Ion source automatic beam adjusting method, radiotherapy system and related equipment

Abstract

The invention discloses an ion source automatic beam adjusting method, a radiotherapy system and related equipment, and relates to the technical field of radiotherapy, and the method comprises the steps: monitoring and adjusting a plurality of control parameters in real time, and obtaining an optimal control parameter combination; under the optimal control parameter combination, the variable quantity of each control parameter before and after adjustment and the performance change of the proton beam are obtained; performing a pulse width charge test according to the variation of each parameter before and after adjustment and the performance change of the proton beam; obtaining an optimal adjustment parameter and an adjustment amount through a pulse width charge test result; and through the optimal adjustment parameter and adjustment amount, automatic beam adjustment is realized, stable and efficient acceleration of the proton beam in the synchrocyclotron system is realized, and the stability and consistency of the proton beam are ensured.

Description

[0001] This application is a divisional application of the Chinese application with the application number CN202510000792.0, the application date of January 2, 2025, and the invention name of "Radio frequency signal control device, method and related equipment". TECHNICAL FIELD

[0002] The present application relates to the field of radiotherapy, in particular to an ion source automatic beam tuning method, a radiotherapy system and related equipment. BACKGROUND

[0003] Particle radiotherapy systems, particularly proton therapy systems, play an increasingly important role in modern cancer treatment. The treatment effect is highly dependent on the performance of the generated beam, such as beam intensity, stability, beam spot size and uniformity, etc. During system operation, the ion source as the starting point of generating the beam, its performance optimization and stability are the basis to ensure the efficient and accurate work of the whole treatment system.

[0004] The traditional ion source beam tuning process is highly dependent on the experience of the operator. The operator usually needs to manually adjust a series of key control parameters, which faces many challenges: first, due to the large number of control parameters and the complex coupling relationship between them, manually finding the optimal parameter combination not only takes too long, but also is difficult to ensure that the global optimal solution is obtained, resulting in the beam performance not reaching the best state. Secondly, the consistency of the manual beam tuning process is poor, and the adjustment by different operators or the same operator at different times may produce different results, affecting the repeatability of the treatment process and the reliability of the treatment results. Thirdly, the traditional adjustment method lacks systematic optimization strategy, and the parameter adjustment is often based on trial and error, which is difficult to quickly respond to the dynamic changes of the beam state, resulting in low beam tuning efficiency and long time to reestablish a stable beam after treatment interruption or system state change.

[0005] Particle accelerators are important devices in the field of radiotherapy, used to accelerate charged particles to high energy. Among them, the cyclotron is an important type, which accelerates charged particles in a vacuum chamber using alternating voltage and one or more "D-shaped boxes" (the name of the D-shaped electrode in the early cyclotron). These particles move in an axial magnetic field and produce a spiral orbit perpendicular to the magnetic field; as the particles spiral outward, the acceleration electric field is applied to the gap between the D-shaped boxes.

[0006] In the cyclotron, the spiral orbit generated by the accelerated particles is perpendicular to the magnetic field, and as the particles spiral outward, the acceleration electric field is applied to the gap between the D-shaped boxes. Radio frequency (RF) voltage generates an alternating electric field across the gap between the D-shaped boxes, which is synchronized with the periodic orbit of the charged particles in the magnetic field, so that the particles are accelerated by the radio frequency waveform when they repeatedly cross these gaps.

[0007] However, as the energy of the particles increases, relativistic effects become significant. However, when the energy of the particles increases to a level far beyond what can be accelerated by the peak voltage of the applied radio frequency (RF), i.e., when the speed of the charged particles approaches the speed of light, its mass increases, causing the acceleration to become inconsistent, and the time at which the particles reach the gap is no longer synchronized with the peak of the applied voltage. The acceleration process becomes complex. To overcome this challenge, two types of cyclotrons have been developed: isochronous cyclotrons and synchrocyclotrons.

[0008] An isochronous cyclotron maintains synchronization of the acceleration process by gradually increasing the magnetic field strength as the radius increases, while using a constant voltage frequency. However, this approach limits the highest energy that can be achieved, as the required magnetic field strength increases as the energy of the particles increases, which can be difficult to achieve in practical applications.

[0009] In contrast, a synchrocyclotron uses a gradually decreasing magnetic field as the radius gradually increases and a varying acceleration voltage frequency, with discrete "bunches" of charged particles being accelerated to the final energy before the cycle starts again to match the increase in mass caused by the relativistic speed of the charged particles. This approach allows charged particles to be accelerated to higher energy levels.

[0010] However, the RF control system of a synchrocyclotron faces many challenges, and an improved control system is needed to accurately adjust the frequency of the magnetic field strength and the RF voltage. SUMMARY

[0011] Based on the above problems, the purpose of the present application is to provide an ion source automatic beam tuning method, a radiotherapy system and related equipment, to realize stable and efficient acceleration of the proton beam in the synchrocyclotron system, and to ensure the stability and consistency of the proton beam.

[0012] The purpose of the present application is achieved by adopting the following technical solutions: In a first aspect, the present application provides an ion source automatic beam tuning method, comprising: real-time monitoring and adjusting a plurality of control parameters to obtain an optimal control parameter combination; under the optimal control parameter combination, obtaining the change amount before and after adjustment of each control parameter and the performance change of the proton beam; performing pulse width charge testing according to the change amount before and after adjustment of each parameter and the performance change of the proton beam; obtaining the optimal adjustment parameter and adjustment amount through the pulse width charge testing result; and realizing automatic beam tuning through the optimal adjustment parameter and adjustment amount.

[0013] Preferably, the method further comprises: The initialization parameters are set, including a frequency parameter of the radio frequency power signal, so that the accelerator can be stably operated; wherein the radio frequency power signal includes an open radio frequency, a closed radio frequency and an open ion source.

[0014] Preferably, the control parameters include a direct current bias voltage, an amplitude modulation value, a hydrogen flow rate, and Adaptive coil position and operating frequency of the rotating capacitor motor.

[0015] Preferably, the control parameters are adjusted in sequence, including: first adjusting the direct current bias voltage to suppress secondary electron emission, then synchronously adjusting the amplitude modulation value and the hydrogen flow rate, and finally adjusting the adaptive coil position and the operating frequency of the rotating capacitor motor.

[0016] Preferably, the control parameters are monitored and adjusted in real time; and a preferred control parameter combination is obtained, including: Through historical data, the influence curves of each control parameter on the characteristics of the beam are obtained; According to the influence curves of each control parameter on the characteristics of the beam, a first adjustment range of each control parameter is set; Within the first adjustment range, a plurality of continuous control points are set for each control parameter; Through the continuous control points, the control parameters are adjusted to obtain the real-time beam characteristic change trend; Through the real-time beam characteristic change trend, a second adjustment range of each control parameter is obtained; Within the second adjustment range, each control point of each control parameter is adjusted one by one; The values of the related control parameters before and after adjustment are monitored in real time, and by comparing the beam characteristics under different parameter combinations, further adjustment parameters and adjustment amounts are determined; The preferred control parameter combination is obtained through iterative adjustment.

[0017] In a second aspect, the present application provides a particle radiotherapy system, which executes the ion source automatic beam adjustment method described above.

[0018] Preferably, the system includes: An ion source for generating an ion beam; A radio frequency signal control device for realizing closed-loop control of the radio frequency signal by real-time sampling of the power signal of the radio frequency cavity and the coupler and detecting the phase error, and generating a radio frequency base signal matched with the demand of the accelerator based on the phase error.

