Adjustment method of accelerator system, accelerator system, electronic equipment and storage medium

Abstract

The invention provides an accelerator system adjustment method, an accelerator system, electronic equipment and a storage medium. The transmission characteristic data and the charge quantity data of the undeflected beam are obtained through the first beam position detector, and the form and the charge quantity of the undeflected beam are accurately adjusted in combination with a preset adjustment strategy, so that the stability of beam transmission is ensured. And after the form data of the first beam reaches a preset value, monitoring the deflected beam data by using a second beam position detector, and further accurately adjusting the accelerator system to ensure that the deflected beam conforms to the target transmission characteristics. According to the invention, the transmission state of the beam can be accurately controlled in real time, risks of vacuum box breakdown and the like caused by beam mismatch are avoided, the safety and the stability of the system are improved, the possibility of equipment damage is obviously reduced especially under the high-dose-rate transient beam, and the treatment effect and the continuity of Flash radiotherapy are guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of accelerators, and in particular to an adjustment method for an accelerator system, an accelerator system, an electronic device, and a storage medium. Background Art

[0002] A medical electron linear accelerator is a high-precision medical device used for cancer radiotherapy. It mainly accelerates electrons to near the speed of light through an electromagnetic field, then directly emits an electron beam or bombards a tungsten target to generate high-energy X-rays. Finally, the electron beam or X-rays are applied to tumor tissue to destroy the DNA of cancer cells, thereby achieving the purpose of tumor treatment.

[0003] In the existing technology, flash radiotherapy is a transient high-dose rate application scenario, which carries the risk of beam mismatch and vacuum box breakdown. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned technical deficiencies and provide an adjustment method for an accelerator system, an accelerator system, an electronic device, and a storage medium to solve the technical problem in the related art of a high risk of vacuum box breakdown due to beam mismatch in the transient high dose rate scenario of flash radiotherapy.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: In a first aspect, the present invention provides an adjustment method for an accelerator system, which is applied to a control device of the accelerator system, wherein the accelerator system includes at least a first beam position detector and a second beam position detector sequentially arranged on a beam path, the first beam position detector being used to obtain beam transmission characteristic data and charge quantity data of an undeflected beam, and the second beam position detector being used to obtain beam transmission characteristic data and charge quantity data of a deflected beam, the beam transmission characteristic data being used to characterize a set of physical quantities of a spatial distribution state of an electron beam in a transmission path; the method comprising: During use of the accelerator, at least the beam transmission characteristic data and charge quantity data of the first beam are determined by the first beam position detector; wherein the first beam is the electron beam current before the electron beam is deflected; executing a preset first adjustment strategy based on the beam transmission characteristic data and the charge quantity data of the first beam to adjust a first target device in the accelerator system so that the beam transmission characteristic data and the charge quantity data of the first beam approach a first preset value; When the morphological data of the first beam reaches a first preset value, beam transmission characteristic data and charge quantity data of the second beam are determined by the second beam position detector, wherein the second beam represents the electron beam after the electron beam is deflected; Based on the beam transmission characteristic data and charge quantity data of the second beam, a preset second adjustment strategy is executed to adjust the second target device in the accelerator system so that the beam transmission characteristic data and charge quantity data of the second beam tend to second preset values.

[0006] In a second aspect, the present invention provides an accelerator system, comprising at least a control device and: a first target device, which is used to generate an initial electron beam, accelerate the initial electron beam, and adjust the beam transmission characteristics of the accelerated electron beam; a first beam position detector, configured to obtain beam transmission characteristic data and charge quantity data of an undeflected beam; wherein the beam transmission characteristic data is a set of physical quantities representing a spatial distribution state of the electron beam in a transmission path; a second target device, configured to deflect the beam; a second beam position detector, which is used to obtain beam transmission characteristic data and charge quantity data of the deflected beam; The control device is used to, during the use of the accelerator, determine the beam transmission characteristic data and charge quantity data of the first beam at least through the first beam position detector; based on the beam transmission characteristic data and charge quantity data of the first beam, execute a preset first adjustment strategy to adjust the first target device in the accelerator system so that the beam transmission characteristic data and charge quantity data of the first beam tend to a first preset value; when the morphological data of the first beam reaches the first preset value, determine the beam transmission characteristic data and charge quantity data of the second beam through the second beam position detector; based on the beam transmission characteristic data and charge quantity data of the second beam, execute a preset second adjustment strategy to adjust the second target device in the accelerator system so that the beam transmission characteristic data and charge quantity data of the second beam tend to a second preset value.

[0007] In a third aspect, the present invention provides an electronic device comprising: a memory, and one or more processors communicatively connected to the memory; the memory stores instructions executable by the one or more processors, and the instructions are executed by the one or more processors so that the one or more processors implement the above-mentioned method.

[0008] In a fourth aspect, the present invention provides a computer-readable storage medium, wherein the computer program is stored in the computer-readable storage medium, and the computer program implements the above method when executed by a processor.

[0009] Beneficial effects: The present invention effectively solves the problem of beam mismatch in the prior art in the transient high-dose rate scenario of Flash radiotherapy by introducing a multi-stage beam transmission characteristic monitoring and dynamic adjustment mechanism. Specifically, the transmission characteristic data and charge quantity data of the undeflected beam are obtained through the first beam position detector, and combined with the preset adjustment strategy, the shape and charge quantity of the undeflected beam are first accurately adjusted to ensure the stability of the beam transmission. After the shape data of the first beam reaches the preset value, the second beam position detector is used to monitor the beam data after deflection, and the accelerator system is further accurately adjusted to ensure that the deflected beam meets the target transmission characteristics. Through this multi-stage, closed-loop beam adjustment mechanism, the present invention can control the transmission state of the beam in real time and accurately, avoiding the risk of vacuum box breakdown caused by beam mismatch, thereby improving the safety and stability of the system, especially under high-dose rate transient beam, significantly reducing the possibility of equipment damage, and ensuring the therapeutic effect and continuity of Flash radiotherapy. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a flow chart of an adjustment method for an accelerator system provided by an embodiment of the present invention; Figure 2 is a flow chart of an adjustment method for an accelerator system provided by an embodiment of the present invention; Figure 3 is a block diagram of an accelerator system used in an embodiment of the present invention; Figure 4 is a block diagram of an electronic device used in an embodiment of the present invention; In the attached figure: Electron gun-1, accelerating tube-2, microwave source-16, primary focusing coil-3, first-stage guide magnet-4, secondary focusing coil-5, second-stage guide magnet-6, beam intensity dynamic monitoring module-7, first-stage beam position detector-8, transient beam spot imaging unit YAG target-9, achromatic magnet-10, second-stage beam position detector-11, rotating tungsten target-12, multi-leaf grating-13, dose monitoring module-14. DETAILED DESCRIPTION

[0011] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0012] In flash radiotherapy systems, the goal of a medical linear accelerator is to efficiently irradiate tumor tissue using an electron beam at an instantaneous high dose rate while minimizing damage to surrounding healthy tissue. To achieve this, the accelerator must deliver an ultra-high dose rate beam in an extremely short time. This requires the core components of the accelerator system to work together to ensure beam stability and precision.

[0013] In a related art, a medical linear accelerator may include: Electron gun: used to generate the initial electron beam pulse.

[0014] Accelerator tube: Accelerates the electron beam to near the speed of light through a microwave electric field, thereby providing sufficient energy for subsequent beam transport.

[0015] Magnet assembly (guide magnets, focusing coils, and achromatic magnets): These magnet assemblies are responsible for controlling the path and focusing of the electron beam, ensuring that the beam is precisely delivered to the desired location.

[0016] Vacuum box: provides an ultra-high vacuum environment transmission channel to prevent the electron beam from scattering during transmission and reduce beam loss.

[0017] Beam Position Monitor (BPM): monitors the position, divergence angle and charge of the electron beam in real time to ensure the stability of the beam during transmission.

[0018] In this related technology, beam control primarily relies on static magnetic field configuration and single-point monitoring feedback. Specifically, in one related technology, beam control can be performed by presetting magnet currents based on theoretical models and empirical formulas. However, this approach lacks a real-time dynamic compensation mechanism and cannot cope with rapid changes in beam current in transient high-dose rate environments. In another related technology, position correction relies solely on a single beam position detector (BPM), resulting in a limited beam monitoring range that cannot cover the entire beam transmission path. In another related technology, a single charge detector (Faraday cup) is used for monitoring, but there is a lack of an effective cross-validation mechanism to ensure the accuracy of the charge data.

