Sensing end structure of finger target, beam current testing device and beam current regulation and control method

Abstract

The invention relates to the technical field of cyclotrons, and discloses a sensing end structure of a finger target, a beam test device and a beam regulation and control method, the sensing end structure of the finger target comprises a plurality of target fingers, the plurality of target fingers are parallel to a first direction, two adjacent target fingers are arranged at intervals in a second direction, and the beam test device is arranged in the second direction. The plurality of target fingers are sequentially arranged in a third direction; wherein in a projection plane orthogonal to the second direction, each target finger is projected in the second direction to form a target finger projection, and boundaries of two adjacent target finger projections are mutually overlapped in the third direction. The sensing end structure of the finger target overcomes the technical problem that the measurement accuracy of axial distribution of the beam is not high, the axial distribution of the beam in a narrow pulse state can be accurately measured through specific arrangement of a plurality of target fingers, and guidance is provided for debugging of deflection devices such as screw sheet deflection plate voltage and an electrostatic deflection mirror.

Description

Technical Field

[0001] The present invention relates to the technical field of cyclotron accelerators, and in particular to a sensing end structure of a target, a beam testing device and a beam control method. Background Art

[0002] During the debugging process of the cyclotron, it is necessary to measure the beam intensity at various positions from the small radius to the large radius of the cyclotron. The radial target is the main component in the beam diagnostic system to achieve the above function. The radial target is installed on the flange on the side of the vacuum chamber of the cyclotron. The radial target head is inserted into the cyclotron along the radial direction of the cyclotron. The beam intensity measurement at different radii can be completed by controlling the insertion depth. In the existing technology, the head of the radial target is a rectangular copper block, and the target rod is used as the signal transmission line. The copper block transmits the beam signal to the end of the target rod through the target rod for beam measurement. The copper block adopts a water-cooled structure to withstand high-power beam bombardment. The radial drive mechanism of the entire device is set at the tail of the target rod. Among them, the target rod and the vacuum chamber are insulated and sealed.

[0003] In order to adjust and optimize the beam, technicians usually need to adjust the beam in the cyclotron. The beam is deflected from the axial injection line to the central plane through various forms of deflection devices such as spiral deflection plates and electrostatic deflection mirrors. The beam characteristics at the exit of the deflection device determine the beam quality during the beam acceleration and extraction process. A beam diagnostic system is needed to measure the axial distribution of the beam after the deflection device, and adjust the voltage or other parameters of the spiral deflection plate to center the beam axially, so as to achieve the purpose of optimizing beam transmission.

[0004] Before adjusting the beam, it is necessary to understand the beam conditions in the cyclotron. In the prior art, in order to measure the axial distribution of the beam, a graphite strip is set above and below the beam extraction stripping film. When the beam deviates from the center plane, an electrical signal will be generated on the graphite strip, thereby providing guidance for the axial centering adjustment of the beam. However, this measurement method can only measure the deviation of the beam, but not the entire axial distribution of the beam. At the same time, the measurement results of this scheme are too lagging, and the risk of the beam deviating from the center plane and bombarding the magnetic poles to cause device activation increases, and the reference value for the axial centering adjustment of the beam is not great. In another prior art, for example, CN201710724556, a finger target is used to measure the axial distribution of the beam. In order to prevent the secondary electrons generated by the finger target from interfering with the measurement of other target fingers, the target fingers must be spaced apart. The spaced target fingers cannot accurately measure the axial beam, that is, the axial distribution of the measured beam is inaccurate. In the process of adjusting the beam, due to the inaccurate axial distribution of the measured beam, adjusting the beam with reference to the measurement result will lead to an increase in the error of adjusting the beam, that is, it cannot effectively guide the beam adjustment.

[0005] In the prior art, how to improve the accuracy of measuring the axial distribution of the beam is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0006] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the embodiments of the present invention provide a sensing end structure of a finger target, a beam test device and a beam control method. The beam test device can accurately measure the axial distribution of the beam under a narrow pulse state by specifically arranging multiple target fingers, and provide guidance for the debugging of deflection devices such as the spiral deflection plate voltage and the electrostatic deflection mirror.

[0007] The sensing end structure of the finger target of the first embodiment of the present invention is used in a cyclotron to measure the axial distribution of the beam. The sensing end structure of the finger target includes:

[0008] A plurality of target fingers, wherein the plurality of target fingers are parallel to a first direction, two adjacent target fingers are arranged at intervals in a second direction, and the plurality of target fingers are arranged in sequence in a third direction;

[0009] Wherein, in a projection plane orthogonal to the second direction, each of the target fingers is projected in the second direction to form a target finger projection, and boundaries of two adjacent target finger projections overlap with each other in the third direction;

[0010] The first direction, the second direction and the third direction are orthogonal to each other.

[0011] The sensing end structure of the finger target can solve the technical problem of how to improve the accuracy of measuring the axial distribution of the beam. By staggering multiple target fingers to ensure mutual insulation between the target fingers, it ensures that the electrical signal measured by each target finger will not be affected by other target fingers, thereby improving the accuracy of target finger measurement. In addition, multiple target fingers are arranged in sequence in the third direction, which can be used to measure the axial distribution of the beam under a narrow pulse state, provide guidance for locating the axial loss position, and provide a reference for beam debugging. In addition, the boundaries of the projections of two adjacent target fingers overlap in the third direction, which can prevent the beam from passing through the gap between the two adjacent target fingers, that is, the axially distributed beam can all hit the target finger, thereby improving the accuracy of measuring the axial distribution of the beam.