[0019] Preferably, the radio frequency signal control device includes: A phase detection module for real-time detection of the phase error of the incident power on the directional coupler and the D-box power, and generating an oscillation driving signal when the phase is matched; an amplification module configured to amplify the oscillation driving signal; a base signal generation module configured to generate a radio frequency base signal according to the received oscillation driving signal to ensure that the frequency and phase of the radio frequency signal match the requirements of the synchrotron; The device further comprises an amplitude modulation module configured to adjust the gain of the radio frequency base signal; the amplitude modulation module further comprises a time slice division unit configured to divide the power amplification time interval into a plurality of time slices and control the gain signal loaded in each time slice.

[0020] Preferably, the radio frequency signal control device further comprises: a master control module configured to execute the radio frequency signal control logic, including receiving a sample signal, signal processing and feedback adjustment; a sampling module configured to collect the signals of the radio frequency cavity, including the D-box power, and the incident power and reflected power on the directional coupler in real time and feed back to the master control module.

[0021] Preferably, the power amplification time interval is divided into a plurality of time slices, and the gain signal loaded in each time slice is controlled; including: According to the change trend of the radio frequency signal, the time slices are dynamically divided; wherein a preset threshold for judging the change rate of the signal is set, and when the change rate of the signal exceeds the preset threshold, the time slice is shortened, and when the change rate is lower than or equal to the threshold, the time slice is lengthened; Based on the real-time signal characteristics and the preset gain strategy, the gain value in the current time slice is determined; The gain value is loaded to the digital adjustable gain device to control the gain of the radio frequency signal.

[0022] In a third aspect, the present application provides an electronic device, which comprises a memory and a processor, the memory stores a computer program, and the processor executes the computer program to execute the steps of the method of any one of the embodiments of the present application.

[0023] In a fourth aspect, the present application provides a computer readable storage medium, which stores computer instructions, and when the computer reads the computer instructions, the computer executes the steps of the method of any one of the embodiments of the present application.

[0024] Compared with the prior art, the beneficial effects of the present application at least include: under the preferred control parameter combination, the change amount before and after the adjustment of each control parameter is recorded, and the performance change of the proton beam is monitored at the same time, including the stability of the beam intensity, the uniformity of the beam spot size, etc.; based on the change amount before and after the adjustment of each parameter and the performance change of the proton beam, further pulse width charge test is carried out; the pulse width charge test is a method for evaluating the performance of the proton beam by changing the pulse width and charge amount of the proton beam; through the test, the influence of each control parameter on the performance of the proton beam can be more accurately understood; according to the results of the pulse width charge test, the optimal adjustment parameters and adjustment amounts are analyzed and determined, which can make the performance of the proton beam reach the best state. Finally, according to the optimal adjustment parameters and adjustment amounts, each control parameter is automatically adjusted to realize the automatic beam tuning of the ion source. At the same time, the performance of the proton beam is continuously monitored, and fine tuning is carried out as needed to ensure the stability and consistency of the proton beam; the closed loop control link can monitor the amplitude and phase of the radio frequency signal in real time, accurately adjust the output of the radio frequency signal through the feedback mechanism, and ensure the stability and accuracy of the radio frequency signal in the transmission process, which helps to reduce the measurement error of the pulse width charge (Pulse Width Charge) and improve the measurement accuracy. The introduction of the analog-to-digital conversion and digital-to-analog conversion modules enables the system to process digital signals, enhances the flexibility and programmability of the system, and facilitates subsequent function expansion and optimization. The calibration module can accurately calibrate the frequency points of the radio frequency scanning period, control the opening time of the radio frequency power and the ion source, and improve the control accuracy and efficiency of the system; the amplitude modulation module realizes accurate adjustment of the gain of the radio frequency base signal through the step attenuator and the digital adjustable gain amplifier, improving the output performance and stability of the system. The setting of the fixed attenuator and the hardware safety interlock module ensures that the maximum output amplitude of the radio frequency signal is within the safe range and meets the safety interlock design requirements of medical regulations, preventing system overload or damage or accidental opening of the radio frequency signal. The radio frequency cavity adopts a three-quarter wavelength cavity design, which can efficiently convert energy in the radio frequency signal range of 85MHz to 133.5MHz to provide a stable electric field for ion acceleration. Combined with the radio frequency signal control device, closed loop control of the radio frequency signal is realized, improving the stability and control accuracy of the system and ensuring the stability and reliability of the ion acceleration process. The automatic beam tuning algorithm can automatically adjust the operating parameters of the accelerator according to the real-time performance parameters of the beam to optimize the output of the beam, which helps to improve the beam intensity because more optimized operating parameters can more effectively accelerate the ion beam; the automatic beam tuning algorithm can monitor the quality parameters of the beam (such as beam spot size, beam divergence angle, etc.) in real time and automatically adjust the operating parameters of the accelerator according to these parameters, which helps to reduce the loss and scattering of the beam and improve the quality of the beam. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1Figure 1 is a schematic diagram of a radio frequency signal control device according to an embodiment of the present application; Figure 2 Figure 2 is a schematic diagram of a radio frequency system according to an embodiment of the present application; Figure 3 Figure 3 is a schematic diagram of a radio frequency power amplification device according to an embodiment of the present application; Figure 4 Figure 4 is a schematic diagram of a radio frequency signal control method according to an embodiment of the present application; Figure 5 Figure 5 is a schematic diagram of an ion source automatic beam tuning method according to an embodiment of the present application; Figure 6 Figure 6 is a schematic diagram of a flow of an ion source automatic beam tuning method according to an embodiment of the present application. DETAILED DESCRIPTION

[0026] Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments, however, can be implemented in many different forms and should not be construed as limited to the implementations set forth in this disclosure; rather, these implementations are provided so that this disclosure will be thorough and complete, and fully convey the inventive aspects of example embodiments to those skilled in the art. Like reference numerals refer to like elements throughout the figures, and descriptions of the same elements will be omitted from descriptions of subsequent figures.

[0027] The words expressing position and direction described in the present application are described by taking the drawings as an example, but changes can also be made as needed, and the changes made are included in the protection scope of the present application.

[0028] Referring to the drawings Figure 1 The embodiment of the present application provides a radio frequency signal control device for realizing closed-loop control of a radio frequency signal of a synchrotron, characterized in that the device comprises: a master control module for execution of radio frequency signal control logic, including receiving a sample signal, signal processing and feedback adjustment; a sampling module for real-time acquisition of a signal of a radio frequency cavity and incident power and reflected power on a directional coupler and feedback to the master control module, the signal of the radio frequency cavity including power of a D-box; a phase detection module for real-time detection of phase error of the incident power and the power of the D-box, and generation of an oscillation driving signal when phase matching; an amplification module for amplifying the oscillation driving signal; a base signal generation module for generating a radio frequency base signal according to the received oscillation driving signal to ensure that the frequency and phase of the radio frequency signal accurately match the requirements of the synchrotron.

[0029] In some embodiments, the master control module comprises an FPGA and a central processor.

[0030] The working principle and effects of the above technical solution are as follows: the sampling module is used to collect signals of the radio frequency cavity in real time, including the power of the D-box, the incident power and the reflected power on the directional coupler, the sampling signals are fed back to the main control module for subsequent signal processing and feedback adjustment, after the main control module receives the sampling signals, the radio frequency signal control logic is executed, the FPGA and the central processing unit jointly process the signals and analyze the current state of the radio frequency system, according to the analysis result, the main control module generates corresponding feedback adjustment instructions to adjust the frequency and phase of the radio frequency system.

[0031] The phase detection module detects the phase error of the incident power and the D-box power in real time, when the phase is matched, that is, the phase error of the incident power and the D-box power is within the allowable range, the phase detection module (usually a phase detector) generates an oscillation driving signal, the amplification module (usually an operational amplifier) receives the driving signal and amplifies it to a sufficient power level, the amplified driving signal is used to generate a radio frequency base signal subsequently, the base signal generation module (usually including a voltage-controlled oscillator) generates a radio frequency base signal according to the received amplified driving signal, the radio frequency base signal is used to confirm that the current state is stable and can continue to accelerate the process to ensure that the radio frequency signal matches the requirements of the synchrotron.

