Secondary beam profile detector and method of using the same

Abstract

The present invention relates to the field of heavy ion accelerator beam diagnostic technology, and in particular to a secondary beam profile detector and a method for using the same. The secondary beam profile detector comprises: a probe assembly, provided with an emission film for generating secondary electrons and a high-voltage wire mesh for providing an electric field; a moving probe, comprising an outer tube, a vacuum sealing flange sleeved on the outer tube, and an inner tube slidably connected to the outer tube; a camera, mounted on the vacuum sealing flange and located below the outer tube; wherein the probe assembly is mounted on the end of the inner tube cantilevered out of the outer tube, and the probe assembly further comprises an MCP assembly and a fluorescent screen arranged parallel to and spaced apart from the emission film; the fluorescent screen is tilted 45° with respect to the camera lens and its center coincides with the central axis of the camera lens. In the present invention, the probe assembly adopts a readout method of a microchannel plate combined with a fluorescent screen, which can be used to measure beam profiles in a larger flow range, taking into account both strong and weak secondary beam currents.

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 secondary electron emission while studying the properties of high-temperature gases. However, it wasn't until 1950 that Alvarez and Cohen applied this phenomenon as a detection method in accelerators, such as fission research and nuclear reaction product analysis. In the 1950s, scintillator or semiconductor detectors were used to collect and multiply the accelerated secondary electrons. However, because scintillator and semiconductor detectors are insensitive to electrons with energies below 5 keV, voltages of 5 kV or even higher were required. Furthermore, this method only achieved temporal resolution in the nanosecond range. Consequently, with the advancement of multiplication equipment, from two-stage multipliers to channel multipliers and finally to microchannel plates (MCPs), significant improvements in temporal resolution, position resolution, and operational stability were achieved.

[0003] In 1990, Charles Evans et al. in the United States applied MCP to online measurement of weak beam currents, addressing the problem of measuring beam currents in the range of [1E5 pps, 1E10 pps]. Weak beam currents below 1E5 pps can be accurately measured using semiconductor detectors, while strong beam currents above 1E10 pps can be measured using electromagnetic induction probes. The gap between these two ranges is a weakness of slow extraction measurement. In terms of its operating principle, after the beam passes through a metal film, the energy loss caused by the film surface is transferred to the atoms or molecules on the surface, which emit secondary electrons. The secondary electrons generated by this method have very low energy, mostly less than 100 eV. A negative high voltage is applied to the metal film, followed by a high-voltage wire mesh with a lower negative voltage than the metal film. The generated electric field guides the secondary electrons toward the top surface of the MCP. MCPs can be stacked in pairs. Negative high voltage is applied to the top surface of the MCP, while the bottom surface of the MCP is connected to a protective ground. The guided secondary electrons enter the tiny tubes of the MCP, where they are amplified by avalanche and then attracted by the positive high voltage on the surface of the phosphor screen, where they strike the screen and produce visible light. Finally, a camera (CCD) transmits the image to the client.

[0004] It's important to note that the number of secondary electrons emitted by a single particle after passing through the emitter film, also known as the secondary electron yield, directly affects the detector's lower current measurement limit and signal-to-noise ratio. In 1990, H.L. Seifert of Los Alamos National Laboratory in the United States demonstrated that vapor-depositing cesium iodide (CsI) on an aluminum film significantly increased its secondary electron yield. In 2013, Harasimowicz Janusz of the University of Liverpool in the United Kingdom proposed in his doctoral dissertation that a mesh structure with both vertical and horizontal high-voltage wires effectively reduces the effects of electric field distortion. Furthermore, the voltage differential between the emitter film and the high-voltage wire mesh (5 mm apart) is greater than 2000V, ensuring the detector's position resolution.

[0005] Measuring beam profiles, especially those of weak beams, is crucial for radioactive separation devices. However, existing technologies, such as striped ionization chambers, fluorescent targets, and multi-wire proportional chambers, suffer from high energy losses, failing to meet the requirements of radioactive separation devices and lacking the ability to monitor secondary beam profiles in real time.

[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 address at least one of the technical problems existing in the related art. To this end, the present invention provides a secondary beam profile detector and its use method, which enables real-time online measurement of the radioactive secondary beam profile to obtain secondary beam optics. This can be compared with simulated beam optics, thereby effectively reducing beam tuning time and improving beam quality at the experimental terminal.