[0019] In related technologies, although existing technologies can provide certain beam control capabilities at low dose rates, some problems still exist in the transient high dose rate scenario of flash radiotherapy. Specifically: Understandably, the magnet assembly has a strong inductive characteristic, which results in a long delay in adjusting the magnetic field strength in the case of transient high-dose beam currents. The beam pulse width required for flash radiotherapy is often much less than 1ms, which makes it difficult for the magnetic field response to keep up with beam current changes, resulting in beam mismatch.

[0020] Moreover, existing technologies rely on a single BPM for beam monitoring, but the BPM sensor itself has drift errors (typical drift rate ≥ 0.1% / h). In high-dose rate environments, these errors will be amplified, resulting in inaccurate beam feedback signals, which in turn affects the beam adjustment accuracy.

[0021] Secondly, when the beam center offset exceeds ±1.5mm or the divergence angle exceeds 2mrad, the local power density will reach the voltage limit of the metal wall of the vacuum box, which will cause micro-discharge breakdown in the vacuum box, thereby causing equipment damage and system failure.

[0022] In summary, in the prior art, in the transient high dose rate scenario of Flash radiotherapy, there is a technical problem of beam mismatch, which leads to a high risk of vacuum box breakdown.

[0023] This embodiment provides an adjustment method for an accelerator system, which is applied to a control device of the accelerator system. The accelerator system includes at least a first beam position detector and a second beam position detector sequentially arranged on a beam path. The first beam position detector is used to obtain beam transmission characteristic data and charge quantity data of an undeflected beam (in one possible embodiment, the first beam position detector is used to obtain beam transmission characteristic data and charge quantity data before achromatic deflection), and the second beam position detector is used to obtain beam transmission characteristic data and charge quantity data of a deflected beam (in one possible embodiment, the second beam position detector is used to obtain beam transmission characteristic data and charge quantity data of achromatic deflection). The beam transmission characteristic data is a set of physical quantities used to characterize the spatial distribution state of the electron beam in the transmission path.

[0024] In this embodiment, the control device may be a DSP (digital signal processor), an MCU (microcontroller unit), an embedded controller, an FPGA (field programmable gate array), or an embedded computing platform, etc. It is understood that the control device is electrically connected to the devices, modules, or units involved in the accelerator system.

[0025] In this embodiment, the beam transmission characteristic data further includes beam position parameters and beam profile parameters. Specifically, the beam position parameters can be used to characterize the spatial position coordinates of the electron beam in the transmission path. The beam profile parameters can be used to characterize the spatial distribution state of the electron beam on the beam cross section. More specifically, the beam profile parameters may include: The transverse RMS radius, which can be used to characterize the degree of beam spread in a certain transverse plane (horizontal direction X or vertical direction Y); The divergence angle represents the angle between the particle motion direction at the edge of the beam and the central axis. emittance, which characterizes the cross-sectional area of ​​the beam in phase space; Ellipticity, which describes the geometric deformation of the beam cross section.

[0026] In this embodiment, the accelerator system may be a medical accelerator system. In a specific embodiment, the medical accelerator system may include, in addition to the first beam position detector, the second beam position detector, and the control device, the following: like Figure 1 As shown, the method includes: Step S12: During use of the accelerator, the beam transmission characteristic data and charge quantity data of the first beam are determined at least by the first beam position detector; wherein the first beam represents the electron beam current before the electron beam is deflected.

[0027] In this embodiment, the first beam position detector may be a Beam Position Monitor (BPM). It will be appreciated that a BPM can monitor beam position, shape, divergence angle, and other information in real time. The BPM utilizes electromagnetic signal induction principles to detect changes in the electric field as the beam passes through, thereby obtaining precise beam position and shape data.

[0028] In this embodiment, the first beam position detector may also be a quadrupole electric field beam position detector or an optical beam monitoring system, etc.

[0029] In this embodiment, the beam transmission characteristic data and charge quantity data of the first beam can be determined by the first beam position detector. Alternatively, the charge quantity data can be determined jointly by a charge quantity monitoring unit and the first beam position detector. Alternatively, the beam transmission characteristic data can be determined jointly by a beam spot imaging unit and the first beam position detector.

[0030] Step S14: Based on the beam transmission characteristic data and charge quantity data of the first beam, execute a preset first adjustment strategy to adjust the first target device in the accelerator system so that the beam transmission characteristic data and charge quantity data of the first beam tend to a first preset value.

[0031] In this embodiment, the first adjustment strategy can be a difference-based adjustment strategy. The difference is input into the first adjustment strategy to generate a control instruction for the first target device (which can be related to current, voltage, power, etc.). The control device then sends the control instruction to the first target device to adjust the first target device in the accelerator system so that the beam transmission characteristic data and charge quantity data of the first beam approach first preset values. Specifically, the beam transmission characteristic data and charge quantity data of the first beam can be first differentiated from the first preset value to obtain the difference between the beam transmission characteristic data and the first preset value, and the difference between the charge quantity data and the first preset value. The first preset value can include a first target beam position parameter, a first target beam profile parameter, or a first target charge quantity. More specifically, the first adjustment strategy can adopt a PID control model, and the difference between the first target beam position parameter and the beam transmission characteristic data (beam position parameter), the difference between the first target beam profile parameter and the beam transmission characteristic data (beam profile parameter), and the difference between the first target charge amount and the charge amount data can be input into the PID control model to obtain corresponding adjustment amounts (magnetic field strength adjustment amount, current adjustment amount, pulse voltage and power adjustment amount, etc.), and then generate corresponding control instructions based on the above adjustment amounts.

[0032] In this embodiment, if the first adjustment strategy is based on the difference, it can be based on PID control (proportional-integral-derivative control). Alternatively, it can be based on fuzzy logic control. For example, based on an expert rule base, the difference can be converted into a fuzzy linguistic variable (e.g., "positive is large" and "negative is small"), and the control variable can be output after reasoning. Alternatively, it can be based on state feedback control (LQR / LQG).

[0033] In this embodiment, the first adjustment strategy can be a real-time value adjustment strategy, that is, the beam transmission characteristic data and charge quantity data of the first beam are directly input into the first adjustment strategy to generate control instructions for the first target device. Specifically, when the first adjustment strategy is based on real-time values, the first adjustment strategy can be an adjustment strategy based on model predictive control (MPC). For example, the first adjustment strategy can use rolling horizon optimization to predict future system states and solve for the optimal control sequence. The first adjustment strategy can also be an adjustment strategy based on neural network control. For example, a deep neural network (DNN) can be used to learn the nonlinear mapping from real-time data to control instructions. The first adjustment strategy can also be an adjustment strategy based on feedforward-feedback composite control.

[0034] In this embodiment, the first target device includes at least one level of guide magnets, at least one level of focusing coils, and an electron injection device, which may further include an electron gun, an accelerating tube, and a microwave source.

[0035] Step S16: When the morphological data of the first beam reaches a first preset value, the beam transmission characteristic data and charge quantity data of the second beam are determined by the second beam position detector: wherein the second beam represents the electron beam after deflection.

[0036] In this embodiment, the second beam position detector may be a Beam Position Monitor (BPM). It is understood that a BPM can monitor beam position, shape, divergence angle, and other information in real time. The BPM utilizes electromagnetic signal induction principles to detect changes in the electric field as the beam passes through, thereby obtaining precise beam position and shape data.

[0037] In this embodiment, the second beam position detector may also be a Faraday cup, a quadrupole electric field beam position detector, or an optical beam monitoring system, etc.

[0038] Step S18: Based on the beam transmission characteristic data and charge quantity data of the second beam, execute a preset second adjustment strategy to adjust the second target device in the accelerator system so that the beam transmission characteristic data and charge quantity data of the second beam tend to a second preset value.

[0039] In this embodiment, the preset second adjustment strategy can also be an adjustment strategy based on the difference (beam transmission characteristic data and charge quantity data of the second beam and the second preset value), or it can be an adjustment strategy based on the real-time value (based on the beam transmission characteristic data and charge quantity data of the second beam).

[0040] In this embodiment, the second target device may be an achromatic magnet.

[0041] In this embodiment, the second target device may also be a deflection magnet. Deflection magnets are used to deflect the electron beam, causing it to deviate from its original path by a specific angle. Deflection magnets can also be used to control the direction of the beam path, changing the propagation direction of the electron beam at a preset angle (e.g., 90°, 120°, etc.).

[0042] In this embodiment, the second target device may also be a quadrupole magnet.

[0043] In this embodiment, the second target device may also be a sextupole magnet.

