A synchrotron fast-response magnetic alloy high-frequency system

Abstract

The present invention relates to a synchrotron fast-response magnetic alloy high-frequency system, comprising: a control circuit for generating a waveform signal; a full-solid-state power source for receiving the waveform signal and performing power synthesis to generate a power signal; an impedance phase compensator for realizing impedance rise and fall and phase compensation; an impedance transformer for realizing impedance transformation to achieve impedance matching between the full-solid-state power source and the magnetic alloy-loaded resonant cavity; a magnetic alloy-loaded resonant cavity for receiving the power signal and generating a radio frequency signal to operate on the heavy ion beam; and a sampling circuit for sampling the radio frequency signal and feeding it back to the control circuit. The synchrotron fast-response magnetic alloy high-frequency system provided by the technical solution of the present invention has performance indicators of low frequency, high bandwidth, fast rising of voltage signal and response, and can output single-sine and half-sine waveforms, realizing the functions of capturing, accelerating and Barrier Bucket bunch accumulation for various heavy ion beams.

Description

Technical Field

[0001] The present invention relates to the technical field of medical heavy ion accelerators, and particularly to a fast-response magnetic alloy high-frequency system for a synchrotron. Background Art

[0002] Synchrotrons have important applications in various industries of national production. For example, in the field of health care, they can be used for radiotherapy, production of medical isotopes, irradiation disinfection, etc. Miniaturized and high-performance synchrotrons are an important development direction for commercialization, and they have broad prospects in materials science, nuclear medicine, radiation biology, diagnosis and treatment of diseases.

[0003] At present, conventional technologies can already accelerate proton beams based on synchrotrons to achieve proton radiotherapy. With the progress of technology, heavy ion therapy has also been increasingly applied. Compared with conventional proton radiotherapy, heavy ion therapy has a shorter tumor treatment course, less damage to normal tissues, a stronger tumor cell killing effect, and particularly has a unique effect on refractory tumors and tumors resistant to conventional rays.

[0004] Heavy ion accelerators have become important tools for studying frontier scientific issues of atomic nuclei. However, the inventors of the present application found in their research that to accelerate heavy ion beams, compared with proton beams, heavy ions have a larger mass. Accelerating heavy ions requires a lower operating frequency and higher energy. At the same time, to accelerate different types of heavy ion beams, a wider bandwidth range is required. For the Barrier Bucket bunch accumulation function, the high-frequency system can output a single sine or even a half-sine waveform. For the Fourier spectrum analysis of the single sine waveform, multiple harmonic components need to be synthesized, and the expansion of the half-sine waveform is richer than that of the single sine. Therefore, the high-frequency system requires a very wide operating bandwidth (>15 times the bandwidth) and the ability of rapid rise and response speed of the high voltage gradient. Existing high-frequency systems are difficult to achieve the above performance indicators. Summary of the Invention

[0005] Aiming at the above problems, the purpose of the present invention is to provide a fast-response magnetic alloy high-frequency system for a synchrotron, which has the performance indicators of low frequency, high bandwidth, rapid rise and response of voltage signals, and can output single sine and half-sine waveforms, so as to achieve the functions of capturing, accelerating and Barrier Bucket bunch accumulation for various heavy ion beams.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] The present application provides a fast-response magnetic alloy high-frequency system for a synchrotron, including:

[0008] A control circuit for generating waveform signals;

[0009] A fully solid-state power source that receives the waveform signal and performs power synthesis to generate a power signal;

[0010] An impedance phase angle compensator that realizes impedance lifting and phase compensation;

[0011] An impedance converter that realizes impedance transformation to achieve impedance matching between the fully solid-state power source and the magneto-alloy loaded resonant cavity;

[0012] A magneto-alloy loaded resonant cavity that receives the power signal and generates a radio frequency signal to operate on the heavy ion beam;

[0013] And a sampling circuit that samples the radio frequency signal and feeds it back to the control circuit;

[0014] The control circuit, the fully solid-state power source, the impedance phase angle compensator, the impedance converter, the magneto-alloy loaded resonant cavity, and the sampling circuit are sequentially connected to form a loop.

[0015] In an implementation scheme of the present application, the magneto-alloy loaded resonant cavity is a coaxial resonant cavity loaded with a low-Q magneto-alloy ring.

[0016] In an implementation scheme of the present application, the magneto-alloy ring has a magnetic core wound with an iron-based nanocrystalline soft magnetic alloy strip with a thickness of 13 - 18 μm.

