Secondary beam profile detector and use method thereof

Abstract

The invention relates to the technical field of heavy ion accelerator beam diagnosis, in particular to a secondary beam profile detector and a use method thereof. The secondary beam profile detector comprises a probe assembly which is provided with an emission film used for generating secondary electrons and a high-voltage wire mesh used for providing an electric field; the motion probe comprises an outer tube, a vacuum sealing flange sleeved on the outer tube and an inner tube in sliding connection with the outer tube; the camera is installed on the vacuum sealing flange and located below the outer pipe; wherein the probe assembly is installed at the end, extending out of the outer tube, of the inner tube in a suspending mode, and the probe assembly further comprises an MCP assembly and a fluorescent screen which are arranged in parallel with the emission film in a spaced mode; the fluorescent screen and the lens of the camera are inclined by 45 degrees, and the center of the fluorescent screen coincides with the central axis of the lens of the camera. According to the invention, the probe assembly adopts a reading mode of combining the micro-channel plate with the fluorescent screen, can be used for measuring a beam profile in a large beam intensity range, and gives consideration to strong and weak secondary beams.

Description

Technical Field

[0001] The present invention relates to the technical field of heavy ion accelerator beam diagnosis, and in particular to a secondary beam profile detector and a method for using the same. Background Art

[0002] In 1902, American physicists Louis Austin and Stark first discovered the phenomenon of secondary electron emission when studying the properties of high-temperature gases. However, it was not until 1950 that Alvarez and Cohen applied this phenomenon as a detection method in the field of accelerators, such as fission research and nuclear reaction product analysis. In the 1950s, scintillator detectors or semiconductor detectors were used to collect and multiply accelerated secondary electrons. However, because scintillator detectors and semiconductor detectors are not sensitive to electrons with energies below 5keV, a voltage of 5kV or even higher is required. At the same time, the time resolution obtained by this method can only be in the order of ns. Therefore, with the replacement of multiplication equipment, from secondary multipliers to channel multipliers, and finally to microchannel plates (MCPs), a great leap in the time resolution, position resolution, and working stability of multiplication equipment has been achieved.

[0003] In 1990, Charles Evans and others in the United States applied MCP to the online measurement of weak beams to solve the problem of beam measurement in the range of [1E5pps, 1E10pps]. Because weak beams with current intensity below 1E5pps can be accurately measured using semiconductor detectors, and strong beams with current intensity above 1E10pps can be measured by electromagnetic induction probes, and the blank area between the two is the weakness of slow extraction current intensity measurement. From the working principle, after the beam passes through the metal film, the energy loss caused by the surface of the metal film is transferred to the atoms or molecules on the surface to emit secondary electrons. The secondary electrons generated in this way have very low energy, most of which are less than 100eV. Negative high voltage is set on the metal film, and a high voltage wire mesh is added behind it. A negative high voltage lower than the metal film is set on the high voltage wire mesh. The generated electric field guides the secondary electrons to the upper surface of the MCP. MCP can be stacked in one or two pieces. Negative high voltage is applied to the upper surface of the MCP, and the lower surface of the MCP is connected to the protective ground. The guided secondary electrons enter the tiny pipe of MCP, and after avalanche amplification, they are attracted by the positive high voltage on the surface of the fluorescent screen and hit the fluorescent screen to produce visible light. Finally, the image seen is transmitted to the client using a camera (CCD).

[0004] It should be pointed out that the number of secondary electrons emitted by a single particle after passing through the emission film, also known as the secondary electron yield, directly affects the lower limit of the current measurement and the signal-to-noise ratio of the entire detector. In 1990, the experimental results of HL Seifert of the Los Alamos National Laboratory in the United States showed that evaporating cesium iodide (CsI) on the surface of the aluminum-coated film can greatly increase the secondary electron yield on the surface of the aluminum-coated film. In 2013, Harasimowicz Janusz of the University of Liverpool in the United Kingdom mentioned in his doctoral thesis that the high-voltage wire adopts a vertical and horizontal mesh structure, which can effectively reduce the influence of electric field distortion. At the same time, the voltage difference between the emission film and the high-voltage wire mesh (5mm apart) is greater than 2000V, which can ensure the position resolution of the detector.

[0005] For radioactive separation devices, the measurement of beam profiles, especially weak beam profiles, is of great significance. However, the existing stripe ionization chambers, fluorescent targets, multi-wire proportional chambers, etc., have high energy losses, cannot meet the requirements of radioactive separation devices, and do not have the disadvantages of real-time monitoring of secondary beam profile information.