[0044] This embodiment effectively solves the problem of beam mismatch in the prior art in the transient high-dose rate scenario of Flash radiotherapy by introducing a multi-stage beam transmission characteristic monitoring and dynamic adjustment mechanism. Specifically, the transmission characteristic data and charge quantity data of the undeflected beam are obtained through the first beam position detector. Combined with the preset adjustment strategy, the shape and charge quantity of the undeflected beam are first accurately adjusted to ensure the stability of the beam transmission. After the shape data of the first beam reaches the preset value, the second beam position detector is used to monitor the beam data after deflection, and the accelerator system is further accurately adjusted to ensure that the deflected beam meets the target transmission characteristics. Through this multi-stage, closed-loop beam adjustment mechanism, this embodiment can accurately control the transmission state of the beam in real time, avoiding the risk of vacuum box breakdown caused by beam mismatch, thereby improving the safety and stability of the system, especially under high-dose rate transient beam, significantly reducing the possibility of equipment damage, and ensuring the therapeutic effect and continuity of Flash radiotherapy.

[0045] In some embodiments, the accelerator system further includes a charge quantity monitoring unit, and when the accelerator system adopts the first mode, the accelerator system is further configured with a beam spot imaging unit; wherein the charge quantity monitoring unit is used to obtain charge quantity data of the first beam, and the beam spot imaging unit is used to obtain beam transmission characteristic data of the first beam.

[0046] In this embodiment, the charge quantity monitoring unit may be a beam current transformer (BCT) dynamic monitoring module for beam intensity.

[0047] In this embodiment, the charge monitoring unit may also be a charge detector. The charge detector may be designed based on capacitance or electric field sensing principles and can be used to detect the charge of the electron beam in real time. This device can convert changes in the electric field of the electron beam into charge data.

[0048] In this embodiment, the charge amount monitoring unit may also be an integrating current detector.

[0049] In this embodiment, the charge amount monitoring unit may also be a microwave current detector.

[0050] In this embodiment, the beam spot imaging unit may be a transient beam spot imaging unit YAG target.

[0051] In this embodiment, the beam spot imaging unit may also be a CCD camera system.

[0052] In this embodiment, the beam spot imaging unit may also be a photomultiplier tube.

[0053] In this embodiment, the beam spot imaging unit may also be a tungsten target imaging system.

[0054] In this embodiment, the beam spot imaging unit may also be a microlens array.

[0055] In this embodiment, the beam spot imaging unit may also be a transient beam spot imaging unit YAG target + CCD camera system.

[0056] In this embodiment, the first mode refers to a mode in which the beam intensity is below the breakdown threshold of the beam spot imaging unit. The second mode refers to a mode in which the beam intensity is greater than or equal to the breakdown threshold of the beam spot imaging unit. It should be understood that in high-energy accelerators, beam intensity refers to the total charge or current carried by the electron beam per unit time. In a beam spot imaging unit (YAG target), when the beam intensity exceeds its tolerance, the YAG target material may become overexcited or damaged, preventing it from effectively providing beam imaging information or even causing device failure. This condition is referred to as breakdown. The breakdown threshold refers to the maximum beam intensity that the beam spot imaging unit can withstand. When the beam intensity exceeds this threshold, the imaging unit will experience breakdown or damage due to the excessive energy density. In the first mode, the beam intensity is controlled below the breakdown threshold, ensuring safe and stable operation of the beam spot imaging unit and effective beam imaging and monitoring. In the first mode, the beam intensity is maintained at a low level to ensure that the beam current or charge does not exceed the breakdown threshold of the beam spot imaging unit. For example, the beam current can be set below a set value to prevent damage to the imaging unit due to excessive charge or flux. In the second mode, the beam intensity reaches or exceeds the breakdown threshold of the beam spot imaging unit. The beam current can be very high, for example, tens of milliamperes or even higher, ensuring a sufficiently high radiation dose for specialized treatments such as flash radiotherapy. In the second mode, due to the high beam intensity, direct use of the beam spot imaging unit (YAG target) could damage the equipment. Therefore, to protect the equipment, a calibrated first beam position detector and charge monitoring unit can be used for data acquisition and monitoring, rather than direct real-time imaging using the beam spot imaging unit.

[0057] It is understood that due to the high beam intensity, the beam spot imaging unit may be damaged by the strong beam current. Therefore, a pre-calibrated first beam position detector can be used. This first beam position detector has been calibrated to adapt to the high beam intensity environment. This first beam position detector can provide key information such as beam position, shape, and divergence angle without directly relying on the beam spot imaging unit for real-time feedback.

[0058] The step of determining the beam transmission characteristic data and charge quantity data of the first beam at least by the first beam position detector during use of the accelerator includes: Step S122: When the accelerator system adopts the first mode, the beam transmission characteristic data of the first beam is determined by the first beam position detector and the beam spot imaging unit, and the charge quantity data of the first beam is determined by the first beam position detector and the charge quantity monitoring unit; wherein the first mode indicates that in this mode, the beam intensity is lower than the breakdown threshold of the beam spot imaging unit.

[0059] In this embodiment, when the accelerator system is operating in the first mode and the outputs of the first beam position detector and the beam spot imaging unit differ, the beam transmission characteristic data obtained by the beam spot imaging unit can be directly determined as the beam transmission characteristic data for the first beam (it can be assumed that, in many cases, the results output by the beam spot imaging unit are more precise and accurate, and therefore more reliable). Alternatively, the beam transmission characteristic data output by the first beam position detector and the beam spot imaging unit can be averaged or weighted averaged to obtain the beam transmission characteristic data for the first beam. It is understood that in many cases, when the beam spot imaging unit can provide more detailed beam morphology (shape, size, divergence angle) and position data, the beam transmission characteristic data obtained by the beam spot imaging unit can be directly determined as the beam transmission characteristic data for the first beam. This is because the beam morphology data provided by the beam spot imaging unit (YAG target) has higher resolution and accuracy and can better reflect the actual beam conditions. In some cases, both devices may have errors or measurement deviations, so taking an average can improve the overall stability and robustness of the accelerator system. Understandably, when there are discrepancies between the two outputs and it's difficult to determine which is more accurate, employing an averaging strategy can ensure a more balanced data output. This is especially true when the beam propagation characteristics data is complex or the system is sensitive, where averaging can help reduce data fluctuations.

[0060] It can be understood that the charge quantity data of the first beam is determined by the first beam position detector and the charge quantity monitoring unit, and the charge quantity data output by the charge quantity monitoring unit can also be the charge quantity data of the first beam. The charge quantity data output by the first beam position detector and the charge quantity monitoring unit can be averaged or weighted averaged, etc.

[0061] Step S124: When the accelerator system adopts the second mode, the beam transmission characteristic data of the first beam is determined by the first beam position detector that has been pre-calibrated by the beam spot imaging unit, and the charge quantity data of the first beam is determined by the first beam position detector and the charge quantity monitoring unit; wherein the second mode indicates a mode in which the beam intensity is higher than or equal to the breakdown threshold of the beam spot imaging unit.

[0062] In this embodiment, before the accelerator system adopts the second mode, the first beam position detector can be calibrated using a beam spot imaging unit. After calibration, the beam spot imaging unit is removed from the accelerator system or removed from the beam transmission path. Specifically, before the accelerator system enters the second mode, the first beam position detector is first calibrated using the beam spot imaging unit. The core purpose of this process is to ensure that the first beam position detector (BPM) can accurately monitor beam transmission characteristics under high-intensity beam conditions. During calibration, when the beam intensity is low and stable, the beam spot imaging unit (YAG target) is used to obtain accurate beam morphology data (beam center, divergence angle, and shape). The beam imaging data provided by the beam spot imaging unit often has high resolution and high accuracy, making it suitable for high-precision beam position monitoring. The output data from the beam spot imaging unit is compared with the output data from the first beam position detector to check the consistency of the beam transmission characteristics between the two devices, and adjustments are made based on any deviations. This calibration data helps accurately correct for any possible systematic errors or deviations in the first beam position detector. After calibration, it is ensured that the first beam position detector can accurately reflect the transmission characteristics of the beam and can work stably under high-intensity beam current.

[0063] It is understandable that, because the beam intensity in the second mode is greater than or equal to the breakdown threshold of the beam spot imaging unit, continued use of the beam spot imaging unit may cause it to be damaged due to overload. To protect the equipment, it needs to be removed from the accelerator system or removed from the beam transmission path.

