T-shaped tie rod is fitted with a spring that connects to the inner wall of the movable groove.

[0010] As a preferred embodiment of the present invention, which facilitates the resolution measurement of the beam cross-section size inside the accelerating tube, a CCD camera is provided on one side of the observation window.

[0011] As a preferred embodiment of the present invention, which facilitates the resolution measurement of the beam cross-section size inside the accelerating tube, the intracavity reflector is made of gold sheet.

[0012] The beneficial effects of the resolution measurement fixture of the present invention, which facilitates improving the beam cross-sectional area of ​​an accelerating tube, are as follows: 1. This invention employs a fluorescent target to emit fluorescence, which is reflected by an intracavity mirror, extracted from the right observation window, and then passed through an optical path assembly to be imaged by a CCD camera at the observation window. A calibration target is also installed at the same position and angle as the fluorescent target to calibrate the scaling factor of the system imaging. Additionally, an OTR target is installed at a different angle, and OTR radiation is extracted from the left observation window and captured by a CCD camera. This structure allows the beam spot shape to be observed using a CCD camera. The intracavity mirror placed in the vacuum chamber improves the resolution when viewing the beam and prevents the point spread function of the system from being affected by excessive target thickness.

[0013] 2. In this invention, the operator rotates the connecting frame to move the spring at the ratchet, causing the spring to undergo elastic deformation. When rotated to a suitable angle, the spring can engage with the ratchet's outer wall under its own elastic force, thus satisfying the angle adjustment. When it is necessary to move forward, the T-shaped lever can be pulled to compress the spring at the spring, causing the spring to separate from the ratchet. Then, the connecting frame can be flipped forward to readjust the angle. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the internal optical path structure of the cross-sectional target of the present invention; Figure 2 This is a three-dimensional cross-sectional view of the present invention; Figure 3 This is a three-dimensional structural diagram of the present invention; Figure 4 This is a schematic diagram of the front cross-sectional structure of the present invention; Figure 5 This is a top sectional view of the independent adjustable support base and the intracavity reflector of the present invention. Figure 6 For the present invention Figure 5 A magnified structural diagram at point A; Figure 7 This is a schematic diagram of the right-side cross-sectional structure of the independent adjustable support base and the intracavity reflector of the present invention; Figure 8 This is a schematic diagram of particle beam energy correlation detection data under the PYDM interface of the present invention; Figure 9 This is a schematic diagram of the beam emittance measurement operation interface of the four-level magnet scanning method of the present invention.

[0015] In the diagram: 1. Vacuum chamber; 2. Target frame; 3. Linear electric drive device; 4. Observation window; 5. Independent adjustable support base; 501. Support frame; 502. Fixed shaft; 503. Ratchet; 504. Annular groove; 505. Movable groove; 506. T-shaped tie rod; 507. Spring; 508. Spring; 509. Connecting frame; 6. Intracavity reflector; 7. Fluorescent target. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1, such as Figure 1-9 As shown, this invention provides a technical solution: a resolution measurement fixture for improving the beam cross-section size inside an accelerating tube, comprising two sets of observation windows 4 disposed on the side of a vacuum chamber 1 away from an independent adjustable support base 5, a fluorescent target 7 disposed inside a target frame 2, a linear electric drive device 3 connected to the vacuum chamber 1 via the target frame 2 on one side of its output end, a CCD camera disposed on one side of the observation windows 4, and an intracavity reflector 6 made of gold sheet. This mechanism uses the fluorescent target 7 as a light source and utilizes a spatial separation method to shield against COTR radiation interference. (See below) Figure 1As shown, the fluorescent target 7 is installed with the normal to the beam direction at an angle of 8.1°. The beam interacts with the fluorescent target 7 to produce isotropic fluorescence. The lateral dimension of the single-electron imaging, a point spread function, is affected by the observation angle and the target thickness at different observation angles. When a 6.76° observation angle is selected on the same side as the beam for measurement, the measurement point spread function caused by the thickness of the fluorescent target 7 is 0. The fluorescence is reflected by the intracavity mirror 6, extracted from the right observation window, and then, after passing through the optical path assembly, is imaged by the CCD camera at observation window 4. A calibration target is also installed at the same position and angle on the fluorescent target 7 to calibrate the system imaging scaling factor. An OTR target is installed at 45 degrees, extracting OTR radiation from the left observation window and imaged by the CCD camera. This structure allows for observation of the beam spot shape via a CCD camera. The intracavity mirror in the vacuum chamber 1 improves the resolution when viewing the beam and prevents the target thickness from affecting the system's point spread function.