[0032] Through the cooperative work of the sampling module, the main control module, the phase detection module, the amplification module and the base signal generation module, a closed-loop control system is formed, which can monitor the state of the radio frequency system in real time and adjust it as needed to ensure the stability and accuracy of the radio frequency signal.

[0033] The FPGA is responsible for implementing complex control logic and algorithms, the FPGA can process sampling signals at high speed and generate feedback adjustment instructions in real time. The central processing unit is responsible for the overall management and coordination of the system, the central processing unit processes the feedback adjustment instructions from the FPGA and communicates with other modules to ensure the stable operation of the system.

[0034] In summary, the radio frequency signal control device provided by the embodiment of the application realizes closed-loop control of the radio frequency signal of the synchrotron through the cooperative work of the sampling module, the main control module, the phase detection module, the amplification module and the base signal generation module; the device can monitor the state of the radio frequency system in real time and adjust it as needed to ensure the stability and accuracy of the radio frequency signal.

[0035] In some embodiments, the driving signal of the phase detection module is directly amplified through the signal amplification module, and then drives the base signal generation module to generate a radio frequency base signal.

[0036] In some embodiments, the device further comprises an analog-to-digital conversion module and a digital-to-analog conversion module; the analog-to-digital conversion module is configured to convert the oscillation driving signal into a digital signal; and the digital-to-analog conversion module is configured to convert the digital signal into an analog signal. The driving signal of the phase detection module is converted into a digital signal by the analog-to-digital conversion module, then enters the main control module, is processed by the main control module, and then is converted into an analog signal by the digital-to-analog conversion module and amplified, and finally drives the base signal generation module to generate the radio frequency base signal.

[0037] The working principle and effects of the above technical solutions are as follows: The driving signal generated by the phase detector can drive the base signal generation module to generate the radio frequency base signal through a pure analog link, that is, the driving signal is directly amplified by the signal amplification module to enhance the power and stability of the signal. The amplified driving signal drives the base signal generation module to generate a radio frequency base signal with a specific frequency and amplitude. The radio frequency base signal is output to subsequent circuits or devices. The driving signal is directly amplified by the amplification module before driving the base signal generation module to obtain the radio frequency base signal. Since the driving signal is directly amplified, the time delay of digital signal processing is saved, making the response speed of the entire system faster and enabling the radio frequency base signal to be adjusted more quickly according to the phase error.

[0038] The driving signal generated by the phase detector can also drive the generation of the radio frequency base signal in a digital manner. That is, the driving signal generated by the phase detector is converted into a digital signal by the analog-to-digital conversion module. This helps to realize digital processing of the signal and improve the accuracy and stability of the signal. The digital signal enters the main control module for further processing and analysis. The main control module filters, adjusts, or optimizes the digital signal according to a pre-set algorithm or logic to meet specific application requirements. After processing by the main control module, the processed signal is converted back to an analog form so that subsequent circuits or devices can recognize and process it. The digital signal is converted into an analog signal by the digital-to-analog conversion module. The converted analog signal is amplified by the signal amplification module. The amplified analog signal drives the base signal generation module to generate a radio frequency base signal with a specific frequency and amplitude. The radio frequency base signal is output to subsequent circuits or devices. The driving signal is converted into a digital signal by the analog-to-digital conversion module, then enters the main control module, is processed by the main control chip, and then is converted into an analog signal by the digital-to-analog conversion module and amplified, and finally drives the base signal generation module to generate the radio frequency base signal. The high-precision processing capability of the main control module can be used to finely adjust the signal, thereby improving the accuracy and stability of the radio frequency base signal. Digital signals have the characteristics of easy storage, transmission, and processing, and can be more flexible in adapting to different application scenarios and requirements.

[0039] In some embodiments, the apparatus further includes a calibration module, which is used to calibrate the frequency points of the radio frequency scan cycle using a radio frequency power signal; The radio frequency power signal includes turning on the radio frequency, turning off the radio frequency, and turning on the ion source; the calibration module controls the on-time interval of the radio frequency power and the on-time of the ion source in each scan cycle.

[0040] The working principle and effect of the above technical solution are as follows: The radio frequency (RF) power signals mainly include three types: RF On, RF Off, and Ion On. These signals are generated by the main control chip FPGA in the RF signal control device according to preset logic and algorithms, and transmitted to the calibration module through corresponding circuits. The calibration module receives the RF power signals from the RF signal control system. Based on the signal type (RF On, RF Off, or Ion On), the calibration module determines the corresponding frequency point within the RF scan cycle. Within each RF scan cycle, the calibration module precisely controls the on-time interval of the RF power and the on-time of the ion source according to preset logic and algorithms, ensuring that the on-time of the RF power and the ion source matches the system's operating requirements and beam characteristics, thereby achieving optimized control. The sampling module in the RF signal control system collects signals from the RF cavity (such as D-cell power, incident power, and reflected power) and the output signal of the calibration module in real time. The sampled signals are fed back to the main control chip FPGA for real-time monitoring of the system's operating status and beam characteristics. Based on the feedback signal, the main control chip can adjust the radio frequency power and the ion source turn-on time in real time to further optimize the beam characteristics and system stability. Through the calibration module's precise control of the radio frequency power and ion source turn-on time in each scan cycle, the system can flexibly adjust the beam characteristics in each cycle, which helps to achieve stable acceleration and precise control of the proton bundle, thereby improving the accuracy and effect of proton radiotherapy in medical accelerators.

[0041] In some embodiments, the apparatus further includes an amplitude modulation module (AM table modulation) for adjusting the gain of the radio frequency base signal; the amplitude modulation module includes a step attenuator and a digitally adjustable gainer, wherein the radio frequency base signal is attenuated by the step attenuator and the attenuated signal is amplified again by the digitally adjustable gainer.

[0042] In some embodiments, the amplitude modulation module further includes a time slice division unit for dividing the power amplification time interval into multiple time slices and controlling the applied gain signal within each time slice.

[0043] In some embodiments, the apparatus further includes a remote interaction module for controlling the amplitude gain of a digitally adjustable gain unit.

[0044] The working principle and effect of the above technical solution are as follows: Based on the generation of the RF base signal, the next step is to modulate the amplitude of the signal to a range acceptable to the subsequent amplifier. In this invention, the signal gain can be adjusted with maximum range and high precision by combining digital and analog methods. First, the signal of the voltage-controlled oscillator (RF base signal) is attenuated using a step attenuator, which can dynamically adjust the amplitude of the base signal. After passing through the step attenuator, a digitally adjustable gain converter is used to amplify the signal again. The purpose of adding this module is to enable the control system to develop a user interface for remote control of the amplitude gain. The time-slice division unit divides the power amplification time interval into multiple time slices. Within each time slice, the gain signal loaded onto that time slice is controlled. The control range depends on the linear gain range of the gain converter, and the control precision depends on the number of digital bits of the high-speed digital-to-analog converter. Through the coordinated work of the step attenuator and the digitally adjustable gain converter, the loaded gain signal is precisely controlled. The RF signal after amplitude modulation is output for subsequent processing or transmission.

[0045] In some embodiments, the apparatus further includes a fixed attenuator and / or a hardware safety interlock module, the fixed attenuator being used to limit the maximum output amplitude of the radio frequency signal; The hardware safety interlock module determines whether the modulated radio frequency signal meets the preset conditions. If yes, the modulated radio frequency signal is sent to the radio frequency amplifier; if no, the radio frequency signal is safely cut off.

