A method and system for diagnosing high-frequency magnetic perturbations in a quasi-cyclic symmetric quasi-star device

Abstract

The application provides a kind of quasi-circular symmetry quasi-star device high frequency magnetic disturbance diagnostic method and system, it is related to quasi-star device technical field, including the three-dimensional size of magnetic probe body is designed in combination with physical research target and vacuum chamber space limit condition, and the magnetic probe entity suitable for experimental environment is prepared;According to the triangular magnetic configuration characteristics of CFQS quasi-star device, the spatial layout of magnetic probe array is designed, and the positioned magnetic probe array is obtained;Using the positioned magnetic probe array, a signal transmission link is constructed to form a qualified calibration system;According to the qualified calibration system, a multi-channel time domain voltage signal set is generated;The multi-channel time domain voltage signal set is combined with the frequency response correction of the transfer function database, the disturbance mode structure and propagation direction are analyzed through time-frequency spectrum analysis and array phase difference, and finally the three-dimensional magnetic disturbance evolution characteristics are output.The beneficial effects of the application are that it has three-dimensional high frequency magnetic disturbance measurement capability, can collect multi-channel high fidelity signals, and improves experimental data quality and physical analysis capability.

Description

Technical Field

[0001] This invention relates to the field of stellarator technology, and more specifically, to a diagnostic method and system for high-frequency magnetic disturbances in a quasi-toroidal stellarator. Background Technology

[0002] High-frequency magnetic perturbations (typically ranging from tens to hundreds of kilohertz) in magnetically confined fusion plasmas are closely related to Alfvén instabilities excited by high-energy particles and various microscopic turbulences excited by plasma inhomogeneities. These perturbations have a significant impact on plasma energy and particle confinement and transport. For non-axisymmetric magnetic confinement devices such as stellarators, the neoclassical transport of the plasma itself is usually stronger than that in tokamak devices, making magnetically confined particles more prone to loss. The excitation of high-frequency magnetic perturbations will accelerate the loss of confined particles in the plasma, which is something that should be avoided or mitigated as much as possible. Therefore, high spatiotemporal resolution measurement and research of high-frequency magnetic perturbations are of great significance for understanding and controlling plasma behavior. For magnetically confined fusion experimental devices, magnetic probe diagnostics is a fundamental and very important method for diagnosing plasma magnetic perturbations. The physical and engineering design of magnetic probe diagnostics usually needs to be combined with the characteristics of the magnetic confinement device itself (such as device size, installation environment in the vacuum chamber, and experimental operating conditions) and related physical research objectives. It is difficult to simply copy the magnetic probe design from other devices.

[0003] China's first quasi-axisymmetric stellarator (CFQS), as a novel three-dimensional magnetic confinement fusion device, has a more complex three-dimensional structure in its magnetic field and vacuum chamber compared to tokamak devices, which are among the mainstream magnetic confinement fusion devices. This presents greater challenges to the design of the CFQS magnetic probe: Two-dimensional magnetic probes, commonly used in tokamaks to measure high-frequency magnetic disturbances in plasma, cannot meet the measurement requirements of the three-dimensional magnetic field and disturbances in the CFQS stellarator, necessitating the design of a three-dimensional magnetic probe suitable for the CFQS stellarator; the CFQS vacuum chamber is small in size, not allowing adults to stand inside for installation operations, and the three-dimensionally distorted inner wall structure and limited vacuum chamber windows increase the difficulty of installing and positioning the magnetic probe; the CFQS experiment will undergo high-temperature (approximately 120°C) wall baking before operation, and a high vacuum (100°C) must be maintained during the experiment. -5 The addition of Pa increases the limitations on the selection of magnetic probe materials. Since the CFQS device does not have a protection limiter, a magnetic probe protection component needs to be designed to cope with the effects of high plasma particle and thermal bombardment, as well as plasma radiation.

