Ion source collimation detection method, detection system and proton heavy ion accelerator

Abstract

The invention provides an ion source collimation detection method. The method comprises the following steps: S10, acquiring a plasma current intensity value of an ion source; s20, measuring an actual extraction beam intensity value of the ion source by means of a beam measurement device; s30, dividing the actual extraction beam intensity value by the plasma current intensity value to obtain an extraction efficiency value; and S40, the extraction efficiency value is compared with a preset standard value, if the extraction efficiency value is smaller than the standard value, it is judged that the ion source deviation exceeds a specified value, and if the extraction efficiency value is larger than or equal to the standard value, it is judged that the ion source deviation does not exceed the specified value. According to the ion source collimation detection method, the detection process is simple, shutdown and shell disassembly are not needed, and the detection precision and safety are both considered while the cost is reduced. The invention also provides a detection system for realizing the detection method and the proton heavy ion accelerator.

Description

Technical Field

[0001] The invention relates to the field of proton and heavy ion accelerators, and in particular to a method for detecting the collimation of an ion source, and a detection system and a proton and heavy ion accelerator for realizing the detection method. Background Art

[0002] Electron Cyclotron Resonance Ion Source (ECRIS) is one of the common devices used in proton and heavy ion accelerators to produce heavy ion beams. The electron cyclotron resonance ion source is a plasma ion source that uses an electric field to draw ions out of a plasma. The drawn ions are then screened and accelerated by the subsequent equipment to become proton and heavy ion beams used to treat patients.

[0003] The electron cyclotron resonance ion source requires a high-voltage insulation environment, so the insulation of the cavity is very important, and different spare parts need to be replaced frequently to ensure that the dark current is as small as possible. After multiple replacements of spare parts, the electron cyclotron resonance ion source is prone to collimation deviation in the lead-out structure, and if the electron cyclotron resonance ion source experiences a drop in current intensity during normal use, it is difficult to determine whether it is caused by the collimation deviation exceeding the specified value. Existing collimation detection methods rely on manual visual inspection or laser calibration, which have problems such as low accuracy, the need for downtime, limited construction conditions, and high maintenance costs. Summary of the invention

[0004] The purpose of the present invention is to provide a method for detecting the alignment of an ion source, which has a simple detection process, does not require shutdown and housing disassembly, and takes into account both detection accuracy and safety while reducing costs.

[0005] Another object of the present invention is to provide an ion source alignment detection system, which has a simple detection process and does not require shutdown or housing removal, thereby reducing costs while taking into account both detection accuracy and safety.

[0006] Another object of the present invention is to provide a proton and heavy ion accelerator, wherein the detection process of the ion source alignment is simple and does not require shutdown or removal of the outer shell, thereby reducing costs while taking into account both detection accuracy and safety.

[0007] The present invention provides a method for detecting the collimation of an ion source, comprising: S10: acquiring an ion body current intensity value of an ion source; S20: measuring an actual extraction beam intensity value of the ion source by means of a beam current measuring device; S30: obtaining an extraction efficiency value by dividing the actual extraction beam intensity value by the ion body current intensity value; and S40: comparing the extraction efficiency value with a preset standard value, if the extraction efficiency value is less than the standard value, determining that the ion source deviation exceeds a specified value, and if the extraction efficiency value is greater than or equal to the standard value, determining that the ion source deviation does not exceed the specified value.

[0008] Compared with the method of determining the alignment by manual visual inspection or laser collimator, the ion source alignment detection method verifies the ion source alignment by calculating the beam extraction efficiency value, which has lower costs while ensuring accuracy. In addition, when using the ion source alignment detection method, the ion source does not need to be shut down or the casing removed, which prevents people from touching the hardware and improves operational safety.

[0009] In another schematic implementation of the method for detecting the collimation of the ion source, S10 includes: S11: setting the ion source high-voltage power supply to load a normal operating voltage to the ion source body, obtaining the current value output by the ion source high-voltage power supply, and recording it as a leakage current value; S12: setting the ion source power amplifier to load a normal operating power to the ion source body, obtaining the current value output by the ion source high-voltage power supply, and recording it as a working current value; and S13: subtracting the leakage current value from the working current value to obtain the ion body current intensity value.