[0017] In an implementation scheme of the present application, the magneto-alloy loaded resonant cavity includes: a cavity housing, and a vacuum acceleration pipe and a plurality of magneto-alloy rings coaxially arranged inside the cavity housing;

[0018] The magneto-alloy ring includes: a magneto-alloy ring outer lining, a magneto-alloy ring inner lining, a magneto-alloy strip, a heat-conducting encapsulation material, and several magneto-alloy ring support plates;

[0019] The magneto-alloy strip is wound between the magneto-alloy ring outer lining and the magneto-alloy ring inner lining; the heat-conducting encapsulation material is disposed on the surface of the magneto-alloy strip between the magneto-alloy ring outer lining and the magneto-alloy ring inner lining; both ends of the magneto-alloy ring support plate are respectively connected to the magneto-alloy ring outer lining and the magneto-alloy ring inner lining, and there is a reserved space between the magneto-alloy ring support plate and the heat-conducting encapsulation material.

[0020] In an implementation scheme of the present application, the heat-conducting encapsulation material is a surface-cured epoxy resin material with a thermal conductivity not less than 2 W / m·K and a thickness not higher than 0.1 mm;

[0021] The scale of the reserved space between the magneto-alloy ring support plate and the heat-conducting encapsulation material is 3 - 4 mm.

[0022] In an implementation solution of the present application, the cavity housing includes an upper housing and a lower housing;

[0023] The magnetic alloy ring is fixed on the lower housing through at least two magnetic alloy ring support plates;

[0024] The upper housing is a flip - up structure relative to the lower housing.

[0025] In an implementation solution of the present application, the upper housing includes an electromagnetic shielding cover plate and an inner cavity cover plate;

[0026] Square holes are provided on the electromagnetic shielding cover plate; round holes are provided on the inner cavity cover plate.

[0027] In an implementation solution of the present application, the magnetic alloy resonant cavity further includes a cooling fan provided on the lower housing.

[0028] In an implementation solution of the present application, the impedance transformer adopts broadband transmission line transformer technology, and is wound with coaxial cables with different characteristic impedances and ferrite magnetic rings with different sizes and performances to achieve broadband impedance matching with a predetermined impedance ratio, and make the standing - wave ratio of the entire frequency band of the magnetic alloy - loaded resonant cavity less than a preset value.

[0029] In an implementation solution of the present application, the impedance phase - angle compensator adopts an LC series - parallel network circuit to achieve impedance rise and fall and phase compensation, improve the impedance value and detuning phase value of the magnetic alloy - loaded resonant cavity away from the resonant frequency point, and achieve broadband impedance matching.

[0030] In an implementation solution of the present application, the all - solid - state power source adopts push - pull broadband transmission line step - up / down transformer technology to perform power synthesis on 2N power amplifier tubes, so that the synthesized power value reaches a preset power value, and at the same time makes the impedance of the all - solid - state power source reach a preset characteristic impedance; where N is a natural number.

[0031] In an implementation solution of the present application, the control circuit includes: a CPCI computer control system, a digital signal processing board, an ADC / DAC board, and a clock circuit.

[0032] In an implementation solution of the present application, the digital signal processing board adopts an FPGA + DSP hardware architecture; the FPGA realizes precise control of the amplitude and phase of the cavity voltage based on a feedback plus adaptive iterative control algorithm, and the DSP realizes the calculation of voltage and frequency control points.

[0033] In an implementation solution of the present application, the sampling circuit is a differential sampling circuit, including an attenuation circuit network, a differential signal processing circuit, a bias circuit, and a power supply circuit and a drive circuit.

[0034] Due to the above technical solutions adopted by the present invention, it has the following advantages: In the solution of the present invention application, the synchrotron fast-response magnetic alloy high-frequency system provided generates a waveform signal through a control circuit. The all-solid-state power source receives the waveform signal and amplifies the power to generate a power signal. Then, through the impedance increase and decrease and phase compensation of the impedance phase angle compensator and the impedance transformation of the impedance converter, the power signal is input into the magnetic alloy-loaded resonant cavity, and a radio frequency signal in a resonant state is generated to operate on the heavy ion beam. Then, the sampling circuit samples the radio frequency signal and feeds it back to the control circuit for the control circuit to perform precise control, so that the high-frequency system has the performance indicators of low frequency, high bandwidth, fast rise of the voltage signal and response, and can output single-sine and half-sine waveforms, realizing the functions of capturing, accelerating and Barrier Bucket bunch accumulation for various heavy ion beams. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a schematic structural diagram of a synchrotron fast-response magnetic alloy high-frequency system provided by an embodiment of the present application;

[0036] Figure 2 is a schematic external structural diagram of a magnetic alloy-loaded resonant cavity provided by an embodiment of the present application;

