Online ion beam diagnosis system

Abstract

The invention discloses an online ion beam current diagnosis system. The on-line ion beam diagnosis system is used for the cyclotron, the on-line ion beam diagnosis system comprises a phase selection assembly and a radial probe, and the phase selection assembly is at least partially arranged in a central area of the cyclotron and is used for measuring an ion beam located in the central area; the radial probe is at least partially arranged in an acceleration region of the cyclotron and is used for measuring an ion beam current in the acceleration region; and the radial probe is matched with the phase selection assembly to perform phase selection on the ion beam current in the central area and measure the acceleration efficiency of the cyclotron. The extraction efficiency of the cyclotron can be measured through the radial probe, the acceleration efficiency of the cyclotron can be measured through the phase selection assembly and the radial probe, the cyclotron can be conveniently adjusted, the accelerated ion beam can meet the radiation requirement, and the energy waste of the cyclotron is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of accelerators, and in particular to an online ion beam current diagnosis system. Background Art

[0002] Cyclotrons are widely used in various fields such as nuclear physics, isotope production, environment, biology, etc. In recent years, the development of nuclear medicine PET (positron emission tomography) diagnosis has put forward higher demands on positron isotopes. Cyclotrons are widely used in the production of radioactive isotopes due to their compactness, small footprint, low power consumption, high flux and other technical features.

[0003] Ions are generated in the ion source, extracted into the acceleration zone through the ion source extraction system, and then accelerated through magnetic and electric field focusing and multiple electric field acceleration gaps to obtain energy before entering the target system to produce the required nuclides. In the related technology, how to measure the acceleration efficiency and extraction efficiency of the accelerator has become an urgent problem to be solved. Summary of the invention

[0004] The invention provides an on-line ion beam current diagnosis system.

[0005] The online ion beam current diagnostic system of the embodiment of the present application is used for a cyclotron, and the online ion beam current diagnostic system includes a phase selection component and a radial probe. The phase selection component is at least partially arranged in the central area of ​​the cyclotron, and is used to measure the ion beam current located in the central area; the radial probe is at least partially arranged in the acceleration area of ​​the cyclotron, and is used to measure the ion beam current located in the acceleration area; the radial probe cooperates with the phase selection component to perform phase selection on the ion beam current in the central area and measure the acceleration efficiency of the cyclotron.

[0006] In this way, the extraction efficiency of the cyclotron can be measured by the radial probe, and the acceleration efficiency of the cyclotron can be measured by the phase selection component and the radial probe, so that the cyclotron can be adjusted according to the measurement results, so that the accelerated ion beam meets the radiation requirements and reduces energy waste in the cyclotron.

[0007] In some embodiments, the phase selection component includes a slit plate, which is located in the central region and moves radially along the central region. The slit plate is formed with a through hole, and the through hole is used for an ion beam that meets preset conditions to pass through the central region.

[0008] In this way, the ion beam that does not meet the preset conditions in the central area can be intercepted by the slit, so that the ion beam that does not meet the preset conditions is deposited in the central area, thereby improving the acceleration efficiency and extraction efficiency of the cyclotron.

[0009] In some embodiments, the movement radius of the slit plate in the central area ranges from 28 mm to 60 mm.

[0010] When it is within the above range, the energy of the ion beam current is small, the movement speed is slow, and the movement circle distance is large, which makes it easier for the slit to measure and screen the ion beam current.

[0011] In some embodiments, the phase selection component includes a first driving mechanism, which is connected to the slit plate and is used to drive the slit plate to move radially along the central area.

[0012] In this way, the slit is driven to move radially along the central area by the first driving mechanism, so as to measure the ion beam current at each radial position within the moving radius, which is beneficial to improving the flexibility of the slit measurement.

[0013] In some embodiments, the phase selection component includes a first processor connected to the slit plate and configured to read the ion beam current signal collected by the slit plate.

[0014] In this way, the ion beam current signal collected by the slit is read by the first processor without shutting down the cyclotron or removing the slit from the central area of ​​the cyclotron, thereby achieving online and real-time measurement of the ion beam current in the central area, thereby improving the convenience of signal acquisition.

[0015] In certain embodiments, the radial probe includes a current target that is located in the acceleration zone and moves in a radial direction of the acceleration zone.