[0010] In another exemplary embodiment of the method for detecting the alignment of the ion source, in S11 and S12, the current value output by the ion source high voltage power supply is obtained by using the current detection function of the ion source high voltage power supply, thereby further reducing the cost.

[0011] In another exemplary implementation of the method for detecting the alignment of an ion source, in S20, the actual extracted beam intensity value is measured using a Faraday cup.

[0012] In another exemplary embodiment of the method for detecting the collimation of the ion source, S20 includes: S21: setting a driving device, the driving device can drive the Faraday cup to move to the path of the particle beam generated by the ion source or outside the path of the particle beam; S22: setting the driving device to drive the Faraday cup to move to the path of the particle beam and measure the actual extracted beam intensity value; and S23: setting the driving device to drive the Faraday cup to move outside the path of the particle beam. In this way, it is convenient to switch between the detection mode and the normal use mode.

[0013] The present invention also provides an ion source collimation detection system, comprising an ion source high voltage power supply, an ion source power amplifier, a beam current measurement device and a data processing unit. The ion source high voltage power supply is used to apply a normal working voltage to the ion source body. The ion source power amplifier is used to load a normal working power to the ion source to excite plasma. The beam current measurement device is used to measure the actual extraction beam current intensity value of the ion source on the path of the particle beam generated by the ion source. The data processing unit signal is connected to the beam measuring device and can receive the actual extracted beam intensity value. The data processing unit can also obtain the current value output by the ion source high-voltage power supply and save it as the leakage current value after the ion source high-voltage power supply loads the normal operating voltage to the ion source body, and obtain the current value output by the ion source high-voltage power supply and save it as the working current value after the ion source power amplifier loads the normal operating power to the ion source body. The data processing unit is configured to use the working current value to subtract the leakage current value to obtain the ion body current intensity value, and use the actual extracted beam intensity value to divide the ion body current intensity value to obtain the extraction efficiency value, and compare the extraction efficiency value with a preset standard value. If the extraction efficiency value is less than the standard value, a collimation deviation signal is generated, and if the extraction efficiency value is greater than or equal to the standard value, a collimation normal signal is generated.

[0014] In another exemplary embodiment of the ion source alignment detection system, the ion source high voltage power supply can monitor the output current value, and the data processing unit signal is connected to the ion source high voltage power supply and can receive the current value output by the ion source high voltage power supply.

[0015] In another exemplary embodiment of the system for detecting the alignment of an ion source, the beam current measuring device is a Faraday cup.

[0016] In another exemplary embodiment of the ion source collimation detection system, the ion source collimation detection system further includes a driving device, which can drive the beam measurement device to move to the path of the particle beam generated by the ion source or outside the path of the particle beam, thereby conveniently switching between the detection mode and the normal use mode.

[0017] The present invention also provides a proton and heavy ion accelerator, comprising the above-mentioned ion source collimation detection system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The following drawings are only used to schematically illustrate and explain the present invention, and do not limit the scope of the present invention.

[0019] Figure 1 The present invention is a flow chart of a schematic implementation of a method for detecting the alignment of an ion source.

[0020] Figure 2 Schematic diagram of the implementation of the method for detecting the alignment of the ion source.

[0021] Figure 3 A partial flow chart of a method for detecting ion source alignment.

[0022] Figure 4 Another partial flow chart of the method for detecting the alignment of the ion source.

[0023] Figure 5 FIG. 4 is a schematic diagram of another implementation of a method for detecting the alignment of an ion source.

[0024] Description of symbols

[0025] 10 Ion source high voltage power supply

[0026] 20 Ion source power amplifier

[0027] 30 Beam measurement device

[0028] 40 Data Processing Unit

[0029] 50 Drive unit

[0030] 60 Ion source body

[0031] 61 Particle Beam DETAILED DESCRIPTION

[0032] In order to have a clearer understanding of the technical features, purposes and effects of the invention, the specific embodiments of the present invention are now described with reference to the accompanying drawings. The same reference numerals in the drawings represent components with the same structure or similar structures but the same functions.