[0037] Figure 3 is a schematic structural diagram of the magnetic alloy-loaded resonant cavity installed on a bracket in an embodiment of the present application;

[0038] Figure 4 is a schematic internal structural diagram of the magnetic alloy-loaded resonant cavity after the cavity housing is opened in an embodiment of the present application;

[0039] Figure 5 is an axial schematic diagram of a magnetic alloy ring in an embodiment of the present application;

[0040] Figure 6 is a schematic three-dimensional structural diagram of a magnetic alloy ring and a schematic structural diagram of a magnetic alloy ring support plate in an embodiment of the present application;

[0041] Figure 7 is a schematic circuit module structural diagram of a synchrotron high-frequency system in an embodiment of the present application;

[0042] Figure 8 is a schematic structural diagram of a digital signal processing board in an embodiment of the present application;

[0043] Figure 9 is a signal flow schematic diagram of an adaptive iterative control algorithm provided by an embodiment of the present application;

[0044] Figure 10Schematic diagram of the control circuit in the embodiments of the present application for outputting single-sine and half-sine waveforms;

[0045] Figure 11 Schematic diagram of the single-cycle operating voltage and frequency curves of the high-frequency system in the embodiments of the present application;

[0046] Figure 12 Schematic diagram of the structure of the all-solid-state power source in the embodiments of the present application;

[0047] Figure 13 Schematic diagram of the circuit structures of the impedance phase compensator and impedance converter in the embodiments of the present application;

[0048] Figure 14 Schematic diagram of the effect of compensation and equalization in the embodiments of the present application;

[0049] Figure 15 Schematic diagram of the structure of the sampling circuit in the embodiments of the present application. Detailed implementation manners

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention fall within the scope of protection of the present invention.

[0051] Aiming at the technical problem that existing technologies in the medical field mainly achieve the acceleration of proton beams in synchrotrons, and thus it is difficult to meet the performance requirements for operating various heavy ion beams. The technical solution of the present application provides a fast-response magnetic alloy high-frequency system for a synchrotron (abbreviated as the high-frequency system in some embodiments of the present application), including: a control circuit for generating waveform signals; an all-solid-state power source for receiving the waveform signals and performing power synthesis to generate power signals; an impedance phase compensator for realizing impedance increase / decrease and phase compensation; an impedance converter for realizing impedance transformation to achieve impedance matching between the all-solid-state power source and the magnetic alloy-loaded resonant cavity; a magnetic alloy-loaded resonant cavity for receiving the power signals and generating radio frequency signals to operate on heavy ion beams; and a sampling circuit for sampling the radio frequency signals and feeding them back to the control circuit. The fast-response magnetic alloy high-frequency system for a synchrotron provided by the technical solution of the present application has performance indicators of low frequency, high bandwidth, fast voltage signal rise, and response, and can output single-sine and half-sine waveforms, and realizes the functions of capturing, accelerating, and Barrier Bucket bunch accumulation for various heavy ion beams.

[0052] The technical solution of the present application will be described in more detailed embodiments of the present application below with reference to the accompanying drawings.

[0053] See also Figure 1 , which is a structural schematic diagram of a synchrotron fast response magnetic alloy high frequency system provided in an embodiment of the present application.

[0054] Specifically, the synchrotron fast response magnetic alloy high frequency system in the embodiment of the present application includes:

[0055] A control circuit 101 for generating a waveform signal;

[0056] An all-solid-state power source 102 that receives a waveform signal and performs power synthesis to generate a power signal;

[0057] An impedance phase angle compensator 103 for realizing impedance rise and fall and phase compensation;

[0058] An impedance transformer 104 is provided to realize impedance transformation, so as to achieve impedance matching between the all-solid-state power source 101 and the magnetic alloy loaded resonant cavity 105;

[0059] A magnetic alloy loading resonant cavity 105 that receives a power signal and generates a radio frequency signal to operate a heavy ion beam;

[0060] and a sampling circuit 106 for sampling the radio frequency signal and feeding back the sample to the control circuit 101;

[0061] The control circuit 101, all-solid-state power source 102, impedance phase angle compensator 103, impedance converter 104, magnetic alloy loaded resonant cavity 105 and sampling circuit 106 are sequentially connected to form a loop.

[0062] The synchrotron fast response high frequency system in the embodiment of the present application is mainly used to operate various heavy ion beams. Compared with proton beams, heavy ion beams have a large mass, and accelerating heavy ion beams requires lower frequencies and higher energy. At the same time, a variety of non-through types of heavy ion beam operations are required, which requires a wider working frequency band. Therefore, the high frequency system needs to have functions such as low frequency, large bandwidth, high voltage gradient and fast response. Correspondingly, the magnetic alloy loaded resonant cavity 105 in the high frequency system of the embodiment of the present application adopts low Q value, high performance iron-based nanocrystalline soft magnetic alloy ring loading cavity technology to achieve the physical design requirements of low frequency, large bandwidth and fast response.

