Sensing end structure of a target, beam testing device and beam control method

Abstract

The present application relates to the technical field of cyclotron and discloses a sensing end structure of a target, a beam test device and a beam regulation method, the sensing end structure of the 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 plurality of target fingers are sequentially arranged in a third direction; wherein, in a projection plane orthogonal to the second direction, each target finger projects to form a target finger projection in the second direction, and the boundaries of two adjacent target finger projections coincide with each other in the third direction. The sensing end structure of the target overcomes the technical problem that the axial distribution measurement accuracy of the beam is not high, through specific arrangement of the plurality of target fingers, the axial distribution of the beam under narrow pulse state can be accurately measured, and debugging of deflection devices such as a spiral deflection plate voltage and an electrostatic deflection mirror is guided.

Description

Technical Field

[0001] This invention relates to the field of cyclotron technology, specifically to the sensing end structure of a target, a beam testing device, and a beam control method. Background Technology

[0002] During the commissioning of a cyclotron, it is necessary to measure the beam intensity at various locations from the small radius to the large radius of the cyclotron. The radial target is the main component in the beam diagnostic system that enables this function. The radial target is mounted on a flange on the side of the vacuum chamber of the cyclotron. The target head is inserted radially into the cyclotron, and beam intensity measurements at different radii can be performed by controlling the insertion depth. In existing technology, the head of the radial target is a rectangular copper block, and a target rod is used as the signal transmission line. The copper block transmits the beam signal to the end of the target rod for beam measurement. The copper block is water-cooled to withstand high-power beam bombardment. The radial drive mechanism of the entire device is located at the tail of the target rod. The target rod is insulated and sealed from the vacuum chamber.

[0003] To adjust and optimize the beam, technicians typically need to adjust the beam in a cyclotron. The beam is deflected from the axial injection line to the central plane by various deflection devices such as spiral deflectors and electrostatic deflectors. The beam characteristics at the exit of the deflector determine the beam quality during the acceleration and extraction process. A beam diagnostic system is needed to measure the axial distribution of the beam after the deflector and adjust the voltage or other parameters of the spiral deflector to center the beam axis, thereby optimizing beam transmission.

[0004] Before adjusting the beam, it is necessary to understand the beam conditions within the cyclotron. In existing technology, to measure the axial distribution of the beam, a graphite strip is placed above and below the beam extraction stripping film. When the beam deviates from the central plane, an electrical signal is generated on the graphite strip, thus guiding the axial alignment adjustment of the beam. However, this measurement method can only measure the deviation of the beam, not the overall axial distribution. Furthermore, the measurement results are too lagging, the risk of device activation due to the beam deviating from the central plane bombarding the magnetic poles increases, and it has little reference value for beam axial alignment adjustment. In another existing technology, such as CN201710724556, the axial distribution of the beam is measured using a finger target. To avoid secondary electron interference from the finger target to other target finger measurements, the target fingers must be spaced apart. However, spaced target fingers cannot accurately measure the axial distribution of the beam, meaning the axial distribution of the beam is not accurately measured. During beam adjustment, the inaccurate axial distribution measurement leads to increased error when adjusting the beam based on this measurement result, thus failing to effectively guide beam adjustment.

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

[0006] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a sensing end structure for a finger target, a beam testing device, and a beam control method. The beam testing device, by arranging multiple finger targets in a specific manner, can accurately measure the axial distribution of the beam under narrow pulse conditions, providing guidance for the debugging of deflection devices such as the deflection plate voltage and the electrostatic deflection mirror.

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

[0008] Multiple target fingers, the multiple target fingers are parallel to a first direction, two adjacent target fingers are spaced apart in a second direction, and the multiple target fingers are arranged sequentially in a third direction;

[0009] In the 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 the boundaries of two adjacent target finger projections coincide 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 sensor end structure of the target finger addresses the technical challenge of improving the accuracy of beam axial distribution measurements. By staggering multiple target fingers, mutual insulation between them is ensured, guaranteeing that the electrical signal measured by each finger is not affected by other fingers, thus improving the accuracy of the target finger measurements. Furthermore, the sequential arrangement of multiple target fingers in the third direction allows for the measurement of beam axial distribution under narrow pulse conditions, providing guidance for locating axial loss positions and offering a reference for beam tuning. Additionally, the overlapping boundaries of the projected boundaries of adjacent target fingers in the third direction prevent the beam from passing through gaps between adjacent fingers; that is, the axially distributed beam can be entirely bombarded by the target fingers, further improving the accuracy of beam axial distribution measurements.