[0046] The working principle and effect of the above technical solution are as follows: A fixed attenuator is an electronic device used to reduce signal strength. It effectively controls signal power by introducing a specific attenuation amount in the signal path. In radio frequency (RF) systems, fixed attenuators are used to limit the maximum output amplitude of RF signals to prevent excessively strong signals from damaging or interfering with the system. Specifically, a fixed attenuator uses fixed resistive elements or attenuation networks internally. When an RF signal passes through, these elements disperse the signal energy into forms such as heat energy for attenuation, thereby reducing the signal power. By limiting the maximum output amplitude of the RF signal, a fixed attenuator can protect other components in the system (such as RF amplifiers) from damage caused by strong signals.

[0047] The hardware safety interlock module is a safety protection mechanism that complies with the safety interlock design requirements of medical regulations; the module includes a signal detection unit, a judgment logic unit, and an execution unit.

[0048] The signal detection unit is used to detect the modulated radio frequency signal and extract its key parameters (such as frequency and power).

[0049] The judgment logic unit is used to judge the detected signal parameters based on preset conditions (such as signal frequency range, power threshold, etc.).

[0050] When the judgment result is "the preset conditions are met", the execution unit sends a control signal to the radio frequency amplifier, allowing it to amplify the radio frequency signal; when the judgment result is "the preset conditions are not met", it prevents the radio frequency signal from entering the amplifier or triggers safety measures such as alarms.

[0051] By using the hardware safety interlock module, it can be ensured that only radio frequency signals that meet the preset conditions can enter the radio frequency amplifier for amplification, preventing unqualified signals from damaging the system and protecting radio frequency system components from high-power damage.

[0052] See attached document Figure 2 This invention provides a radio frequency (RF) system for controlling ion acceleration in a synchrotron accelerator. The system includes: The radio frequency power amplifier is used to amplify the input low-amplitude radio frequency signal by a fixed gain before outputting it to the radio frequency cavity; ensuring that the output signal has sufficient power to meet acceleration requirements; the radio frequency cavity is used for radio frequency signal transmission and proton beam energy conversion; The radio frequency signal control device described in any embodiment of the present invention is used to acquire a sampling signal, real-time feedback power value and phase error, and generate a drive signal based on the power value and phase error to control the operation of the radio frequency power amplifier and the radio frequency cavity, thereby realizing closed-loop control of the radio frequency signal.

[0053] In some embodiments, the radio frequency cavity adopts a three-quarter wavelength cavity design, the radio frequency signal range is 85MHz to 133.5MHz, the power can withstand 20KW, and under a specific magnetic field, it can pull out a relatively static proton bundle and accelerate it to 230MeV for use in medical accelerator proton radiotherapy.

[0054] See attached document Figure 3 Radio frequency power amplifiers are high-power devices that amplify low-amplitude radio frequency signals by a fixed gain before outputting them into a cavity. They also have good dynamic response and continuous stable output capability.

[0055] The working principle of the above technical solution is as follows: Radio frequency (RF) power amplifiers are high-power devices with excellent dynamic response and stable output capabilities. They amplify low-amplitude RF signals to a fixed gain before outputting them into the RF cavity. The amplified RF signal needs to have sufficient power to meet the energy requirements for proton beam acceleration.

[0056] As the transmission medium for radio frequency signals and the site of proton bundle energy conversion, the radio frequency cavity plays a crucial role in ion acceleration. The radio frequency cavity in this embodiment employs a three-quarter wavelength cavity design, capable of covering the center frequency range and adapting to most wavelength frequencies; the range of radio frequency signal parameters is set from 85MHz to 133.5MHz, and it can withstand power up to 20KW. Under specific magnetic field conditions, this radio frequency cavity can pull out relatively static proton bundles and accelerate them to an energy level of 230MeV, helping to optimize the transmission efficiency of radio frequency signals and the energy conversion efficiency of proton bundles; it is suitable for proton radiotherapy applications in medical accelerators.

[0057] As the control core of the radio frequency system, the radio frequency signal control device is responsible for acquiring the sampled signal, providing real-time feedback of power values ​​and phase errors, and generating drive signals based on this information to control the operation of the radio frequency power amplifier and the radio frequency cavity.

[0058] The specific workflow is as follows: The sampling module acquires signals from the RF cavity (such as D-cell power) and the incident and reflected power from the directional coupler in real time, and feeds these sampled signals back to the main control module. The main control module processes the sampled signals and analyzes the current state of the RF system. The phase detection module detects the phase error between the incident power and the D-cell power in real time and generates an oscillation drive signal when phase matching occurs; the amplification module receives and amplifies the drive signal, and then sends it to the substrate signal generation module. The substrate signal generation module generates an RF substrate signal based on the amplified drive signal to adjust the frequency and phase of the RF system to ensure they match the motion state of the proton bundle.

[0059] The closed-loop control radio frequency signal control device forms a closed-loop control system through steps such as real-time sampling, signal processing, phase detection, signal amplification, and substrate signal generation. It can continuously adjust the frequency and phase of the radio frequency signal to cope with various changes that may occur during proton acceleration, thereby achieving stable ion acceleration control.

[0060] In a synchrotron accelerator, the radio frequency system achieves precise control of ion acceleration through the aforementioned working principle; the specific process is as follows: A proton bundle is drawn into the radio frequency cavity under specific magnetic field conditions; The radio frequency power amplifier amplifies the low-amplitude radio frequency signal to a sufficient power before outputting it to the radio frequency cavity; The radio frequency signal in the radio frequency cavity interacts with the proton bundle, transferring energy to the proton bundle and accelerating it; The radio frequency (RF) signal control device monitors the signal and power status in the RF cavity in real time, as well as the phase error between the incident power and the D-cell power. Based on the monitoring results, the RF signal control device generates corresponding drive signals to adjust the operating parameters of the RF power amplifier and the RF cavity, ensuring that the frequency and phase of the RF signal match the motion state of the proton bundle. By continuously adjusting and optimizing the frequency and phase of the RF signal, the RF system achieves stable acceleration control of the proton bundle, ultimately accelerating it to the required energy level (e.g., 230 MeV).

[0061] This invention provides a particle radiotherapy system, comprising: An ion source, used to generate an ion beam; The radio frequency system described in this embodiment of the invention is used to provide radio frequency signals to generate an accelerating electric field for accelerating an ion beam to a desired energy level.

[0062] Radio frequency (RF) systems generate high-frequency alternating electromagnetic fields, creating an accelerating electric field inside a particle accelerator. When charged particles (such as ions) pass through this electric field, they are subjected to electric force, thus gaining energy and accelerating. By adjusting parameters such as the frequency, amplitude, and phase of the RF signal, the strength and distribution of the accelerating electric field can be precisely controlled, thereby achieving precise regulation of the charged particle acceleration process.

[0063] See attached document Figure 4 This invention provides a radio frequency (RF) signal control method for achieving closed-loop control of the RF signal in a synchrotron accelerator. The method is implemented using any of the RF signal control devices described in this invention, and includes: The signals of the radio frequency cavity and the incident and reflected power on the directional coupler are acquired in real time. The signals of the radio frequency cavity include the D-cell power. The phase error between the incident power and the D-cell power is detected in real time, and an oscillation drive signal is generated when the phase is matched. The base signal generation module is driven by the driving signal to obtain the radio frequency base signal.

[0064] The working principle of the above technical solution is as follows: the sampling module collects the signals of the radio frequency cavity in real time, including the power of the D-cell, as well as the incident power and reflected power on the directional coupler. The sampled signals are fed back to the main control module for subsequent signal processing and feedback adjustment. After receiving the sampled signals, the main control module executes the radio frequency signal control logic. The FPGA and the central processing unit jointly process these signals and analyze the current state of the radio frequency system. Based on the analysis results, the main control module generates corresponding feedback adjustment commands to adjust the frequency and phase of the radio frequency system.