[0012] Optionally, the distance between two adjacent target fingers in the second direction is greater than the flight radius of secondary electrons generated by the beam bombarding the target fingers.

[0013] Optionally, the size of the target finger in the third direction is larger than the flight radius of secondary electrons generated by the beam bombarding the target finger.

[0014] The beam testing device of the second embodiment of the present invention comprises:

[0015] The sensing end structure of the above-mentioned finger target;

[0016] A target head block, the target head block having a first surface and a second surface arranged opposite to each other in the second direction, the first surface being used for beam bombardment;

[0017] A mounting base is provided on the second surface, and the target finger is mounted on the mounting base.

[0018] The beam test device can solve the technical problem of how to quickly measure the total intensity of the beam and the axial distribution intensity of the beam. By combining the target finger and the target head block, the target head block can be adjusted so that the beam can bombard the first surface or the second surface. When the beam bombards the first surface, the target head block can accept the beam bombardment of the narrow pulse or DC state of the cyclotron for a long time to complete the beam intensity measurement, which is used to evaluate the central area extraction intensity, accelerator beam transmission efficiency and accelerator beam stability and other indicators, and provide a reference for the beam debugging of the cyclotron. When the beam bombards the second surface, that is, the beam bombards the target finger, it can be used to measure the axial distribution of the beam under the narrow pulse state, provide guidance for the debugging of deflection devices such as the spiral deflection plate voltage and the electrostatic deflection mirror, and provide guidance for locating the axial loss position, and provide a reference for beam debugging.

[0019] Optionally, the mounting block is provided with a plurality of protrusions protruding toward the second direction, the plurality of protrusions are arranged in sequence in the third direction, the protrusion sizes of two adjacent protrusions are different, the target finger is located at the top of the protrusion, and the target finger corresponds to the protrusion one by one.

[0020] Optionally, the first surface intersects the second direction.

[0021] Optionally, a first signal transmission line is connected to the target head block;

[0022] Each of the target fingers is connected with a second signal transmission line.

[0023] Optionally, the target head block has a third surface orthogonal to the first direction, a heat exchange space for accommodating a heat exchange medium is provided inside the target head block, a heat exchange outlet and a heat exchange inlet located on the third surface are provided on the target head block, and the beam test device further includes:

[0024] a first tube, the first tube being connected to the heat exchange outlet;

[0025] A second tube is connected to the heat exchange inlet.

[0026] Optionally, the beam testing device further includes:

[0027] A target rod, the target rod being connected to the third surface of the target head block;

[0028] A driver is connected to the target rod, and the driver can drive the target rod to move back and forth in the first direction and drive the target rod to rotate.

[0029] A beam control method according to another embodiment of the present invention includes:

[0030] The beam control method of the third embodiment of the present invention includes the above-mentioned beam testing device, and the beam control method includes:

[0031] S1: installing the beam test device at a corresponding position on the cyclotron, and starting the cyclotron;

[0032] S2: preset various parameters of the cyclotron accelerator, as well as expected axial beam parameters and radial beam parameters;

[0033] S3: controlling the driver to drive the target head block to reciprocate in the first direction and to drive the target head block to rotate, so as to measure the real-time axial beam parameters and radial beam parameters;

[0034] S4: comparing the real-time axial beam parameters and radial beam parameters obtained in step S3 with expected axial beam parameters and radial beam parameters respectively, and determining whether the expected axial beam parameters and radial beam parameters are achieved;

[0035] If reached, jump to step S6;

[0036] If not reached, continue to step S5;

[0037] S5: adjusting the control parameters of the cyclotron to act on the beam, and returning to step S3;

[0038] S6: Stop the driver to complete the regulation of the beam current.

[0039] The beam control method can solve the problem of how to quickly debug the beam, by using a beam test device to measure the beam axial distribution and the beam radial distribution, that is, the beam intensity, the beam axial distribution and the beam radial distribution can be measured by the beam test device. In order to make the beam intensity, the beam axial distribution and the beam radial distribution in the cyclotron meet the preset beam intensity, the preset beam axial distribution and the preset beam radial distribution, it is necessary to compare and analyze the beam intensity and the preset beam intensity, the beam axial distribution and the preset beam axial distribution, and the beam radial distribution and the preset beam radial distribution, and then adjust the control parameters of the cyclotron accelerator to adjust the beam, so as to quickly realize the adjustment of the beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Schematic diagram of an explosion of the beam test device in this specific implementation.

[0041] Figure 2 Schematic diagram of an explosion of the beam test device in this specific implementation.

[0042] Figure 3 It is a three-dimensional schematic diagram of the target finger in this specific implementation.

[0043] Figure 4 It is a schematic diagram of the layout of the target fingers in this specific implementation.

[0044] Figure 5 It is a projection schematic diagram of the target finger in this specific implementation.