[0004] Therefore, CFQS needs to study high-frequency magnetic disturbances in plasma ranging from 50 to 300 kHz. The design of the magnetic probe needs to balance the effective area and resonant frequency to meet the physical research objectives. Furthermore, the effective area and in-situ frequency response of the magnetic probe need to be accurately calibrated. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for diagnosing high-frequency magnetic disturbances in a quasi-toroidal stellarator, thereby improving the aforementioned problems. To achieve this objective, the technical solution adopted by this invention is as follows:

[0006] In a first aspect, this application provides a method for diagnosing high-frequency magnetic disturbances in a quasi-toroidal stellarator, including:

[0007] Based on the measurement principle and signal transmission path of Faraday's law of electromagnetic induction, the three-dimensional dimensions of the magnetic probe body were designed in combination with the physical research objectives and the spatial constraints of the vacuum chamber. The frequency response characteristics were optimized by a layered winding scheme and protective components adapted to the experimental environment were selected to prepare a magnetic probe body adapted to the experimental environment. The effective area of ​​the magnetic probe in the circumferential, radial and polar directions was calibrated by using a 100Hz AC excitation solenoid and a standard probe comparison method.

[0008] Based on the magnetic probe entity, the array spatial layout was designed according to the triangular magnetic configuration characteristics of the CFQS stellarator. After the probe was encapsulated in a stainless steel protective box, the circumferential measurement coil was arranged perpendicular to the circumferential magnetic field lines. The magnetic probe was positioned and installed near the window of the vacuum chamber using a laser tracker to obtain the positioned magnetic probe array. The array's circumferential modulus resolution and poloidal wavenumber resolution were verified.

[0009] Using a positioned magnetic probe array, a signal transmission link is constructed from a twisted pair cable inside the vacuum chamber to a 30-meter coaxial cable outside the vacuum chamber. An impedance analyzer is connected to measure the total impedance. The transfer function is calculated by combining the known electrical parameters of the magnetic probe. It is confirmed that the resonant frequency of all channels is >400kHz and changes gradually within 300kHz. A calibration qualified system and a transfer function database are output to form a calibration qualified system.

[0010] Based on the calibrated qualified system, the maximum sampling rate of 1.25MS / s, trigger time and acquisition duration parameters are dynamically set to synchronously acquire the original output voltage of all channels during plasma discharge and generate a multi-channel time-domain voltage signal set.

[0011] The multi-channel time-domain voltage signal set is combined with the transfer function database for frequency response correction to restore the real induced voltage. The magnetic field change rate is calculated using the effective area, and the magnetic field disturbance is obtained through numerical integration. At the same time, the disturbance mode structure and propagation direction are analyzed by time-frequency spectrum analysis and array phase difference analysis, and finally the three-dimensional magnetic disturbance evolution characteristics are output.

[0012] Preferably, the magnetic probe array is designed based on the triangular magnetic configuration characteristics of the CFQS stellarator, and after encapsulating the probe in a stainless steel protective box, the circumferential measurement coils are arranged perpendicular to the circumferential magnetic field lines. The magnetic probe is positioned and installed near the vacuum chamber window using a laser tracker, resulting in a positioned magnetic probe array, which includes:

[0013] Based on the triangular magnetic configuration characteristics of the CFQS stellarator, a characteristic area on the inner wall of the vacuum chamber is selected as the magnetic probe mounting position. According to the three-dimensional direction characteristics of the magnetic field lines, the magnetic probe array layout is designed, and then the spatial coordinate scheme is output.

[0014] Based on the spatial coordinate scheme, the magnetic probe is encapsulated in a stainless steel protective box and installed through a limited window in a vacuum chamber, so that the circumferential measuring coil is perpendicular to the circumferential magnetic field lines. A laser tracker is used to calibrate the spatial position and complete the deployment of the positioning array.

[0015] Based on the calibrated array spatial coordinates, the circumferential modulus resolution and poloidal wavenumber resolution are calculated, and an array performance verification report is output.

[0016] Preferably, the signal transmission link is constructed using a positioned magnetic probe array, connecting a twisted-pair cable inside the vacuum chamber to a 30-meter coaxial cable outside the vacuum chamber. The total impedance is measured using an impedance analyzer, and the transfer function is calculated based on the known electrical parameters of the magnetic probes. It is confirmed that the resonant frequency of all channels is >400kHz and changes gradually within 300kHz. A calibrated system and its effective area and transfer function database are output, forming a calibrated system, including:

[0017] Before positioning and installing the magnetic probe array, place the magnetic probe to be installed and the standard magnetic probe side by side at the center of the 100Hz AC excitation solenoid, and measure the induced electromotive force of both simultaneously using a multimeter.