[0008] In a first aspect, the present invention provides a secondary beam profile detector, comprising:

[0009] A probe assembly is provided with an emission film for generating secondary electrons and a high-voltage wire mesh for providing an electric field;

[0010] The moving probe comprises an outer tube, a vacuum sealing flange sleeved on an end of the outer tube, and an inner tube slidably connected to the outer tube;

[0011] a camera, wherein the 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;

[0012] The probe assembly is located on the other side of the vacuum sealing flange and is installed on 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 apart from the emission film.

[0013] The fluorescent screen is inclined at 45° to the camera lens and its center coincides with the central axis of the camera lens.

[0014] 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 mounted on the upper end of the support rod from top to bottom to form a field cage for guiding secondary electrons toward the MCP assembly;

[0015] The MCP assembly and the fluorescent screen are sequentially installed on the lower end of the support rod from top to bottom.

[0016] 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 distance therebetween, and the thickness of the partition plate is 5 mm.

[0017] 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 arranged in sequence from top to bottom.

[0018] According to a secondary beam profile detector provided by the present invention, the moving probe further comprises a high-voltage feedthrough, which is provided at an end of the inner tube overhanging the outer tube;

[0019] The probe assembly is electrically connected to the high voltage feedthrough for transmitting signals or substances under a sealed vacuum environment.

[0020] According to a secondary beam profile detector provided by the present invention, the moving probe further includes:

[0021] a probe support, arranged parallel to and above the outer tube, the length of the probe support being greater than the length of the outer tube, and one end of the probe support being fixedly connected to the vacuum sealing flange;

[0022] 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;

[0023] A motion guide rail is fixed to the probe support, facing the side of the outer tube and arranged parallel to the axis of the outer tube;

[0024] 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.

[0025] 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.

[0026] According to a secondary beam profile detector provided by the present invention, the thickness of the emission film is less than 2 μm.

[0027] According to the 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.

[0028] 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.

[0029] S1. Remove the probe assembly and place it in a vacuum target chamber;

[0030] 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 to the end of the inner tube from the vacuum target chamber;

[0031] 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;

[0032] S4. The camera is electrically connected to a host computer disposed outside the vacuum target chamber, and the monitoring image of the secondary beam is viewed through the camera reading software.

[0033] The above one or more technical solutions in the present invention have at least one of the following technical effects:

[0034] 1. The probe assembly adopts a readout method of microchannel plate combined with fluorescent screen, which can be used to measure the beam profile in a large range of flux intensities, taking into account both strong and weak secondary beam currents.

[0035] 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.

[0036] 3. The secondary beam profile detector of the present application can also observe the longitudinal structure of the beam, compare the relative intensities of the beams, and distinguish the measurements of the primary beam and the secondary beam.

[0037] 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.

[0038] 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 can be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. 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 any creative work.

[0040] Figure 1 A schematic diagram of the three-dimensional structure of a secondary beam profile detector provided in an embodiment of the present invention.

[0041] Figure 2 This is a cross-sectional structural diagram along the longitudinal symmetry plane of the secondary beam profile detector provided by an embodiment of the present invention.

[0042] Figure 3 A schematic diagram of the wire spacing of the high-voltage wire mesh provided in an embodiment of the present invention.

[0043] Figure 4 A schematic diagram of a bias voltage application method for a probe assembly provided in an embodiment of the present invention.

[0044] Figure 5 A schematic diagram of using a secondary beam profile detector in a vacuum target chamber according to an embodiment of the present invention.

[0045] Reference numerals:

[0046] 100, probe assembly; 110, emission 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

[0047] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0048] 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", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship 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 device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0049] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on the specific circumstances.

[0050] In the embodiments of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," and "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 at a higher level than the second feature. A first feature being "below," "below," and "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 at a lower level than the second feature.

[0051] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" 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 embodiments 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 can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0052] In order to address the shortcomings of existing technologies such as striped ionization chambers, fluorescent targets, and multi-wire proportional chambers, which have high energy losses, cannot meet the requirements of radioactive separation devices, and cannot monitor secondary beam profile information in real time, a secondary beam profile detector is introduced in an embodiment of the present invention.

[0053] 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 .