[0063] In one embodiment of the present application, the synchrotron fast response magnetic alloy high frequency system is suitable for particle operations of various beam types in the range of 0.1-10MHz. The cavity loading magnetic alloy ring can be wound with 13-18um iron-based nanocrystalline soft magnetic alloy strip. Studies have found that magnetic rings wound with strips of different thicknesses have different high-frequency characteristics at different frequency points. Therefore, the technical solution of the present application is designed for working voltage curves in different frequency ranges, and magnetic rings are wound with strips of different thicknesses to maximize the high-frequency cavity performance of the working frequency band.

[0064] Please also see Figures 2 to 6 In a detailed embodiment of the present application, a schematic diagram of the structure of a magnetic alloy loaded resonant cavity in a high frequency system is provided.

[0065] The magnetic alloy loaded resonant cavity in the embodiment of the present application comprises: a cavity shell, and a vacuum acceleration pipe 13 and a plurality of magnetic alloy rings 11 coaxially arranged inside the cavity shell.

[0066] The magnetic alloy ring 11 includes: a magnetic alloy ring outer lining 1101 , a magnetic alloy ring inner lining 1102 , a magnetic alloy strip, a thermally conductive packaging material 1103 and a plurality of magnetic alloy ring support plates 1104 .

[0067] Specifically, the magnetic alloy ring outer lining 1101 and the magnetic alloy ring inner lining 1102 may be made of, but not limited to, stainless steel material and have a circular ring structure.

[0068] The magnetic alloy strip is wound between the magnetic alloy ring outer lining 1101 and the magnetic alloy ring inner lining 1102. The magnetic alloy strip can be a 13-18um low Q value high performance iron-based nanocrystalline soft magnetic alloy material.

[0069] In the embodiment of the present application, a distributed capacitance is formed between the magnetic alloy ring lining 1102 and the vacuum acceleration pipe 13. This distributed capacitance not only affects the resonant frequency of the magnetic alloy loaded resonant cavity, but also causes the impedance of the entire cavity to decrease. In the design scheme of the present application, the distance between the inner diameter of the magnetic alloy ring and the vacuum acceleration pipe is reasonably designed to adjust the resonant frequency of the cavity.

[0070] In the embodiment of the present application, the magnetic alloy ring loaded in the cavity should be designed to have a low Q value, maximize the working bandwidth, and design its μ' p The Qf value has a good match between the impedance value in the main working frequency band and the output impedance of the solid-state power source, and the standing wave coefficient is small. The design impedance of the cavity loaded magnetic alloy ring is determined by the following formula:

[0071] Single-loop design impedance × number of single-channel coupled magnetic rings = 50 × impedance transformer ratio × magnetic ring cavity impedance reduction ratio.

[0072] Wherein, the designed output characteristic impedance of the solid-state power source in the above formula is specifically 50Ω.

[0073] It is difficult for existing synchrotron high-frequency systems to achieve low-frequency, high-bandwidth, and fast-rising electrical signals, and it is difficult for existing magnetic alloy-loaded resonant cavities in this working environment to solve the problem of low heat dissipation efficiency.

[0074] Regarding the problem of heat dissipation efficiency, in the design of the magnetic alloy ring in the embodiments of the present application, the thermally conductive encapsulation material 1103 is disposed on the surface of the magnetic alloy strip between the outer lining 1101 and the inner lining 1102 of the magnetic alloy ring. The technical solution of the present application develops a high-performance and high-thermal conductivity oxygen resin material as the surface encapsulation material of the magnetic ring, with a thermal conductivity greater than 2 W / m·K and the thickness of the surface encapsulation coating of the magnetic ring less than 0.1 mm. This design can effectively increase the heat dissipation inside the magnetic core and improve the air-cooling efficiency.