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

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

[0014] The beam testing apparatus of the second embodiment of the present invention includes:

[0015] The aforementioned sensor end structure of the target;

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

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

[0018] The beam testing device solves the technical problem of rapidly measuring the total beam intensity and the axial distribution intensity of the beam. By combining the target finger and the target head block, the beam can be adjusted to bombard either the first or second surface. When the beam bombards the first surface, the target head block can receive the beam bombardment from the cyclotron under narrow pulse or DC conditions for an extended period, completing the beam intensity measurement. This measurement is used to evaluate indicators such as the central region extraction current intensity, accelerator beam transmission efficiency, and accelerator beam stability, providing a reference for cyclotron beam tuning. When the beam bombards the second surface, i.e., the target finger, it can be used to measure the axial distribution of the beam under narrow pulse conditions. This provides guidance for the tuning of deflection devices such as the deflection plate voltage and electrostatic deflection mirror, and for locating the axial loss position, providing a reference for beam tuning.

[0019] Optionally, the mounting base is provided with a plurality of protrusions protruding in the second direction, the plurality of protrusions being arranged sequentially and continuously in the third direction, the protrusions of adjacent two protrusions having different protrusion sizes, the target finger being located at the top of the protrusion, and the target finger corresponding to the protrusion one by one.

[0020] Optionally, the first face intersects with the second direction.

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

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

[0023] Optionally, the target block has a third surface orthogonal to the first direction, the interior of the target block is provided with a heat exchange space for accommodating a heat exchange medium, and the target block has a heat exchange outlet and a heat exchange inlet located on the third surface. The beam testing device further includes:

[0024] The first pipe is connected to the heat exchange outlet;

[0025] The second pipe is connected to the heat exchange inlet.

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

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

[0028] A driver connected to the target rod, the driver being capable of driving the target rod to reciprocate in the first direction and driving the target rod to rotate.

[0029] Another embodiment of the beam current control method of the present invention includes:

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

[0031] S1: Install the beam testing device at the corresponding position on the cyclotron and start the cyclotron;

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

[0033] S3: By controlling the driver to drive the target block to reciprocate in the first direction and drive the target block to rotate, the axial beam parameters and radial beam parameters are measured in real time.

[0034] S4: Compare the real-time axial beam parameters and radial beam parameters obtained in step S3 with the expected axial beam parameters and radial beam parameters respectively, and determine whether the expected axial beam parameters and radial beam parameters have been achieved.

[0035] If the condition is met, proceed to step S6.

[0036] If the condition is not met, proceed to step S5.

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

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

[0039] Beam control methods can solve the problem of how to quickly adjust the beam. By using a beam testing device to measure the axial and radial distribution of the beam, that is, the beam intensity, axial distribution, and radial distribution can be measured. In order to make the beam intensity, axial distribution, and radial distribution in the cyclotron conform to the preset beam intensity, axial distribution, and radial distribution, it is necessary to compare and analyze the beam intensity with the preset beam intensity, axial distribution with the preset beam axial distribution, and radial distribution with the preset beam radial distribution. By adjusting the control parameters of the cyclotron, the beam can be adjusted, thereby quickly achieving beam control. Attached Figure Description

[0040] Figure 1This is an exploded schematic diagram of the beam testing device in this specific implementation.

[0041] Figure 2 This is an exploded schematic diagram of the beam testing device in this specific implementation.

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

[0043] Figure 4 This is a schematic diagram of the target finger arrangement in this specific implementation.

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

[0045] Figure 6 This is a schematic diagram of the beam bombardment of the target in this specific implementation.

[0046] Figure 7 This is a schematic diagram of the beam bombardment of the target block in this specific implementation.

[0047] Figure 8 This is a front view of the installation base in this specific implementation.

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

[0049] Figure 10 This is a left-side view of the beam testing device used in this specific implementation.

[0050] Reference numerals: 1000-Beam testing 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 Implementation

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

[0052] The sensing end structure of the finger target according to an embodiment of the present invention will be described below with reference to the accompanying drawings. Figures 1 to 8As shown, the sensing end structure of the finger target in this embodiment of the invention includes multiple finger targets 100.