[0064] This embodiment introduces a combination of a charge quantity monitoring unit and a beam spot imaging unit to achieve precise monitoring and dynamic adjustment of beam transmission characteristics and charge quantity in different modes. Specifically, when the accelerator system is in the first mode, the beam intensity is lower than the breakdown threshold of the beam spot imaging unit. The beam transmission characteristic data can be safely acquired through the beam spot imaging unit, while the charge quantity data can be acquired in conjunction with the charge quantity monitoring unit, thereby ensuring precise control of the accelerator system under low-intensity beams. In the second mode, when the beam intensity is higher than or equal to the breakdown threshold, the accelerator system avoids directly using the beam spot imaging unit by using a pre-calibrated first beam position detector and charge quantity monitoring unit, thereby reducing the risks that high-intensity beams may pose to the equipment. This strategy not only improves the safety and reliability of the accelerator system under different beam intensities, but also ensures precise monitoring of beam transmission characteristics and charge quantity, effectively reducing the risk of equipment damage and ensuring the therapeutic effect and continuity of high-dose rate applications such as flash radiotherapy.

[0065] In some embodiments, the step of determining the charge amount data of the first beam using the first beam position detector and the charge amount monitoring unit includes: Step S1202: sending data acquisition signals to the first beam position detector and the charge quantity monitoring unit respectively.

[0066] In this embodiment, the control device can send a data acquisition signal to the first beam position detector, instructing it to begin collecting beam-related data, particularly beam transmission characteristic data such as position, shape, and divergence angle. Simultaneously, the control device sends a data acquisition signal to the charge monitoring unit (BCT), instructing it to begin measuring the electron beam charge (current intensity) and prepare feedback data.

[0067] Step S1204: receiving charge quantity data fed back by the first beam position detector and the charge quantity monitoring unit respectively.

[0068] In this embodiment, the control device can compare the charge data fed back by the charge monitoring unit with the charge data fed back by the first beam position detector. If the difference between the charge data exceeds a preset allowable error range (for example, an error exceeding a certain percentage), the two data are considered inconsistent, and the next step of the processing flow is entered. If the data are consistent, no further processing is required, and the control device can directly use either data set as the accurate charge data.

[0069] Step S1206: Determine whether the charge quantity data fed back by the charge quantity monitoring unit is consistent with the charge quantity data fed back by the first beam position detector.

[0070] In this embodiment, if the charge data provided by the charge monitoring unit is deemed more reliable or more accurate, the control device may directly adopt that data as the charge data for the first beam. In this case, the control device trusts the measurement results of the charge monitoring unit, as charge monitoring units are typically designed to accurately measure charge and are not subject to interference from beam position or other sensors.

[0071] Step S1208: In the event of inconsistency, the charge data fed back by the charge monitoring unit is directly determined as the charge data of the first beam, or a preset error fitting algorithm is executed on the charge data fed back by the charge monitoring unit and the charge data fed back by the first beam position detector to obtain the charge data of the first beam.

[0072] In this embodiment, the error fitting algorithm may be a weighted average method.

[0073] In this embodiment, the error fitting algorithm may be a least squares method. For processing charge data, the least squares method can automatically adjust the values ​​of the two data sources to make them closer to the true values.

[0074] In this embodiment, the error fitting algorithm may be a linear regression algorithm.

[0075] In this embodiment, the error fitting algorithm may be a polynomial fitting algorithm.

[0076] This embodiment combines the feedback data from the first beam position detector and the charge monitoring unit to more accurately acquire the charge data for the first beam. By comparing the outputs of the two monitoring units during the data acquisition process, the control device can adopt a reasonable compensation strategy when the charge data from the two units are inconsistent: first, directly using the feedback data from the charge monitoring unit; second, correcting the data using a preset error fitting algorithm to obtain a more accurate charge value. This method effectively improves the accuracy and reliability of the charge data, ensuring that the control device can accurately adjust the beam transmission characteristics during high-precision beam monitoring, avoiding improper adjustments due to data errors, and thus optimizing the stability and safety of the accelerator system. This is of great significance for application scenarios requiring high-precision control (such as flash radiotherapy), and can effectively ensure the treatment effect and long-term stable operation of the equipment.

[0077] In some embodiments, the accelerator system further includes a first target device, the first target device including at least one level of guide magnet, at least one level of focusing coil and electron injection device, and the beam transmission characteristic data includes beam position parameters and beam profile parameters.

[0078] In this embodiment, the accelerator system can be configured with at least one level of guide magnets. Multiple levels of guide magnets can be configured. Specifically, the guide magnets can guide the path of the electron beam by applying a magnetic field so that it propagates in a predetermined direction. In the accelerator system, the guide magnets can be used to adjust the direction of the beam to ensure that the electron beam is accurately transmitted to the target area along the desired path. It is understandable that the guide magnets can correct the offset of the electron beam by adjusting the magnetic field strength to ensure that the center of the beam is accurately aligned with the predetermined trajectory. By adjusting the magnetic field strength, the deflection angle of the beam can be precisely controlled, making the transmission of the beam more stable.

[0079] In this embodiment, the accelerator system can be configured with at least one level of focusing coils, and can be configured with multiple levels of focusing coils. The focusing coils can be used to control the shape and divergence angle of the beam, ensuring that the beam maintains an appropriate shape after passing through the accelerator so that it can be accurately transmitted to the predetermined location. The focusing coils can converge or expand the beam by applying an appropriate magnetic field to the electron beam, thereby adjusting the focus of the beam. During transmission, the beam may undergo morphological distortion. The focusing coils adjust their current to ensure that the beam always maintains a predetermined shape, thereby preventing morphological distortion from negatively impacting treatment or experimental results.

[0080] In this embodiment, the accelerator system is equipped with an electron injection device. This device may include an electron gun, an accelerator, and a microwave power source. The electron gun is used to generate an initial electron beam under pulsed high voltage; the microwave power source outputs microwaves to the accelerator tube, which creates a high-frequency electromagnetic field in the accelerator tube to accelerate the initial electron beam.

[0081] The first adjustment strategy at least includes: a preset first beam position data adjustment strategy, a preset first beam profile data adjustment strategy, and a preset first beam charge data adjustment strategy; like Figure 2 As shown, the step of executing a preset first adjustment strategy based on the beam transmission characteristic data and the charge quantity data of the first beam to adjust the first target device in the accelerator system so that the beam transmission characteristic data and the charge quantity data of the first beam tend to a first preset value includes: Step S142: Based on the beam position parameters, a preset first beam position data adjustment strategy is executed to generate a current adjustment instruction corresponding to the at least one level of guide magnet; wherein the current adjustment instruction of the guide magnet is used to correct the beam center offset.

[0082] In this embodiment, first, the difference between the beam position parameter (the beam center coordinate fed back by the first beam position detector) and the preset first target beam position parameter can be calculated: In the formula, and Represents the current beam position parameter, and Expressed as the first target beam position parameter. It can be expressed as the position deviation of the beam center in the horizontal direction (X axis), It can be expressed as the position deviation of the beam center in the vertical direction (Y axis).

[0083] The difference is then input into the PID control algorithm: In the formula, It can be expressed as a magnetic field strength adjustment amount. It can be understood that the magnetic field strength of the guide magnet needs to be adjusted to correct the position offset of the beam center. It can be expressed as a proportional coefficient, which is used to adjust the current error ( ) directly adjusts the magnetic field strength and quickly responds to instantaneous deviations. It can be expressed as an integral coefficient, which is used to adjust the magnetic field strength according to the accumulated amount of historical errors (integral term) to eliminate long-term steady-state errors. It can be expressed as a differential coefficient, which is used to predict future trends based on the rate of change of the error (derivative term) and suppress overshoot and oscillation.

[0084] Finally, according to the linear model of the current-magnetic field strength of the guide magnet, Converted into current adjustment command: In the formula, is the current adjustment instruction, =Magnet sensitivity (the change in magnetic field strength per unit current). In the presence of multiple guide magnets (primary and secondary), the adjustment can be distributed according to preset weights to avoid overshoot caused by magnetic field superposition.

[0085] Step S144: Based on the beam profile parameters, execute a preset first beam profile data adjustment strategy to generate current adjustment instructions corresponding to at least one level of focusing coils; wherein the current adjustment instructions of the focusing coils are used to suppress beam divergence and morphological distortion.

[0086] In this embodiment, the beam profile parameters may include: Transverse RMS radius ; Divergence angle ; Symmetry parameters ; First, the difference between the beam profile parameter and the preset value can be calculated: In the formula, Expressed as the difference in lateral RMS radius, Expressed as the difference in divergence angles, Expressed as the difference in symmetry parameters.

[0087] Then, the difference can be input into a preset fuzzy adaptive control algorithm to obtain the current adjustment of the focusing coil. Specifically, the fuzzy adaptive control algorithm can be preset with a fuzzy rule base, which can be: if, > 0 (beam over-diffusion), increase the focusing current to enhance the magnetic field focusing force; if, <0 (insufficient divergence angle), then reduce the current to allow moderate diffusion; if, ≠0 (asymmetric distribution), the current weights of the multi-stage focusing coils are adjusted differentially.

