Apparatus and method for measuring proton beam energy distribution

Abstract

The application relates to a device and a method for measuring the energy distribution of a proton beam, and relates to the technical field of proton beam detection. The device comprises a deflection magnet for controlling the deflection direction of the proton beam; a first single-slit is arranged at the outlet end of the deflection magnet and is used for allowing the beam current within a preset width to pass; an alternating current sensor ACCT is arranged at the outlet end of the first single-slit and is used for measuring the flow intensity of the beam current passing through the first single-slit; a controller is connected with the first single-slit and is used for controlling the first single-slit to move along a target direction, and the distance of each movement is a preset width; a processor is connected with the deflection magnet, the controller and the ACCT respectively, is used for acquiring the magnetic induction intensity of the deflection magnet, the various control instructions of the controller and the various flow intensities measured by the ACCT, and obtaining the energy distribution of the proton beam according to the magnetic induction intensity, the various position information of the first single-slit and the various flow intensities. The application has the effect of accurately measuring the energy distribution of the proton beam.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of proton beam detection, in particular to a device and method for measuring energy distribution of a proton beam. BACKGROUND

[0002] The energy distribution of a proton beam can provide important information about the energy distribution characteristics of the proton beam in space. Measuring the energy distribution of a proton beam is of great significance in guiding the design of a proton treatment plan, evaluating treatment effectiveness, ensuring treatment safety, etc., and as an important indicator of quality control and quality assurance, the energy distribution of a proton beam can help improve the accuracy, effectiveness and safety of proton therapy. Therefore, how to measure the energy distribution of a proton beam is an important problem.

[0003] In the prior art, some measuring devices can directly obtain the energy distribution map or energy profile of a proton beam in space, but the specific energy values of each part of the proton beam cannot be accurately determined by the image alone. SUMMARY

[0004] To solve the problem of how to measure the energy distribution of a proton beam, the present application provides a device and method for measuring the energy distribution of a proton beam.

[0005] In a first aspect, the present application provides a device for measuring the energy distribution of a proton beam, which adopts the following technical solution:

[0006] A device for measuring the energy distribution of a proton beam comprises:

[0007] A deflection magnet for controlling the deflection direction of the proton beam;

[0008] A first single-slit provided at the outlet end of the deflection magnet for allowing the beam within a preset width to pass through;

[0009] An alternating current sensor ACCT provided at the outlet end of the first single-slit for measuring the flow intensity of the beam passing through the first single-slit;

[0010] A controller connected to the first single-slit for controlling the first single-slit to move along a target direction, and the distance of each movement is the preset width;

[0011] A processor connected to the deflection magnet, the controller and the ACCT respectively for obtaining the magnetic induction intensity of the deflection magnet, each control instruction of the controller and each flow intensity measured by the ACCT, and obtaining the energy distribution of the proton beam according to the magnetic induction intensity, each position information of the first single-slit and the each flow intensity; the each position information of the first single-slit is determined according to the each control instruction.

[0012] By adopting the technical scheme, the device comprises a deflection magnet, a first single slit, an ACCT, a controller and a processor, the controller can control the first single slit to move along a target direction, and the processor obtains the energy distribution of the proton beam flow according to the magnetic induction intensity of the deflection magnet, the position information of each of the first single slit and the measured flow intensity of each of the ACCT, so as to realize automatic measurement of the energy distribution of the proton beam flow.

[0013] Optionally, the device further comprises:

[0014] A beam cross-section fluorescence target camera is arranged at the outlet end of the ACCT and is used to acquire a profile of the beam flow passing through the first single slit.

[0015] The processor is connected with the beam cross-section fluorescence target camera and is further used to acquire the profile and filter out data not in the profile.

[0016] By filtering out the data not in the profile of the beam flow, the effectiveness of the data can be ensured, and the accuracy of measuring the energy distribution of the proton beam flow is improved.

[0017] Optionally, the device further comprises:

[0018] A second single slit is arranged at the inlet end of the deflection magnet and is used to allow the beam flow near the central energy to pass through.

[0019] By adopting the technical scheme, the second single slit is arranged to allow the beam flow near the central energy to pass through, and the energy distribution of the beam flow near the central energy is measured subsequently, so that the measurement accuracy is improved.