[0075] In the embodiments of the present application, the magnetic alloy ring is also designed with a number of magnetic alloy ring support plates 1104, for example, but not limited to 6, which can be evenly arranged every 60° on the circumferential direction. All or part of the magnetic alloy support plates 1104 have the function of fixing the magnetic alloy ring to the cavity outer shell of the cavity. In addition, both ends of the magnetic alloy ring support plate 1104 are respectively connected to the outer lining 1101 and the inner lining 1102 of the magnetic alloy ring. For example, but not limited to, a gasket 1105 can be disposed on the outer lining 1101 of the magnetic alloy ring. The magnetic alloy ring support plate 1104 can be bolted to the gasket 1105 through a screw hole 1107 at one end, and the magnetic alloy ring support plate 1104 can be bolted to the inner lining 1102 of the magnetic alloy ring through a screw hole 1106 at the other end. In the solution of the present application, there is a reserved space 1108 between the magnetic alloy ring support plate 1104 and the thermally conductive encapsulation material, and the dimension of the reserved space 1108 is 3-4 mm. The purpose of designing this reserved space is, on the one hand, to ensure the timely dissipation of the heat of this part of the magnetic core, and on the other hand, it is a reserved stress release space for the magnetic alloy material to expand and contract thermally under the influence of environmental temperature and humidity during long-term use, so as to avoid the obvious decline of the magnetic ring performance.

[0076] In the embodiments of the present application, the cavity outer shell of the magnetic alloy loaded resonator cavity includes an upper outer shell and a lower outer shell. The magnetic alloy ring 11 is fixed to the lower outer shell through two magnetic alloy ring support plates 1104 at the lower part. The vacuum acceleration pipe 13 coaxially passes through a plurality of magnetic alloy rings 11, and uses the radio frequency signal in the resonant state of the resonator cavity to control the velocity of the heavy ion beam in the acceleration slit 12. The vacuum acceleration pipe 13 can be connected to more pipes through a flange 5 to form an ion beam pipe with a set length.

[0077] The upper outer shell in the embodiments of the present application is a flip-up structure relative to the lower outer shell. For example, both the upper outer shell and the lower outer shell can be semi-circular ring structures, and one end of the upper outer shell can be connected to one end of the lower outer shell through a hinge, so that the upper outer shell can be in an open state under the action of an external force relative to the lower outer shell.

[0078] To further improve the air-cooling efficiency, more specifically, in the embodiments of the present application, the upper housing may include an electromagnetic shielding cover plate 1 and an inner cavity cover plate 2. First, the electromagnetic shielding cover plate 1 has a signal shielding function, which can better keep the resonant cavity in a resonant state during operation. In addition, through fluid simulation design, a plurality of regularly arranged square holes (with a side length of 2.5 mm) are designed on the electromagnetic shielding cover plate 1, and circular holes (with a hole diameter of 8 mm) are designed on the inner cavity cover plate 2 of the inner layer. Correspondingly, a plurality of cooling fans 14 are also provided on the lower housing, which can better dissipate heat through the above-mentioned holes.

[0079] In the embodiments of the present application, the lower housing is connected with a three-dimensional adjustable bracket 6, and the three-dimensional adjustable bracket is arranged on a fixed bracket 7.

[0080] The magnetic alloy-loaded resonant cavity in the high-frequency system in the above embodiments includes a cavity housing, and a vacuum acceleration pipeline and a plurality of magnetic alloy rings coaxially arranged inside the cavity housing. The magnetic alloy rings include a magnetic alloy ring outer liner, a magnetic alloy ring inner liner, magnetic alloy strips, a heat-conducting encapsulation material, and several magnetic alloy ring support plates. By arranging the heat-conducting encapsulation material on the surface of the magnetic alloy strips between the magnetic alloy ring outer liner and the magnetic alloy ring inner liner, heat can be effectively and quickly dissipated, and there is a reserved space between the magnetic alloy ring support plates and the heat-conducting encapsulation material, which can effectively cope with the magnetostrictive effect.

[0081] In Figure 7 the schematic diagram of, the circuit schematic diagram of the high-frequency system in an embodiment of the present application is shown. Among them, the control circuit mainly consists of a CPCI (Compact Peripheral Component Interconnect) computer control system, a digital signal processing board, a high-speed ADC / DAC board, and a clock system.

[0082] The hardware architecture of the digital signal processing board is as Figure 8 shown, adopting the hardware architecture of FPGA+DSP. The FPGA realizes the precise control of the amplitude and phase of the cavity voltage, and the DSP realizes the calculation of the voltage and frequency control points. Adopting Figure 9 the feedback plus adaptive iterative control algorithm shown, the problem of precise control of the voltage amplitude and phase driving pulse spikes is solved, and the single-cycle variable-energy working mode is successfully realized, improving the efficiency and beam quality of the medical heavy ion accelerator.

[0083] The control circuit of the embodiments of the present application realizes specific functions, including:

[0084] (1) It can realize the storage of 512 groups of voltage and frequency waveforms;

[0085] (2) It can receive optical event signals and perform corresponding operations;

[0086] (3) It can achieve stable control of the amplitude and phase of ultra-narrow sharp pulses;

[0087] (4) It can automatically calculate voltage and frequency data according to the calculation formula given by accelerator physics.