[0006] Therefore, there is an urgent need for a profile detector suitable for radioactive beam lines to meet the requirements of real-time online measurement of secondary beam profiles and application in secondary beam optics. Summary of the invention

[0007] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the present invention proposes a secondary beam profile detector and a method of using the same to achieve real-time online measurement of the radioactive secondary beam profile to obtain the secondary beam optics, which can be compared with the simulated calculated beam optics, thereby effectively reducing the beam adjustment time and improving the experimental terminal beam quality.

[0008] In a first aspect, the present invention provides a secondary beam profile detector, comprising: A probe assembly is provided with an emission film for generating secondary electrons and a high-voltage wire mesh for providing an electric field; The moving probe comprises an outer tube, a vacuum sealing flange sleeved on the end of the outer tube, and an inner tube slidably connected to the outer tube; A camera, wherein a lens of the camera is embedded in the vacuum sealing flange, and the camera and the outer tube are located on one side of the vacuum sealing flange; The probe assembly is located at the other side of the vacuum sealing flange and is installed at the end of the inner tube that protrudes out of the outer tube. The probe assembly also includes an MCP assembly and a fluorescent screen that are arranged parallel to and spaced from the emission film. The fluorescent screen is inclined at 45° with respect to the camera lens and its center coincides with the central axis of the camera lens.

[0009] According to a secondary beam profile detector provided by the present invention, the probe assembly further comprises a support rod, the emission film and the high-voltage wire mesh are sequentially installed on the upper end of the support rod from top to bottom to form a field cage for guiding secondary electrons to the MCP assembly; The MCP assembly and the fluorescent screen are sequentially installed on the lower end of the support rod from top to bottom.

[0010] According to a secondary beam profile detector provided by the present invention, the probe assembly further includes a partition plate arranged between the emission film and the high-voltage wire mesh for increasing the spacing, and the thickness of the partition plate is 5 mm.

[0011] According to a secondary beam profile detector provided by the present invention, the MCP assembly includes an MCP, an MCP upper electrode plate, an MCP middle plate, and an MCP lower electrode plate which are arranged in sequence from top to bottom.

[0012] According to a secondary beam profile detector provided by the present invention, the moving probe further comprises a high voltage feedthrough, which is arranged at the end of the inner tube hanging out of the outer tube; The probe assembly is electrically connected to the high voltage feedthrough for transmitting signals or substances under the condition of vacuum environment sealing.

[0013] According to a secondary beam profile detector provided by the present invention, the moving probe further includes: A probe support is arranged in parallel above the outer tube, the length of the probe support is greater than the length of the outer tube, and one end of the probe support is fixedly connected to the vacuum sealing flange; A cylinder, mounted on the probe support and extending from the other end of the probe support in a direction away from the vacuum sealing flange, for driving the inner tube to slide out of the outer tube; A motion guide rail is fixed to the probe support, facing the side of the outer tube and arranged parallel to the axial direction of the outer tube; Wherein, the inner tube is connected to the slider of the motion guide rail, and the telescopic rod of the cylinder is connected to the slider.

[0014] According to a secondary beam profile detector provided by the present invention, the high-voltage wire mesh is made of gold-plated tungsten wires with a diameter less than 50 μm, and the wire spacing of the high-voltage wire mesh is greater than or equal to 1 mm.

[0015] According to a secondary beam profile detector provided by the present invention, the emission film has a thickness of less than 2 μm.

[0016] According to a secondary beam profile detector provided by the present invention, the vacuum sealing flange is provided with a glass window, and the lens of the camera is arranged in close contact with the glass window.

[0017] In a second aspect, the present invention further provides a method for using a secondary beam profile detector, which is applied to any of the secondary beam profile detectors described above. S1. Remove the probe assembly and place it in a vacuum target chamber; S2, fixing the secondary beam profile detector to the outside of the vacuum target chamber through the vacuum sealing flange, and then installing the probe assembly from the vacuum target chamber to the end of the inner tube; S3, electrically connecting a bias source disposed outside the vacuum target chamber to the probe assembly through a high-voltage feedthrough installed at the end of the inner tube; S4, the camera is electrically connected to a host computer arranged outside the vacuum target chamber, and the monitoring image of the secondary beam is viewed through the camera reading software.

[0018] The above one or more technical solutions in the present invention have at least one of the following technical effects: 1. The probe assembly adopts a readout method of a microchannel plate combined with a fluorescent screen, which can be used to measure the beam profile in a large range of current intensities, taking into account both strong and weak secondary beam currents.