[0053] Multiple target fingers 100 are parallel to the first direction 1. Two adjacent target fingers 100 are arranged at intervals in the second direction 2. Multiple target fingers 100 are arranged sequentially in the third direction 3. In the 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. The boundaries 111 of two adjacent target finger projections 110 coincide with each other in the third direction 3. 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 target finger according to a specific embodiment of the present invention, by arranging multiple target fingers 100 in an alternating manner, it is ensured that the target fingers 100 are mutually insulated, guaranteeing that the electrical signal measured by each target finger 100 is not affected by other target fingers 100, thereby improving the accuracy of the target finger 100 measurement. Furthermore, the multiple target fingers 100 are arranged sequentially in the third direction 3, which can be used to measure the axial distribution of the beam under narrow pulse conditions, providing guidance for locating the axial loss position and a reference for beam adjustment. In addition, the boundaries 111 of two adjacent target finger projections 110 coincide in the third direction 3, preventing the beam from passing through the gap between adjacent target fingers 100; that is, the axially distributed beam can be completely bombarded on the target fingers 100, improving the accuracy of measuring the axial distribution of the beam.

[0055] like Figures 1 to 8 As shown, to make the technical solution of this application easier to understand, the technical solution of this application will be described in more detail below using a specific embodiment of the beam testing device 1000. Wherein, as Figure 1 The forward and backward directions shown are the first direction 1, such as... Figure 1 The up-down direction shown is the second direction 2, such as... Figure 3 The left and right directions shown are the third direction 3. The first direction 1, the second direction 2 and the third direction 3 are orthogonal to each other.

[0056] In some specific embodiments, such as Figures 1 to 7 As shown, multiple target fingers 100 are parallel to the first direction 1, and two adjacent target fingers 100 are arranged at intervals in the second direction 2. Multiple target fingers 100 are arranged sequentially in the third direction 3. In the 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. The boundaries 111 of two adjacent target finger projections 110 coincide with each other in the third direction 3. The first direction 1, the second direction 2 and the third direction 3 are orthogonal to each other.

[0057] Specifically, such as Figure 4As shown, the specific arrangement of the multiple target fingers 100 can be in mode (a), mode (b), and mode (c), etc. These arrangement methods are provided for ease of understanding of this technical solution and do not represent all arrangement methods in this technical solution. Preferably, mode (a) is the preferred arrangement of the multiple target fingers 100 in this specific embodiment.

[0058] Arranging multiple target fingers 100 in the manner described above ensures that the target fingers 100 are mutually insulated, prevents mutual interference of electrical signals between the target fingers 100, ensures that the signal measured by each target finger 100 is not affected by other target fingers 100, and improves the accuracy of the target finger 100 measurement.

[0059] Furthermore, multiple target fingers 100 are arranged sequentially along the third direction 3, that is, along the axial direction of the cyclotron. This arrangement can be used to measure the axial distribution of the beam under narrow pulse conditions, providing guidance for locating axial loss and a reference for beam tuning. 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. The arrangement of the multiple target fingers 100 along the third direction 3, i.e., along the axial direction of the cyclotron, allows the beam bombardment surface to be divided into axially arranged strip-shaped bombardment areas. Each strip-shaped bombardment area represents the beam intensity in that region, thus allowing the measurement of the beam's axial distribution. Furthermore, once the axial distribution of the beam is understood, the beam distribution across the entire bombardment surface can be obtained from the axial distribution of the beam. That is, it can be used to measure the axial distribution of the beam under narrow pulse conditions, to guide the location of axial loss, and to provide a reference for beam debugging.

[0060] Furthermore, the boundaries 111 of two adjacent target finger projections 110 coincide 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 region. That is, when the beam bombards the region corresponding to multiple target fingers 100, there are no gaps between the multiple target fingers 100, which can prevent the beam from passing through the gap between two adjacent target fingers 100. In other words, the axially distributed beam can all bombard the target fingers 100, improving the accuracy of measuring the axial distribution of the beam.

[0061] In the cyclotron, after the beam bombards the target finger 100, a nuclear reaction occurs. Some electrons in the target finger 100 gain energy and 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 an electric current. By measuring this current, beam diagnostic measurements can be achieved.

[0062] In summary, by arranging multiple target fingers 100 in a specific manner, it can be used to measure the axial distribution of the beam current under narrow pulse conditions, providing guidance for the debugging of deflection devices such as the deflection plate voltage and the electrostatic deflection mirror.