[0016] In this way, the ion beam currents at different phases in the acceleration region can be measured through the movement of the current target, which is convenient for evaluating and adjusting the performance of the cyclotron accelerator.

[0017] In some embodiments, the current target includes an upper target, a middle target and a lower target, which are stacked and the centering of the ion beam is measured by the upper target, the middle target and the lower target.

[0018] In this way, by measuring the neutrality of the ion beam through the current target, the ion beam current can be adjusted to minimize the radial precession of the ion beam current and reduce the occurrence of coherent oscillations, which is beneficial to maintaining a stable growth of the ion beam trajectory radius during the acceleration process, thereby improving the extraction efficiency of the cyclotron accelerator.

[0019] In some embodiments, the end surface of the current target facing the central region is parallel to the incident direction of the ion beam.

[0020] In this way, the ion beam current can be completely deposited inside the current target, and the ion beam current intensity measured by the current target is maximized, thereby improving the accuracy of ion beam current intensity measurement.

[0021] In some embodiments, the radial probe includes a second driving mechanism connected to the current target and configured to drive the current target to move radially along the acceleration zone.

[0022] In this way, the second driving mechanism drives the current target to move radially along the acceleration zone, so as to measure the ion beam current at each radial position in the acceleration zone, which is beneficial to improving the flexibility of current target measurement.

[0023] In some embodiments, the radial probe includes a second processor connected to the current target and configured to read the ion beam current signal collected by the current target.

[0024] In this way, the ion beam current signal collected by the current target is read by the second processor without shutting down the cyclotron or removing the current target from the acceleration zone of the cyclotron, thereby achieving online and real-time measurement of the ion beam current in the acceleration zone, thereby improving the convenience of signal acquisition.

[0025] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 is a schematic structural diagram of an online ion beam current diagnostic system according to an embodiment of the present invention; Figure 2 is a schematic structural diagram of a phase selection component according to an embodiment of the present invention; Figure 3 is a schematic structural diagram of a slit sheet according to an embodiment of the present invention; Figure 4 yes Figure 2 An enlarged schematic diagram of part I; Figure 5 is a schematic structural diagram of a radial probe according to an embodiment of the present invention; Figure 6 Schematic diagram of the structure of the current target according to the embodiment of the present invention.

[0027] Explanation of the reference numerals: 100, online ion beam current diagnostic system; 10, phase selection assembly; 11, slit; 12, through hole; 13, first driving mechanism; 14, first driving member; 15, first connecting member; 20, radial probe; 21, current target; 22, upper target; 23, middle target; 24, lower target; 25, second driving mechanism; 26, second connecting member; 27, guide rail; 200, cyclotron; 210, groove. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0029] In the description of the present invention, it should 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" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; 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. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0032] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0033] See also Figure 1 The online ion beam current diagnostic system 100 of the embodiment of the present application is used for a cyclotron 200. The online ion beam current diagnostic system 100 includes a phase selection component 10 and a radial probe 20. The phase selection component 10 is at least partially disposed in the central area of ​​the cyclotron 200 for measuring the ion beam current located in the central area; the radial probe 20 is at least partially disposed in the acceleration area of ​​the cyclotron 200 for measuring the ion beam current located in the acceleration area; the radial probe 20 cooperates with the phase selection component 10 to perform phase selection on the ion beam current in the central area and measure the acceleration efficiency of the cyclotron 200.

[0034] In this way, the extraction efficiency of the cyclotron 200 can be measured by the radial probe 20, and the acceleration efficiency of the cyclotron 200 can be measured by the phase selection component 10 and the radial probe 20, so that the cyclotron 200 can be adjusted according to the measurement results, so that the accelerated ion beam meets the radiation requirements and reduces energy waste in the cyclotron 200.

[0035] Specifically, the cyclotron 200 can be divided into a central area, an acceleration area, and an extraction area. The cyclotron 200 includes an ion source, which is located at the center of the central area. The ion source is used to generate an ion beam, the central area is used to extract the ion beam and perform beam focusing inside the central area, the acceleration area is used to accelerate the ion beam to a target energy, and the extraction area is used to extract the accelerated ion beam. In one embodiment, the central area is a circular area with a radius of 160 mm, the acceleration area is an annular area with a radius of 160 mm to 750 mm, and the extraction area is an area with a radius greater than 750 mm.