[0088] In the presence of multiple focusing coils (primary, secondary), the total current adjustment can be distributed according to preset weights: In the formula, It can be expressed as the current adjustment (total) output by the fuzzy adaptive control algorithm, It can be expressed as the current adjustment amount allocated to the primary focusing coil, which is responsible for global coarse adjustment. The weight of can be higher. The current adjustment amount allocated to the secondary focusing coil is responsible for local fine-tuning, and its corresponding The weight can be lower.

[0089] Finally, based on the corresponding current adjustment amount, the corresponding current adjustment command (primary, secondary) is generated.

[0090] Step S146: Based on the charge quantity data, execute the preset first beam charge quantity data adjustment strategy to generate emission control parameters and / or microwave excitation source power adjustment instructions corresponding to the electron injection device; wherein the emission control parameters and / or microwave excitation source power adjustment instructions of the electron injection device are used to match the first target charge quantity.

[0091] In this embodiment, the emission control parameters are a set of physical quantities representing the control of the electron gun cathode temperature and initial acceleration conditions. Specifically, the emission control parameters may include pulse voltage and filament current.

[0092] In this embodiment, similarly, a difference is calculated based on the charge amount data and a first preset value (a target charge amount, which may be set according to a radiotherapy plan), and the difference is input into a PID control algorithm or a proportional-integral control (PI algorithm) to obtain an adjustment amount of the emission control parameters of the electron gun (an adjustment amount of the pulse voltage and an adjustment amount of the filament current), and the difference is input into a feedforward-feedback composite control algorithm to obtain an adjustment amount of the microwave source power.

[0093] Specifically, the feedforward module in the feedforward-feedback composite control algorithm can predict the microwave power demand based on the changes in the emission control parameters (pulse voltage): In the formula, is the accelerating tube efficiency parameter, which is used to characterize the efficiency of converting microwave energy into beam kinetic energy. is the pulse width, is the target charge (first preset value), is the beam energy, is the feedforward microwave power (theoretical demand value).

[0094] The feedback correction module in the feedforward-feedback composite control algorithm can be based on Dynamic adjustment of microwave power: In the formula, Expressed as the feedback gain coefficient, it adjusts the intensity of feedback correction. is the charge deviation ( - ), is the target charge (first preset value), is the rated microwave power, is the feedback correction power.

[0095] Then perform power synthesis to obtain: In the formula, is the final power adjustment of the microwave source.

[0096] Finally, the control device may generate an adjustment instruction for the emission control parameter of the electron gun and a power adjustment instruction for the microwave source based on the adjustment amount of the emission control parameter and the power adjustment amount of the microwave source.

[0097] Step S148: sending the current adjustment instruction of the guide magnet, the current adjustment instruction of the focusing coil, the emission control parameters of the electron injection device and / or the microwave excitation source power adjustment instruction to the corresponding first target device.

[0098] Specifically, the control device can send the current adjustment instruction of the guide magnet to the guide magnet, the current adjustment instruction of the focusing coil to the focusing coil, the adjustment instruction of the emission control parameter to the electron gun, and the power adjustment instruction to the microwave source.

[0099] This embodiment ensures the efficient operation of the first target device in the accelerator system by executing a series of precise adjustment strategies, thereby achieving precise adjustment of the first beam. Specifically, based on the beam's position parameters, profile parameters, and charge data, the control device sequentially generates and sends guidance magnet current adjustment instructions, focusing coil current adjustment instructions, and emission control parameters of the electron injection device and microwave excitation source power adjustment instructions. These instructions help correct beam center offset, suppress beam divergence and morphological distortion, and ensure precise charge matching. Through this multi-level adjustment mechanism, the stability and accuracy of beam transmission can be significantly improved, and the performance of the accelerator system can be optimized. In particular, in high-precision application scenarios (flash radiotherapy), the reliability of the treatment effect and the long-term stable operation of the equipment are guaranteed. This embodiment can effectively enhance the system's adaptability and control accuracy, ensuring that the electron beam can be precisely adjusted under different operating conditions.

[0100] In some embodiments, the first preset value includes a first target beam position parameter, a first target beam profile parameter, and a first target charge amount; Step S142: The step of executing a preset first beam position data adjustment strategy based on the beam position parameter to generate a magnetic field strength adjustment instruction corresponding to the at least one level of guide magnet includes: Step S1422: Calculating position error data based on the beam position parameter and the first target beam position parameter.

[0101] Step S1424: inputting the error data into a position error-magnetic field strength mapping model to obtain the magnetic field strength adjustment amount of the at least one level of guide magnet; Step S1426: Generate the magnetic field strength adjustment instruction based on the magnetic field strength adjustment amount.

[0102] In this embodiment, the position error-magnetic field strength mapping model can be used to convert beam position deviation (horizontal / vertical offset) into the required magnetic field strength adjustment for the guide magnet. This model can be a linear model, a nonlinear model, a fuzzy control model, or a learnable model based on deep learning.

[0103] Alternatively, step S144: executing a preset first beam profile data adjustment strategy based on the beam profile parameters to generate a current adjustment instruction corresponding to at least one level of focusing coils includes: Step S1442: Calculating beam profile error data based on the beam profile parameters and the first target beam profile parameters; Step S1444: inputting the beam profile error data into a beam profile error-current mapping model to obtain a current adjustment value of the at least one level of focusing coil; Step S1446: Generate the current adjustment instruction based on the current adjustment amount.

[0104] In this embodiment, the beam profile error-current mapping model can convert deviations in beam profile parameters (divergence angle, RMS radius) into current adjustments for the focusing coil. Similarly, this model can be a linear model, a nonlinear model, a fuzzy control model, or a learnable model based on deep learning.

[0105] Alternatively, step S146: the step of executing a preset first beam charge data adjustment strategy based on the charge data to generate emission control parameters corresponding to the electron injection device and / or microwave excitation source power adjustment instructions includes: Step S1462: Calculating charge amount error data based on the charge amount data and the first target charge amount; Step S1464: inputting the charge error data into a charge error-emission control parameter and power mapping model to obtain the emission control parameter and power adjustment value of the electron injection device; Step S1466: Generate a transmission control parameter and a power adjustment instruction based on the transmission control parameter and the power adjustment amount.

[0106] In this embodiment, the charge error-emission control parameter and power mapping model can dynamically adjust the emission control parameters (pulse voltage and filament current) and microwave power of the electron injection device through the charge deviation.

[0107] This embodiment ensures efficient and stable beam transmission in the accelerator system through precise feedback control and adjustment strategies. During this process, based on the beam position parameters, beam profile parameters, and charge data, the control device generates corresponding adjustment instructions for the guide magnet, focusing coil, and electron injection device, respectively, thereby precisely controlling the beam transmission characteristics. Specifically, the control device can achieve precise calibration and adjustment of the beam by calculating the beam position error and adjusting the magnetic field strength, calculating the beam profile error and adjusting the focusing coil current, and adjusting the emission control parameters and power of the electron injection device based on the charge error. This multi-dimensional control scheme improves the stability and accuracy of the accelerator system, especially in application scenarios requiring high-precision beam control (Flash radiotherapy), which can significantly optimize the treatment effect, reduce errors, and improve the accuracy and safety of treatment.

[0108] In some embodiments, the first adjustment strategy further includes a preset joint optimization strategy. Before the step of sending the current adjustment instruction of the guide magnet, the current adjustment instruction of the focusing coil, and the emission control parameters of the electron injection device and / or the microwave excitation source power adjustment instruction to the corresponding first target device, the method further includes: Step S147: Input the current adjustment instructions of the guide magnet, the current adjustment instructions of the focusing coil, and the pulse voltage and / or power adjustment instructions into the preset joint optimization strategy to coordinate the parameter adjustment amounts of each first target device, thereby avoiding secondary errors caused by parameter coupling, and obtaining the optimized current adjustment instructions of the guide magnet, the current adjustment instructions of the focusing coil, and the emission control parameters and / or microwave excitation source power adjustment instructions.

[0109] In this embodiment, the emission control parameter may include a pulse voltage.

[0110] In this embodiment, the mutual influence rules between the various control instructions are determined in advance through experiments and simulations. For example, although increasing the guide magnet current can correct the beam position, it may slightly increase the divergence angle. Increasing the focusing coil current can compress the beam cross section, but it may cause the charge to fluctuate due to the energy dispersion effect. Increasing the electron gun voltage will increase the charge, but it may cause position deviation due to microwave power lag. Therefore, the optimization target can be constructed in advance based on the mutual influence rule. It can be understood that the goal of joint optimization is to minimize the error in the system and ensure that the beam can be transmitted in an ideal manner in the accelerator. Specific goals include: Reduce beam position error: Ensure the beam is stably transmitted along the predetermined trajectory.