[0019] 2. The secondary beam profile detector of the present application has a compact mechanical structure and is economical and applicable. Compared with expensive multi-channel data acquisition, it can also provide two-dimensional information, has a greater cost advantage, can be widely used in the field of accelerator beam diagnosis, and can be widely used in radioactive separation devices.

[0020] 3. The secondary beam profile detector of the present application can also observe the longitudinal structure of the beam, compare the relative flow intensities of the beam, and distinguish the measurement of the primary beam and the secondary beam.

[0021] 4. The secondary beam profile detector can measure the radioactive secondary beam profile in real time online to obtain the secondary beam optics, which can be compared with the simulated beam optics, thereby effectively reducing the beam adjustment time of accelerator personnel, improving the beam quality at the experimental terminal, and increasing the effective beam supply time.

[0022] In addition to the technical problems solved by the present invention, the technical features of the technical solutions constituted, and the advantages brought about by the technical features of these technical solutions described above, other technical features of the present invention and the advantages brought about by these technical features will be further explained in conjunction with the accompanying drawings or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A schematic diagram of the three-dimensional structure of a secondary beam profile detector provided in an embodiment of the present invention.

[0025] Figure 2 A cross-sectional structural diagram along the longitudinal symmetry plane of the secondary beam profile detector provided in an embodiment of the present invention.

[0026] Figure 3 A schematic diagram of the wire spacing of the high-voltage wire mesh provided in an embodiment of the present invention.

[0027] Figure 4 A schematic diagram of a bias voltage application method of a probe assembly provided in an embodiment of the present invention.

[0028] Figure 5 A schematic diagram of using a secondary beam profile detector in a vacuum target chamber provided by an embodiment of the present invention.

[0029] Reference numerals: 100. Probe assembly; 110. Transmitter film; 120. High-voltage wire mesh; 130. MCP assembly; 140. Fluorescent screen; 150. Support rod; 160. Partition; 200. Moving probe; 210. Outer tube; 220. Inner tube; 230. Vacuum sealing flange; 231. Glass window; 240. High-voltage feedthrough; 250. Probe support; 260. Cylinder; 270. Moving guide rail; 300. Camera. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0032] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0033] In the embodiments of the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0034] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms are not limited to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0035] In order to solve the shortcomings of the existing stripe ionization chamber, fluorescent target, multi-wire proportional chamber, etc., which have high energy loss, cannot meet the requirements of radioactive separation device, and cannot monitor the secondary beam profile information in real time, a secondary beam profile detector is introduced in an embodiment of the present invention.

[0036] like Figure 1 and Figure 2 As shown, the secondary beam profile detector mainly includes: a probe assembly 100 , a moving probe 200 and a camera 300 .

[0037] The probe assembly 100 is provided with an emission film 110 for generating secondary electrons and a high-voltage wire mesh 120 for providing an electric field.

[0038] The moving probe 200 includes an outer tube 210 , a vacuum sealing flange 230 sleeved on an end of the outer tube 210 , and an inner tube 220 slidably connected to the outer tube 210 .

[0039] Specifically, the vacuum sealing flange 230 includes a mounting plate sleeved with the outer tube 210 and an annular flange edge arranged along the outer peripheral edge of the mounting plate. Preferably, the flange edge is offset and protrudes toward one side of the mounting plate, so that a groove is formed on one side of the vacuum sealing flange 230.

[0040] The lens of the camera 300 is embedded in the vacuum sealing flange 230. The camera 300 and the outer tube 210 are located on one side of the vacuum sealing flange 230. Specifically, two sockets are provided on the mounting plate of the vacuum sealing flange 230, one for embedding the end of the outer tube 210, and the other for embedding the lens of the camera 300. The lens of the camera 300 and the outer tube 210 are parallel to each other, and the camera 300 and the outer tube 210 are located on one side of the vacuum sealing flange 230 away from the offset direction of the flange edge.

[0041] The probe assembly 100 is located on the other side of the vacuum sealing flange 230 and is installed on the end of the inner tube 220 that protrudes out of the outer tube 210, so that the moving probe 200 can drive the probe assembly 100 to move to the center of the beam pipe or away from the center of the beam pipe by driving the inner tube 220 to slide in the outer tube 210.

[0042] The probe assembly 100 further includes an MCP assembly 130 and a fluorescent screen 140 which are arranged parallel to and spaced apart from the emission film 110 .