[0018] Calculate the effective area of ​​the magnetic probe to be installed in the circumferential, radial, and polar directions, and output the calibrated effective area;

[0019] Based on the parameters of the calibrated effective area, a high-frequency impedance analyzer with a scanning frequency of 1kHz–1MHz is connected to the end of the signal transmission line to measure the amplitude-frequency and phase-frequency characteristics of the total impedance of the system after installation; combined with the known electrical parameters of the magnetic probe, the frequency response of the transfer function is calculated by measuring the total output impedance of the system circuit of the magnetic probe, and a transfer function database is generated.

[0020] Based on the transfer function database and impedance data, verify that the resonant frequency of all probe channels is >400kHz and the variation within 300kHz is ≤±3dB. After confirming that the high-frequency disturbance measurement requirements are met, output a calibration qualified system including its effective area and transfer function database.

[0021] Preferably, the process involves combining a multi-channel time-domain voltage signal set with a transfer function database for frequency response correction to restore the true induced voltage, calculating the magnetic field change rate using the effective area, and obtaining the magnetic field disturbance through numerical integration. Simultaneously, the disturbance mode structure and propagation direction are analyzed through time-spectrum analysis and array phase difference, ultimately outputting three-dimensional magnetic disturbance evolution characteristics, including:

[0022] Based on a multi-channel time-domain voltage signal set and transfer function database, the multi-channel time-domain voltage signal set is converted to the frequency domain by Fourier transform, divided by the transfer function to compensate for transmission distortion, and then restored to the true induced voltage by inverse Fourier transform; the magnetic field change rate is calculated using the calibrated effective area, and the three-dimensional magnetic field disturbance is obtained by numerical integration, and the magnetic field disturbance time-domain sequence is output.

[0023] Based on the spatiotemporal distribution of magnetic field disturbances, the frequency-amplitude evolution characteristics are analyzed using short-time Fourier transform. Simultaneously, by combining the array spatial coordinates, the phase difference between adjacent probe signals is calculated to determine the circumferential modulus n, the poloidal modulus m, and the propagation direction, generating three-dimensional magnetic disturbance evolution characteristics. Secondly, this application also provides a diagnostic system for high-frequency magnetic disturbances in a quasi-circular symmetric stellarator, including:

[0024] Fabrication module: Based on the measurement principle and signal transmission path of Faraday's law of electromagnetic induction, it designs the three-dimensional dimensions of the magnetic probe body in combination with the physical research objectives and the space constraints of the vacuum chamber, optimizes the frequency response characteristics through a layered winding scheme, and selects protective components adapted to the experimental environment to fabricate a magnetic probe entity adapted to the experimental environment.

[0025] Verification module: Based on the magnetic probe entity, the array spatial layout is designed according to the triangular magnetic configuration characteristics of the CFQS stellarator. The probe is encapsulated in a stainless steel protective box and positioned and installed through the vacuum chamber window. The circumferential measurement coil is arranged perpendicular to the circumferential magnetic field lines. The magnetic probe is positioned and installed near the vacuum chamber window using a laser tracker to obtain the positioned magnetic probe array. The array's circumferential modulus resolution and poloidal wavenumber resolution are verified.

[0026] Verification Module: For the magnetic probe array to be installed, the effective area of ​​the magnetic probe to be installed in the circumferential, radial, and polar directions is calibrated using a standard probe comparison method through a 100Hz AC excitation solenoid. A signal transmission link is constructed from the twisted pair inside the vacuum chamber to a 30-meter coaxial cable outside the vacuum chamber. An impedance analyzer is connected to measure the total impedance. The transfer function is calculated based on the known electrical parameters of the magnetic probe. It is confirmed that the resonant frequency of all channels is >400kHz and changes gradually within 300kHz. The system with qualified calibration and its database of effective area and transfer function are output, forming a qualified calibration system.