[0054] 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.

[0055] 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 .

[0056] Specifically, the vacuum sealing flange 230 includes a mounting plate that is sleeved with the outer tube 210 and an annular flange edge provided 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.

[0057] The camera 300's lens 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, the mounting plate of the vacuum-sealing flange 230 has two sockets: one for embedding the end of the outer tube 210, and the other for embedding the camera 300's lens. The camera 300's lens and the outer tube 210 are parallel to each other and are located on the side of the vacuum-sealing flange 230 that is offset from the flange edge.

[0058] 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. Therefore, 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.

[0059] 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 .

[0060] The fluorescent screen 140 is tilted 45° with respect to the lens of the camera 300 , and the center of the fluorescent screen 140 coincides with the central axis of the lens of the camera 300 .

[0061] Furthermore, the fluorescent screen 140 is made of a 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.

[0062] 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. It is suitable for measuring beam profiles in a larger flow intensity range, taking into account both strong and weak secondary beam currents.

[0063] Based on the above embodiment, another embodiment of the present invention introduces a secondary beam profile detector.

[0064] To secure the emission film 110, high-voltage wire mesh 120, MCP assembly 130, and phosphor screen 140 together, the probe assembly 100 further includes a support rod 150. The emission film 110 and high-voltage wire mesh 120 are sequentially mounted on the upper end of the support rod 150 from top to bottom to form a field cage for guiding secondary electrons toward the MCP assembly 130.

[0065] 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.

[0066] In particular, if Figure 4 As shown, the emitting film 110 is applied with a voltage of -5000V or higher. The high-voltage wire mesh 120 is applied with a voltage of -2000V. The top surface of the MCP assembly 130 is applied with a voltage of -1400V to -2000V. The bottom surface of the MCP assembly 130 is grounded or connected to a protective resistor and then to ground. The top surface of the phosphor screen 140 is applied with a voltage of +5000V.

[0067] After the beam penetrates the emitter film 110, secondary electrons are generated on its surface. The electric field formed between the emitter film 110 and the high-voltage wire mesh 120 guides these electrons toward the MCP assembly 130. After avalanche amplification by the MCP assembly 130, these electrons strike the fluorescent screen 140, generating visible light. The image on the fluorescent screen 140 is then transmitted to the host computer using the camera 300.

[0068] Based on the above embodiment, another embodiment of the present invention introduces a secondary beam profile detector.

[0069] The probe assembly 100 further includes a spacer 160 disposed between the emission film 110 and the high-voltage wire mesh 120 to increase the distance therebetween. The spacer 160 has a thickness of 5 mm.

[0070] like Figure 3 As shown, 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 1mm, considering that the high-voltage wire mesh 120 is placed at a 45° angle, the spacing in the other direction is equivalent to , which is 707μm. The transmittance η of the high-voltage wire mesh 120 is calculated as follows:

[0071] ;

[0072] Wherein, d represents the wire diameter.

[0073] 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:

[0074] ;

[0075] Based on the above embodiment, another embodiment of the present invention introduces a secondary beam profile detector.

[0076] 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.

[0077] Furthermore, the number of MCPs can be 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.

[0078] The maximum gain of one MCP is 1E4, and the maximum gain of two MCPs is 1E6. If two MCPs are used, they must be installed in a V-shaped configuration, with the microchannel holes of the MCPs facing 180 degrees.

[0079] Based on the above embodiment, another embodiment of the present invention introduces a secondary beam profile detector.

[0080] The moving probe 200 further includes a probe support 250 , a cylinder 260 and a moving guide rail 270 .

[0081] 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.

[0082] 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.

[0083] 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.

[0084] Furthermore, the moving probe 200 further includes a high-voltage feedthrough 240 . The high-voltage feedthrough 240 is provided at the end of the inner tube 220 that overhangs the outer tube 210 .

[0085] The probe assembly 100 is electrically connected to the high-voltage feedthrough 240 for transmitting signals or substances in a sealed vacuum environment.

[0086] The high voltage input terminals of the emitting film 110 and the high voltage wire mesh 120 are both connected to the output terminal of the high voltage feedthrough 240. The high voltage input terminals of the MCP assembly 130 and the phosphor screen 140 are both connected to the output terminal of the high voltage feedthrough 240.