[0033] In this document, “exemplary” means “serving as an example, instance or illustration”, and any diagram or implementation described in this document as “exemplary” should not be interpreted as a more preferred or more advantageous technical solution.

[0034] In order to simplify the drawings, each figure only schematically shows the parts related to the present invention, which do not represent the actual structure of the product.

[0035] The invention provides a method for detecting the collimation of an ion source. Figure 1 The present invention is a flow chart of a schematic implementation of a method for detecting the alignment of an ion source. Figure 2 Schematic diagram of the implementation of the method for detecting the alignment of the ion source. Figure 1 and Figure 2 , the method for detecting the alignment of the ion source includes S10 to S40.

[0036] S10: Obtaining the ion current intensity value of the ion source. Obtaining the ion current intensity value requires removing the interference of the leakage current. Figure 3 This is a partial flow chart of the method for detecting the alignment of the ion source. Figure 3 , S10 specifically includes S11 to S13.

[0037] S11: Set the ion source high voltage power supply 10 to load the normal operating voltage to the ion source body 60, obtain the current value output by the ion source high voltage power supply 10, and record it as the leakage current value. The leakage current is the current when only the normal operating voltage (for example, 24KV) is loaded and the plasma is not excited, which is usually caused by high-voltage insulation defects or stray electric fields. Usually, the ion source high voltage power supply 10 has a current detection function, and the output current value can be directly read from the ion source high voltage power supply 10 without adding an additional current measurement device, further reducing costs.

[0038] S12: Set the ion source power amplifier 20 to load normal working power to the ion source body 60, obtain the current value output by the ion source high voltage power supply 10, and record it as the working current value. The working current is the total current after the ion source body 60 is loaded with normal working power (for example, -14dbm), including leakage current.

[0039] S13: Subtract the leakage current value from the working current value to obtain the plasma current intensity value. The leakage current interference is eliminated by subtraction to obtain the pure plasma current intensity.

[0040] S20: Measure the actual extracted beam intensity value of the ion source by means of the beam current measuring device 30. In the exemplary embodiment, the beam current measuring device 30 is a Faraday cup, which is a commonly used device for measuring beam current intensity, and has high measurement accuracy and low cost, so the proton and heavy ion accelerator is usually equipped with a Faraday cup.

[0041] During the measurement of the beam intensity, the Faraday cup will block the particle beam 61 between the ion source and the treatment chamber, so after the measurement is completed, the Faraday cup needs to be moved out of the path of the particle beam 61 . Figure 4 Another partial flow chart of the method for detecting the alignment of the ion source. Figure 5 FIG. 2 is another schematic diagram of another implementation of the method for detecting the alignment of an ion source. Figures 2 to 5 , S20 includes S21 to S23.

[0042] S21: a driving device 50 is provided, and the driving device 50 can drive the Faraday cup to move onto the path of the particle beam 61 generated by the ion source or outside the path of the particle beam 61 .

[0043] S22: The driving device 50 is set to drive the Faraday cup to move to the path of the particle beam 61, and measure the actual extracted beam intensity value.

[0044] S23: The driving device 50 is set to drive the Faraday cup to move outside the path of the particle beam 61. After the measurement is completed, the Faraday cup is moved outside the path of the particle beam 61 of the ion source by means of the driving device 50, so that the particle beam 61 generated by the ion source can reach the treatment room. In this way, it is convenient to switch between the detection mode and the normal use mode.

[0045] S30: The actual extracted beam intensity value is divided by the plasma current intensity value to obtain an extraction efficiency value.

[0046] S40: Compare the extraction efficiency value with a preset standard value. If the extraction efficiency value is less than the standard value, it is determined that the ion source deviation exceeds the specified value. If the extraction efficiency value is greater than or equal to the standard value, it is determined that the ion source deviation does not exceed the specified value.