[0027] Construction Module: Based on the constructed signal transmission link from the twisted pair cable inside the vacuum chamber to the 30-meter coaxial cable outside the vacuum chamber and the calibrated qualified system, the maximum sampling rate of 1.25MS / s, trigger time and acquisition duration parameters are dynamically set to synchronously acquire the original output voltage of all channels during plasma discharge and generate a multi-channel time-domain voltage signal set;

[0028] The calculation module is used to perform frequency response correction by combining the multi-channel time-domain voltage signal set with a transfer function database, restore the true induced voltage, calculate the magnetic field change rate using the effective area, and obtain the magnetic field disturbance through numerical integration. Simultaneously, it analyzes the disturbance mode structure and propagation direction through time-spectrum analysis and array phase difference, ultimately outputting the three-dimensional magnetic disturbance evolution characteristics. Thirdly, this application also provides a diagnostic device for high-frequency magnetic disturbances in a quasi-toroidal symmetric stellarator, including:

[0029] Memory, used to store computer programs;

[0030] A processor is configured to implement a diagnostic method for high-frequency magnetic disturbances in the quasi-toroidal stellarator when executing the computer program.

[0031] Fourthly, this application also provides a readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described diagnostic method for high-frequency magnetic disturbances in a quasi-toroidal symmetric stellarator.

[0032] The beneficial effects of this invention are as follows:

[0033] Each magnetic probe in this invention integrates measurement coils in three directions: pole, radial, and circumferential, forming a three-dimensional resolution capability, which better measures the three-dimensional magnetic field and magnetic disturbances on the CFQS stellarator. The magnetic probe resonant frequency is greater than 400kHz, which meets the magnetic disturbance measurement research requirements of the CFQS stellarator within 300kHz. It has a high-resolution measurement capability for the propagation characteristics (direction and phase) and spatial mode structure (pole and circumferential modes) of magnetic disturbances. For example, the circumferential mode can be resolved up to n = ±18, which is a significant improvement over the circumferential mode resolution capability of the existing low-frequency magnetic probe array of the CFQS stellarator (which can measure magnetic disturbances up to <50kHz and can resolve up to n = ±6). The proposed diagnostic calibration method ensures the accuracy of diagnostic measurements.

[0034] This invention employs a fixed-length coaxial cable, differential acquisition, and a high-speed PXI acquisition card to construct a reliable signal acquisition chain, ensuring high signal fidelity under multi-channel, long-distance, and high-speed transmission conditions. Furthermore, with the addition of controllable triggering logic and flexible sampling parameter configuration, it can support precise measurements under different discharge conditions, thereby improving the quality of experimental data and physical analysis capabilities.

[0035] The magnetic probe materials used in this invention are selected to balance heat resistance, high vacuum compatibility, and non-magnetic properties (such as PEEK skeleton, polyimide wire, and 316L stainless steel protective shell). They can withstand the heat load, plasma radiation, and long-term vacuum encapsulation under the unrestricted protection of the CFQS stellarator. The size of the magnetic probes is matched with the magnetic field and vacuum chamber wall characteristics of the CFQS. Based on the three-dimensional directional characteristics of the magnetic field lines, the physical research objectives, and the convenience of installation and spatial positioning, the spatial arrangement of the magnetic probe array is completed.

[0036] This invention provides strong experimental support for the study of magnetic configuration reconstruction, plasma instability, and plasma confinement and transport in the CFQS stellarator.

[0037] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0038] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the diagnostic method for high-frequency magnetic disturbances in a quasi-toroidal stellarator as described in this embodiment of the invention.

[0040] Figure 2 This is a schematic diagram of the diagnostic system for high-frequency magnetic disturbances in the quasi-toroidal stellarator described in this embodiment of the invention.

[0041] Figure 3 This is a schematic diagram of the diagnostic device for high-frequency magnetic disturbances in the quasi-toroidal stellarator described in this embodiment of the invention.

[0042] Figure 4 This is a schematic diagram of the composition of the CFQS quasi-ring symmetric stellarator high-frequency magnetic probe array diagnostic system in the diagnostic method for high-frequency magnetic disturbances in the quasi-ring symmetric stellarator described in this embodiment of the invention.