[0020] Optionally, the device further comprises a first stepper motor.

[0021] The controller is connected with the first stepper motor and is used to control the first stepper motor to move along the target direction, and the distance of each movement is the preset width.

[0022] The first stepper motor is connected with the first single slit and is used to drive the first single slit to move along the target direction, and the distance of each movement is the preset width.

[0023] By adopting the technical scheme, the first single slit is driven to move by the first stepper motor, the distance of each movement of the first single slit can be accurately controlled to be the preset width, the overall scanning range of the first single slit is ensured to cover the outlet end of the deflection magnet, and the accuracy of measuring the energy distribution is improved.

[0024] Optionally, the first stepper motor comprises a first motor and a second motor, and the first single slit comprises a first slit plate and a second slit plate.

[0025] The first motor is connected with a first surface of the first slit plate, and is configured to drive the first slit plate to move in the target direction within a first preset range, and the distance of each movement is the preset width, and the first surface is a surface of the first slit plate away from the beam;

[0026] The second motor is connected with a second surface of the second slit plate, and is configured to drive the second slit plate to move in the target direction within a second preset range, and the distance of each movement is the preset width, and the second surface is a surface of the second slit plate away from the beam.

[0027] By using the above technical solution, the two motors are used to drive the two slit plates to move in the same direction by the preset width, so that the distance between the two slit plates is always unchanged, and then the beam passing through the first single slit each time is of the same width, and the uniformity of the beam measured each time is ensured.

[0028] Optionally, the deflection magnet is a dipole magnet.

[0029] In a second aspect, the application provides a method for measuring the energy distribution of a proton beam, which uses the following technical solution: a method for measuring the energy distribution of a proton beam, applied to the device for measuring the energy distribution of a proton beam in any of the first aspect, comprising:

[0030] controlling the first single slit to move in the target direction, collecting the position information of the first single slit and the flow intensity measured by the ACCT each time the first single slit moves to a position, and the distance of each movement is the preset width;

[0031] obtaining the magnetic induction intensity of the deflection magnet, the position information of the first single slit, and the flow intensity measured by the ACCT;

[0032] obtaining the energy distribution of the proton beam according to the magnetic induction intensity, the position information, and the flow intensity.

[0033] Optionally, controlling the first single slit to move in the target direction comprises:

[0034] controlling the first motor to drive the first slit plate to move in the target direction within a first preset range, and the distance of each movement is the preset width;

[0035] controlling the second motor to drive the second slit plate to move in the target direction within a second preset range, and the distance of each movement is the preset width.

[0036] Optionally, the energy distribution of the proton beam is obtained according to the magnetic induction intensity, the position information of each position, and the flow intensity of each position, including:

[0037] The number of protons is obtained by the following formula: Wherein, n is the number of protons, q is the amount of charge carried by the proton, I is the flow intensity; the deflection radius of the proton is determined according to the position information of the first single slit;

[0038] The beam energy is obtained by the following formula: E = mv 2 = m(rqb / m) 2 = (rqb) 2 / m; wherein E is the beam energy, v is the speed of the proton, m is the mass of the proton, q is the amount of charge carried by the proton, b is the magnetic induction intensity of the deflection magnet, and r is the deflection radius of the proton;

[0039] According to the corresponding relationship between the number of protons and the beam energy, the one-dimensional distribution of the beam energy is obtained by normal fitting.

[0040] Optionally, the one-dimensional distribution of the beam energy is obtained by normal fitting according to the corresponding relationship between the number of protons and the beam energy, including:

[0041] According to the number of protons and the corresponding beam energy of each number of protons, the expression of the beam energy is obtained by normal fitting.

[0042] In summary, the present application includes at least one of the following beneficial technical effects:

[0043] 1. The present application provides a device for measuring the energy distribution of a proton beam, including a deflection magnet, a first single slit, an ACCT, a controller and a processor, so that the proton beam can pass through the deflection magnet, the first single slit and the ACCT in turn, the controller can control the first single slit to move along the target direction, and the processor can obtain the energy distribution of the proton beam according to the magnetic induction intensity of the deflection magnet, the position information of each position of the first single slit and the flow intensity measured by the ACCT, thereby realizing the automatic measurement of the energy distribution of the proton beam.