[0063] In some specific embodiments, such as 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 the secondary electrons generated by the beam bombardment of the target fingers 100. Each target finger 100 can accurately represent the beam axial distribution during beam axial distribution measurement, and the distance between two adjacent target fingers 100 in the second direction 2 itself has no impact on the accuracy of the obtained beam axial distribution measurement results.

[0064] Specifically, the principle of nuclear reaction charge measurement applied to beam diagnostics is as follows: Taking a proton cyclotron accelerator as an example, nuclear reactions occur at different positions 100° when the beam strikes the target perpendicularly. The maximum kinetic energy of the secondary electron is estimated. It is assumed that the proton energy in the extraction region is approximately 200 MeV; the formula for the secondary electron energy is:

[0065]

[0066] Among them, E max It is the maximum energy of a secondary electron; m e m p These are the masses of the electron and the proton, respectively; E p θ is the energy of the incident proton; θ is the angle between the incident proton and the emitted electron.

[0067] For an incident proton with an energy of approximately 200 MeV, the maximum kinetic energy of the resulting secondary electrons does not exceed 400 keV. Since the kinetic energy of the secondary electrons is less than the rest energy of the electrons, the relativistic effects of the secondary electrons can be ignored here. Therefore:

[0068] m e =m e0

[0069] Where, m e m e0 These are the electron's mass and rest mass, respectively.

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

[0071]

[0072] Where, m e m e0 These are the electron's mass and rest mass, respectively, and v is the electron's velocity;

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

[0074]

[0075] Where, m e m p These are the masses of the secondary electron and the proton, respectively; E p E e These are the energies of the incident proton and the secondary electron, respectively; r p r e These are the cyclotron radius of the proton and the cyclotron radius of the secondary electron, respectively; v p v e These are the velocity of the incident proton and the velocity of the secondary electron, respectively.

[0076] Preferably, according to the Nyquist sampling theorem, for multiple target fingers 100, the distance between target fingers 100 is greater than or equal to 2r. e Given that the proton energy in the extraction region is approximately 200 MeV, the spacing between the target fingers 100 is calculated to be 2 mm based on the aforementioned principle. This ensures that the generated secondary electrons escape and prevent them from flying onto adjacent target fingers 100. After the secondary electrons escape, the positively charged particles remaining inside the target fingers 100 and the relative motion of the escaped electrons form a current. By measuring the current magnitude of each target finger 100, the beam position is analyzed. This method yields more accurate measurement results. Simultaneously, the target head block 200 can perform intermittent motion for real-time measurement and feedback of position information, resulting in even higher positional accuracy.

[0077] In some specific embodiments, such as 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 bombardment of the target finger. Specifically, its working principle and the technical effect achieved are the same as that 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 bombardment of the target finger 100, which will not be elaborated here.

[0078] In some specific embodiments, such as Figure 1 As shown, each target finger 100 is connected to a second signal transmission line. Specifically, each target finger 100 is connected to a second signal transmission line, which can transmit the electrical signal of the corresponding target finger 100 to the analysis system for analysis of the electrical signal of each target finger 100. Furthermore, to facilitate electrical connection between the second signal transmission line and the target finger 100, a terminal block is added between the target finger 100 and the insulating pad to achieve electrical connection between the second signal transmission line and the target finger 100.

[0079] In some specific embodiments, such as 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 target finger 100 can be cylindrical, sheet-like, etc., as long as the size of the target finger projection 110 corresponding to the target finger 100 in the third direction 3 is greater than the secondary electron flight radius generated by the beam bombardment of the target finger 100. In this specific embodiment, the target finger 100 is preferably a rectangular sheet. The rectangular sheet shape is used because it has a relative width and a clear boundary, which makes it easier to achieve the overlap of the boundaries 111 of two adjacent target finger projections 110 in the third direction 3 compared to a filamentous target finger.