[0043] Figure 5 This is a schematic diagram of the CFQS quasi-ring symmetric stellarator high-frequency magnetic probe model and its three-dimensional dimensions in the diagnostic method for high-frequency magnetic disturbances in the quasi-ring symmetric stellarator described in this embodiment of the invention.

[0044] Figure 6This is a schematic diagram of the equivalent circuit model of the CFQS quasi-ring symmetric stellarator high-frequency magnetic probe diagnosis in the diagnostic method for high-frequency magnetic disturbances in the quasi-ring symmetric stellarator described in the embodiments of the present invention.

[0045] Figure 7 This is a schematic diagram showing the spatial position information of the high-frequency magnetic probe array on the CFQS quasi-toroidal stellarator in the diagnostic method for high-frequency magnetic disturbances in the quasi-toroidal stellarator described in this embodiment of the invention.

[0046] Figure 8 This is a schematic diagram of the in-situ frequency response calibration results of the three-dimensional high-frequency magnetic probe on the CFQS quasi-ring symmetric stellarator in the diagnostic method for high-frequency magnetic disturbance in the quasi-ring symmetric stellarator described in the embodiments of the present invention. Figures (a) and (b) show the amplitude and phase frequency response of the total line output impedance of the high-frequency magnetic probe, respectively, and Figures (c) and (d) show the amplitude and phase frequency response of the total line transfer function of the high-frequency magnetic probe, respectively.

[0047] In the diagram: 701, Preparation module; 702, Verification module; 703, Confirmation module; 704, Construction module; 705, Calculation module; 800, Diagnostic device for high-frequency magnetic disturbances in a quasi-ring symmetric stellarator; 801, Processor; 802, Memory; 803, Multimedia component; 804, I / O interface; 805, Communication component. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0049] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0050] Example 1:

[0051] As a three-dimensional magnetic confinement fusion device, the stellarator, compared to the tokamak, one of the mainstream magnetic confinement fusion devices, has a more complex three-dimensional structure in its magnetic field and vacuum chamber. The design of magnetic probes on the stellarator is difficult to replicate the commonly used two-dimensional magnetic probe design of tokamaks. This paper addresses the complex three-dimensional magnetic field and vacuum chamber characteristics of the CFQS quasi-toroidal symmetric stellarator, overcoming a series of engineering challenges, and designs a diagnostic method and system for high-frequency magnetic disturbance measurement suitable for the stringent experimental operating conditions of CFQS.

[0052] This embodiment provides a diagnostic method for high-frequency magnetic disturbances in a quasi-toroidal stellarator.

[0053] See Figure 1 The figure shows that the method includes steps S100, S200, S300, S400 and S500.

[0054] S100, based on the measurement principle and signal transmission path of Faraday's law of electromagnetic induction, combined with the physical research objectives and the spatial constraints of the vacuum chamber, the three-dimensional dimensions of the magnetic probe body are designed, and the frequency response characteristics are optimized by a layered winding scheme and protective components adapted to the experimental environment are selected to prepare a magnetic probe entity adapted to the experimental environment. The effective area of ​​the magnetic probe in the circumferential, radial and polar directions is calibrated by using a 100Hz AC excitation solenoid and a standard probe comparison method.

[0055] Understandably, this step includes sub-steps such as the three-dimensional dimension design of the magnetic probe, the frequency response characteristic design of the magnetic probe, the selection of materials for the magnetic probe, and the spatial arrangement design of the magnetic probe array. Among these, the magnetic probe used to measure magnetic disturbances on a magnetic confinement fusion experimental device is typically designed as a tightly wound coil with multiple turns. Assuming its winding cross-sectional area is S and it has N turns, according to Faraday's law of electromagnetic induction, if the magnetic field B passing through this coil changes with time t, an induced electromotive force ε will be generated in the coil.

[0056]

[0057] in, It is the differential of the magnetic field B with respect to time t. It can be calculated from the measured induced electromotive force ε by calibrating the effective area (NS) of the magnetic probe. The change of the magnetic field over time, B(t), can be obtained through numerical integration.