[0088] Among them, for the Barrier Bucket beam accumulation function proposed by experimental physics in the high-frequency system, a magnetic alloy-loaded cavity high-frequency system with wide bandwidth and fast response characteristics is designed. Single-sine and half-sine waveforms with multiple harmonic components are successfully output. After Fourier spectrum analysis, when the harmonic components of the single-sine and half-sine waveforms are at least 15 times the fundamental frequency or more, the waveforms will not be distorted; the magnetic alloy cavity of the high-frequency system outputs single-sine and half-sine waveforms, enabling the Barrier Bucket to overcome the influence of the space charge effect and beam loading effect to achieve multiple accumulations of bunches, thereby increasing the beam current intensity. The output sine waveform and half-sine waveform are respectively as shown in Figure 10 1001 and 1002 in. The schematic diagram of the single-cycle working voltage and frequency curve of the high-frequency system is Figure 11 , with the characteristics of low frequency, wide bandwidth, and fast voltage rise.

[0089] The high-frequency system in the embodiment of the present application further includes an all-solid-state power source.

[0090] The broadband solid-state power source is one of the core devices of the high-frequency system, and its main function is to provide all the power energy for the high-frequency system. The wide-band power source of the synchrotron adopts the all-solid-state type, and its main characteristics are multi-stage synthesis of small-power modules, low-voltage power supply, and strong anti-reflection ability, etc.; according to the design requirements of wide bandwidth, high voltage, and fast response of the high-frequency system, the power source adopts the broadband transmission line transformer step-up impedance synthesis technology, and successfully achieves the design goal of excellent impedance characteristics in the wide band and the entire frequency band; due to the fact that filters cannot be designed for the wide-band working mode power source, resulting in poor harmonic suppression of the power source, the solution of the present application adopts the class-A working mode of the power amplifier tube (class-A working has good waveform output and the waveform is distortion-free in the entire frequency band) and the push-pull power synthesis technology (suppresses even harmonics), effectively improving the harmonic suppression of the power source in the entire frequency band. The measured harmonic suppression of the designed power source is better than -30 dBc, effectively improving the beam quality.

[0091] Figure 12 Schematically shows the structural schematic diagram of the all-solid-state power source in the embodiment of the present application.

[0092] The all-solid-state power source adopts the push-pull broadband transmission line step-up / down transformer technology to synthesize the power of 2N power amplifier tubes, so that the synthesized power value reaches the preset power value, and at the same time makes the impedance of the all-solid-state power source reach the preset characteristic impedance; where N is a natural number. For example, in a specific example, the characteristic impedance of the all-solid-state power source is usually 50Ω. When using 7Ω power amplifier tubes for push-pull power synthesis, the number of power amplifier tubes required is 8.

[0093] In the embodiment of the present application, as Figure 13 shown, the synchrotron fast-response magnetic alloy high-frequency system further includes an impedance phase angle compensator 1301 and an impedance converter 1302.

[0094] Among them, the function of the impedance phase angle compensator 1301 is to compensate the impedance and the detuning phase angle at both ends of the equilibrium magnetic alloy cavity far from the resonance point. The characteristics of the heavy-ion medical high-frequency magnetic alloy cavity are that the lower the frequency is below the resonance frequency point and the farther away from the resonance point, the lower the impedance and the larger the detuning angle; while above the resonance point, the farther away from the resonance point, the higher the impedance and the larger the detuning angle; the design purpose of the impedance phase angle compensator 1301 is to make the impedance in the whole frequency band close to the intermediate impedance value of 50Ω, and the smaller the detuning angle at both ends of the frequency is better.

[0095] In a specific embodiment, the compensation circuit of the impedance phase angle compensator 1301 adopts an LC series network, which presents capacitive reactance at low frequencies and inductive reactance at high frequencies, which is exactly opposite to the reactance characteristics of the cavity, cancels out the reactance part at both ends of the cavity, and at the same time serves the purpose of making the detuning angles at both ends of the frequency smaller; at the same time, the "L" type network is used to transform the real part of the impedance of the cavity, so that in the whole frequency band, the impedance transformation ratio at the low end is larger and the impedance transformation ratio at the high end is smaller, effectively playing the role of impedance balance; according to the measured results, the input voltage standing wave ratio in the whole frequency band after compensation and balance is controlled within 1.3. The schematic diagram of compensation and balance is as Figure 14 shown, where the thin straight line and the dotted line are the impedance and phase angle before compensation and balance, and the thick straight line and the dotted line are the impedance and phase angle curves after compensation.