[0047] The specified value and standard value are determined according to the actual situation of the proton and heavy ion accelerator. The deviation value of the extraction structure can be adjusted in advance to reach the specified value. For example, the extraction structure is adjusted so that the deviation value is 0.5 mm. At this time, the extraction efficiency value is 0.8 obtained through detection and calculation. In the subsequent detection process, the standard value can be set to 0.8. If the extraction efficiency value obtained during the detection process is less than 0.8, it can be inferred that the deviation value of the extraction structure exceeds 0.5 mm.

[0048] Compared with the method of determining the collimation by manual visual inspection or laser collimator, the ion source collimation detection method provided by the present invention verifies the collimation of the ion source by calculating the extraction efficiency value of the particle beam, which has lower cost while ensuring accuracy. In addition, when using the ion source collimation detection method, the ion source does not need to be shut down or the casing removed, which prevents people from touching the hardware with high voltage, thereby improving the safety of operation.

[0049] The present invention also provides a detection system for the alignment of an ion source. Figure 2 and Figure 5 The ion source alignment detection system includes an ion source high voltage power supply 10 , an ion source power amplifier 20 , a beam current measurement device 30 and a data processing unit 40 .

[0050] The ion source high voltage power supply 10 is used to apply a normal operating voltage to the ion source body 60. The ion source power amplifier 20 is used to load the normal operating power to the ion source to excite the plasma. The beam current measurement device 30 is used to measure the actual extraction beam current intensity value of the ion source on the path of the particle beam 61 generated by the ion source. In the exemplary implementation, the beam current measurement device 30 is a Faraday cup.

[0051] The data processing unit 40 is connected to the beam current measuring device 30 by signal and can receive the actual extracted beam current intensity value. The data processing unit 40 can also obtain the current value output by the ion source high voltage power supply 10 after the ion source high voltage power supply 10 loads the normal working voltage to the ion source main body 60 and save it as the leakage current value, and obtain the current value output by the ion source high voltage power supply 10 after the ion source power amplifier 20 loads the normal working power to the ion source main body 60 and save it as the working current value.

[0052] The data processing unit 40 is configured to obtain a plasma current intensity value by subtracting a leakage current value from a working current value, obtain an extraction efficiency value by dividing an actual extracted beam intensity value by the plasma current intensity value, compare the extraction efficiency value with a preset standard value, and generate a collimation deviation signal if the extraction efficiency value is less than the standard value, and generate a collimation normal signal if the extraction efficiency value is greater than or equal to the standard value. The collimation deviation signal and the collimation normal signal are used to display corresponding information on a display device, or to drive an alarm device to send an alarm signal.

[0053] The ion source alignment detection system provided by the present invention verifies the alignment of the ion source by calculating the extraction efficiency value of the beam, which ensures accuracy and has lower costs. In addition, when using the ion source alignment detection system, the ion source does not need to be shut down or the housing removed, which prevents people from touching hardware with high voltage, thereby improving operational safety.

[0054] In the exemplary embodiment, the ion source high voltage power supply 10 can monitor the output current value, and the data processing unit 40 is connected to the ion source high voltage power supply 10 and can receive the current value output by the ion source high voltage power supply 10. Thereby, there is no need to add an additional current measuring device, further reducing the cost.

[0055] In an exemplary embodiment, referring to Figure 2 and Figure 5 The ion source alignment detection system further includes a driving device 50, which may be a cylinder, and can drive the beam measuring device 30 to move onto or outside the path of the particle beam 61. The driving device 50 can be used to drive the beam measuring device 30 without opening the particle beam pipeline, and conveniently switch between the detection mode and the normal use mode.

[0056] The present invention also provides a proton and heavy ion accelerator, comprising the above-mentioned ion source collimation detection system.

[0057] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0058] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation scheme or changes that do not deviate from the technical spirit of the present invention, such as combination, division or repetition of features, should be included in the scope of protection of the present invention.