[0058] It's important to note that this only considers the magnetic probe itself. In actual physics experiments, the induced signal generated by the magnetic probe needs to pass through a signal transmission line of a certain length before being acquired by the data acquisition system and then uploaded to the server. The corresponding control system can flexibly control the diagnostic measurements. The components of a magnetic probe diagnostic system for measuring high-frequency magnetic disturbances are as follows: Figure 4 The diagram shown is shown in the image.

[0059] S200: Based on the magnetic probe entity, the array spatial layout is designed according to the triangular magnetic configuration characteristics of the CFQS stellarator. The probe is encapsulated in a stainless steel protective box and positioned and installed through the vacuum chamber window. The circumferential measurement coil is perpendicular to the circumferential magnetic lines of force and a space is reserved for laser calibration. The array's circumferential modulus resolution and poloidal wavenumber resolution are verified to obtain the positioned magnetic probe array.

[0060] It is understood that step S200 includes S201, S202, and S203, wherein:

[0061] S201. Based on the triangular magnetic configuration characteristics of the CFQS stellarator, the characteristic area of ​​the inner wall of the vacuum chamber is selected as the magnetic probe mounting position. According to the three-dimensional direction characteristics of the magnetic field lines, the array layout and poloidal probe layout are designed, and then the spatial coordinate scheme is output.

[0062] S202. Based on the spatial coordinate scheme, the magnetic probe is encapsulated in a stainless steel protective box and installed through the limited window of the vacuum chamber to ensure that the circumferential measuring coil is strictly perpendicular to the circumferential magnetic field lines. The spatial position is calibrated using a laser tracker to complete the deployment of the positioning array.

[0063] S203. Calculate the circumferential modulus resolution and poloidal wavenumber resolution based on the calibrated array spatial coordinates, and output an array performance verification report.

[0064] It should be noted that the required size of the magnetic probe in this step cannot be too small, as this would be detrimental to the processing and winding of the winding skeleton. The size of the magnetic probe also cannot be too large, as this would weaken the spatial resolution of the magnetic probe. Moreover, it would be unfavorable for the installation and positioning of large magnetic probes on the three-dimensional tortuous vacuum chamber wall surface of China's first quasi-toroidal symmetric stellarator (CFQS).

[0065] Understandably, the minimum distance between the outermost closed magnetic surface of the plasma and the vacuum chamber wall in the CFQS design is 28mm. This serves as the upper limit for the design height of the magnetic probe. Taking into account the spatial resolution of the magnetic probe, the winding frame, and the number of winding turns, the final design of the magnetic probe's length, width, and height is 36mm, 25mm, and 19mm, respectively. Figure 5 As shown, its height, including its protective shell, is less than 23 mm.

[0066] Furthermore, increasing the effective area (NS) of the magnetic probe can increase the output amplitude of the magnetic probe's induced signal, but it will reduce the resonant frequency of the magnetic probe, thus reducing the magnetic probe's ability to measure high-frequency magnetic disturbances. Therefore, a balance needs to be struck between the effective area design and the resonant frequency design. An equivalent schematic diagram of the magnetic probe diagnostic circuit model for measuring magnetic disturbances is shown below. Figure 6 As shown, the magnetic probe itself has inductance, resistance, and capacitance, respectively represented by L. p Rp and C p This indicates that the signal transmission line connected to the magnetic probe also has inductance, resistance, and capacitance, denoted by L2, R2, and C2 respectively. The initial induced signal of the magnetic probe is denoted by V. p The output signal after passing through the signal transmission line is represented by V. out The selected coaxial cable is model RG-316. Other equivalent resistances are 50mΩ / m, equivalent inductance is 0.21μH / m, and equivalent capacitance is 100pF / m. Based on the laboratory conditions, the magnetic probe signal transmission line is designed to be 30 meters long. Therefore, the total equivalent resistance of the signal line is 1.5Ω, the total equivalent inductance is 6.3μH, and the total equivalent capacitance is 3nF.