[0065] The phase detection module monitors the phase error between the incident power and the D-cell power in real time. When the phases match, i.e., the phase error between the incident power and the D-cell power is within the allowable range, the phase detection module generates an oscillation drive signal. The amplification module (usually an operational amplifier) ​​receives the drive signal and amplifies it to a sufficient power level. The amplified drive signal is used to generate the RF base signal. The base signal generation module (including a voltage-controlled oscillator) generates the RF base signal based on the received amplified drive signal. The RF base signal is used to confirm that the current state is stable and that the acceleration process can continue, ensuring that the RF signal matches the requirements of the synchrotron accelerator.

[0066] Through the coordinated operation of the sampling module, main control module, phase detection module, amplification module, and base signal generation module, a closed-loop control system is formed to monitor the status of the radio frequency system in real time and make adjustments as needed to ensure the stability and accuracy of the radio frequency signal.

[0067] In some embodiments, the radio frequency signal control method includes: if there is a phase mismatch, i.e., the phase error between the incident power and the D-cell power exceeds the allowable range, then the frequency and phase of the radio frequency base signal are automatically adjusted by the main control module according to the magnitude and direction of the error; if the phase mismatch still occurs after a preset time or number of adjustments, then an early warning is triggered. The system automatically adjusts the frequency and phase of the RF base signal based on the magnitude and direction of the error via the main control module. This includes adjusting the phase error according to the preset adjustment amount first if the phase error exceeds the preset adjustment amount, and then detecting the limit error again after the system stabilizes. The time interval between two consecutive adjustments must meet the following conditions: T interval ≥(1±α)*(Tr+Ts)+Tb Tb=max(Tr,Ts) / m Among them, T interval The time interval between two consecutive adjustments is given by α, where 0 < α < 0.5, Tr is the system response time, Ts is the system settling time, Tb is the time safety margin, and m is a constant. <m<5。

[0068] The working principle of the above technical solution is as follows: First, the phase error between the incident power and the D-cell power is detected; If the phase error exceeds the allowable range, the adjustment process will begin.

[0069] If the phase error exceeds the preset adjustment amount, the frequency and phase of the RF base signal are first adjusted according to the preset adjustment amount. The preset adjustment amount is set in advance according to the system characteristics and requirements, aiming to ensure that the adjustment process is neither too aggressive nor too conservative.

[0070] After the adjustments are completed, a period of time will be waited to ensure that the system can stabilize in the new state.

[0071] Once stabilized, the phase error will be monitored again to assess the effectiveness of the adjustment.

[0072] If the phase error has been reduced to within the allowable range, the adjustment process ends.

[0073] If the phase error still exceeds the allowable range, proceed to the next adjustment process.

[0074] A certain time interval is required between two consecutive adjustments.

[0075] If the phases still do not match after a preset time or number of adjustments, an alert will be triggered.

[0076] The above technical solution achieves the following effects: By monitoring the phase error between the incident power and the D-cell power in real time, and automatically adjusting the frequency and phase of the RF substrate signal when the error exceeds the allowable range, it can quickly respond to phase mismatch issues, thereby maintaining stable system operation. When the phase error exceeds the preset adjustment amount, it is first adjusted according to the preset adjustment amount, which avoids system instability caused by overly aggressive adjustments and ensures the effectiveness of the adjustment. Simultaneously, after the system stabilizes, the limit error is monitored again, further improving the accuracy of the adjustment. By controlling the time interval between two adjacent adjustments, potential damage to the system hardware caused by frequent adjustments is avoided. The calculation of the time interval considers the system response time and settling time, and introduces a time safety margin, ensuring that the system has sufficient time to adapt and adjust, thereby extending the lifespan of the hardware. Through reasonable adjustment strategies and time interval control, the system can achieve phase matching in a relatively short time, thereby improving overall work efficiency. If the phase mismatch persists after a preset time or number of adjustments, the system triggers an early warning mechanism, which not only promptly alerts operators to system anomalies but also provides a valuable time window for subsequent fault diagnosis and repair, thereby enhancing system reliability.

[0077] In some embodiments, driving the substrate signal generation module with the driving signal to obtain the radio frequency substrate signal includes: The driving signal is directly amplified and then used to drive the substrate signal generation module to obtain the radio frequency (RF) substrate signal. Alternatively, the driving signal can be directly amplified by an amplification module to drive the substrate signal generation module and obtain the RF substrate signal. In some embodiments, driving the substrate signal generation module with the driving signal to obtain the radio frequency substrate signal includes: The driving signal is converted into a digital signal by the analog-to-digital converter module and then enters the main control module. After being processed by the main control chip, it undergoes digital-to-analog conversion and amplification, and finally drives the base signal generation module to generate the radio frequency base signal. That is, the driving signal of the phase detection module is converted into a digital signal by the analog-to-digital converter module and then enters the main control module. After being processed by the main control module, it undergoes digital-to-analog conversion and amplification, and finally drives the base signal generation module to generate the radio frequency base signal.

[0078] In some embodiments, the radio frequency signal control method further includes: The frequency points of the radio frequency scanning cycle are calibrated using radio frequency power signals; the radio frequency power signals include turning on radio frequency, turning off radio frequency, and turning on the ion source. The frequency point of the radio frequency scan cycle is determined by calibrating the radio frequency power signal; including: Set the scan range and scan step size to scan the frequency of the radio frequency signal; Real-time monitoring of incident power on the directional coupler; recording the incident power value at each frequency point; The peak or stable region of incident power is obtained by measuring the incident power at each frequency point. The calibration condition is triggered when the incident power reaches a preset threshold or stabilizes within a preset range. This includes setting the scan range and scan step size to scan the frequency of the radio frequency signal; including: The initial scan range is obtained by using historical data; The system monitors the ion source system status information in real time, including the accelerator load and temperature; and dynamically adjusts the scanning range based on the system status information. Set the initial scan step size; set a relatively large initial step size to quickly traverse the scan range; Based on the scanned frequency data, the step size of subsequent scans is dynamically adjusted; if multiple valid matching points are found in a certain frequency range, the step size is reduced to increase scanning accuracy; the iterative optimization method gradually approaches the optimal frequency point through multiple scans and step size adjustments.

[0079] The working principle and effect of the above technical solution are as follows: the frequency point of the radio frequency scanning cycle is accurately calibrated by radio frequency power signal, especially in scenarios involving complex radio frequency power signals such as radio frequency on, radio frequency off and ion source on.

[0080] First, the system determines an initial scan range based on historical data, which typically covers the region that may contain the optimal frequency point. The system monitors the status information of the ion source system in real time, including the accelerator load and temperature, and dynamically adjusts the scan range based on this status information to ensure that the scan process can cover the region most likely to contain the optimal frequency point.

[0081] After determining the scanning range, a relatively large initial step size is set to quickly traverse the entire scanning range. The purpose of this step is to quickly find the frequency range that may contain effective matching points. As the scan proceeds, the incident power value corresponding to each frequency point is recorded, and the peak or stable region of the incident power is determined by analyzing these data.

[0082] When multiple valid matching points are found within a certain frequency range, an iterative optimization method is used to gradually approach the optimal frequency point. Specifically, the system reduces the step size to increase scanning accuracy and rescans the frequency range at each smaller step size. Through multiple scans and adjustments to the step size, the search range can be gradually narrowed, and a more accurate optimal frequency point can be found.