[0043] The fluorescent screen 140 is inclined at 45° with respect to the lens of the camera 300 . In addition, the center of the fluorescent screen 140 coincides with the central axis of the lens of the camera 300 .

[0044] Furthermore, the fluorescent screen 140 is made of transparent material, and the distance between the upper surface of the fluorescent screen 140 and the lower surface of the MCP assembly 130 is less than 2 mm.

[0045] In this embodiment, the probe assembly 100 adopts a readout method of a microchannel plate combined with a fluorescent screen 140, which can enable secondary electrons to generate visible light on the fluorescent screen 140 through avalanche amplification, and then use the camera 300 to transmit the image on the fluorescent screen 140 to the host computer, and then measure the radioactive secondary beam profile in real time online to obtain the secondary beam optics, which is suitable for measuring beam profiles in a larger current intensity range, taking into account both strong and weak secondary beam currents.

[0046] Based on the above embodiment, in another embodiment of the present invention, a secondary beam profile detector is introduced.

[0047] In order to fix the emission film 110, the high-voltage wire mesh 120, the MCP assembly 130 and the fluorescent screen 140 as a whole, the probe assembly 100 further includes a support rod 150. The emission film 110 and the high-voltage wire mesh 120 are sequentially installed on the upper end of the support rod 150 from top to bottom to form a field cage for guiding secondary electrons to the MCP assembly 130.

[0048] The MCP assembly 130 and the fluorescent screen 140 are sequentially installed on the lower end of the support rod 150 from top to bottom.

[0049] In particular, if Figure 4 As shown, the emission film 110 is loaded with a voltage of -5000V or higher. The high-voltage wire mesh 120 is loaded with a voltage of -2000V. The upper surface of the MCP component 130 is loaded with a voltage of -1400V to -2000V. The lower surface of the MCP component 130 is grounded or connected to a protective resistor and then grounded. The upper surface of the phosphor screen 140 is loaded with a voltage of +5000V.

[0050] In this way, after the beam penetrates the emission film 110, secondary electrons are generated on the surface of the emission film 110. Under the action of the electric field formed between the emission film 110 and the high-voltage wire mesh 120, the secondary electrons are guided toward the MCP component 130. After avalanche amplification of the MCP component 130, the secondary electrons hit the fluorescent screen 140 to generate visible light, and then the image on the fluorescent screen 140 is transmitted to the host computer using the camera 300.

[0051] Based on the above embodiment, in another embodiment of the present invention, a secondary beam profile detector is introduced.

[0052] The probe assembly 100 further includes a partition 160 disposed between the emission film 110 and the high-voltage wire mesh 120 for increasing the distance therebetween. The thickness of the partition 160 is 5 mm.

[0053] like Figure 3 As shown in FIG. 1 , when calculating the transmittance η of the high-voltage wire mesh 120, the dotted line represents the effective calculation area. Since the wire spacing of the high-voltage wire mesh 120 is 1 mm, considering that the high-voltage wire mesh 120 is placed at a 45° inclination, the spacing in the other direction is equivalent to , that is, 707μm. The transmittance η of the high-voltage wire mesh 120 is calculated as follows: ; Here, d represents the wire diameter.

[0054] For example, if the wire diameter of the high-voltage wire mesh 120 is set to 15 μm, the calculation process of the transmittance η is as follows: ; Based on the above embodiment, in another embodiment of the present invention, a secondary beam profile detector is introduced.

[0055] The MCP assembly 130 includes an MCP, an MCP upper electrode plate, an MCP middle plate, and an MCP lower electrode plate which are sequentially arranged from top to bottom.

[0056] Furthermore, the MCP can be selected as 1 or 2. The voltage difference of each MCP does not exceed 1500V, and the voltage difference between the upper surface and the lower surface is negative.

[0057] The maximum gain of one MCP is 1E4, and the maximum gain of two MCPs is 1E6. If two MCPs are used, they need to be installed in a V-shaped structure, that is, the microchannel holes of the MCP are placed at 180°.

[0058] Based on the above embodiment, in another embodiment of the present invention, a secondary beam profile detector is introduced.

[0059] The moving probe 200 further includes a probe support 250 , a cylinder 260 and a moving guide rail 270 .

[0060] The probe support 250 is fixedly connected to the vacuum sealing flange 230 and is located above the outer tube 210. The cylinder 260 is installed on the probe support 250 to drive the inner tube 220 to slide out of the outer tube 210.