Claims

1. A method for detecting the collimation of an ion source, characterized in that: include: S10: obtaining the ion current intensity value of the ion source; S20: measuring the actual extraction beam intensity value of the ion source by means of a beam current measuring device; S30: Dividing the actual extracted beam intensity value by the plasma current intensity value to obtain an extraction efficiency value; as well as S40: Compare the extraction efficiency value with a preset standard value. If the extraction efficiency value is less than the standard value, it is determined that the ion source deviation exceeds the specified value. If the extraction efficiency value is greater than or equal to the standard value, it is determined that the ion source deviation does not exceed the specified value.

2. The method for detecting the alignment of an ion source according to claim 1, characterized in that: S10 includes: S11: Setting the ion source high voltage power supply to load a normal operating voltage to the ion source body, obtaining a current value output by the ion source high voltage power supply, and recording it as a leakage current value; S12: Setting the ion source power amplifier to load normal working power to the ion source body, obtaining the current value output by the ion source high voltage power supply, and recording it as the working current value; and S13: Subtract the leakage current value from the working current value to obtain the ion current intensity value.

3. The method for detecting the alignment of an ion source according to claim 2, characterized in that: In S11 and S12, the current value output by the ion source high voltage power supply is acquired by utilizing the current detection function of the ion source high voltage power supply.

4. The method for detecting the alignment of an ion source according to claim 1, characterized in that: In S20, the actual extracted beam intensity value is measured using a Faraday cup.

5. The method for detecting the alignment of an ion source according to claim 4, characterized in that: The S20 includes: S21: providing a driving device, wherein the driving device is capable of driving the Faraday cup to move to a path of a particle beam generated by an ion source or outside the path of the particle beam; S22: setting the driving device to drive the Faraday cup to move to the path of the particle beam, and measuring the actual extracted beam intensity value; and S23: Setting the driving device to drive the Faraday cup to move outside the path of the particle beam.

6. A system for detecting the collimation of an ion source, characterized in that: include: An ion source high voltage power supply (10) for applying a normal operating voltage to the ion source body; An ion source power amplifier (20) for applying normal operating power to the ion source to excite plasma; A beam current measuring device (30) is used to measure the actual extracted beam current intensity value of the ion source on the path of the particle beam generated by the ion source; as well as A data processing unit (40) whose signal is connected to the beam current measuring device (30) and is capable of receiving the actual extracted beam current intensity value. The data processing unit (40) is also capable of obtaining the current value output by the ion source high voltage power supply (10) and saving it as a leakage current value after the ion source high voltage power supply (10) loads the normal operating voltage to the ion source body, and obtaining the current value output by the ion source high voltage power supply (10) and saving it as a working current value after the ion source power amplifier (20) loads the normal operating power to the ion source body. The data processing unit (40) is configured to obtain an ion body current intensity value by subtracting the leakage current value from the working current value, obtain an extraction efficiency value by dividing the actual extracted beam current intensity value by the ion body current intensity value, compare the extraction efficiency value with a preset standard value, generate a collimation deviation signal if the extraction efficiency value is less than the standard value, and generate a collimation normal signal if the extraction efficiency value is greater than or equal to the standard value.

7. The ion source alignment detection system according to claim 6, characterized in that: The ion source high voltage power supply (10) is capable of monitoring the output current value, and the data processing unit (40) is signal-connected to the ion source high voltage power supply (10) and is capable of receiving the current value output by the ion source high voltage power supply (10).

8. The ion source alignment detection system according to claim 6, characterized in that: The beam current measuring device (30) is a Faraday cup.

9. The ion source alignment detection system according to claim 8, characterized in that: The ion source collimation detection system further comprises a driving device (50), wherein the driving device (50) is capable of driving the beam current measurement device (30) to move onto the path of the particle beam current generated by the ion source or outside the path of the particle beam current.

10. Proton and heavy ion accelerator, characterized in that: A detection system for ion source alignment comprising the system described in any one of claims 6 to 9.

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