[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, such as Figure 1 , Figure 2 , Figure 6 and Figure 7 As shown, the target block 200 has a first surface 210 and a second surface 220 arranged opposite to each other in the second direction 3. The first surface 210 is used for beam bombardment. Specifically, the first surface 210 of the target block 200 can be used for beam bombardment. A nuclear reaction occurs on the first surface 210, and some of the electrons that gain energy escape from the target block 200. Positively charged particles remain in the target block 200 after the electrons escape. The positively charged particles move relative to the escaped electrons, forming an electric current. The beam diagnostic measurement can then be indirectly completed by measuring this current. In addition, multiple target fingers 100 are located on one side of the second surface 220. That is, by combining the target fingers 100 and the target head block 200, the beam can be adjusted to bombard either the first surface 210 or the second surface 220. When the beam bombards the first surface 210, the target head block 200 can receive the beam bombardment of the cyclotron under narrow pulse or DC conditions for an extended period, completing the beam intensity measurement. This is used to evaluate indicators such as the central region extraction current intensity, accelerator beam transmission efficiency, and accelerator beam stability, providing a reference for cyclotron beam tuning. When the beam bombards the second surface 220, that is, when the beam bombards the target fingers 100, it can be used to measure the axial distribution of the beam under narrow pulse conditions, providing guidance for the tuning of deflection devices such as the deflection plate voltage and electrostatic deflection mirror, and for locating the axial loss position, providing a reference for beam tuning.

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

[0084] In some specific embodiments, such as 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, thereby forming a certain angle between the beam direction and the first surface 210. When the beam bombards the first surface 210, the beam will generate a large amount of heat on the target block 200. Since a certain angle is formed between the beam direction and the first surface 210, the heat deposited in the target block 200 can be at different depths, avoiding the accumulation of heat in the local area of ​​the target block 200, preventing the target block 200 from being damaged due to excessively high local temperature, and indirectly reducing the local heat flux density of the target block 200. In other words, the end face of the target block 200 used to block the beam is not perpendicular to the beam cross section. That is, the first face 210 intersects 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 block 200, it is deposited in different places inside the target block 200, reducing the local heat flux density of the target block 200.

[0085] In some specific embodiments, such as Figure 1 As shown, a first signal transmission line is connected to the target head block 200. Specifically, the first signal transmission line transmits the electrical signals of the target head block 200 to the analysis system for analysis. Furthermore, to facilitate electrical connection between the first signal transmission line and the target head block 200, a terminal block is installed on the target head block 200 using screws, and then the first signal transmission line is connected to the terminal block to achieve electrical connection between the first signal transmission line and the target finger 100.

[0086] In some specific embodiments, such as 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, such as Figure 1 As shown, the mounting base 300 is located 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. This ensures that the target finger 100 and the target head block 200 are isolated from each other, avoiding mutual interference of electrical signals between the target finger 100 and the target head block 200. It also allows the target finger 100 and the target head block 200 to form a whole. According to the actual measurement needs, the target finger 100 and the target head block 200 can be switched so that the beam target finger 100 or the target head block 200 can bombard the target, enabling beam diagnosis under different operating conditions.

[0088] In some specific embodiments, the mounting base 300 is made of aluminum nitride. Aluminum nitride not only ensures that the mounting base 300 has good insulation properties, but also has good heat transfer properties. When the beam bombards the target finger 100, a large amount of heat is generated on the target finger 100. The aluminum nitride mounting base 300 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 target finger 100 from becoming too hot, which could lead to deformation or damage.

[0089] In some specific embodiments, such as Figure 1 As shown, a through hole is provided at one end of the target finger 100, and a through hole is provided on the mounting base 300. A screw passes through the target finger 100 and the mounting base 300 in sequence and is screwed onto the second surface 220 of the target head block 200. An insulating washer 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, thus preventing the measurement of the target finger 100 from being affected. Alternatively, the bolt can be made of a material with insulating properties 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. Furthermore, the mounting base 300 is made of an insulating material.

[0090] In some specific embodiments, such as Figure 8 As shown, the mounting base 300 has multiple protrusions 310 protruding in the second direction 2. These protrusions 310 are arranged sequentially in the third direction 3, with adjacent protrusions 310 having different protrusion sizes. Target fingers 100 are located on top of the protrusions 310, and each target finger 100 corresponds one-to-one with a protrusion 310. Specifically, to ensure the specific arrangement of the multiple target fingers 100, it is necessary to specify that adjacent protrusions 310 have different protrusion sizes. In other words, the dimensions of the multiple protrusions 310 on the mounting base 300 are designed to accommodate the specific arrangement of the multiple target fingers 100.