[0111] Reduce beam shape distortion: Ensure that the beam shape (e.g., beam center and divergence angle) meets predetermined standards.

[0112] During the optimization process, multi-objective optimization algorithms can be used. For example, weighted least squares, genetic algorithms, or particle swarm optimization algorithms can be used to balance multiple objectives (beam position, shape, charge, etc.) to find the best adjustment solution, so that the final device adjustment instructions can reach the global optimum.

[0113] This implementation introduces a joint optimization strategy. After generating adjustment instructions for each target device, it optimizes the current adjustment instructions for the guide magnet, the current adjustment instructions for the focusing coil, and the pulse voltage and power adjustment instructions for the electron injection device. This effectively coordinates the adjustment parameters of each device and avoids secondary errors caused by parameter coupling between devices. This strategy allows the control device to comprehensively consider the mutual influence of each device during the adjustment process, ensuring coordination and consistency between the various adjustment instructions, thereby achieving more efficient and precise beam control. This optimization process not only improves the stability and accuracy of the accelerator system but also reduces errors caused by mutual interference between devices. This can significantly improve treatment accuracy and system reliability, especially in applications requiring high-precision control, such as flash radiotherapy.

[0114] In some embodiments, the second preset value includes a second target beam position parameter, a second target beam profile parameter, and a second target charge; the beam transmission characteristic data includes a beam position parameter and a beam profile parameter, and the second target device is an achromatic magnet.

[0115] In this embodiment, the second preset value is a set of target parameters for the achromatic magnet control phase, ensuring that the deflected beam (second beam) meets the combined requirements of spatial distribution, energy stability, and dose accuracy along its propagation path. Specifically, the second target beam position parameter characterizes the ideal spatial coordinates of the beam center within the vacuum chamber after deflection. This ensures that the beam, after being deflected by the achromatic magnet, propagates strictly along the predetermined path, avoiding collisions with the vacuum chamber walls or failure to establish effective beam propagation due to trajectory deviation. The second target beam profile parameters, including the divergence angle and root mean square radius, are used to suppress beam spread caused by energy dispersion, maintain dose uniformity, prevent local power density violations due to excessive cross-sectional expansion, and reduce the risk of vacuum chamber breakdown.

[0116] The step of executing a preset second adjustment strategy based on the beam transmission characteristic data and the charge quantity data of the second beam to adjust the second target device in the accelerator system so that the beam transmission characteristic data and the charge quantity data of the second beam tend to a second preset value includes: Step S180: Calculating a beam position deviation, a beam profile deviation, and a charge amount deviation based on the beam position parameter and the second target beam position parameter, the beam profile parameter and the second target beam profile parameter, and the charge amount data and the second target charge amount, respectively; Step S182: Calculating an initial magnetic field strength adjustment of the achromatic magnet based on the beam position deviation and a preset proportional-integral control strategy, and obtaining an additional magnetic field gradient adjustment of the achromatic magnet based on the charge deviation and a preset charge-magnetic field gradient coupling model; In this embodiment, the control device calculates a preliminary magnetic field intensity adjustment based on the beam position deviation using a proportional-integral control strategy. This proportional-integral control strategy, also known as a feedback control strategy, combines the deviation value with the proportional, integral, and differential elements to minimize the error through control input.

[0117] In this embodiment, the charge-magnetic field gradient coupling model can be a mathematical model used to describe the relationship between charge and magnetic field. In a particle beam, the charge and the magnetic field of the beam influence each other. Changes in the magnetic field (especially the magnetic field gradient) can affect the motion trajectory and energy distribution of the particle beam, thereby affecting the charge of the beam. In an accelerator system, a dispersionless magnet is primarily used to adjust the momentum space of the beam, particularly the velocity distribution of the beam. Deviations in charge may be affected by factors such as beam divergence, beam morphological distortion, or uneven energy distribution. In this case, by adjusting the magnetic field gradient, the deviation in charge can be compensated, thereby bringing the charge of the beam closer to the target value.

[0118] Specifically, the charge-magnetic field gradient coupling model can be derived based on experimental data or theoretical derivation to describe how charge deviations are compensated by adjusting the magnetic field gradient. In other words, when charge deviations occur, the magnetic field gradient needs to be adjusted accordingly to ensure that the charge distribution and beam morphology return to the desired state. This model can be linear, nonlinear, or even learnable (machine learning or deep learning).

[0119] It can be understood that based on the charge deviation and the charge-magnetic field gradient coupling model, the control device can calculate an additional magnetic field gradient adjustment. This adjustment is used to further refine the beam charge adjustment. If the charge deviation is positive, indicating that the beam charge is higher than the target value, it is necessary to reduce the magnetic field gradient to slow the beam convergence. If the charge deviation is negative, indicating that the beam charge is lower than the target value, it is necessary to increase the magnetic field gradient to make the beam more focused, thereby increasing the charge. Therefore, combining the charge deviation and the coupling model, the control device can calculate an additional magnetic field gradient adjustment that will compensate for the shortfall in the original magnetic field strength adjustment, thereby ensuring that the beam charge reaches the desired target.

[0120] Step S184: Based on the beam profile deviation, the initial magnetic field intensity adjustment amount is corrected for energy dispersion compensation to generate an optimized magnetic field intensity adjustment amount.

[0121] In this embodiment, the control device uses energy dispersion compensation to modify the initial magnetic field intensity adjustment based on the beam profile deviation, generating an optimized magnetic field intensity adjustment. The core purpose of this process is to eliminate the effects of energy dispersion on the beam, further optimize the beam transmission characteristics, and ensure efficient and stable beam transmission within the accelerator.

[0122] It can be understood that energy dispersion refers to the difference in energy distribution among particles in a beam, which results in an uneven spatial dispersion of the particle beam. For example, the kinetic energy of different particles in a beam may be inconsistent, which can cause deviations in their motion trajectories, thereby affecting the stability and accuracy of the beam. For another example, the different energies between particles can cause them to have different deflection angles during propagation, thus affecting the overall shape and position of the beam. Because energy dispersion can cause the beam to diverge or distort its shape, the control device needs to compensate for this effect to ensure that the beam can be transmitted along the predetermined path and shape.

[0123] It is also understandable that beam profile deviations can cause the beam's propagation path in the accelerator to deviate and increase the beam's energy divergence. For example, when the beam divergence angle is large, the effect of energy divergence is exacerbated, resulting in a more uneven beam energy distribution.

[0124] In this embodiment, the beam lateral size deviation ( ) is decomposed into different frequencies ( ) of the energy dissipation harmonic component: In the formula, It is expressed as the frequency domain representation of the beam transverse RMS radius deviation, reflecting the influence of energy dispersion of different frequency components on beam diffusion. Expressed as the amplitude of the nth-order harmonic, it quantifies the contribution of energy dispersion to the beam profile deviation. is the energy dispersion characteristic frequency, corresponding to the periodic fluctuation frequency of particle energy, is the sampling time interval, is the upper limit of harmonic order.

[0125] It can be understood that complex contour deviation = the superposition of multiple simple harmonic motions (energy dispersion fluctuations). Through Fourier transform, the contour deviation ( ) is decomposed into energy dissipation harmonic components of different frequencies ( ).

[0126] In this embodiment, the compensation magnetic field adjustment amount can be generated according to the energy dissipation contribution: In the formula, The magnetic field adjustment required to compensate for energy dissipation, a negative value means reducing the magnetic field, a positive value means increasing the magnetic field, is the energy dissipation-magnetic field coupling coefficient, which can be calibrated experimentally (that is, the linear relationship between the energy dissipation effect and the magnetic field response is calibrated). is the initial magnetic field strength, that is, the reference magnetic field value when the adispersion magnet is not compensated. is the nominal beam energy, is the maximum allowable energy dissipation. Exceeding this value may cause beam runaway. In this formula, the energy dissipation harmonic component ( ) contribution, calculate the magnetic field adjustment amount, and offset the influence of energy dispersion on the beam. In other words, this formula uses the decomposition result of the above formula ( ), combined with physical parameters ( , , ), calculate the magnetic field adjustment amount .