[0036] A part of the phase selection component 10 can be disposed in the central region of the cyclotron 200 and another part can be disposed outside the central region. A part of the radial probe 20 can be disposed in the acceleration region of the cyclotron 200 and another part can be disposed outside the acceleration region.

[0037] The acceleration efficiency of the cyclotron 200 can be the ratio of the current intensity of the ion beam at the large radius position of the acceleration zone to the current intensity of the ion beam at the small radius position of the acceleration zone. Further, the acceleration efficiency of the cyclotron 200 can be the ratio of the current intensity of the ion beam at the end position of the acceleration zone to the current intensity of the ion beam at the starting position of the acceleration zone.

[0038] The extraction efficiency of the cyclotron 200 may be a ratio of the current intensity of the ion beam after being extracted from the acceleration region to the current intensity of the ion beam in the acceleration region.

[0039] See also Figure 2 and Figure 3 In some embodiments, the phase selection component 10 includes a slit plate 11, which is located in the central area and moves radially along the central area. The slit plate 11 is formed with a through hole 12, and the through hole 12 is used for an ion beam that meets preset conditions to pass through the central area.

[0040] In this way, the ion beam that does not meet the preset conditions in the central area can be intercepted by the slit 11, so that the ion beam that does not meet the preset conditions is deposited in the central area, thereby improving the acceleration efficiency and extraction efficiency of the cyclotron 200.

[0041] Specifically, the slit 11 can be designed to be insulated from electrical signals, and the slit 11 can be embedded and installed in the central area. The slit 11 can measure the ion beam current. The slit 11 moves radially along the central area to obtain ion beam currents of different phases to evaluate the beam output performance of the ion source. The slit 11 is used to pass an ion beam current with a larger ion beam current and intercept an ion beam current with a smaller ion beam current. The movement trajectory of the slit 11 in the central area can be a straight line or a curve.

[0042] The size of the slit sheet 11 and the position and size of the through hole 12 can be designed according to actual needs. Figure 3 In one embodiment, the thickness of the slit 11 is 1 mm, the effective height D1 of the slit 11 in contact with the ion beam is 12 mm, the effective width D2 of the slit 11 in contact with the ion beam is 16 mm, the height D3 of the through hole 12 is 6 mm, and the width D4 of the through hole 12 in the radial direction of the central region is 1 mm. The central plane of the through hole 12 in the height direction may coincide with the central plane of the ion beam in the radial direction of the central region.

[0043] In some embodiments, the movement radius of the slit plate 11 in the central area ranges from 28 mm to 60 mm.

[0044] When it is within the above range, the energy of the ion beam current is small, the moving speed is slow, and the moving circle distance is large, which makes it easy for the slit plate 11 to measure and screen the ion beam current.

[0045] Combination Figure 4 The cyclotron 200 may be formed with a groove 210 in the radial direction of the central area within a radius range of 28 mm to 60 mm, and the slit sheet 11 moves in the groove 210 .

[0046] See also Figure 2 In some embodiments, the phase selection component 10 includes a first driving mechanism 13, which is connected to the slit plate 11 and is used to drive the slit plate 11 to move radially along the central area.

[0047] In this way, the first driving mechanism 13 drives the slit plate 11 to move radially along the central area, so as to measure the ion beam current at each radial position within the moving radius, which is beneficial to improving the measurement flexibility of the slit plate 11.

[0048] Specifically, the first driving mechanism 13 may adopt an electrical signal insulation design, and the first driving mechanism 13 may include a first driving member 14 and a first connecting member 15, the first driving member 14 may be a motor, a cylinder, etc., and the first connecting member 15 connects the first driving member 14 and the slit sheet 11. The first driving mechanism 13 may drive the slit sheet 11 to move precisely within the range of motion, for example, the first driving mechanism 13 may drive the slit sheet 11 to move 1 mm, 1.5 mm, 2 mm, etc. each time.

[0049] In one embodiment, the first driving mechanism 13 can provide a vacuum sealing environment inside the central area, so that the ion beam in the central area can move in a vacuum, preventing impurity molecules in the air from affecting the ion beam.

[0050] In some embodiments, the phase selection component 10 includes a first processor, which is connected to the slit plate 11 and is used to read the ion beam current signal collected by the slit plate 11.