[0045] Figure 6 It is a schematic diagram of the beam bombarding the target finger in this specific implementation.

[0046] Figure 7 Schematic diagram of the beam bombarding the target block head in this specific implementation.

[0047] Figure 8 It is a front view schematic diagram of the mounting base in this specific implementation.

[0048] Fig. 9 It is a front view schematic diagram of the beam testing device in this specific implementation.

[0049] Fig.10 It is a left side schematic diagram of the beam testing device in this specific implementation.

[0050] Figure markings: 1000-beam test device, 100-target finger, 110-target finger projection, 111-boundary, 200-target head block, 210-first surface, 220-second surface, 230-third surface, 240-heat exchange outlet, 250-heat exchange inlet, 300-mounting base, 310-protrusion, 400-first tube, 500-second tube, 600-target rod, 610-first hole, 620-second hole, 700-driver, 710-first motor, 720-second motor, 800-support frame, 810-sliding plate, 820-support plate, 830-groove track, 1-first direction, 2-second direction, 3-second direction, 4-projection plane. DETAILED DESCRIPTION

[0051] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0052] The following describes the sensing end structure of the target according to the embodiment of the present invention with reference to the accompanying drawings. Figures 1 to 8 As shown, the sensing end structure of the finger target according to the embodiment of the present invention includes a plurality of target fingers 100 .

[0053] A plurality of target fingers 100 are parallel to a first direction 1, two adjacent target fingers 100 are spaced apart in a second direction 2, and a plurality of target fingers 100 are sequentially arranged in a third direction 3, wherein, in a projection plane 4 orthogonal to the second direction 2, each target finger 100 is projected in the second direction 2 to form a target finger projection 110, boundaries 111 between two adjacent target finger projections 110 overlap in the third direction 3, and the first direction 1, the second direction 2, and the third direction 3 are orthogonal to each other.

[0054] According to the sensing end structure of the finger target in the specific embodiment of the present invention, by staggering the plurality of target fingers 100, it is ensured that the target fingers 100 are insulated from each other, and it is ensured that the electrical signal measured by each target finger 100 will not be affected by other target fingers 100, thereby improving the accuracy of the measurement of the target finger 100. In addition, the plurality of target fingers 100 are arranged in sequence in the third direction 3, which can be used to measure the axial distribution of the beam under the narrow pulse state, provide guidance for locating the axial loss position, and provide a reference basis for beam debugging. In addition, the boundaries 111 of the projections 110 of two adjacent target fingers overlap with each other in the third direction 3, which can prevent the beam from passing through the gap between the two adjacent target fingers 100, that is, the axially distributed beam can all bombard the target finger 100, thereby improving the accuracy of measuring the axial distribution of the beam.

[0055] like Figures 1 to 8 In order to make the technical solution of the present application easier to understand, the technical solution of the present application is described in more detail below with reference to a specific embodiment of the beam testing device 1000. Figure 1 The front-to-back direction shown is a first direction 1, such as Figure 1 The up and down direction shown is the second direction 2. Figure 3 The left-right direction shown is a third direction 3 , and the first direction 1 , the second direction 2 and the third direction 3 are orthogonal to each other.

[0056] In some specific embodiments, Figures 1 to 7 As shown, a plurality of target fingers 100 are parallel to a first direction 1, two adjacent target fingers 100 are spaced apart in a second direction 2, and a plurality of target fingers 100 are sequentially arranged in a third direction 3, wherein, in a projection plane 4 orthogonal to the second direction 2, each target finger 100 is projected in the second direction 2 to form a target finger projection 110, boundaries 111 between two adjacent target finger projections 110 overlap in the third direction 3, and the first direction 1, the second direction 3 and the third direction 3 are orthogonal to each other.

[0057] Specifically, Figure 4As shown, the specific arrangement of the multiple target fingers 100 can be manner (a), manner (b) and manner (c), etc., wherein these arrangements are for the convenience of quick understanding of the technical solution and do not represent all arrangements in the technical solution. Preferably, the arrangement of the multiple target fingers 100 in this specific embodiment is preferably manner (a).

[0058] Arranging multiple target fingers 100 in the above manner can ensure that the target fingers 100 are insulated from each other, prevent the electrical signals between the target fingers 100 from interfering with each other, ensure that the signal measured by each target finger 100 will not be affected by other target fingers 100, and improve the accuracy of the measurement of the target fingers 100.

[0059] In addition, multiple target fingers 100 are arranged in sequence in the third direction 3, that is, multiple target fingers 100 are arranged in sequence in the axial direction of the cyclotron, which can be used to measure the axial distribution of the beam in the narrow pulse state, provide guidance for locating the axial loss position, and provide a reference basis for beam debugging. In other words, when the beam direction is parallel to the second direction 2 and the axial direction of the cyclotron is parallel to the third direction 3, the beam can directly bombard the multiple target fingers 100. Multiple target fingers 100 are arranged in sequence in the third direction 3, that is, multiple target fingers 100 are arranged in sequence in the axial direction of the cyclotron. Through the arrangement of multiple target fingers 100, the bombardment surface of the beam can be cut into axially arranged strip bombardment areas, each strip bombardment area represents the beam intensity of the area, and then the axial distribution of the beam can be measured. Furthermore, when the axial distribution of the beam is known, the beam distribution of the entire bombardment surface corresponding to the beam can be obtained according to the axial distribution of the beam, that is, it can be used to measure the axial distribution of the beam under a narrow pulse state, provide guidance for locating the axial loss position, and provide a reference for beam debugging.