[0044] 2. The present application provides a method for measuring the energy distribution of a proton beam, which is applied to a device for measuring the energy distribution of a proton beam, and controls the first single slit to move along the target direction. The position information of the first single slit and the flow intensity measured by the ACCT are collected every time the first single slit moves to a position. The energy distribution of the proton beam is obtained according to the magnetic induction intensity of the deflection magnet, the position information of each position of the first single slit and the flow intensity measured by the ACCT. The method can accurately measure the energy distribution of the proton beam by deriving the specific energy value from the data of magnetic induction intensity, position information and flow intensity. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 is an application scenario of a device for measuring the energy distribution of a proton beam provided by an embodiment of the present application.

[0046] Figure 2 is a structural diagram of a device for measuring the energy distribution of a proton beam provided by an embodiment of the present application.

[0047] Figure 3 is a connection diagram of a first stepper motor and a first single slit provided by an embodiment of the present application.

[0048] Figure 4 is a flowchart of a method for measuring the energy distribution of a proton beam provided by an embodiment of the present application.

[0049] Figure 5 is a schematic diagram of a proton trajectory provided by an embodiment of the present application.

[0050] Legend: 101, proton beam generator; 102, measuring device; 201, magnet device; 202, first single slit; 203, ACCT; 204, controller; 205, processor; 206, beam cross-section fluorescence target camera; 207, second single slit; 208, first stepper motor; 209, second stepper motor; 301, first motor; 302, second motor; 303, first slit plate; 304, second slit plate. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solutions and advantages of the present application clearer, the following will further describe the present application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application. Figures 1-5 The present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0052] Measuring the energy distribution of a proton beam has the following significance:

[0053] 1. Proton treatment plan design.

[0054] Understanding the energy distribution of the proton beam in the target tissue can help determine the appropriate proton beam energy and intensity to ensure the required dose distribution and coverage in the tumor area.

[0055] 2. Dose delivery accuracy.

[0056] By measuring the energy distribution of the proton beam, it can be evaluated whether there are problems such as dose mismatch, dose funnel or dose peak in the spatial scanning and transmission process of the proton beam, which helps to adjust the treatment parameters to ensure the accuracy and consistency of dose delivery.

[0057] 3. Treatment effect evaluation.

[0058] By comparing the expected energy distribution with the actual energy distribution, it can be assessed whether the treatment has achieved the intended goal and whether the energy distribution of the proton beam meets the requirements of the treatment plan.

[0059] 4. Safety evaluation.

[0060] An inappropriate energy distribution can lead to unnecessary dose deposition in healthy tissues, increasing the risk of treatment-induced side effects and complications. By monitoring the energy distribution, the accurate targeting and proper dose distribution of the proton beam can be ensured, thereby improving the safety of the treatment.

[0061] 5. Quality control and quality assurance.

[0062] By regularly measuring and analyzing the energy distribution, the performance and stability of the proton beam can be checked, and potential problems or changes can be identified, thereby ensuring the quality and consistency of proton therapy.

[0063] In summary, measuring the energy distribution of the proton beam is of great importance in various aspects of proton therapy. In order to solve the problem of how to measure the energy distribution of the proton beam, the embodiments of the present application disclose a device for measuring the energy distribution of the proton beam, which is referred to as a measuring device for short in the following description.

[0064] Please refer to Figure 1 The application scenario of a device for measuring the energy distribution of the proton beam provided by the embodiments of the present application is shown in the figure. The application scenario includes a proton beam generator 101 and a measuring device 102.

[0065] The proton beam generator 101, as a basic device for proton therapy or other proton-related experiments, is used to generate a proton beam. The arrow indicates the direction of the beam. The measuring device 102 is placed at the outlet end of the proton beam generator 101 and is used to receive the proton beam and measure the energy distribution of the proton beam. The process of how the measuring device 102 measures the energy distribution of the proton beam will be introduced below.

[0066] As introduced above, the specific structure of the measuring device 102 is introduced below. Please refer to Figure 2 The structure diagram of a device for measuring the energy distribution of the proton beam provided by the embodiments of the present application is shown in the figure. The device includes a deflection magnet 201, a first single-slit 202, an alternating current sensor ACCT 203, a controller 204, and a processor 205.

[0067] The deflection magnet 201 is used to control the deflection direction of the proton beam.