[0018] Example 2, as Figure 1-7 As shown, the present invention provides a technical solution: a resolution measurement fixture for improving the beam cross-section size in an accelerating tube, comprising a vacuum chamber 1, a target frame 2, and a linear electric drive device 3. An independently adjustable support base 5 is provided inside the vacuum chamber 1, and an intracavity reflector 6 is provided inside the independently adjustable support base 5. The independently adjustable support base 5 includes a support frame 501 and a fixed shaft 502. The fixed shaft 502 is installed inside the support frame 501, and a ratchet 503 is installed on the outer wall of the fixed shaft 502. An annular groove 504 is installed on the outer wall of the support frame 501 via a bearing, and a connecting frame 509 connected to the intracavity reflector 6 is installed on the outer wall of the annular groove 504. A movable groove 505 is formed inside the annular groove 504. The internal part of component 05 is equipped with a T-shaped pull rod 506. The bottom end of the T-shaped pull rod 506 is fitted with a spring piece 507 that matches the outer wall of the ratchet 503. The outer wall of the T-shaped pull rod 506 is fitted with a spring 508 that connects to the inner wall of the movable groove 505. When the operator rotates the connecting frame 509, the spring piece 507 moves at the ratchet 503, causing the spring piece 507 to undergo elastic deformation. When rotated to a suitable angle, the spring piece 507 can engage with the ratchet 503 under its own elastic force, thus satisfying the angle adjustment. When it is necessary to move to the forward position, the T-shaped pull rod 506 can be pulled to compress the spring 508 at the spring piece 507, causing the spring piece 507 to separate from the ratchet 503. Then, the connecting frame 509 can be flipped forward to readjust the angle.

[0019] Working principle: First, an external power supply is connected. The beam cross-section probe is driven by a linear electric drive device 3, without using a grating ruler. A fluorescent target 7 is used as the light source, and spatial separation is used to shield against COTR radiation interference. Figure 1As shown, the fluorescent target 7 is installed with the normal to the beam direction at an angle of 8.1°. The beam interacts with the fluorescent target 7 to produce isotropic fluorescence. The lateral dimension of the single-electron image, a point spread function, is affected by the observation angle and the target thickness at different observation angles. When a 6.76° observation angle is selected on the same side as the beam for measurement, the measurement point spread function caused by the thickness of the fluorescent target 7 is 0. The fluorescence is reflected by the intracavity mirror 6, extracted from the right observation window, and then, after passing through the optical path assembly, imaged by the CCD camera at observation window 4. A calibration target is also installed at the same position and angle on the fluorescent target 7 to calibrate the system's imaging scaling factor. An OTR target is installed at 45 degrees, extracting OTR radiation from the left observation window and imaged by the CCD camera. This structure allows observation of the beam spot shape via a CCD camera. The intracavity mirror 6 within the vacuum chamber 1 improves the resolution when viewing the beam. The system's point spread function will not be affected by excessive target thickness, thus requiring adjustment of the angle of the cavity reflector 6. The operator can rotate the connecting frame 509 to move the spring 507 at the ratchet 503, causing the spring 507 to undergo elastic deformation. When rotated to the appropriate angle, the spring 507 can engage with the outer wall of the ratchet 503 under its own elastic force, thus satisfying the angle adjustment. When it is necessary to move forward, the T-shaped lever 506 can be pulled to compress the spring 508 at the spring 507, causing the spring 507 to separate from the ratchet 503. Then, the connecting frame 509 can be flipped forward to readjust the angle.

[0020] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A resolution measurement fixture for improving the cross-sectional size of the beam inside an accelerating tube, comprising a vacuum chamber (1), a target holder (2), and a linear electric drive device (3), characterized in that: The vacuum chamber (1) is equipped with an independent adjustable support base (5), and an internal reflector (6) is installed inside the independent adjustable support base (5). Two sets of observation windows (4) are installed on the side of the vacuum chamber (1) away from the independent adjustable support base (5). A fluorescent target (7) is installed inside the target frame (2).

2. The resolution measurement fixture for improving the beam cross-sectional area inside an accelerating tube according to claim 1, characterized in that: The output end of the linear electric drive device (3) is connected to the vacuum chamber (1) through the target frame (2).

3. The resolution measurement fixture for improving the beam cross-sectional area inside an accelerating tube according to claim 1, characterized in that: The independent adjustable support base (5) includes a support frame (501) and a fixed shaft (502). The fixed shaft (502) is installed inside the support frame (501), and a ratchet (503) is installed on the outer wall of the fixed shaft (502). An annular groove (504) is installed on the outer wall of the support frame (501) through a bearing, and a connecting frame (509) connected to the cavity reflector (6) is installed on the outer wall of the annular groove (504).

4. The resolution measurement fixture for improving the beam cross-sectional area inside an accelerating tube according to claim 3, characterized in that: The annular groove (504) has a movable groove (505) inside, and a T-shaped pull rod (506) is provided inside the movable groove (505). A spring piece (507) adapted to the outer wall of the ratchet (503) is installed at the bottom end of the T-shaped pull rod (506).

5. The resolution measurement fixture for improving the beam cross-sectional area inside an accelerating tube according to claim 4, characterized in that: The outer wall of the T-shaped tie rod (506) is fitted with a spring (508) that is connected to the inner wall of the movable groove (505).

6. The resolution measurement fixture for improving the beam cross-sectional area inside an accelerating tube according to claim 1, characterized in that: A CCD camera is installed on one side of the observation window (4).

7. The resolution measurement fixture for improving the beam cross-sectional area inside an accelerating tube according to claim 1, characterized in that: The intracavity reflector (6) is made of gold sheet.

Images