[0083] Throughout the process, the incident power on the directional coupler is monitored in real time to ensure the accuracy and integrity of the data. Calibration conditions are triggered when the incident power reaches a preset threshold or stabilizes within a preset range. In summary, by dynamically adjusting the scanning range and step size, monitoring and analyzing incident power data in real time, and iterative optimization, the precise calibration of the frequency points of the RF scanning cycle was achieved.

[0084] In some embodiments, the radio frequency signal control method further includes: The gain of the RF base signal is adjusted by an amplitude modulation module, which includes a step attenuator and a digitally adjustable gainer. The RF base signal is attenuated by the step attenuator, and the attenuated signal is amplified again by the digitally adjustable gainer. The power amplification time interval is divided into multiple time slices, and the applied gain signal is controlled within each time slice; The amplitude gain of the digitally adjustable gain controller is controlled via a remote interactive module.

[0085] In some embodiments, dividing the power amplification time interval into multiple time slices and controlling the applied gain signal within each time slice includes: The power amplification time interval is divided into multiple time slices based on the clock frequency, with the number of slices being 2 to the power of n, where n is a positive integer. A preset gain strategy or algorithm determines the gain value to be applied in each time slice. The gain value can be implemented using a digitally adjustable gain converter (such as a VGA, variable gain amplifier). The preset gain strategy or algorithm, such as an automatic gain control (AGC) algorithm, adjusts the gain value in real time by monitoring the peak and average power characteristics of the input signal, or finds the corresponding gain value on the gain curve based on the characteristics of the real-time RF signal (such as intensity and frequency).

[0086] The working principle and effect of the above technical solution are as follows: The radio frequency substrate signal first passes through a step attenuator to precisely attenuate the signal as needed. The attenuated signal is then amplified by a digitally adjustable gain converter (such as a VGA). The VGA can adjust its gain value according to the control signal, thereby achieving precise control of the radio frequency signal amplitude.

[0087] The power amplification time interval is divided into multiple time slices on an average basis according to the clock frequency, with the number of divisions being 2 to the power of n (n is a positive integer); this helps to simplify time management and signal processing, while ensuring that the signal characteristics within each time slice are relatively stable.

[0088] Within each time slice, the gain value to be applied is determined according to a preset gain strategy or algorithm (such as an automatic gain control algorithm). The automatic gain control algorithm adjusts the gain value in real time by monitoring the peak value, average power and other characteristics of the input signal to maintain the stability of the output signal. Alternatively, the corresponding gain value can be found on a preset gain curve based on the characteristics of the real-time RF signal (such as intensity and frequency).

[0089] The remote interaction module allows users to easily control the amplitude gain of the digitally adjustable gain unit, providing additional flexibility and allowing users to adjust the system gain settings according to actual needs.

[0090] By employing precise amplitude modulation and time-slot division, the system can more accurately control the gain of the radio frequency signal, thereby optimizing signal quality. This helps reduce signal distortion and noise interference, improving system performance.

[0091] Automatic gain control algorithms can monitor the characteristics of the input signal in real time and adjust the gain value as needed, which helps to maintain the stability of the output signal and reduce system instability caused by signal fluctuations.

[0092] In some embodiments, dividing the power amplification time interval into multiple time slices and controlling the applied gain signal within each time slice includes: Real-time monitoring of radio frequency signals, including signal strength, frequency, and phase characteristics; Perform data analysis on the monitored signals to identify trends in signal changes; Based on the changing trend of the radio frequency signal, time slices are dynamically divided; in areas where the signal changes rapidly, shorter time slices are used to capture the details of the signal change; in areas where the signal changes slowly, longer time slices are used to reduce the amount of computation. Based on the real-time monitored RF signal characteristics and the preset gain strategy, calculate the gain value that should be applied within the time slice; The calculated gain value is loaded onto a digitally adjustable gain controller to achieve gain control of the radio frequency signal.

[0093] The working principle and effects of the above technical solution are as follows: Real-time monitoring of the intensity, frequency, and phase characteristics of radio frequency signals.

[0094] The system performs data analysis on the monitored signals to identify their changing trends, including amplitude fluctuations, frequency drift, and phase stability. Based on these trends, time slices are dynamically divided. In regions of rapid signal change, shorter time slices are used to capture the details of the changes; conversely, in regions of slow signal change, longer time slices are used to reduce computation and improve processing efficiency. Specifically, these include: Set an initial time slice length.

[0095] Set a threshold ΔV_threshold for the rate of signal change to determine whether the signal is changing rapidly; Set a scale_factor for adjusting the time slice length; At the end of each time slice, monitor the current value Vc of the radio frequency signal and the signal value Vp of the previous time slice; Calculate the change in signal ΔV = |Vc - Vps|; If ΔV > ΔVthreshold, then the signal is considered to be changing rapidly; If ΔV <= ΔVthreshold, the signal is considered to change slowly or remain stable. If the signal is changing rapidly, the time slice length is adjusted to Tnew = Tc / scale_factor, where Tc is the current time slice length and scale_factor is a positive number greater than 1, indicating that the time slice length will be shortened.

[0096] If the signal changes slowly or remains stable, the time slice length is adjusted to Tnew = Tc * scale_factor, where scale_factor is a positive number greater than 1, indicating that the time slice length is extended.

[0097] In order to avoid the time slice being too short or too long, a minimum and a maximum value for the time slice length are set.

[0098] At the start of the next time slice, the new time slice length Tnew is used for partitioning.

[0099] Repeat the above steps until the radio frequency signal control process is complete.

[0100] Within each time slice, the gain value to be applied within that time slice is calculated based on the real-time monitored RF signal characteristics and the preset gain strategy (such as an automatic gain control algorithm or gain curve). Then, the calculated gain value is applied to a digitally adjustable gain unit (such as a VGA) to achieve gain control of the RF signal.

[0101] By dynamically dividing time slices, the details of changes in radio frequency signals can be captured more accurately, thereby improving the precision of signal processing; it helps to reduce signal distortion and noise interference, and improve system performance; in regions where signal changes are slow, dividing the time slices into longer segments reduces the amount of computation, thereby optimizing resource utilization and reducing system power consumption and cost.

[0102] In some embodiments, the radio frequency signal control method further includes: The maximum output amplitude of the radio frequency signal is limited by a fixed attenuator; Determine whether the modulated RF signal meets the preset conditions. If so, send the modulated RF signal into the RF amplifier.

[0103] See attached document Figure 5 and attached Figure 6 Some embodiments of the present invention provide an automatic beam modulation method for an ion source, applicable to particle radiotherapy systems, and particularly to particle radiotherapy systems according to embodiments of the present invention. The method includes: Set initialization parameters, including the frequency parameters of the radio frequency power signal, to ensure stable operation of the accelerator; the radio frequency power signal includes turning on the radio frequency, turning off the radio frequency, and turning on the ion source; Multiple control parameters are monitored and adjusted in real time to obtain an optimal combination of control parameters. These control parameters include the frequency at which the proton beam is generated (Trigger frequency), the DC bias voltage (DC Bias, used to suppress secondary electron emission during proton beam generation), the hydrogen flow rate, the amplitude modulation value (AM Table), the operating frequency of the rotating capacitor motor (RotC), and the adaptive coil position (ACP). Under the optimal combination of control parameters, the changes in each control parameter before and after adjustment and the performance changes of the proton beam are obtained; based on the changes in each parameter before and after adjustment and the performance changes of the proton beam, pulse width charge (PWC) test is performed. The optimal adjustment parameters and adjustment amounts are obtained through test results; automatic beam adjustment is achieved using the optimal adjustment parameters and adjustment amounts.