[0068] The first single slit 202 is arranged at the outlet end of the deflection magnet 201, and is configured to allow the beam within the preset width to pass through.

[0069] The AC current sensor ACCT 203 is arranged at the outlet end of the first single slit 202, and is configured to measure the flow intensity of the beam passing through the first single slit 202.

[0070] The controller 204 is connected to the first single slit 202, and is configured to control the first single slit 202 to move along the target direction by a preset width each time.

[0071] The processor 205 is connected to the deflection magnet 201, the controller 204 and the ACCT 203 respectively, and is configured to acquire the magnetic induction intensity of the deflection magnet 201, the control instructions of the controller 204 and the flow intensities measured by the ACCT 203, and obtain the energy distribution of the proton beam according to the magnetic induction intensity, the position information of the first single slit 202 and the flow intensities.

[0072] Specifically, the deflection magnet 201 is a magnet device arranged on the path of the proton beam. In actual use, the inlet end of the deflection magnet 201 can be aligned with the outlet end of the proton beam generator 101. When the proton beam generated by the proton beam generator 101 enters the deflection magnet 201, it is deflected due to the magnetic field. The magnetic field at the inlet end deflects the proton beam to one side, causing the proton beam to bend or change direction in the magnet. After passing through the deflection magnet 201, the proton beam is emitted from the outlet end and continues to move in a new direction and track.

[0073] The size of the proton beam can be limited by adjusting the slit width of the first single slit 202, and the flow direction of the proton beam can be controlled by adjusting the position of the first single slit 202. After the proton beam is emitted from the outlet end of the deflection magnet 201, it enters the first single slit 202. The slit width of the first single slit 202 is adjusted to a preset width, which is a fixed width set in advance, so that the beam within the preset width can pass through. The controller 204 controls the first single slit 202 to move along the target direction by a distance each time, and the distance is the same as the preset width. The total distance moved by the first single slit 202 is greater than or equal to the width of the outlet end of the deflection magnet 201. For example, the width of the outlet end of the deflection magnet 201 is 20 mm, and the first single slit 202 moves from the negative limit to the positive limit (-10 mm to 10 mm).

[0074] The ACCT 203 is an evolution of the active transformer first proposed by Hereward in 1960, with the advantages of low noise, low DC bias output, good long-term stability, etc. The single-winding structure of the sensor only needs a pair of lines between the sensor and the electronic device, and when long cables are used, it has the advantage of better anti-electromagnetic interference. The ACCT 203 is a non-intercepted pulsed beam current measuring instrument widely used in particle accelerators. Its principle is based on the principle of electromagnetic induction. By means of induced current, the beam current can be measured in real time. When the first single slit 202 moves to each position, the proton beam passes through the first single slit 202 and enters the ACCT 203, and the ACCT 203 can measure the beam current passing through the first single slit 202.

[0075] Wherein, the target direction is perpendicular to the direction of the outlet end of the deflection magnet 201. The position information of the first single slit 202 is determined according to each control instruction. The position information of the first single slit 202 can be the position coordinates of the center point of the first single slit 202.

[0076] For example, the processor 205 obtains each control instruction of the controller 204, determines that the distance of each movement of the first single slit 202 is x after analysis, and establishes a plane rectangular coordinate system with the starting position of the center point of the first single slit 202 as the origin, the target direction as the X axis, and the direction corresponding to the outlet end of the deflection magnet 201 as the Y axis. Then, the position information of the first single slit 202 is (0, 0), (x, 0), (2x, 0) respectively.

[0077] In a possible embodiment, please continue to refer to Figure 2 The device further comprises a beam cross-section fluorescent target camera 206.

[0078] The beam cross-section fluorescent target camera 206 is arranged at the outlet end of the ACCT 203, and is configured to obtain a profile of the beam passing through the first single slit 202.

[0079] The processor 205 is connected with the beam cross-section fluorescent target camera 206, and is further configured to obtain the profile and filter out data not in the profile.