[0060] In addition, the boundaries 111 of two adjacent target finger projections 110 overlap with each other in the third direction 3, and the beam direction is parallel to the second direction 2. When the beam bombards multiple target fingers 100, the multiple target fingers 100 can completely intercept the beam corresponding to the area, that is, when the beam bombards the area corresponding to the multiple target fingers 100, there is no gap between the multiple target fingers 100, which can prevent the beam from passing through the gap between two adjacent target fingers 100, that is, the axially distributed beam can completely bombard the target finger 100, thereby improving the accuracy of measuring the axial distribution of the beam.

[0061] In the cyclotron, a nuclear reaction occurs after the beam bombards the target finger 100, and some electrons in the target finger 100 gain energy. These electrons can escape from the target finger 100. At the same time, positively charged particles remain in the target finger 100. The escaped electrons move relative to the positively charged particles, thereby forming a current. By measuring the current, beam diagnostic measurement can be achieved.

[0062] In summary, by specifically arranging multiple target fingers 100, it is possible to measure the axial distribution of the beam under a narrow pulse state, and provide guidance for debugging deflection devices such as the spiral deflection plate voltage and the electrostatic deflection mirror.

[0063] In some specific embodiments, Figures 1 to 5 As shown, the distance between two adjacent target fingers 100 in the second direction 2 is greater than the flight radius of secondary electrons generated by the beam bombarding the target finger 100. When measuring the axial distribution of the beam, each target finger 100 can accurately express the axial distribution of the beam, and the distance between two adjacent target fingers 100 in the second direction 2 itself has no effect on the accuracy of the measurement result of the axial distribution of the beam.

[0064] Specifically, the principle of charge measurement for nuclear reactions in beam diagnosis is as follows: Taking the proton cyclotron as an example, when the beam vertically bombards the target at 100 different positions, the maximum kinetic energy of the secondary electrons is estimated. Now, it is assumed that the proton energy in the extraction region is about 200 MeV; the secondary electron energy formula is:

[0065]

[0066] Among them, E max is the maximum energy of the secondary electron; m e 、m p are the masses of electrons and protons respectively; E p is the energy of the incident proton; θ is the angle between the incident proton and the outgoing electron.

[0067] For an incident proton energy of about 200 MeV, the maximum kinetic energy of the secondary electrons produced does not exceed 400 keV. Since the kinetic energy of the secondary electrons produced is less than the rest energy of the electrons, the relativistic effect of the secondary electrons can be ignored. Then:

[0068] m e =m e0

[0069] Among them, m e 、m e0 are the mass and rest mass of the electron respectively;

[0070] According to the kinetic energy theorem, the kinetic energy of an electron is:

[0071]

[0072] Among them, m e 、m e0 are the mass and rest mass of the electron respectively, and v is the velocity of the electron;

[0073] Under the same magnetic field, the cyclotron ratio of secondary electrons to protons is:

[0074]

[0075] Among them, m e 、m p are the masses of secondary electrons and protons respectively; E p 、E e are the energy of the incident proton and the energy of the secondary electron, respectively; r p 、r e are the cyclotron radius of the proton and the cyclotron radius of the secondary electron respectively; v p 、v e are the speed of the incident proton and the speed of the secondary electron, respectively.

[0076] Preferably, according to the Nyquist sampling theorem, for multiple target fingers 100, the distance between the target fingers 100 is greater than or equal to 2r e Spacing, under the premise that the proton energy in the extraction zone is about 200MeV, the spacing between the target fingers 100 is calculated to be 2mm according to the above principle, which ensures that the generated secondary electrons escape and can avoid flying to the adjacent target fingers 100. After the secondary electrons escape, the positively charged particles remaining inside the target finger 100 and the relative movement of the escaped electrons form a current. By measuring the current size of each target finger 100 to analyze the beam position, this method has more accurate measurement results. At the same time, the target head block 200 can perform intermittent motion to perform real-time measurement and feedback position information, and the position accuracy is higher.

[0077] In some specific embodiments, Figures 1 to 5 As shown, the size of the target finger 100 in the third direction 3 is larger than the flight radius of the secondary electrons generated by the beam bombarding the target finger. Specifically, its working principle and technical effect achieved are the same as the distance between two adjacent target fingers 100 in the second direction 2 is larger than the flight radius of the secondary electrons generated by the beam bombarding the target finger 100, which will not be repeated here.

[0078] In some specific embodiments, Figure 1 As shown, a second signal transmission line is connected to each target finger 100. Specifically, a second signal transmission line is connected to each target finger 100, and the second signal transmission line can transmit the electrical signal of the corresponding target finger 100 to the analysis system, so as to analyze the electrical signal of each target finger 100. In addition, in order to facilitate the electrical connection between the second signal transmission line and the target finger 100, a wiring terminal is added between the target finger 100 and the insulating gasket to realize the electrical connection between the second signal transmission line and the target finger 100.