[0061] Specifically, the moving probe 200 is arranged in parallel above the outer tube 210. The length of the probe support 250 is greater than the length of the outer tube 210. One end of the probe support 250 is fixedly connected to the vacuum sealing flange 230, and the other end of the probe support 250 extends and protrudes from the overhanging end of the outer tube 210. The cylinder extends from the other end of the probe support 250 in a direction away from the vacuum sealing flange 230. The moving guide rail 270 is fixed to the side of the probe support 250 facing the outer tube 210. In addition, the moving guide rail 270 is arranged parallel to the axial direction of the outer tube 210.

[0062] The inner tube 220 is connected to the slider of the motion guide rail 270. The telescopic rod of the cylinder 260 is connected to the slider.

[0063] Furthermore, the motion probe 200 further includes a high voltage feedthrough 240 . The high voltage feedthrough 240 is disposed at the end of the inner tube 220 that overhangs the outer tube 210 .

[0064] The probe assembly 100 is electrically connected to the high voltage feedthrough 240 for transmitting signals or substances under the condition of vacuum sealing.

[0065] The high voltage input terminals of the emitting film 110 and the high voltage input terminals of the high voltage wire mesh 120 are connected to the output terminals of the high voltage feedthrough 240. The high voltage input terminals of the MCP assembly 130 and the phosphor screen 140 are connected to the output terminals of the high voltage feedthrough 240.

[0066] The moving probe 200 further includes a high voltage transfer connector disposed at the lower side of the cylinder 260. The input end of the high voltage feedthrough 240 is connected to the output end of the high voltage transfer connector. The high voltage feedthrough 240 is connected to the high voltage transfer connector via a high voltage short line.

[0067] Furthermore, the high-voltage wire mesh 120 is made of gold-plated tungsten wires with a diameter less than 50 μm. The wire spacing of the high-voltage wire mesh 120 is greater than or equal to 1 mm.

[0068] Furthermore, the thickness of the emission film 110 is less than 2 μm. The emission film 110 needs to have sufficient ductility to ensure that the surface of the emission film 110 has no obvious displacement or shaking under the action of the electric field.

[0069] Furthermore, the vacuum sealing flange 230 is provided with a glass window 231. The lens of the camera 300 is closely arranged with the glass window 231. The center of the lower surface of the fluorescent screen 140 is on the center line of the glass window 231, and the two are 45° or 135°. In this way, the probe assembly 100 is driven to the center of the beam pipe by the solenoid valve controlling the cylinder 260. Then, the aperture and focal length of the camera 300 are controlled and adjusted so that the camera 300 focuses on the fluorescent screen 140, so that the image clarity obtained by the camera 300 is optimal.

[0070] On the other hand, the present invention also provides a method for using the secondary beam profile detector, which can help experimenters make full use of the secondary beam profile detector described in the above embodiments.

[0071] The steps of the method of use include: S1, removing the probe assembly 100 and placing it in a vacuum target chamber.

[0072] S2. Fix the secondary beam profile detector to the outside of the vacuum target chamber through the vacuum sealing flange 230, and then install the probe assembly 100 to the end of the inner tube 220 from the vacuum target chamber.

[0073] S3. The bias source disposed outside the vacuum target chamber is electrically connected to the probe assembly 100 through the high voltage feedthrough 240 installed at the end of the inner tube 220 .

[0074] S4, the camera 300 is electrically connected to a host computer disposed outside the vacuum target chamber, and the monitoring image of the secondary beam is viewed by reading software through the camera 300.

[0075] like Figure 5 As shown, a vacuum target chamber is set up, and the probe assembly 100 of the secondary beam profile detector is placed in the vacuum target chamber. The camera 300 is fixed downstream of the fluorescent screen 140. The network port of the camera 300 is connected to the network port connector of the high-voltage feedthrough 240. The α radiation source is placed upstream of the radiation film and fixed. The activity of the α radiation source needs to be greater than 1E4Bq. The output end of the bias source is connected to the high-voltage input end of the high-voltage feedthrough 240. The host computer is connected to the network port connector and the power connector of the high-voltage feedthrough 240.

[0076] remove Figure 5 In addition to the device shown in the figure, there are also mechanical pumps, molecular pumps, vacuum gauges and other equipment. After the vacuum target chamber is sealed, a mechanical pump is used to evacuate the chamber until the pressure reaches below 1E-1mbar. Then, the molecular pump is turned on to evacuate the chamber to below 1E-6mbar.