[0080] Specifically, the beam-profile indicator 206 is a set of equipment for measuring the beam profile, which is a combination of a fluorescent screen and a CCD camera. The principle of the beam-profile indicator 206 is based on the principle of radiation luminescence. When the proton bombards the fluorescent screen, ionization excitation is generated. When the electron-ion pair generated by ionization recombines, the electron binding energy is emitted in the form of electromagnetic radiation. The charged ions excite atoms and molecules, and the excited atoms and molecules emit photons in the process of returning to the ground state. The profile obtained by the beam-profile indicator 206 is a black and white image. The black part is the background, and the bright part is the beam. The brighter the place, the more protons.

[0081] After the processor 205 obtains the profile, the processor 205 performs grayscale processing on the profile to obtain a grayscale image. If the grayscale value of each pixel point of the grayscale image is 0, that is, the image is all black, it indicates that there is no beam, and the data is filtered out. If the grayscale value of some pixel points of the grayscale image is not 0, that is, the image has bright spots, it indicates that there is a beam, and the data is retained. The data filtered out by the processor 205 refers to the position information of the first single slit 202 and the beam intensity measured by the ACCT 203 in the current period.

[0082] In a possible implementation, please continue to refer to Figure 2 The device further comprises:

[0083] The second single slit 207 is arranged at the inlet end of the deflection magnet 201, and is configured to: allow the beam around the central energy to pass through.

[0084] Specifically, in actual use, the inlet end of the second single slit 207 is placed at the outlet end of the proton beam generator 101. The slit width of the second single slit 207 can be adjusted according to the width of the outlet end of the proton beam generator 101. For example, the slit width of the second single slit 207 is calculated according to historical beam data around the central energy. The second single slit 207 is connected with the controller 204. The controller 204 can pre-adjust the slit width of the second single slit 207 to allow the beam around the central energy to pass through. Subsequent measurement of the energy distribution of the beam around the central energy can improve the measurement accuracy.

[0085] In a possible implementation, please continue to refer to Figure 2 The device further comprises a first stepper motor 208.

[0086] The controller 204 is connected with the first stepper motor 208, and is configured to: control the first stepper motor 208 to move along a target direction, and the distance of each movement is a preset width.

[0087] The first stepper motor 208 is connected with the first single slit 202, and is configured to: drive the first single slit 202 to move along a target direction, and the distance of each movement is a preset width.

[0088] Specifically, the controller 204 can send a control instruction to the first stepper motor 208 every other period, and the first stepper motor 208 moves the first single slit 202 along the target direction according to the control instruction, and the distance of each movement is the same as the preset width.

[0089] In the embodiment of the application, the first stepper motor 208 drives the first single slit 202 to move, so that the distance of each movement of the first single slit 202 can be accurately controlled to be the preset width, and the overall scanning range of the first single slit 202 covers the outlet end of the deflection magnet 201, thereby improving the accuracy of measuring the energy distribution.

[0090] In a possible embodiment, refer to Figure 3 The first stepper motor and the first single slit provided in the embodiment of the application are connected as shown in the schematic diagram. The first stepper motor 208 includes a first motor 301 and a second motor 302, and the first single slit 202 includes a first slit plate 303 and a second slit plate 304.

[0091] The first motor 301 is connected to a first face of the first slit plate 303, and is configured to drive the first slit plate 303 to move along the target direction within a first preset range, and the distance of each movement is the preset width. The first face is a face of the first slit plate 303 that is away from the beam.

[0092] The second motor 302 is connected to a second face of the second slit plate 304, and is configured to drive the second slit plate 304 to move along the target direction within a second preset range, and the distance of each movement is the preset width. The second face is a face of the second slit plate 304 that is away from the beam.

[0093] Specifically, the controller 204 sends a first control instruction to the first motor 301, and the first motor 301 moves the first slit plate 303 along the target direction according to the first control instruction, and the distance of each movement is the same as the preset width. Meanwhile, the controller 204 sends a second control instruction to the second motor 302, and the second motor 302 moves the second slit plate 304 along the target direction according to the second control instruction, and the distance of each movement is also the same as the preset width. The first slit plate 303 and the second slit plate 304 move along the same direction by the same distance, i.e., the preset width, so that the distance between the first slit plate 303 and the second slit plate 304, i.e., the slit width of the first single slit 202, remains unchanged and is always the preset width.

[0094] In the embodiment of the present application, the two motors respectively drive the two slit plates to move in the same direction by a preset width, so that the distance between the two slit plates is always unchanged, thereby ensuring that the beam passing through the first single slit each time is of the same width, and ensuring the uniformity of the beam measured each time.