[0091] In some specific embodiments, such as Figure 1As shown, the target block 200 has a third surface 230 orthogonal to the first direction 1. The target block 200 has an internal heat exchange space for containing a heat exchange medium. The target block 200 has a heat exchange outlet 240 and a heat exchange inlet 250 located on the third surface 230. The beam testing device 1000 also includes a first tube 400 and a second tube 500. 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 block 200, the heat exchange medium can be used to exchange heat with the target block 200, removing its temperature and preventing damage or deformation due to excessive heat. Heat is generated when the beam bombards the target block 200. Traditional finger or radial targets lack water cooling. During cyclotron commissioning, structural damage to these targets may occur before beam commissioning is complete, necessitating frequent replacements and prolonging the commissioning process. Compared to existing technologies, this solution combines the functions of both finger and radial targets with water cooling. It enables simultaneous measurement of both radial and axial beam distribution parameters and withstands prolonged beam bombardment, providing effective guidance for cyclotron beam commissioning, reducing commissioning difficulty, shortening commissioning time, and improving commissioning efficiency.

[0092] In some specific embodiments, such as Figure 1 As shown, the first pipe 400 can be connected to the heat exchange outlet 240 via a water connector, and the second pipe 500 can be connected to the heat exchange inlet 250 via a water connector. The water connector is a threaded straight-through connector, and the orifice sizes of the second pipe 500 and the first pipe 400 are adapted to the orifice sizes of the threaded straight-through connector. Simultaneously, the orifice sizes of the heat exchange outlet 240 and the heat exchange inlet 250 are adapted to the orifice sizes of the threaded straight-through connector. Furthermore, both the second pipe 500 and the first pipe 400 are made of flexible plastic tubing to facilitate quick installation on the water connector.

[0093] In some specific embodiments, such as 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 can be 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 target block 200 is made of copper, which has excellent thermal conductivity and can effectively conduct the heat of the target 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, such as 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 by ceramic screws. An insulating washer is added between the target rod 600 and the target head block 200. The ceramic screws and insulating washers can prevent the electrical signals on the target head block 200 from being conducted to the target rod 600, thus avoiding affecting the measurement accuracy of the target head block 200.

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

[0097] In some specific embodiments, such as Figure 1 As shown, the target rod 600 is hollow. 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, such as Figure 1 As shown, the target rod 600 is made of 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 positions 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 along the axis of the cyclotron, and can measure the beam intensity at different radii. The measurements are used to evaluate indicators such as the central region extraction current intensity, accelerator beam transmission efficiency, and accelerator beam stability, providing a reference for the beam debugging of the cyclotron. In other words, by controlling the target rod 600 through the driver 700, the target finger 100 or the target head block 200 can be moved along the axis of the cyclotron and the working mode of the target finger 100 or the target head block 200 can be switched, thus completing beam diagnosis under different working conditions. That is, the radial and axial distribution of the beam can be measured through a beam testing device 1000, which improves the efficiency of cyclotron beam commissioning, reduces the number of devices in the cyclotron vacuum chamber, improves beam measurement accuracy, and reduces the cost of beam commissioning.

[0101] In some specific embodiments, the beam modulation method includes the aforementioned beam testing device 1000, and the beam modulation method includes:

[0102] S1: Install the beam test device 1000 at the 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 magnet of the cyclotron by screws, and the support plate 820 is fixed to the main vacuum chamber of the cyclotron by screws. The side of the support plate 820 that contacts the vacuum chamber of the cyclotron is provided with a slot for installing a sealing ring. A dynamic sealing structure is provided between the support plate 820 and the target rod 600. After installation, the target rod 600 and the target head block 200 are located in the vacuum chamber of the accelerator, with the central axis located in the central plane of the cyclotron.

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

[0105] Specifically, based on the physical design of the cyclotron and the previous commissioning records, the parameters of the cyclotron, such as the magnetic field, electric field, and ion source, are preset. The goal is to obtain a beam that meets the commissioning requirements of the cyclotron. That is, the preset parameters of the cyclotron ensure that the expected axial distribution, radial distribution, and total current intensity of the beam meet the commissioning requirements of the cyclotron.

[0106] S3: By controlling the driver 700 to drive the target block 200 to reciprocate in the first direction and to drive the target block 200 to rotate, the axial beam parameters and radial beam parameters are measured in real time.