[0127] Step S186: superimposing the magnetic field gradient additional adjustment amount and the optimized magnetic field intensity adjustment amount to obtain a final magnetic field intensity adjustment amount; Step S188: generating an adjustment instruction for the achromatic magnet based on the final magnetic field intensity adjustment amount; Step S1810: Sending the adjustment instruction of the achromatic magnet to the achromatic magnet.

[0128] This embodiment optimizes the adjustment process for the achromatic magnet by precisely calculating deviations in beam position, profile, and charge, and combining it with pre-set control strategies and models. Through a proportional-integral control strategy and a charge-magnetic field gradient coupling model, the control device can effectively calculate the initial magnetic field intensity adjustment and further optimize the adjustment results through energy dispersion compensation correction. This precise adjustment not only ensures the accuracy of the beam position and profile, but also eliminates the effects of beam divergence and energy dispersion, thereby maximizing the optimization of beam transmission characteristics. Ultimately, through the comprehensive optimization of the magnetic field intensity adjustment, the control device can generate precise achromatic magnet adjustment instructions, ensuring the stability and accuracy of the beam in high-precision applications. This strategy significantly improves the control capabilities of the accelerator system, especially in applications requiring high precision (flash radiotherapy), ensuring the accuracy and reliability of treatment.

[0129] This embodiment provides an accelerator system, which includes at least a control device and the following components arranged in sequence on a beam path: The first target device is used to generate an initial electron beam, accelerate the initial electron beam, and adjust the beam transmission characteristics of the accelerated electron beam.

[0130] Furthermore, on the beam path, the first target device may include: Electron gun: used to generate the initial electron beam under pulsed high voltage; Accelerator tube and microwave source: used to jointly perform microwave pre-acceleration on the initial electron beam and output the accelerated electron beam; Primary focusing coil: used to apply a strong focusing magnetic field to the accelerated electron beam to overcome the beam envelope expansion caused by the space charge effect and output a high-energy beam; First-stage guide magnet: used to correct and stabilize the high-energy beam; Secondary focusing coil: used for precise collimation of high energy beam; Secondary guide magnet: used to further adjust and stabilize the beam deflected by the primary guide magnet.

[0131] In this embodiment, between the first target device and the first beam position detector, there may further be provided: Beam intensity dynamic monitoring module BCT: used to monitor the electron beam intensity (charge) in real time.

[0132] The first beam position detector BPM1 is used to obtain beam transmission characteristic data and charge quantity data of the undeflected beam; wherein the beam transmission characteristic data is a set of physical quantities used to characterize the spatial distribution state of the electron beam in the transmission path.

[0133] In this embodiment, between the first beam position detector BPM1 and the second target device, there may further be provided: Transient beam spot imaging unit YAG target: monitors the current beam morphology.

[0134] a second target device, configured to deflect the beam; The second beam position detector is used to obtain beam transmission characteristic data and charge quantity data of the deflected beam.

[0135] In this embodiment, the following may be further provided after the second beam position detector: Rotating tungsten target: X-rays are generated when the electron beam bombards the target; Multileaf grating: used to perform dynamic correction of the leaf position. Specifically, the multileaf grating can even out the generated bremsstrahlung radiation, thereby improving the planar dose uniformity and thus improving the planar uniformity.

[0136] Dose monitoring module: used to output dose distribution matrix and monitor dose conditions online.

[0137] The control device is used to, during the use of the accelerator, determine the beam transmission characteristic data and charge quantity data of the first beam at least through the first beam position detector; based on the beam transmission characteristic data and charge quantity data of the first beam, execute a preset first adjustment strategy to adjust the first target device in the accelerator system so that the beam transmission characteristic data and charge quantity data of the first beam tend to a first preset value; when the morphological data of the first beam reaches the first preset value, determine the beam transmission characteristic data and charge quantity data of the second beam through the second beam position detector; based on the beam transmission characteristic data and charge quantity data of the second beam, execute a preset second adjustment strategy to adjust the second target device in the accelerator system so that the beam transmission characteristic data and charge quantity data of the second beam tend to a second preset value.

[0138] Specifically, the control device can be electrically connected to the electron gun through a high-voltage pulse modulation interface, can be electrically connected to the accelerator tube through a microwave power coupling interface, can be electrically connected to the microwave source through a digital control bus, can be electrically connected to the primary / secondary focusing coil through a constant current source drive interface, can be electrically connected to the primary / secondary guide magnet through a PWM drive interface, can be electrically connected to the beam intensity dynamic monitoring module BCT through an analog acquisition card, can be electrically connected to BPM1 / BPM2 through a high-speed digital interface, can be electrically connected to the YAG target through a mechanical drive interface + optical acquisition interface, can be electrically connected to the achromatic magnet through a current source, can be electrically connected to the multi-leaf grating through a servo motor control interface, and can be electrically connected to the dose monitoring module through a multi-channel ADC interface.

[0139] like Figure 3 As shown, in a specific embodiment, a medical linear accelerator is provided: Electron gun 1: used to generate an initial electron beam under pulsed high voltage; The accelerating tube 2 and the microwave source 16 are used to jointly perform microwave pre-acceleration on the initial electron beam and output the accelerated electron beam; Primary focusing coil 3: used to apply a strong focusing magnetic field to the electron beam to overcome the beam envelope expansion caused by the space charge effect and output a high-energy beam; Primary guide magnet 4: used to correct and stabilize the high-energy beam; Secondary focusing coil 5: used for precise collimation of the high energy beam; Secondary guide magnet 6: used to further adjust and stabilize the beam deflected by the primary guide magnet; Beam intensity dynamic monitoring module 7: used to monitor the electron beam intensity (charge) in real time; The first-stage beam position detector 8 is used to detect the morphological data of the electron beam at the current position (for example, the position of the beam center and the beam shape) and the charge amount; Transient beam spot imaging unit YAG target 9: monitors the current beam morphology; Achromatic magnet 10: used to apply momentum space dispersion to the electron beam, so that the electron beam is deflected to a target angle. The target angle can be 90 degrees, 120 degrees, etc. The specific deflection angle depends on the design of the achromatic magnet itself; The second-stage beam position detector 11 is used to detect the morphological data of the electron beam at the current position (for example, the position of the beam center and the beam shape) and the charge amount.

[0140] Rotating tungsten target 12: X-rays are generated after the electron beam bombards the target; Multi-leaf grating 13: Evens out the generated bremsstrahlung radiation to improve the planar dose uniformity and improve the planar uniformity.

[0141] Dose monitoring module 14: used to output the dose distribution matrix and monitor the dose situation online.

[0142] According to an embodiment of the present invention, an electronic device is provided. Figure 4 The electronic device in this embodiment may include one or more of the following components: a processor, a network interface, a memory, a non-volatile memory, and one or more applications, wherein the one or more applications may be stored in the non-volatile memory and configured to be executed by one or more processors, and the one or more programs are configured to execute the method described in the aforementioned method embodiment.

[0143] According to an embodiment of the present invention, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a computer, the computer executes the method described in any one of the above embodiments.

[0144] According to an embodiment of the present invention, a computer program product comprising instructions is further provided. When the instructions are executed by a computer, the computer is enabled to perform a method in any one of the above embodiments.

[0145] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in a sequence other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0146] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments, and this embodiment will not be described in detail here.

[0147] The serial numbers of the above embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0148] In the above embodiments of the present application, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0149] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for adjusting an accelerator system, characterized in that: A control device for an accelerator system, the accelerator system comprising at least a first beam position detector and a second beam position detector sequentially arranged on a beam path, the first beam position detector being used to obtain beam transmission characteristic data and charge quantity data of an undeflected beam, and the second beam position detector being used to obtain beam transmission characteristic data and charge quantity data of a deflected beam, the beam transmission characteristic data being used to characterize a set of physical quantities of a spatial distribution state of an electron beam in a transmission path; the method comprising: During use of the accelerator, at least the beam transmission characteristic data and charge quantity data of the first beam are determined by the first beam position detector; wherein the first beam is the electron beam current before the electron beam is deflected; executing a preset first adjustment strategy based on the beam transmission characteristic data and the charge quantity data of the first beam to adjust a first target device in the accelerator system so that the beam transmission characteristic data and the charge quantity data of the first beam approach a first preset value; When the morphological data of the first beam reaches a first preset value, beam transmission characteristic data and charge quantity data of the second beam are determined by the second beam position detector, wherein the second beam represents the electron beam after the electron beam is deflected; Based on the beam transmission characteristic data and charge quantity data of the second beam, a preset second adjustment strategy is executed to adjust the second target device in the accelerator system so that the beam transmission characteristic data and charge quantity data of the second beam tend to second preset values.