[0095] In a possible embodiment, the deflection magnet 201 is a dipole magnet.

[0096] In a possible embodiment, the controller 204 can be connected with the second single slit 207, for adjusting the slit width of the second single slit 207.

[0097] In the embodiment of the present application, the controller 204 can adjust the slit width of the second single slit 207, so as to ensure that the beam near the central energy passes through the second single slit 207.

[0098] In a possible embodiment, the device further comprises a second stepping motor 209.

[0099] The controller 204 is connected with the second stepping motor 209, for controlling the second stepping motor 209 to move.

[0100] The second stepping motor 209 is connected with the second single slit 207, for adjusting the slit width of the second single slit 207.

[0101] In a possible embodiment, the second stepping motor 209 comprises a third motor and a fourth motor, and the second single slit 207 comprises a third slit plate and a fourth slit plate.

[0102] The third motor is connected with a third face of the third slit plate, for driving the third slit plate to move in a specified direction, the third face being a face of the third slit plate away from the beam.

[0103] The fourth motor is connected with a fourth face of the fourth slit plate, for driving the fourth slit plate to move in a direction opposite to the specified direction, the fourth face being a face of the fourth slit plate away from the beam.

[0104] In the embodiment of the present application, the two motors respectively drive the two slit plates to move in opposite directions, so as to adjust the distance between the two slit plates, i.e. the slit width of the second single slit 207.

[0105] It should be noted that the connection mode of the third motor with the third slit plate refers to the connection mode of the first motor with the first slit plate in the first aspect of the present application, and the connection mode of the fourth motor with the fourth slit plate refers to the connection mode of the second motor with the second slit plate in the first aspect of the present application. Figure 3 Figure 3 It should be noted that the connection mode of the third motor with the third slit plate refers to the connection mode of the first motor with the first slit plate in the first aspect of the present application, and the connection mode of the fourth motor with the fourth slit plate refers to the connection mode of the second motor with the second slit plate in the first aspect of the present application.

[0106] ​In summary, the embodiment of the present application provides a device for measuring energy distribution of proton beam, so that the proton beam can pass through the second single slit 207, the deflection magnet 201, the first single slit 202 and the ACCT 203 in turn. The device uses the controller 204 to control the first single slit 202 to move along the target direction, each time by a preset width. The device uses the processor 205 to process the magnetic induction intensity of the deflection magnet 201, the position information of the first single slit 202 and the flow intensity measured by the ACCT 203, so as to obtain the energy distribution of the proton beam, thereby realizing automatic measurement of the energy distribution of the proton beam.

[0107] As introduced above, the structure of the measuring device 102, i.e., the device for measuring energy distribution of proton beam, the embodiment of the present application also discloses a method for measuring energy distribution of proton beam, which is applied to Figure 2 the device for measuring energy distribution of proton beam.

[0108] Please refer to Figure 4 the flowchart of the method for measuring energy distribution of proton beam provided by the embodiment of the present application, and the following will introduce the measurement process of the energy distribution of the proton beam. Figure 4

[0109] S401, control the first single slit to move along the target direction, and collect the position information of the first single slit and the flow intensity measured by the ACCT each time the first single slit moves to a position.

[0110] Specifically, the controller 204 can control the first stepper motor 208 to drive the first single slit 303 to move along the target direction. The processor 205 obtains the control instruction sent by the controller 204 to the first stepper motor 208 each time the first single slit 202 moves to a position, obtains the position information of the first single slit 202 according to the control instruction, and directly collects the flow intensity measured by the ACCT 203.

[0111] In a possible embodiment, the controller 204 can control the first motor 301 to drive the first slit plate 303 to move along the target direction in a first preset range, and each time the distance of movement is a preset width. The controller 204 can also control the second motor 302 to drive the second slit plate 304 to move along the target direction in a second preset range, and each time the distance of movement is a preset width.