[0104] The working principle of the above technical solution is as follows: Before automatic beam tuning begins, a series of initialization parameters need to be set. These parameters include the frequency parameters of multiple radio frequency power signals to ensure stable operation of the accelerator and avoid frequency conflicts or instability. The radio frequency power signals mainly include three states: RF on, RF off, and ion source on, corresponding to the on / off state of the radio frequency system and the on / off state of the ion source, respectively. The frequency parameters of RF On, RF Off, and Ion On are set on the host computer, which interacts with the radio frequency signal control system via network communication.

[0105] A series of control parameters are monitored and adjusted in real time, including the frequency that triggers proton beam generation, DC bias voltage (used to suppress secondary electron emission during proton beam generation), hydrogen flow rate, amplitude modulation value, operating frequency of the rotary capacitor motor, and adaptive coil position.

[0106] The adjustment of control parameters is achieved through a feedback mechanism, that is, the system dynamically adjusts these parameters based on the real-time monitored proton beam performance (such as beam intensity, beam spot size, etc.) to obtain the optimal proton beam performance, thereby obtaining the preferred combination of control parameters. Under the optimal combination of control parameters, the changes in each control parameter before and after adjustment are recorded, and the performance changes of the proton beam are monitored simultaneously. These performance changes include the stability of beam intensity and the uniformity of beam spot size. Based on the changes in each parameter before and after adjustment and the performance changes of the proton beam, pulse width and charge testing is further performed. Pulse width and charge testing is a method to evaluate the performance of a proton beam by changing the pulse width and charge of the proton beam. Through testing, the influence of each control parameter on the performance of the proton beam can be understood more accurately.

[0107] Based on the pulse width charge test results, the optimal adjustment parameters and values ​​are analyzed and determined. These optimal parameters and values ​​enable the proton beam performance to reach its best state. Finally, based on the optimal adjustment parameters and values, various control parameters are automatically adjusted to achieve automatic beam tuning of the ion source. Simultaneously, the proton beam performance is continuously monitored, and fine-tuning is performed as needed to ensure the stability and consistency of the proton beam.

[0108] In some embodiments, the real-time monitoring and adjustment of control parameters to obtain a preferred combination of control parameters includes: Adjust the DC bias voltage to suppress secondary electron emission; After completing the DC bias voltage regulation, adjust the amplitude modulation value and simultaneously adjust the hydrogen flow rate; Adjust the position of the adaptive coil and the operating frequency of the rotary capacitor motor; The optimal combination of control parameters is obtained by adjusting the results of each adjustment.

[0109] The working principle and effects of the above technical solution are as follows: First, adjusting the DC bias voltage (RF DC bias) aims to suppress secondary electron emission. During ion beam generation, high-energy ions bombarding the material surface may trigger secondary electron emission. If these secondary electrons are not controlled, they may affect the stability and purity of the ion beam. By adjusting the DC bias voltage, an electric field can be created that suppresses secondary electron emission, thereby maintaining the stability of the ion beam. The host computer interacts with the RF signal control system via network communication, sending commands to adjust the DC bias voltage. Upon receiving the commands, the RF signal control system adjusts the corresponding circuit parameters to change the DC bias voltage.

[0110] The amplitude modulation value determines the intensity variation pattern of the radio frequency signal. By adjusting the amplitude modulation value, the generation efficiency and energy distribution of the ion beam can be changed. Meanwhile, the hydrogen flow rate is the raw material for proton production, and its magnitude directly affects the intensity and stability of the ion beam. Therefore, simultaneously adjusting these two parameters can further optimize the performance of the ion beam.

[0111] After completing the DC bias voltage adjustment, the host computer continues to send instructions to adjust the amplitude modulation value. The radio frequency signal control system adjusts the parameters of the amplitude modulation circuit according to the instructions. At the same time, the hydrogen flow rate is synchronously adjusted by controlling the valve opening of the hydrogen supply system. The adjustment of these two parameters is interdependent and requires iterative adjustment to find the optimal combination.

[0112] Adaptive coil position adjustment is a fine-tuning technique that indirectly corrects the magnetic field strength distribution by changing the relative position of the superconducting magnet coil support, which helps optimize the trajectory and focusing performance of the ion beam.

[0113] After the amplitude modulation value and hydrogen flow rate are adjusted to a certain level, the host computer sends a command to adjust the position of the adaptive coil. Upon receiving the command, the radio frequency signal control system or a dedicated mechanical control system drives the corresponding actuator (such as a stepper motor) to change the position of the coil support. The operating frequency of the rotary capacitor motor affects the phase and frequency stability of the radio frequency signal. By adjusting its operating frequency, the performance and stability of the ion beam can be further optimized.

[0114] After the adaptive coil position adjustment is completed, the host computer sends a command to adjust the operating frequency of the rotary capacitor motor. Upon receiving the command, the radio frequency signal control system or motor control system adjusts the motor's operating frequency.

[0115] The adjustments to all the parameters mentioned above are interrelated and require iterative adjustments to find the optimal combination. After each parameter adjustment, the RF signal control system monitors the values ​​of relevant parameters (such as beam current intensity and beam spot size) in real time and feeds these values ​​back to the host computer. The host computer automatically calibrates, dynamically adjusts, and records the parameter changes before and after the adjustment, as well as the adjustment results of each parameter, based on the feedback results.

[0116] After multiple iterations and adjustments, the host computer will determine the optimal combination of control parameters based on the monitoring results.

[0117] In some embodiments, the real-time monitoring and adjustment of control parameters to obtain a preferred combination of control parameters includes: By using historical data, we can obtain the influence curves of each control parameter on various characteristics of the beam; Based on the influence curves of each control parameter on various characteristics of the beam, the first adjustment range of each control parameter is set. Within the first adjustment range, multiple continuous control points are set for each control parameter; By continuously controlling the points and adjusting the control parameters, the trend of beam characteristic changes can be obtained. The second adjustment range of each control parameter is obtained by observing the real-time beam characteristic change trend; Within the second adjustment range, adjust each control point of each control parameter one by one; The values ​​of each control parameter before and after adjustment are monitored in real time. By comparing the beam characteristics under different parameter combinations, the parameters that significantly affect the beam performance are identified, and further iterative adjustments are made to the parameters that significantly affect the beam performance. The optimal combination of control parameters is obtained through iterative adjustments.

[0118] The working principle of the above technical solution is as follows: using historical data, analyze and plot the influence curves of various control parameters (such as trigger frequency, DC bias voltage, hydrogen flow rate, amplitude modulation value, rotary capacitor motor frequency, adaptive coil position) on beam characteristics (such as current intensity, stability, etc.); based on the influence curves, set the first adjustment range of each control parameter, which covers the reasonable range of the parameter, so as to carry out preliminary adjustment and observation.

[0119] Within the first adjustment range of each control parameter, multiple consecutive control points are set to gradually adjust and obtain the beam characteristics; through the consecutive control points, each control parameter (such as DC bias voltage, amplitude modulation value, hydrogen flow rate, adaptive coil position, rotating capacitor motor operating frequency, etc.) is gradually adjusted; during this process, the changing trend of beam characteristics (such as beam intensity, beam spot size, beam stability, etc.) is monitored in real time. Based on the changing trend of the beam characteristics, the second adjustment range of each control parameter is determined. The second adjustment range is usually narrower than the first adjustment range and closer to the optimal value. Within the second adjustment range, the control point of each control parameter is precisely adjusted one by one to further refine the adjustment. Each time a parameter is adjusted, other parameters are kept constant to accurately obtain the impact of that parameter on the beam characteristics. Through individual adjustments, the impact of each control parameter on the beam characteristics is further refined, identifying parameters that significantly affect beam performance. During the adjustment of each control parameter, the values ​​of the relevant control parameters before and after adjustment are monitored in real time, and changes in beam characteristics are recorded. By comparing the beam characteristics under different parameter combinations, the optimal control parameter combination is obtained through iterative adjustment of the significantly influencing parameters. For the identified significantly influencing parameters, iterative adjustments are performed. Each time a parameter is adjusted, other parameters are kept constant, and changes in beam characteristics are observed and recorded. Based on the adjustment results, the optimal control parameter combination is gradually approximated. During the iterative adjustment process, various optimization strategies can be used, such as gradient descent, genetic algorithms, and particle swarm optimization, to accelerate the finding of the optimal control parameter combination. A comprehensive analysis of the results of multiple iterative adjustments determines the optimal parameter combination, achieving the best beam performance.