[0079] In some specific embodiments, Figure 1 As shown, the second signal transmission line passes through the second hole 620 of the target rod 600 and extends into the interior of the target rod 600. The second signal transmission line can be routed inside the target rod 600 and can be connected to the outside of the vacuum chamber.

[0080] In some specific embodiments, the shape of the target finger 100 can be a columnar body, a sheet body, etc., as long as the size of the target finger projection 110 corresponding to the target finger 100 in the third direction 3 is ensured to be larger than the flight radius of the secondary electrons generated by the beam bombarding the target finger 100. Among them, the target finger 100 in this specific embodiment is preferably a rectangular thin sheet. The rectangular thin sheet is adopted because it has a relative width and a clear boundary. Compared with a filament-shaped target finger, it is easier to achieve that the boundaries 111 of two adjacent target finger projections 110 overlap each other in the third direction 3.

[0081] In some specific embodiments, the target finger 100 is made of graphite material to ensure that the target finger 100 can withstand high-power beam bombardment, and the graphite material has good conductivity and is not easily activated by the beam.

[0082] In some specific embodiments, Figure 1 , Figure 2 , Figure 6 and Figure 7 As shown, the target head block 200 has a first surface 210 and a second surface 220 that are arranged opposite to each other in the second direction 3, and the first surface 210 is used for beam bombardment. Specifically, the first surface 210 of the target head block 200 can be used for beam bombardment, and a nuclear reaction occurs on the first surface 210, and part of the electrons that obtain energy will escape from the target head block 200. After the electrons escape, positively charged particles remain in the target head block 200, and the positively charged particles move relative to the escaped electrons to form a current, and then the beam diagnostic measurement can be indirectly completed by measuring the current. In addition, a plurality of target fingers 100 are located on one side of the second surface 220, that is, the target fingers 100 and the target head block 200 are combined together, and the target head block 200 can be adjusted so that the beam can bombard the first surface 210 or the second surface 220. When the beam bombards the first surface 210, the target head block 200 can be bombarded by the narrow pulse or direct current state of the cyclotron for a long time, and the beam intensity measurement is completed, so as to be used to evaluate the central area extraction flux intensity, the accelerator beam transmission efficiency and the accelerator beam stability and other indicators, and provide a reference basis for the beam debugging of the cyclotron. When the beam bombards the second surface 220, that is, the beam bombards the target finger 100, it can be used to measure the axial distribution of the beam in the narrow pulse state, provide guidance for the debugging of deflection devices such as the spiral deflection plate voltage and the electrostatic deflection mirror, provide guidance for locating the axial loss position, and provide a reference basis for beam debugging.

[0083] In some specific embodiments, the shape of the target head block 200 can be any shape.

[0084] In some specific embodiments, Figure 1As shown, the first surface 210 intersects with the second direction 2. Specifically, when the beam direction is parallel to the second direction 2, the first surface 210 intersects with the second direction 2, that is, the first surface 210 intersects with the beam direction, so that a certain angle is formed between the beam direction and the first surface 210. After the beam hits the first surface 210, the beam will generate a large amount of heat on the target head block 200. Since a certain angle is formed between the beam direction and the first surface 210, the heat deposited in the target head block 200 can be at different depths, avoiding heat accumulation in a local area of ​​the target head block 200, preventing the local temperature of the target head block 200 from being too high and being damaged, and indirectly reducing the local heat flux density of the target head block 200. That is to say, the end face of the target head block 200 used to block the beam is not perpendicular to the beam cross section, that is, the first face 210 intersects with the beam direction, and there is a certain angle between the first face 210 and the beam direction. After the beam bombards the first face 210 of the target head block 200, it is deposited at different places in the target head block 200, thereby reducing the local heat flux density of the target head block 200.

[0085] In some specific embodiments, Figure 1 As shown, a first signal transmission line is connected to the target head block 200. Specifically, the target head block 200 is connected to the first signal transmission line, and the first signal transmission line can transmit the electrical signal of the target head block 200 to the analysis system, so as to analyze the electrical signal of the target head block 200. In addition, in order to facilitate the electrical connection between the first signal transmission line and the target head block 200, the wiring terminal is installed on the target head block 200 by screws, and then the first signal transmission line is connected to the wiring terminal to achieve electrical connection between the first signal transmission line and the target finger 100.

[0086] In some specific embodiments, Figure 1 As shown, the first signal transmission line passes through the second hole 620 of the target rod 600 and extends into the interior of the target rod 600. The first signal transmission line can be routed inside the target rod 600 and can be connected to the outside of the vacuum chamber.

[0087] In some specific embodiments, Figure 1 As shown, the mounting base 300 is disposed on the second surface 220, and the target finger 100 is mounted on the mounting base 300. Specifically, the target finger 100 is mounted on the mounting base 300, and the mounting base 300 is mounted on the second surface 220, which can ensure that the target finger 100 and the target head block 200 are isolated from each other to avoid mutual interference of electrical signals between the target finger 100 and the target head block 200, and can also make the target finger 100 and the target head block 200 form a whole, and can switch the target finger 100 and the target head block 200 according to actual measurement needs, so that the beam target finger 100 or the target head block 200 is bombarded, and beam diagnosis under different working conditions can be achieved.