[0112] Specifically, the processor 205 obtains the first control instruction sent by the controller 204 to the first motor 301, and obtains the position information of the first slit plate 303 according to the first control instruction. The processor 205 obtains the second control instruction sent by the controller 204 to the second motor 302, and obtains the position information of the second slit plate 304 according to the second control instruction. The position information of the first single slit 202 is determined according to the position information of the first slit plate 303 and the position information of the second slit plate 304. ​

[0113] S402, obtain the magnetic induction intensity of the deflection magnet, the position information of each position of the first single slit, and the flow intensity measured by the ACCT.

[0114] Specifically, the processor 205 can obtain the position information of the first single slit plate 202 and the flow intensity measured by the ACCT 203 at each time when the first single slit plate 202 moves. When the first single slit plate 202 moves from the negative limit position to the positive limit position, the processor 205 can obtain the position information of the first single slit plate 202 and the flow intensity measured by the ACCT 203 at each position, and the position information and the flow intensity are one-to-one correspondence.

[0115] S403, obtain the energy distribution of the proton beam according to the magnetic induction intensity, the position information of each position, and the flow intensity of each position.

[0116] Specifically, after the processor 205 obtains the magnetic induction intensity of the deflection magnet, the position information of each position of the first single slit 202, and the flow intensity measured by the ACCT 203, the energy distribution of the proton beam is obtained by the following steps:

[0117] S1.1, obtain the number of protons by the following formula:

[0118] Wherein, n is the number of protons, q is the charge of the protons, and I is the flow intensity.

[0119] S1.2, determine the deflection radius of the protons according to the position information of the first single slit.

[0120] Since the deflection angle of the central track of the deflection magnet is known, the deflection angle of the different beam parts scanned by the first single slit 202 at different positions can be calculated according to the geometric relationship, and the deflection radius of the protons can be calculated.

[0121] Please refer to Figure 5 , a schematic diagram of a proton running track provided by the embodiment of the present application. Among them, the three curves respectively represent three running tracks of the beam, and the black dots represent protons. R1 represents the deflection radius of the protons in the beam scanned by the first single slit 202 at the first position, and R2 represents the deflection radius of the protons in the beam scanned by the first single slit 202 when it moves to the second position.

[0122] S1.3, obtain the beam energy by the following formula:

[0123] E = mv 2 = m(rqb / m) 2 = (rqb) 2 / m

[0124] Wherein, E is the beam energy, v is the velocity of the proton, m is the mass of the proton, q is the charge amount of the proton, b is the magnetic induction intensity of the deflection magnet, and r is the deflection radius of the proton.

[0125] S1.4, obtaining the one-dimensional distribution of the beam energy by normal fitting according to the correspondence between the number of protons and the beam energy.

[0126] Since the position information and the current are one-to-one corresponding, the calculated number of protons and the beam energy are also one-to-one corresponding. The processor 205 can obtain the expression of the beam energy by normal fitting according to the number of protons and the corresponding beam energy of each number of protons.

[0127] Specifically, the first single slit 202 moves to a position each time, and the processor 205 can obtain a group of data according to the magnetic induction intensity of the deflection magnet, the position information of the first single slit 202 and the current measured by the ACCT. The group of data includes the number of protons and the beam energy of the beam passing through the first single slit 202. The number of protons and the beam energy of all proton beams can be covered by merging a plurality of groups of data. Therefore, normal fitting is performed on the plurality of groups of data, and the expression of the beam energy of the proton beam can be obtained.

[0128] In summary, the present application provides a method for measuring the energy distribution of a proton beam, which is applied to the device for measuring the energy distribution of a proton beam discussed above. The first single slit is controlled to move along the target direction. The position information of the first single slit and the current measured by the ACCT are collected each time the first single slit moves to a position. According to the magnetic induction intensity of the deflection magnet, the position information of the first single slit and the current measured by the ACCT, the correspondence between the number of protons and the beam energy can be derived, and the normal distribution expression of the beam energy can be obtained. The energy distribution of the proton beam can be accurately measured. The calculation of various treatment parameters according to the expression of the beam energy is helpful to improve the accuracy, effect and safety of proton therapy.

[0129] It should be noted that in the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0130] The above are the preferred embodiments of the present application, which do not limit the protection scope of the present application. Any feature disclosed in the specification (including the abstract and the drawings) can be replaced by other equivalent or similar features unless specifically described. That is, each feature is only an example of a series of equivalent or similar features unless specifically described.