[0096] In the embodiment of the present application, after the magnetic alloy ring is loaded on the magnetic alloy cavity, the single-channel coupling impedance usually reaches several hundred ohms. In order to match with the 50 ohms of the solid-state power source and achieve power transmission, an impedance converter 1302 needs to be designed between the cavity and the power source. The impedance converter of the technical solution of the present application adopts the broadband transmission line transformer technology, which can realize broadband impedance adjustment with any turns ratio. For example, the magnetic alloy cavity of the heavy-ion and proton medical treatment device is designed according to voltage and frequency, and usually adopts a turns ratio of 1:4; due to the high single-cavity voltage of the high-intensity heavy-ion magnetic alloy cavity, the impedance converter with a turns ratio of 1:9 or 1:16 is usually used for the cavity power test; while the magnetic alloy cavity of the HIRFL-CSRe cooling storage ring requires a lower voltage, and the impedance converter with a turns ratio of 1:2.25 is used for the cavity power transmission.

[0097] In one embodiment of the present application, the mechanical structure parts of the impedance phase angle compensator 1301 and the impedance converter 1302 can be arranged on the magnetic alloy loaded resonant cavity. For example, in Figure 2 Figures 3 and 4 respectively show the schematic diagrams of the mechanical structures of the impedance phase angle compensator 1301 and the impedance converter 1302.

[0098] In the embodiment of the present application, the magnetic alloy loaded resonant cavity receives the power signal input by the all-solid-state power source and generates a radio frequency power signal to control the speed of the ion beam in the vacuum acceleration pipe. The magnetic alloy loaded resonant cavity also needs to sample and feedback the actual signal in the vacuum acceleration pipe to the control circuit for precise control by the control circuit. As mentioned above, the signal generated by the high-frequency system in the embodiment of the present application has the characteristics of low frequency, wide band, and fast voltage rise. It is difficult for the existing sampling circuits to perform precise sampling. The accuracy of the sampling signal of the cavity directly affects the final beam quality. Voltage sampling usually adopts the types of resistor and capacitor sampling. Since the high-frequency characteristics of capacitors and resistors are different at different frequencies, the wide-band voltage sampling accuracy is affected by the bandwidth and voltage magnitude, and the sampling amplitude-frequency characteristic within the entire frequency band is poor. Therefore, the present application scheme improves the sampling circuit.

[0099] Specifically, as Figure 15 shown, the sampling circuit is a differential sampling circuit, including an attenuation circuit network 1501, a differential signal processing circuit 1502, a bias circuit 1503, and a power supply circuit and a drive circuit 1504. This sampling circuit has excellent wide-band characteristics, with a sampling accuracy reaching 0.1%, and the sampling ratio can be designed from one-thousandth to one-ten-thousandth according to the usage requirements, which well solves the problem of wide-band sampling accuracy. According to the measured results, the sampling accuracy is better than 0.085% in the frequency range of 0.1 - 10 MHz.

[0100] In summary, the synchrotron fast-response magnetic alloy high-frequency system provided in the embodiment of the present application well solves the technical problems mentioned in the background art, has functions such as low frequency, wide band, high gradient, and fast response, and is an excellent place for operating various types of particle beams (multiple types of heavy ion beams and proton beams); this high-frequency system integrates a high-voltage-gradient, wide-band, and fast-response synchronous ring high-frequency system composed of an iron-based nanocrystalline soft magnetic alloy ring loaded high-frequency cavity, a wide-band solid-state power source based on transmission line transformer technology power synthesis, and a high-performance all-digital signal processing system with high-precision amplitude control, and can realize functions such as capture, acceleration, and Barrier Bucket accumulation of multiple heavy ion beams and proton beams.

[0101] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the above division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections between each other can be through some interfaces, and the indirect couplings or communication connections of devices or units can be in electrical, mechanical, or other forms.