[0120] The effects of the above technical solution are as follows: By analyzing historical data in detail, the specific impact of each control parameter on beam characteristics can be understood, enabling more precise setting of the initial adjustment range (first adjustment range), thereby reducing adjustment time and improving the efficiency of parameter adjustment; by setting multiple continuous control points within the first adjustment range and monitoring the changing trend of beam characteristics in real time, the adjustment process becomes more detailed and systematic, helping to capture the significant impact of minute parameter changes on beam characteristics, thus enabling more accurate determination of the second adjustment range and further optimization of the adjustment strategy; by monitoring the numerical changes of relevant control parameters before and after adjustment in real time and comparing beam characteristics under different parameter combinations, parameters that have a significant impact on beam performance (significantly influencing parameters) can be quickly identified, and further iterative adjustments to the significantly influencing parameters can help to gradually approach the optimal parameter combination; this not only improves the accuracy of parameter adjustment but also ensures that the final optimal control parameter combination can maximize beam performance.

[0121] Through scientific methods and systematic adjustment procedures, the optimal combination of control parameters obtained not only performs well under current conditions, but is also more likely to maintain stable beam performance under different times, equipment, or operating conditions, thereby enhancing the repeatability of experiments and the reliability of results, and improving the adjustment efficiency and accuracy of beam performance.

[0122] This invention also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of any of the methods described in this invention or the functions of the apparatus described in this invention.

[0123] This invention also provides a computer-readable storage medium for storing a computer program. When the computer program is executed, it implements the steps of the method in this invention. The specific implementation method is consistent with the implementation method and the technical effect achieved in the above method embodiments, and some contents will not be repeated.

[0124] In this invention, a readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. The program product can take the form of any combination of one or more readable media. A readable medium can be a readable signal medium or a readable storage medium. A readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0125] Computer-readable storage media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The readable storage medium may also be any readable medium capable of sending, propagating, or transmitting a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, or any suitable combination thereof. Program code for performing operations of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar programming languages. The program code may be executed entirely on a user computing device, partially on an associated device, as a standalone software package, partially on a user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing devices can be connected to user computing devices via any type of network, including local area networks (LANs) or wide area networks (WANs), or they can be connected to external computing devices (e.g., via the Internet using an Internet service provider).

[0126] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the invention without departing from the principles and spirit of the invention, and all such changes should fall within the protection scope of the claims of the present invention.

Claims

1. An automatic beam-tuning method for an ion source, characterized in that, The method includes: Real-time monitoring and adjustment of multiple control parameters to obtain the optimal combination of control parameters; Under the optimal combination of control parameters, the changes in each control parameter before and after adjustment and the performance changes of the proton beam are obtained; based on the changes in each parameter before and after adjustment and the performance changes of the proton beam, pulse width charge test is performed. The optimal adjustment parameters and adjustment amounts are obtained through pulse width charge test results; automatic beam adjustment is achieved using the optimal adjustment parameters and adjustment amounts.

2. The automatic beam tuning method for an ion source according to claim 1, characterized in that, The method further includes: Set initialization parameters, including the frequency parameters of the radio frequency power signal, to ensure stable operation of the accelerator; the radio frequency power signal includes turning on the radio frequency, turning off the radio frequency, and turning on the ion source.

3. The automatic beam tuning method for an ion source according to claim 1, characterized in that, The control parameters include DC bias voltage, amplitude modulation value, and hydrogen flow rate, and Adaptive coil position and operating frequency of rotary capacitor motor.

4. The automatic beam tuning method for an ion source according to claim 3, characterized in that, The control parameters are adjusted sequentially, including: first adjusting the DC bias voltage to suppress secondary electron emission, then synchronously adjusting the amplitude modulation value and hydrogen flow rate, and finally adjusting the adaptive coil position and the operating frequency of the rotary capacitor motor.

5. The automatic beam tuning method for an ion source according to claim 1, characterized in that, The real-time monitoring and adjustment of control parameters; obtaining an optimal combination of control parameters, includes: By using historical data, we can obtain the influence curves of each control parameter on various characteristics of the beam; Based on the influence curves of each control parameter on various characteristics of the beam, the first adjustment range of each control parameter is set. Within the first adjustment range, multiple continuous control points are set for each control parameter; By continuously controlling the points and adjusting the control parameters, the real-time beam characteristic change trend can be obtained. The second adjustment range of each control parameter is obtained by observing the real-time beam characteristic change trend; Within the second adjustment range, adjust each control point of each control parameter one by one; Real-time monitoring of the values ​​of relevant control parameters before and after adjustment; by comparing the beam characteristics under different parameter combinations, further adjustment parameters and adjustment amounts are determined. The optimal combination of control parameters is obtained through iterative adjustments.

6. A particle radiotherapy system, characterized in that, The system performs the automatic beam tuning method for the ion source as described in any one of claims 1-5.

7. The particle radiotherapy system according to claim 6, characterized in that, The system includes: An ion source, used to generate an ion beam; The radio frequency signal control device is used to sample the power signals of the radio frequency cavity and coupler in real time and detect the phase error, and generate a radio frequency base signal that matches the requirements of the accelerator based on the phase error, thereby realizing closed-loop control of the radio frequency signal.

8. The particle radiotherapy system according to claim 7, characterized in that, The radio frequency signal control device includes: The phase detection module is used to detect the phase error between the incident power and the D-cell power on the directional coupler in real time, and to generate an oscillating drive signal when the phase is matched. An amplification module is used to amplify the oscillation drive signal; The base signal generation module is used to generate an RF base signal based on the received oscillation drive signal to ensure that the frequency and phase of the RF signal match the requirements of the synchrotron accelerator. The device further includes an amplitude modulation module for adjusting the gain of the radio frequency substrate signal; the amplitude modulation module further includes a time slice division unit for dividing the power amplification time interval into multiple time slices and controlling the applied gain signal in each time slice.

9. The particle radiotherapy system according to claim 7, characterized in that, The radio frequency signal control device further includes: The main control module is used to execute the radio frequency signal control logic, including receiving sampled signals, signal processing, and feedback adjustment; The sampling module is used to collect the signals of the radio frequency cavity and the incident and reflected power on the directional coupler in real time and feed them back to the main control module. The signals of the radio frequency cavity include the D-cell power.

10. The particle radiotherapy system according to claim 7, characterized in that, The process of dividing the power amplification time interval into multiple time slices and controlling the applied gain signal within each time slice includes: The time slices are dynamically divided according to the changing trend of the radio frequency signal; wherein, a preset threshold is set to judge the speed of signal change. When the signal change rate exceeds the preset threshold, the time slice is shortened, and when the change rate is lower than or equal to the threshold, the time slice is extended. Based on real-time signal characteristics and preset gain strategy, determine the gain value within the current time slice; The gain value is applied to a digitally adjustable gain controller to control the gain of the radio frequency signal.

11. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program performing the steps of the method according to any one of claims 1-5.

12. A computer-readable storage medium, characterized in that, The storage medium stores computer instructions, and when the computer reads the computer instructions, the computer executes the steps of the method according to any one of claims 1-5.

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