[0107] Wherein, 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. The second motor 720 enables the target rod 600 to reciprocate in the first direction 1. Specifically, the following operation is described: A sliding plate 810 and a support plate 820 are mounted on the support frame 800. The target rod 600 passes through the mounting hole of the support plate 820 and reciprocates relative to the support plate 820 in the first direction 1. Simultaneously, the target rod 600 rotates relative to the support plate 820. The sliding plate 810 is mounted in the grooved track 830 of the support frame 800 and can move within the grooved track 830. The output end of the first motor 710 is connected to the target rod 600, and the first motor 710 is mounted on the sliding plate 810. The second motor 720 is mounted on the support frame 800. A gear is installed at the output end of the second motor 720, and a gear is also installed inside the grooved track 830. The second motor 720 drives the sliding plate 810 to move within the grooved track 830 via the gears. In other words, according to debugging or measurement needs, the self-rotation of the target rod 600 can be achieved by controlling the first motor 710, and the reciprocating motion of the target rod 600 in the first direction 1 can be achieved by controlling the second motor 720. Both the second motor 720 and the first motor 710 can be servo motors, which can accurately determine the specific position of the target head block 200 through signal feedback. Furthermore, the accurate position of the target head block 200 can also be obtained using a grating ruler.

[0109] S4: Compare the real-time axial beam parameters and radial beam parameters obtained in step S3 with the expected axial beam parameters and radial beam parameters respectively, and determine whether the expected axial beam parameters and radial beam parameters have been achieved.

[0110] If the condition is met, proceed to step S6.

[0111] If the condition is not met, proceed to step S5.

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

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

[0114] Specifically, when adjusting the beam in a cyclotron, the desired beam cannot be obtained by directly specifying the relevant parameters. It is necessary to continuously measure the beam distribution in the cyclotron and continuously adjust the control parameters of the cyclotron in order to complete the beam adjustment.

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

[0116] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0117] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0118] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0119] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0120] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0121] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A sensing end structure for a target, used in a cyclotron accelerator to measure the axial distribution of a beam, characterized in that, include: Multiple target fingers are arranged parallel to a first direction, with adjacent target fingers spaced apart in a second direction. The distance between adjacent target fingers in the second direction is greater than the flight radius of secondary electrons generated by the beam bombarding the target fingers. The multiple target fingers are arranged sequentially in a third direction, and the size of the target fingers in the third direction is greater than the flight radius of secondary electrons generated by the beam bombarding the target fingers. In the 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 the boundaries of two adjacent target finger projections coincide with each other in the third direction. The first direction, the second direction, and the third direction are orthogonal to each other.

2. A beam testing device, characterized in that, include: The sensing end structure of the finger target according to claim 1; A target block having a first surface and a second surface disposed opposite to each other in the second direction, the first surface being used for beam bombardment; The mounting base is disposed on the second surface, and the target finger is mounted on the mounting base.

3. The beam testing device according to claim 2, characterized in that, The mounting base is provided with a plurality of protrusions that protrude in the second direction. The plurality of protrusions are arranged sequentially and continuously in the third direction. The protrusions of two adjacent protrusions are different in size. The target finger is located on the top of the protrusion and the target finger corresponds to the protrusion one by one.

4. The beam testing apparatus according to claim 2, characterized in that, The first face intersects with the second direction.

5. The beam testing apparatus according to claim 2, characterized in that, A first signal transmission line is connected to the target block; Each of the target fingers is connected to a second signal transmission line.

6. The beam testing apparatus according to claim 2, characterized in that, The target block has a third surface orthogonal to the first direction, and the interior of the target block is provided with a heat exchange space for accommodating the heat exchange medium. The target block has a heat exchange outlet and a heat exchange inlet located on the third surface. The beam testing device further includes: The first pipe is connected to the heat exchange outlet; The second pipe is connected to the heat exchange inlet.

7. The beam testing apparatus according to claim 6, characterized in that, Also includes: A target rod, the target rod being connected to the third surface of the target head block; A driver connected to the target rod, the driver being capable of driving the target rod to reciprocate in the first direction and driving the target rod to rotate.

8. A beam control method, characterized in that, The beam control method includes the beam testing apparatus according to claim 7, wherein the beam control method includes: S1: Install the beam testing device at the corresponding position on the cyclotron and start the cyclotron; S2: Preset parameters of the cyclotron, as well as the expected axial and radial beam parameters; S3: By controlling the driver to drive the target block to reciprocate in the first direction and drive the target block to rotate, the axial beam parameters and radial beam parameters are measured in real time. S4: Compare the real-time axial beam parameters and radial beam parameters obtained in step S3 with the expected axial beam parameters and radial beam parameters respectively, and determine whether the expected axial beam parameters and radial beam parameters have been achieved. If the condition is met, proceed to step S6. If the condition is not met, proceed to step S5. S5: Adjust the control parameters of the cyclotron to act on the beam, and return to step S3; S6: Stop the driver to complete the control of the beam.

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