[0102] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A high-frequency system of a synchrotron fast-response magnetic alloy, characterized in that, Comprising: A control circuit for generating a waveform signal; A fully solid-state power source that receives the waveform signal and performs power synthesis to generate a power signal; An impedance phase compensator for implementing impedance rise and fall and phase compensation; An impedance transformer for implementing impedance transformation to achieve impedance matching between the fully solid-state power source and the magneto-alloy loaded resonant cavity; A magneto-alloy loaded resonant cavity that receives the power signal and generates a radio frequency signal to operate on the heavy ion beam; And a sampling circuit for sampling the radio frequency signal and feeding it back to the control circuit; The control circuit, the fully solid-state power source, the impedance phase compensator, the impedance transformer, the magneto-alloy loaded resonant cavity, and the sampling circuit are sequentially connected to form a loop; The magneto-alloy loaded resonant cavity includes: a cavity housing, and a vacuum acceleration pipe and a plurality of magneto-alloy rings coaxially arranged inside the cavity housing; The magneto-alloy ring includes: a magneto-alloy ring outer liner, a magneto-alloy ring inner liner, a magneto-alloy strip, a heat-conducting encapsulation material, and a plurality of magneto-alloy ring support plates; The magneto-alloy strip is wound between the magneto-alloy ring outer liner and the magneto-alloy ring inner liner; the heat-conducting encapsulation material is disposed on the surface of the magneto-alloy strip between the magneto-alloy ring outer liner and the magneto-alloy ring inner liner; both ends of the magneto-alloy ring support plate are respectively connected to the magneto-alloy ring outer liner and the magneto-alloy ring inner liner, and there is a reserved space between the magneto-alloy ring support plate and the heat-conducting encapsulation material.

2. The synchrotron fast-response magnetic alloy high-frequency system according to claim 1, wherein The magneto-alloy loaded resonant cavity is a coaxial resonant cavity loaded with magneto-alloy rings with a low Q value.

3. The synchrotron fast-response magnetic alloy high-frequency system according to claim 2, wherein The magneto-alloy ring has a magnetic core wound with an iron-based nanocrystalline soft magnetic alloy strip of 13 - 18 μm.

4. The synchrotron fast-response magnetic alloy high-frequency system according to claim 1, characterized in that, The heat-conducting encapsulation material is a surface-cured epoxy resin material with a thermal conductivity not less than 2 W / m·K and a thickness not higher than 0.1 mm; The scale of the reserved space between the magneto-alloy ring support plate and the heat-conducting encapsulation material is 3 - 4 mm.

5. The synchrotron fast-response magnetic alloy high-frequency system according to claim 1, wherein The cavity housing includes an upper housing and a lower housing; The magneto-alloy ring is fixed to the lower housing by at least two magneto-alloy ring support plates; The upper housing is a flip-up structure relative to the lower housing.

6. The synchrotron fast-response magnetic alloy high-frequency system according to claim 5, characterized in that, The upper housing includes an electromagnetic shielding cover plate and an inner cavity cover plate; The electromagnetic shielding cover plate is provided with square holes; the inner cavity cover plate is provided with round holes.

7. The synchrotron fast-response magnetic alloy high-frequency system according to claim 5, characterized in that, The magneto-alloy loaded resonant cavity further includes a cooling fan disposed on the lower housing.

8. The synchrotron fast-response magnetic alloy high-frequency system according to claim 1, characterized in that The impedance transformer adopts broadband transmission line transformer technology and is wound with coaxial cables with different characteristic impedances and ferrite magnetic cores with different sizes and performances to achieve wide-band impedance matching with a predetermined impedance ratio, and make the standing wave ratio within the entire frequency band of the magneto-alloy loaded resonant cavity less than a preset value.

9. The synchrotron fast-response magnetic alloy high-frequency system according to claim 1, characterized in that, The impedance phase compensator adopts an LC series-parallel network circuit to achieve impedance rise and fall and phase compensation, improve the impedance value and the detuning phase value of the magneto-alloy loaded resonant cavity away from the resonant frequency point, and achieve wide-band impedance matching.

10. The synchrotron fast-response magnetic alloy high-frequency system according to claim 1, characterized in that, The all-solid-state power source adopts the push-pull broadband transmission line step-up / step-down transformer technology to synthesize the power of 2N power amplifier tubes, so that the synthesized power value reaches the preset power value, and at the same time makes the impedance of the all-solid-state power source reach the preset characteristic impedance; where N is a natural number.

11. The synchrotron fast-response magnetic alloy high-frequency system according to claim 1, characterized in that, The control circuit includes: a CPCI computer control system, a digital signal processing board, an ADC / DAC board, and a clock circuit.

12. The synchrotron fast-response magnetic alloy high-frequency system according to claim 11, characterized in that, The digital signal processing board adopts the hardware architecture of FPGA+DSP; the FPGA realizes the precise control of the amplitude and phase of the cavity voltage based on the feedback plus adaptive iterative control algorithm, and the DSP realizes the calculation of the voltage and frequency control points.

13. The synchrotron fast-response magnetic alloy high-frequency system according to claim 1, characterized in that, The sampling circuit is a differential sampling circuit, including an attenuation circuit network, a differential signal processing circuit, a bias circuit, and a power supply circuit and a drive circuit.

Images