[0088] In some specific embodiments, the mounting base 300 is made of aluminum nitride, which can ensure that the mounting base 300 has good insulation performance and also has good heat transfer performance. When the beam bombards the target finger 100, a large amount of heat will be generated on the target finger 100. The mounting base 300 made of aluminum nitride can transfer the heat of the target finger 100 to the target head block 200, thereby reducing the temperature of the target finger 100 and preventing the temperature of the target finger 100 from being too high, causing deformation or damage to the target finger 100.

[0089] In some specific embodiments, Figure 1 As shown, a through hole is provided on one end of the target finger 100, a through hole is provided on the mounting base 300, and a screw passes through the target finger 100 and the mounting base 300 in sequence, and is screwed to the second surface 220 of the target head block 200. An insulating gasket is added between the bolt and the target finger 100 to prevent the electrical signal of the target finger 100 from being transmitted to the target head block 200 through the screw, thereby preventing the measurement of the target finger 100 from being affected. In addition, the bolt can also be made of a material with insulating properties, which can prevent the electrical signal of the target finger 100 from being transmitted to the target head block 200 through the screw, thereby affecting the measurement of the target finger 100. In addition, the material of the mounting base 300 is an insulating material.

[0090] In some specific embodiments, Figure 8 As shown, the mounting block 300 is provided with a plurality of protrusions 310 protruding toward the second direction 2, and the plurality of protrusions 310 are arranged in sequence in the third direction 3, and the protrusion sizes of two adjacent protrusions 310 are different, and the target finger 100 is located at the top of the protrusion 310, and the target finger 100 corresponds to the protrusion 310 one by one. Specifically, in order to ensure the specific arrangement of the plurality of target fingers 100, it is necessary to stipulate that the protrusion sizes of two adjacent protrusions 310 are different. In other words, the sizes of the plurality of protrusions 310 on the mounting block 300 are to adapt to the specific arrangement of the plurality of target fingers 100.

[0091] In some specific embodiments, Figure 1As shown, the target head block 200 has a third surface 230 orthogonal to the first direction 1, a heat exchange space for accommodating a heat exchange medium is provided inside the target head block 200, a heat exchange outlet 240 and a heat exchange inlet 250 are provided on the target head block 200 and located on the third surface 230, and the beam test device 1000 further includes a first tube 400 and a second tube 500, wherein the first tube 400 is connected to the heat exchange outlet 240, and the second tube 500 is connected to the heat exchange inlet 250. Specifically, by connecting the first tube 400 and the second tube 500 to the target head block 200, the heat exchange medium can be used to exchange heat with the target head block 200, and the temperature of the target head block 200 can be taken away, so as to avoid the target head block 200 being damaged or deformed due to excessive temperature. Heat is generated when the beam bombards the target head block 200. Traditional finger targets or radial targets have no water cooling design. When debugging a cyclotron, the finger target or radial target may be structurally damaged before beam debugging is completed. Frequent replacement of the finger target or radial target is required, which prolongs the debugging process of the cyclotron and makes debugging difficult. Compared with the prior art, this solution not only has the functions of both finger targets and radial targets, but also adds a water cooling design. While being able to simultaneously measure the radial distribution parameters and axial distribution parameters of the beam, it can also withstand a long period of beam bombardment, which can provide effective guidance for beam debugging of the cyclotron, reduce debugging difficulty, shorten debugging time, and improve debugging efficiency.

[0092] In some specific embodiments, Figure 1 As shown, the first tube 400 can be connected to the heat exchange outlet 240 through a water joint, and the second tube 500 can be connected to the heat exchange inlet 250 through a water joint. The water joint is a threaded straight joint, and the aperture sizes of the second tube 500 and the first tube 400 are adapted to the aperture size of the threaded straight joint. At the same time, the aperture sizes of the heat exchange outlet 240 and the heat exchange inlet 250 are adapted to the aperture size of the threaded straight joint. In addition, the second tube 500 and the first tube 400 are both plastic hoses, so that the second tube 500 and the first tube 400 can be quickly installed on the water joint.

[0093] In some specific embodiments, Figure 1 As shown, the first tube 400 and the second tube 500 can extend into the interior of the target rod 600 through the first hole 610 so that the first tube 400 and the second tube 500 are routed inside the target rod 600 so that the first tube 400 and the second tube 500 can be connected to the outside of the vacuum chamber.

[0094] In some specific embodiments, the material of the target head block 200 is copper material. The copper material has excellent thermal conductivity and can effectively transfer the heat of the target head block 200 and the target finger 100 to the heat exchange space, thereby improving the working stability of the system.

[0095] In some specific embodiments, Figure 1 , Figure 2 , Figure 6 and Figure 7 As shown, the target rod 600 is connected to the third surface 230 of the target head block 200. Specifically, the target rod 600 is connected to the target head block 200 through a ceramic screw, wherein an insulating washer is added between the target rod 600 and the target head block 200. The ceramic screw and the insulating washer can prevent the electrical signal on the target head block 200 from being conducted to the target rod 600, thereby affecting the measurement accuracy of the target head block 200.