Claims

1. A device for measuring the energy distribution of a proton beam, characterized in that, include: Deflecting magnets are used to control the deflection direction of proton beams. The first single slit is located at the exit end of the deflecting magnet and is used to allow the beam within a preset width to pass through. An alternating current sensor (ACCT) is disposed at the exit end of the first single slit and is used to measure the current intensity of the beam passing through the first single slit. A controller, connected to the first single slit, is used to: control the first single slit to move along the target direction, wherein the distance moved each time is the preset width; The processor, connected to the deflecting magnet, the controller, and the ACCT respectively, is used to: acquire the magnetic induction intensity of the deflecting magnet, various control commands of the controller, and various current intensities measured by the ACCT, and to obtain the energy distribution of the proton beam based on the magnetic induction intensity, various position information of the first single slit, and the various current intensities; The position information of the first single slit is determined according to the various control commands; The device further includes: A beam cross-section fluorescence target camera, located at the exit end of the ACCT, is used to: acquire a cross-sectional view of the beam passing through the first single slit; The processor, connected to the beam cross-section fluorescence target camera, is also used to: acquire the cross-sectional view and filter out data not in the cross-sectional view; The device further includes: The second single slit, located at the entrance end of the deflecting magnet, is used to: allow the beam near the central energy to pass through; The device also includes a first stepper motor; The controller, connected to the first stepper motor, is used to: control the first stepper motor to move along the target direction, wherein the distance moved each time is the preset width; The first stepper motor is connected to the first single slit and is used to drive the first single slit to move along the target direction, with each movement being the preset width.

2. The device for measuring the energy distribution of a proton beam according to claim 1, characterized in that, The first stepper motor includes a first motor and a second motor, and the first single slit includes a first slit plate and a second slit plate. The first motor is connected to the first surface of the first slit plate and is used to: drive the first slit plate to move along the target direction within a first preset range, the distance of each movement being the preset width, and the first surface being the side of the first slit plate away from the beam; The second motor is connected to the second side of the second slit plate and is used to drive the second slit plate to move along the target direction within a second preset range, the distance of each movement being the preset width, and the second side being the side of the second slit plate away from the beam.

3. The device for measuring the energy distribution of a proton beam according to claim 1, characterized in that, The deflecting magnet is a dipolar magnet.

4. A method for measuring the energy distribution of a proton beam, characterized in that, Applied to the apparatus for measuring the energy distribution of a proton beam as described in any one of claims 1-3, comprising: The first single slit is controlled to move along the target direction. At each position, the position information of the first single slit and the current intensity measured by ACCT are collected. The distance moved each time is the preset width. The magnetic induction intensity of the deflecting magnet, the position information of the first single slit, and the current intensity measured by ACCT are obtained. The energy distribution of the proton beam is obtained based on the magnetic induction intensity, the location information, and the current intensity.

5. The method for measuring the energy distribution of a proton beam according to claim 4, characterized in that, Controlling the first single slit to move along the target direction includes: The first motor is controlled to drive the first slit plate to move along the target direction within a first preset range, and the distance moved each time is the preset width; The second motor is controlled to drive the second slit plate to move along the target direction within a second preset range, and the distance moved each time is the preset width.

6. The method for measuring the energy distribution of a proton beam according to claim 4, characterized in that, Based on the magnetic induction intensity, the location information, and the current intensity, the energy distribution of the proton beam is obtained, including: The number of protons can be obtained using the following formula: Where n is the number of protons, q is the charge carried by the protons, and l is the current intensity; the deflection radius of the protons is determined based on the position information of the first single slit. The beam energy is obtained using the following formula: E = mv 2 =m(rqb / m) 2 =(rqb) 2 / m; where E is the beam energy, v is the velocity of the proton, m is the mass of the proton, q is the charge of the proton, b is the magnetic induction intensity of the deflecting magnet, and r is the deflection radius of the proton. Based on the correspondence between the number of protons and the beam energy, a one-dimensional distribution of the beam energy is obtained through normal fitting.

7. The method for measuring the energy distribution of a proton beam according to claim 6, characterized in that, Based on the correspondence between proton quantity and beam energy, a one-dimensional distribution of beam energy is obtained through normal fitting, including: Based on the number of protons and the beam energy corresponding to each number of protons, the expression for the beam energy is obtained through normal fitting.

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