[0051] In this way, the ion beam current signal collected by the slit 11 is read by the first processor without shutting down the cyclotron 200 or removing the slit 11 from the central area of ​​the cyclotron 200, thereby achieving online and real-time measurement of the ion beam current in the central area, thereby improving the convenience of signal acquisition.

[0052] Specifically, the first processor can be designed with electrical signal insulation, and the first processor can be connected to the slit plate 11 through a signal line to transmit signals. The first processor can be arranged outside the cyclotron 200, and the first processor leads the ion beam signal intercepted by the slit plate 11 to the current amplifier to read the ion beam current strength.

[0053] See also Figure 5In some embodiments, the radial probe 20 includes a current target 21, which is located in the acceleration zone and moves along the radial direction of the acceleration zone.

[0054] In this way, the ion beam currents at different phases in the acceleration region can be measured through the movement of the current target 21 , so as to facilitate the evaluation and adjustment of the performance of the cyclotron 200 .

[0055] Specifically, the current target 21 can be designed to be insulated from electrical signals, and the current target 21 can move within the full radius of the acceleration zone, that is, the current target 21 can move within a radius range of 160 mm to 750 mm, so as to measure the ion beam current at different radial positions. The motion trajectory of the current target 21 in the acceleration zone can be a straight line or a curve.

[0056] See also Figure 6 In some embodiments, the current target 21 includes an upper target 22, a middle target 23 and a lower target 24, which are stacked and the centering of the ion beam is measured by the upper target 22, the middle target 23 and the lower target 24.

[0057] In this way, by measuring the neutrality of the ion beam through the current target 21, the ion beam can be adjusted to minimize the radial precession of the ion beam and reduce the occurrence of coherent oscillations, which is beneficial to maintaining a stable growth of the ion beam trajectory radius during the acceleration process, thereby improving the extraction efficiency of the cyclotron 200.

[0058] Specifically, the upper target 22, the middle target 23 and the lower target 24 can be stacked in the thickness direction, and the radial center plane of the ion beam in the acceleration zone is coincident with the center plane of the thickness direction of the middle target 23. When the ion beam strength of the middle target 23 is greater than the ion beam strength of the upper target 22 and the lower target 24, and the ion beam strength of the upper target 22 is equal to the ion beam strength of the lower target 24, it indicates that the concentricity of the ion beam is better.

[0059] In some embodiments, the end surface of the current target 21 facing the central region is parallel to the incident direction of the ion beam.

[0060] In this way, the ion beam current can be completely deposited inside the current target 21, and the ion beam current intensity measured by the current target 21 is maximized, thereby improving the accuracy of the ion beam current intensity measurement.

[0061] Specifically, the angle between the end face and the side face of the current target 21 facing the central region can be determined according to the angle between the motion trajectory of the current target 21 and the direction of the ion beam. Figure 6 In one embodiment, the angle α between the end surface of the current target 21 facing the central region and the side surface of the current target 21 away from the incident direction of the ion beam is 70°.

[0062] In some embodiments, the radial probe 20 includes a second driving mechanism 25 , which is connected to the current target 21 and is used to drive the current target 21 to move radially along the acceleration zone.

[0063] In this way, the second driving mechanism 25 drives the current target 21 to move radially along the acceleration zone, so as to measure the ion beam current at each radial position in the acceleration zone, which is beneficial to improving the flexibility of the current target 21 measurement.

[0064] Specifically, the second driving mechanism 25 may include a second driving member and a second connecting member 26. The second driving member may be a motor, a cylinder, etc. The second connecting member 26 connects the second driving member and the current target 21. In one embodiment, the second driving mechanism 25 also includes a guide rail 27, which extends radially along the acceleration zone. The second connecting member 26 may be composed of a plurality of trolleys, which are slidably arranged on the guide rail 27, and the current target 21 is arranged on the trolley. The second driving member drives the trolley to move on the guide rail 27, thereby driving the current target 21 to move radially along the acceleration zone. The second driving mechanism 25 can drive the current target 21 to move precisely in the acceleration zone. For example, the second driving mechanism 25 can drive the current target 21 to move 1 mm, 1.5 mm, 2 mm, etc. each time.

[0065] In one embodiment, the second driving mechanism 25 can provide a vacuum sealing environment inside the acceleration region, so that the ion beam in the acceleration region can move in a vacuum, preventing impurity molecules in the air from affecting the ion beam.

[0066] In some embodiments, the radial probe 20 includes a second processor connected to the current target 21 for reading the ion beam current signal collected by the current target 21 .