[0096] In some specific embodiments, Figure 1 As shown, the driver 700 is connected to the target rod, and the driver 700 can drive the target rod 600 to move back and forth in the first direction 1 and drive the target rod 600 to rotate. Specifically, the driver 700 can drive the target rod 600 to move back and forth in the first direction 1, ensuring that the target head block 200 and the target finger 100 move in the radial direction of the cyclotron, so that the target head block 200 and the target finger 100 can measure the distribution of the beam at different radii, provide guidance for locating the axial loss position, provide a reference basis for beam debugging, and provide guidance for debugging of deflection devices such as the spiral deflection plate voltage and the electrostatic deflection mirror.

[0097] In some specific embodiments, Figure 1 As shown, the target rod 600 is hollow, and the first signal transmission line, the second signal transmission line, the first tube 400 and the second tube 500 can all be routed inside the target rod 600, that is, the first signal transmission line, the second signal transmission line, the first tube 400 and the second tube 500 can be connected to the outside of the cyclotron through the hollow target rod 600.

[0098] In some specific embodiments, Figure 1 As shown, the material of the target rod 600 is stainless steel.

[0099] The beam testing device 1000 in this specific embodiment has the following advantages:

[0100] The driver 700 can control the reciprocating motion and rotation of the target rod 600, thereby adjusting the position of the target finger 100 and the target head block 200, so that the beam can bombard the target finger 100 or the target head block 200, that is, the target finger 100 can measure the axial distribution of the beam and the target head block 200 can measure the total intensity of the beam. In addition, the target finger 100 and the target head block 200 can move in the axial direction of the cyclotron, and the beam intensity at different radii can be measured to evaluate the central area extraction intensity, accelerator beam transmission efficiency, accelerator beam stability and other indicators, providing a reference for the beam debugging of the cyclotron. That is to say, by controlling the target rod 600 through the driver 700, the target finger 100 or the target head block 200 can be moved in the axial direction of the cyclotron and the working mode of the target finger 100 or the target head block 200 can be switched to complete the beam diagnosis under different working conditions. That is, the radial distribution and axial distribution of the beam can be measured through a beam test device 1000, which improves the efficiency of cyclotron beam debugging, reduces the number of devices in the cyclotron vacuum chamber, improves the beam measurement accuracy and reduces the cost of beam debugging.

[0101] In some specific embodiments, the beam control method includes the above-mentioned beam testing device 1000, and the beam control method includes:

[0102] S1: Install the beam test device 1000 at a corresponding position on the cyclotron, and start the cyclotron.

[0103] Specifically, the support plate 820 and the support frame 800 are matched with the fixed structure on the cyclotron. The support frame 800 is fixed to the magnetic field of the cyclotron by screws, and the support plate 820 is fixed to the main vacuum chamber of the cyclotron by screws. A slot is set on the side of the support plate 820 that contacts the vacuum chamber of the cyclotron for installing a sealing ring; a dynamic sealing structure is set between the support plate 820 and the target rod 600; after the installation is completed, the target rod 600 and the target head block 200 are located in the accelerator vacuum chamber, and the axis thereof is located in the center plane of the cyclotron.

[0104] S2: Preset various parameters of the cyclotron, as well as the expected axial beam parameters and radial beam parameters.

[0105] Specifically, the magnetic field, electric field, ion source and other parameters of the cyclotron are preset according to the physical design of the cyclotron and the previous debugging records. The goal is to obtain a beam that meets the cyclotron debugging requirements, that is, the various parameters of the cyclotron are preset so that the expected axial distribution, radial distribution and total current intensity of the beam meet the cyclotron debugging requirements.

[0106] S3: Controlling the driver 700 to drive the target head block 200 to reciprocate in the first direction and to drive the target head block 200 to rotate, so as to measure the axial beam parameters and the radial beam parameters in real time.

[0107] The axial beam parameter refers to the axial distribution of the beam, and the radial beam parameter refers to the radial distribution of the beam.

[0108] Specifically, the driver 700 includes a first motor 710 and a second motor 720, the first motor 710 and the second motor 720 are perpendicular to each other and do not interfere with each other, the central axis of the first motor 710 coincides with the central axis of the target rod 600, and the output end of the first motor 710 is connected to the target rod 600, driving the target rod 600 to rotate, and the second motor 720 can make the target rod 600 reciprocate in the first direction 1. Its specific working conditions: a sliding plate 810 and a supporting plate 820 are installed on the support frame 800, the target rod 600 passes through the mounting hole of the supporting plate 820, and the target rod 600 reciprocates in the first direction 1 relative to the supporting plate 820, and at the same time, the target rod 600 rotates relative to the supporting plate 820. The sliding plate 810 is installed in the groove track 830 of the support frame 800, and the sliding plate 810 can move in the groove track 830. Among them, the output end of the first motor 710 is connected to the target rod 600, and the first motor 710 is installed on the sliding plate 810. The second motor 820 is installed on the support frame 800, and a gear is installed at the output end of the second motor 820. A gear is also installed inside the groove track 830. The second motor 820 drives the sliding plate 810 to move inside the groove track 830 through the gear. That is to say, according to the debugging or measurement requirements, the self-rotation of the target rod 600 can be achieved by controlling the first motor 810, and the reciprocating movement of the target rod 600 in the first direction 1 can be achieved by the second motor 820. Among them, the second motor 820 and the first motor 710 can be servo motors, and the servo motor can accurately know the specific position of the target head block 200 through signal feedback. In addition, the accurate position of the target head block 200 can also be obtained by using a grating ruler.