[0087] The moving probe 200 further includes a high-voltage adapter connector disposed on 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 adapter connector. The high-voltage feedthrough 240 is connected to the high-voltage adapter connector via a high-voltage short line.

[0088] Furthermore, 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.

[0089] Furthermore, the thickness of the emitting film 110 is less than 2 μm. The emitting film 110 needs to have sufficient ductility to ensure that the surface of the emitting film 110 does not have obvious displacement or shaking under the action of the electric field.

[0090] Furthermore, the vacuum sealing flange 230 is provided with a glass window 231. The lens of the camera 300 is positioned in close contact with the glass window 231. The center of the lower surface of the fluorescent screen 140 is aligned with the centerline of the glass window 231, with the two forming a 45° or 135° angle. In this manner, the solenoid valve controls the cylinder 260 to move the probe assembly 100 to the center of the beam tube. The aperture and focal length of the camera 300 are then adjusted to focus the camera 300 on the fluorescent screen 140, thereby achieving optimal image clarity.

[0091] On the other hand, the present invention also provides a method for using the secondary beam profile detector, which can help experimenters fully utilize the secondary beam profile detector described in the above embodiments.

[0092] The steps of the method of use include: S1, removing the probe assembly 100 and placing it in a vacuum target chamber.

[0093] 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.

[0094] 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 .

[0095] 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.

[0096] 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 within the vacuum target chamber. A camera 300 is secured downstream of the fluorescent screen 140. The Ethernet port of the camera 300 is connected to the Ethernet connector of the high-voltage feedthrough 240. An alpha radiation source is placed upstream of the radiation film and secured. The activity of the alpha radiation source must be greater than 1E4 Bq. The output of the bias source is connected to the high-voltage input of the high-voltage feedthrough 240. The host computer is connected to the Ethernet connector and power connector of the high-voltage feedthrough 240.

[0097] remove Figure 5 In addition to the apparatus shown in the figure, a mechanical pump, molecular pump, vacuum gauge, and other equipment are also configured. After the vacuum target chamber is sealed, the mechanical pump is used to evacuate the chamber until the pressure reaches below 1E-1 mbar. Then, the molecular pump is turned on to reduce the vacuum to below 1E-6 mbar.

[0098] 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 be set to 5V / s for both the voltage rise and fall speeds. Use the host computer to power the camera 300 and view the image.

[0099] 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 various 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). The probe assembly (100) further includes an MCP assembly (130) and a fluorescent screen (140) that are arranged parallel to and spaced apart from the emission film (110). The probe assembly (100) further comprises a support rod (150), and the emission film (110) and the high-voltage wire mesh (120) are sequentially mounted on the upper end of the support rod (150) from top to bottom to form a field cage for guiding secondary electrons toward 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; The fluorescent screen (140) is tilted 45 degrees relative 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 partition (160) arranged between the emission film (110) and the high-voltage wire mesh (120) for increasing the spacing, and the thickness of the partition (160) is 5 mm.

3. The secondary beam profile detector according to claim 2, 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.

4. The secondary beam profile detector according to any one of claims 1 to 3, characterized in that: The motion probe (200) further includes a high-voltage feedthrough (240) disposed at an end of the inner tube (220) that overhangs 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 sealing.

5. The secondary beam profile detector according to claim 4, characterized in that: The motion probe (200) further comprises: a probe support (250) arranged parallel to and above the outer tube (210); the length of the probe support (250) is greater than the length of the outer tube (210); and 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), for driving the inner tube (220) to slide out of the outer tube (210); A motion guide rail (270) is fixed to the side of the probe support (250) facing the outer tube (210) and is arranged parallel to the axial direction of the outer tube (210); The inner tube (220) is connected to the slider of the motion guide rail (270), and the telescopic rod of the cylinder (260) is connected to the slider.

6. The secondary beam profile detector according to claim 5, 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.

7. The secondary beam profile detector according to claim 5, characterized in that: The emission film (110) has a thickness of less than 2 μm.

8. The secondary beam profile detector according to claim 5, 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).

9. 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 8, 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) to the end of the inner tube (220) from inside the vacuum target chamber; 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, electrically connecting the camera (300) to a host computer arranged outside the vacuum target chamber, and viewing the monitoring image of the secondary beam through the camera (300) reading software.

Images