[0067] In this way, the ion beam current signal collected by the current target 21 is read by the second processor without shutting down the cyclotron 200 or removing the current target 21 from the acceleration zone of the cyclotron 200. Online and real-time measurement of the ion beam current in the acceleration zone can be achieved, thereby improving the convenience of signal acquisition.

[0068] Specifically, the second processor can be connected to the current target 21 through a signal line for signal transmission. The second processor can be arranged outside the cyclotron 200, and the second processor leads the ion beam current signal obtained by the current target 21 to the current amplifier to read the ion beam current strength.

[0069] The phase selection of the ion beam current in the central area can be performed by fixing the current target 21 at the starting position of the acceleration zone, moving the slit 11 in a certain step length, and reading the ion beam current intensity measured by the current target 21 when the slit 11 is at different positions. When the ion beam current intensity measured by the current target 21 is the largest, the position of the slit 11 is the optimal phase position of the slit 11.

[0070] In some embodiments, the slit 11 may be fixed at the optimal phase first, and then the current target 21 may be moved to the starting position of the acceleration zone to obtain the current intensity of the ion beam at the starting position of the acceleration zone, and then the current target 21 may be moved to the ending position of the acceleration zone to obtain the current intensity of the ion beam at the ending position of the acceleration zone, so as to calculate the acceleration efficiency of the cyclotron 200. In one embodiment, the acceleration efficiency of the cyclotron 200 is the ratio of the ion beam current intensity at a radius of 750 mm to the ion beam current intensity at a radius of 160 mm.

[0071] In some embodiments, the current target 21 may be first moved to a certain position in the acceleration region to obtain the current intensity of the ion beam in the acceleration region, and then the ion beam current intensity in the extraction region may be obtained through the external target in the extraction region, thereby calculating the extraction efficiency of the cyclotron 200. In one embodiment, the extraction efficiency of the cyclotron 200 is the ratio of the ion beam current intensity in the extraction region to the ion beam current intensity at a radius of 300 mm.

[0072] In the description of this specification, the description with reference to the terms "one embodiment", "certain embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0073] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An online ion beam current diagnostic system for a cyclotron, characterized in that: include: A phase selection component is at least partially disposed in a central region of the cyclotron and is used to measure a beam current of an ion beam located in the central region; A radial probe, at least partially disposed in an acceleration region of the cyclotron, for measuring a beam current of an ion beam located in the acceleration region; The radial probe cooperates with the phase selection component to perform phase selection on the ion beam current in the central area and measure the acceleration efficiency of the cyclotron.

2. The online ion beam current diagnostic system according to claim 1, characterized in that: The phase selection component includes a slit plate, which is located in the central area and moves radially along the central area. The slit plate is formed with a through hole, and the through hole is used for the ion beam that meets the preset conditions to pass through the central area.

3. The online ion beam current diagnostic system according to claim 2, characterized in that: The movement radius of the slit sheet in the central area ranges from 28 mm to 60 mm.

4. The online ion beam current diagnostic system according to claim 2, characterized in that: The phase selection component includes a first driving mechanism, which is connected to the slit plate and is used to drive the slit plate to move radially along the central area.

5. The online ion beam current diagnostic system according to claim 2, characterized in that: The phase selection component includes a first processor, which is connected to the slit plate and is used to read the ion beam current signal collected by the slit plate.

6. The online ion beam current diagnostic system according to claim 1, characterized in that: The radial probe includes a current target, which is located in the acceleration zone and moves along the radial direction of the acceleration zone.

7. The online ion beam current diagnostic system according to claim 6, characterized in that: The current target comprises an upper target, a middle target and a lower target, wherein the upper target, the middle target and the lower target are stacked and the centering of the ion beam is measured by the upper target, the middle target and the lower target.

8. The online ion beam current diagnostic system according to claim 6, characterized in that: The end surface of the current target facing the central region is parallel to the incident direction of the ion beam.

9. The online ion beam current diagnostic system according to claim 6, characterized in that: The radial probe comprises a second driving mechanism, which is connected to the current target and is used to drive the current target to move radially along the acceleration zone.

10. The online ion beam current diagnostic system according to claim 6, characterized in that: The radial probe includes a second processor connected to the current target and configured to read the ion beam current signal collected by the current target.

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