[0109] S4: comparing the real-time axial beam parameters and radial beam parameters obtained in step S3 with expected axial beam parameters and radial beam parameters respectively, and determining whether the expected axial beam parameters and radial beam parameters are achieved;

[0110] If reached, jump to step S6;

[0111] If not reached, continue to execute step S5.

[0112] Specifically, in step S1, the beam intensity, beam axial distribution and beam radial distribution can be measured by the beam testing device 1000. In order to make the beam intensity, beam axial distribution and beam radial distribution in the cyclotron meet the preset beam intensity, preset beam axial distribution and preset beam radial distribution, it is necessary to compare and analyze the beam intensity and the preset beam intensity, the beam axial distribution and the preset beam axial distribution, and the beam radial distribution and the preset beam radial distribution, and then adjust the control parameters of the cyclotron and further adjust the beam.

[0113] S5: adjusting the control parameters of the cyclotron to act on the beam, and returning to step S3;

[0114] Specifically, when adjusting the beam current in a cyclotron, the expected beam current cannot be obtained by directly specifying relevant parameters. Instead, the beam current adjustment can be completed by continuously measuring the beam current distribution in the cyclotron and continuously adjusting the control parameters of the cyclotron.

[0115] S6: Stop the driver to complete the regulation of the beam current.

[0116] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0117] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0118] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0119] In 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.

[0120] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean 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 present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics 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.

[0121] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A sensing end structure of a finger target, used in a cyclotron accelerator to measure the axial distribution of a beam, characterized in that: include: A plurality of target fingers, wherein the plurality of target fingers are parallel to a first direction, two adjacent target fingers are arranged at intervals in a second direction, and the plurality of target fingers are arranged in sequence in a third direction; Wherein, in a projection plane orthogonal to the second direction, each of the target fingers is projected in the second direction to form a target finger projection, and boundaries of two adjacent target finger projections overlap with each other in the third direction; The first direction, the second direction and the third direction are orthogonal to each other.

2. The sensing end structure of the finger target according to claim 1, characterized in that: The distance between two adjacent target fingers in the second direction is greater than the flight radius of secondary electrons generated by the beam bombarding the target fingers.

3. The sensing end structure of the finger target according to claim 1, characterized in that: The size of the target finger in the third direction is larger than the flight radius of secondary electrons generated by the beam bombarding the target finger.

4. A beam test device, characterized in that: include: The sensing end structure of the target according to any one of claims 1 to 3; A target head block, the target head block having a first surface and a second surface arranged opposite to each other in the second direction, the first surface being used for beam bombardment; A mounting base is provided on the second surface, and the target finger is mounted on the mounting base.

5. The beam testing device according to claim 4, characterized in that: The mounting block is provided with a plurality of protrusions protruding toward the second direction, the plurality of protrusions are arranged in sequence in the third direction, the protrusion sizes of two adjacent protrusions are different, the target finger is located at the top of the protrusion, and the target finger corresponds to the protrusion one by one.

6. The beam testing device according to claim 4, characterized in that: The first surface intersects the second direction.

7. The beam testing device according to claim 4, characterized in that: The target head block is connected with a first signal transmission line; Each of the target fingers is connected with a second signal transmission line.

8. The beam testing device according to claim 4, characterized in that: The target head block has a third surface orthogonal to the first direction, a heat exchange space for accommodating a heat exchange medium is provided inside the target head block, a heat exchange outlet and a heat exchange inlet located on the third surface are provided on the target head block, and the beam test device further includes: a first tube, the first tube being connected to the heat exchange outlet; A second tube is connected to the heat exchange inlet.

9. The beam testing device according to claim 8, characterized in that: Also includes: A target rod, the target rod being connected to the third surface of the target head block; A driver is connected to the target rod, and the driver can drive the target rod to move back and forth in the first direction and drive the target rod to rotate.

10. A beam control method, characterized in that: The beam control method comprises the beam testing device according to claim 9, and the beam control method comprises: S1: installing the beam test device at a corresponding position on the cyclotron, and starting the cyclotron; S2: Preset various parameters of the cyclotron accelerator, as well as expected axial beam parameters and radial beam parameters; S3: controlling the driver to drive the target head block to reciprocate in the first direction and to drive the target head block to rotate, so as to measure the real-time axial beam parameters and radial beam parameters; S4: comparing the real-time axial beam parameters and radial beam parameters obtained in step S3 with expected axial beam parameters and radial beam parameters respectively, and determining whether the expected axial beam parameters and radial beam parameters are achieved; If reached, jump to step S6; If not reached, continue to step S5; S5: adjusting the control parameters of the cyclotron to act on the beam, and returning to step S3; S6: Stop the driver to complete the regulation of the beam current.

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