[0077] After that, turn on the bias source input voltage and press Figure 4The bias voltage application method shown is used to load the probe assembly 100. It should be noted that the voltage of the MCP assembly 130 needs to set the voltage rise speed and the voltage fall speed to 5V / s. Use the host computer to power the camera 300 and view the image.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A secondary beam profile detector, characterized in that: include: A probe assembly (100) is provided with an emission film (110) for generating secondary electrons and a high-voltage wire mesh (120) for providing an electric field; A moving probe (200) comprises an outer tube (210), a vacuum sealing flange (230) sleeved on an end of the outer tube (210), and an inner tube (220) slidably connected to the outer tube (210); A camera (300), wherein a lens of the camera (300) is embedded in the vacuum sealing flange (230), and the camera (300) and the outer tube (210) are located on one side of the vacuum sealing flange (230); The probe assembly (100) is located on the other side of the vacuum sealing flange (230) and is mounted on the end of the inner tube (220) that protrudes out of the outer tube (210), and the probe assembly (100) further comprises an MCP assembly (130) and a fluorescent screen (140) that are arranged parallel to and spaced from the emission film (110); The fluorescent screen (140) is inclined at 45° with respect to the lens of the camera (300), and its center coincides with the central axis of the lens of the camera (300).

2. The secondary beam profile detector according to claim 1, characterized in that: The probe assembly (100) further comprises a support rod (150), the emission film (110) and the high-voltage wire mesh (120) being sequentially mounted on the upper end of the support rod (150) from top to bottom to form a field cage for guiding secondary electrons to the MCP assembly (130); The MCP assembly (130) and the fluorescent screen (140) are sequentially mounted on the lower end of the support rod (150) from top to bottom.

3. The secondary beam profile detector according to claim 2, characterized in that: The probe assembly (100) further comprises a partition (160) arranged between the emission film (110) and the high-voltage wire mesh (120) and used to increase the spacing; the thickness of the partition (160) is 5 mm.

4. The secondary beam profile detector according to claim 3, characterized in that: The MCP assembly (130) comprises an MCP, an MCP upper electrode plate, an MCP middle plate, and an MCP lower electrode plate which are arranged in sequence from top to bottom.

5. The secondary beam profile detector according to any one of claims 1 to 4, characterized in that: The moving probe (200) further comprises a high-voltage feedthrough (240), which is arranged at an end of the inner tube (220) that protrudes out of the outer tube (210); The probe assembly (100) is electrically connected to the high-voltage feedthrough (240) and is used to transmit signals or substances under the condition of vacuum environment sealing.

6. The secondary beam profile detector according to claim 5, characterized in that: The motion probe (200) further comprises: A probe support (250) is arranged in parallel above the outer tube (210); the length of the probe support (250) is greater than the length of the outer tube (210); one end of the probe support (250) is fixedly connected to the vacuum sealing flange (230); A cylinder (260) mounted on the probe support (250) and extending from the other end of the probe support (250) in a direction away from the vacuum sealing flange (230), and used for driving the inner tube (220) to slide out of the outer tube (210); A motion guide rail (270) is fixed to a side of the probe support (250) facing the outer tube (210) and is arranged parallel to an axial direction of the outer tube (210); The inner tube (220) is connected to a slider of the motion guide rail (270), and the telescopic rod of the cylinder (260) is connected to the slider.

7. The secondary beam profile detector according to claim 6, characterized in that: The high-voltage wire mesh (120) is made of gold-plated tungsten wires with a diameter less than 50 μm, and the wire spacing of the high-voltage wire mesh (120) is greater than or equal to 1 mm.

8. The secondary beam profile detector according to claim 6, characterized in that: The emission film (110) has a thickness of less than 2 μm.

9. The secondary beam profile detector according to claim 6, characterized in that: The vacuum sealing flange (230) is provided with a glass window (231), and the lens of the camera (300) is arranged in close contact with the glass window (231).

10. A method for using a secondary beam profile detector, characterized in that: Applicable to the secondary beam profile detector according to any one of claims 1 to 9, S1, removing the probe assembly (100) and placing it in a vacuum target chamber; S2, fixing the secondary beam profile detector to the outside of the vacuum target chamber via the vacuum sealing flange (230), and then installing the probe assembly (100) from inside the vacuum target chamber to the end of the inner tube (220); S3, electrically connecting a bias source disposed outside the vacuum target chamber to the probe assembly (100) via a high-voltage feedthrough (240) installed at the end of the inner tube (220); S4, the camera (300) is electrically connected to a host computer arranged outside the vacuum target chamber, and the monitoring image of the secondary beam is viewed by reading software through the camera (300).

Images