2. The adjustment method according to claim 1, characterized in that: The accelerator system further includes a charge monitoring unit, and when the accelerator system adopts the first mode, the accelerator system is further configured with a beam spot imaging unit; wherein the charge monitoring unit is used to obtain charge data of the first beam, and the beam spot imaging unit is used to obtain beam transmission characteristic data of the first beam; The step of determining the beam transmission characteristic data and charge quantity data of the first beam by at least the first beam position detector during use of the accelerator includes: When the accelerator system adopts a first mode, beam transmission characteristic data of the first beam is determined by the first beam position detector and the beam spot imaging unit, and charge quantity data of the first beam is determined by the first beam position detector and the charge quantity monitoring unit; wherein the first mode indicates that in this mode, the beam intensity is lower than the breakdown threshold of the beam spot imaging unit; When the accelerator system adopts the second mode, beam transmission characteristic data of the first beam is determined by a first beam position detector that has been pre-calibrated by a beam spot imaging unit, and charge quantity data of the first beam is determined by the first beam position detector and a charge quantity monitoring unit; wherein the second mode indicates a mode in which the beam intensity is greater than or equal to a breakdown threshold of the beam spot imaging unit.

3. The adjustment method according to claim 2, characterized in that: The step of determining the charge amount data of the first beam by using the first beam position detector and the charge amount monitoring unit includes: sending data acquisition signals to the first beam position detector and the charge quantity monitoring unit respectively; respectively receiving charge quantity data fed back by the first beam position detector and the charge quantity monitoring unit; Determining whether the charge data fed back by the charge monitoring unit is consistent with the charge data fed back by the first beam position detector; In the event of inconsistency, the charge data fed back by the charge monitoring unit is directly determined as the charge data of the first beam, or a preset error fitting algorithm is executed on the charge data fed back by the charge monitoring unit and the charge data fed back by the first beam position detector to obtain the charge data of the first beam.

4. The adjustment method according to claim 1, characterized in that: The first target device includes at least one level of guide magnet, at least one level of focusing coil and electron injection device, and the beam transmission characteristic data includes beam position parameters and beam profile parameters; The first adjustment strategy at least includes: a preset first beam position data adjustment strategy, a preset first beam profile data adjustment strategy, and a preset first beam charge data adjustment strategy; The step of executing a preset first adjustment strategy based on the beam transmission characteristic data and the charge quantity data of the first beam to adjust the first target device in the accelerator system so that the beam transmission characteristic data and the charge quantity data of the first beam tend to a first preset value includes: Based on the beam position parameter, executing a preset first beam position data adjustment strategy to generate a current adjustment instruction corresponding to the at least one level of guide magnet; wherein the current adjustment instruction of the guide magnet is used to correct the beam center offset; Based on the beam profile parameters, a preset first beam profile data adjustment strategy is executed to generate current adjustment instructions corresponding to at least one level of focusing coils; wherein the current adjustment instructions for the focusing coils are used to suppress beam divergence and morphological distortion; Based on the charge quantity data, executing a preset charge quantity data adjustment strategy for the first beam, generating emission control parameters and / or microwave excitation source power adjustment instructions corresponding to the electron injection device; wherein the emission control parameters and / or microwave excitation source power adjustment instructions of the electron injection device are used to match the first target charge quantity; The current adjustment instruction of the guide magnet, the current adjustment instruction of the focusing coil, the emission control parameters of the electron injection device and / or the microwave excitation source power adjustment instruction are sent to the corresponding first target device.

5. The adjustment method according to claim 4, characterized in that: The first preset value includes a first target beam position parameter, a first target beam profile parameter, and a first target charge amount; The step of executing a preset first beam position data adjustment strategy based on the beam position parameter to generate a magnetic field strength adjustment instruction corresponding to the at least one level of guide magnet includes: calculating position error data based on the beam position parameter and a first target beam position parameter; Inputting the error data into a position error-magnetic field strength mapping model to obtain the magnetic field strength adjustment amount of the at least one level of guide magnet; generating the magnetic field strength adjustment instruction based on the magnetic field strength adjustment amount; Alternatively, the step of executing a preset first beam profile data adjustment strategy based on the beam profile parameters to generate a current adjustment instruction corresponding to at least one level of focusing coil includes: calculating beam profile error data based on the beam profile parameter and a first target beam profile parameter; Inputting the beam profile error data into a beam profile error-current mapping model to obtain a current adjustment amount of the at least one level of focusing coil; generating the current adjustment instruction based on the current adjustment amount; Alternatively, the step of executing a preset first beam charge data adjustment strategy based on the charge data to generate emission control parameters corresponding to the electron injection device and / or microwave excitation source power adjustment instructions includes: calculating charge amount error data based on the charge amount data and a first target charge amount; Inputting the charge error data into a charge error-emission control parameter and power mapping model to obtain the emission control parameter and power adjustment amount of the electron injection device; Based on the transmission control parameter and the power adjustment amount, a transmission control parameter and a power adjustment instruction are generated.

6. The adjustment method according to claim 4, characterized in that: The first adjustment strategy further includes a preset joint optimization strategy. Before the step of sending the current adjustment instruction of the guide magnet, the current adjustment instruction of the focusing coil, the emission control parameters of the electron injection device, and / or the microwave excitation source power adjustment instruction to the corresponding first target device, the method further includes: The current adjustment instructions of the guide magnet, the current adjustment instructions of the focusing coil, and the pulse voltage and / or power adjustment instructions are input into a preset joint optimization strategy to coordinate the parameter adjustment amounts of each first target device, thereby avoiding secondary errors caused by parameter coupling, and obtaining optimized current adjustment instructions of the guide magnet, the current adjustment instructions of the focusing coil, and the emission control parameters and / or microwave excitation source power adjustment instructions.

7. The adjustment method according to claim 1, characterized in that: The second preset value includes a second target beam position parameter, a second target beam profile parameter, and a second target charge; the beam transmission characteristic data includes a beam position parameter and a beam profile parameter, and the second target device is an achromatic magnet; The step of executing a preset second adjustment strategy based on the beam transmission characteristic data and the charge quantity data of the second beam to adjust the second target device in the accelerator system so that the beam transmission characteristic data and the charge quantity data of the second beam tend to a second preset value includes: Calculating a beam position deviation, a beam profile deviation, and a charge amount deviation based on the beam position parameter and a second target beam position parameter, the beam profile parameter and the second target beam profile parameter, and the charge amount data and the second target charge amount, respectively; Based on the beam position deviation and a preset proportional-integral control strategy, an initial magnetic field strength adjustment of the achromatic magnet is calculated, and based on the charge deviation and a preset charge-magnetic field gradient coupling model, an additional magnetic field gradient adjustment of the achromatic magnet is obtained; Based on the beam profile deviation, performing energy dispersion compensation correction on the initial magnetic field intensity adjustment amount to generate an optimized magnetic field intensity adjustment amount; superimposing the additional magnetic field gradient adjustment amount and the optimized magnetic field intensity adjustment amount to obtain a final magnetic field intensity adjustment amount; generating an adjustment instruction for the achromatic magnet based on the final magnetic field strength adjustment amount; The adjustment instruction of the achromatic magnet is sent to the achromatic magnet.

8. An accelerator system, characterized in that: The accelerator system at least includes a control device and the following components arranged in sequence on the beam path: a first target device, which is used to generate an initial electron beam, accelerate the initial electron beam, and adjust the beam transmission characteristics of the accelerated electron beam; a first beam position detector, configured to obtain beam transmission characteristic data and charge quantity data of an undeflected beam; wherein the beam transmission characteristic data is a set of physical quantities representing a spatial distribution state of the electron beam in a transmission path; a second target device for deflecting the beam; a second beam position detector, which is used to obtain beam transmission characteristic data and charge quantity data of the deflected beam; The control device is used to, during the use of the accelerator, determine the beam transmission characteristic data and charge quantity data of the first beam at least through the first beam position detector; based on the beam transmission characteristic data and charge quantity data of the first beam, execute a preset first adjustment strategy to adjust the first target device in the accelerator system so that the beam transmission characteristic data and charge quantity data of the first beam tend to a first preset value; when the morphological data of the first beam reaches the first preset value, determine the beam transmission characteristic data and charge quantity data of the second beam through the second beam position detector; based on the beam transmission characteristic data and charge quantity data of the second beam, execute a preset second adjustment strategy to adjust the second target device in the accelerator system so that the beam transmission characteristic data and charge quantity data of the second beam tend to a second preset value.

9. An electronic device, characterized in that: include: a memory, and one or more processors communicatively coupled to the memory; Instructions executable by the one or more processors are stored in the memory. The instructions are executed by the one or more processors to enable the one or more processors to implement the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that The readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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