[0067] It should be noted that the resistance, capacitance, and inductance of the magnetic probe are calculated using the following formulas. Here, ρ is the resistivity of the magnetic probe wire conductor, l c S is the total length of the magnetic probe wire. c It is the cross-sectional area of ​​the magnetic probe wire. Here, k represents the number of winding layers of the magnetic probe, ε r ε is the relative permittivity, ε0 ​​is the vacuum permittivity, and L ar It is half the average circumference of one turn of the magnetic probe coil, D is the cross-sectional diameter of the magnetic probe wire, and N is half the average circumference of the coil. c It is the number of turns per layer of the magnetic probe winding, d c This is the interlayer distance of the magnetic probe winding. Among them, This is a commonly used empirical formula in engineering, where L... ar It is half the average circumference of one turn of the magnetic probe coil, expressed in cm (N). t denoted by , h is the total number of turns of the magnetic probe winding, h is the winding height of the magnetic probe, expressed in cm, which is equal to the number of turns per layer multiplied by the outer diameter of the winding, and d is the winding thickness of the magnetic probe, expressed in cm, which is equal to the number of winding layers multiplied by the outer diameter of the winding.

[0068] Based on experience and the size of the magnetic probe, select the diameter D of the magnetic probe winding, design the number of winding layers k, and the number of turns N in each layer. c Calculate the corresponding resistance R of the magnetic probe. p Capacitor C p and inductor L p Based on NI Multisim software, the equivalent circuit diagram for magnetic probe diagnosis was drawn. The electrical parameters (resistance, inductance, and capacitance) of the designed magnetic probe and the electrical parameters (resistance, inductance, and capacitance) of the 30-meter signal transmission line were input to calculate the amplitude-frequency response and phase-frequency response curves of the magnetic probe transfer function H. After multiple iterative calculations, the most suitable magnetic probe winding design was selected.

[0069] As shown in Table 1, the magnetic probe winding design consists of two layers of coils, each with 26 turns, used to measure circumferential magnetic disturbances; two layers of coils, each with 16 turns, are wound in the middle layer to measure radial magnetic disturbances; and two layers of coils, each with 26 turns, are wound in the outermost layer to measure poloidal magnetic disturbances. The resonant frequency in each measurement direction is greater than 400 kHz. For low-frequency magnetic disturbances (10 kHz) with an amplitude of 2 Gs, the output induced signal is approximately 0.144–0.160 V; for high-frequency magnetic disturbances (300 kHz) with an amplitude of 0.1 Gs, the output induced signal is approximately 0.216–0.240 V. The output amplitude of the induced signal is appropriate and meets the measurement requirements for CFQS magnetic disturbances.

[0070] Table 1. Three-dimensional winding characteristics of the high-frequency magnetic probe coil of the CFQS quasi-toroidal stellarator and theoretically predicted output amplitude of the induced signal.

[0071]

[0072] Furthermore, the design of the magnetic probe's frequency response requires consideration of the material of the conductor, which needs to be selected based on the conditions before and after the CFQS stellarator experiment. Before the CFQS experiment, the walls will be baked at a high temperature (approximately 120°C), and a high vacuum (100°C) must be maintained during the experiment. -5 For the magnetic probe, a high-temperature resistant and low-emission-rate polyetheretherketone (PEEK) material was selected to make the winding skeleton. A 0.5mm diameter, low-emission-rate, high-temperature resistant enameled wire was selected as the winding material for the magnetic probe. Since the CFQS device does not have a protection limiter, a magnetic probe protection component needs to be designed to cope with the effects of high plasma particles and thermal bombardment, as well as plasma radiation. 316L non-magnetic stainless steel was selected and designed into a cuboid box to enclose the magnetic probe for protection.

[0073] It should be noted that the spatial arrangement of the magnetic probe array first requires roughly determining the installation area of ​​the magnetic probes based on the physical research objectives, and then designing the arrangement scheme according to the characteristics of this area. The CFQS high-frequency magnetic probe array is designed to be installed in the triangular magnetic configuration region characteristic of the CFQS stellarator. Due to the small size of the CFQS vacuum chamber, it cannot support an adult standing inside for installation operations. The three-dimensional twisted inner wall structure of the vacuum chamber and the limited vacuum chamber windows increase the difficulty of installing and positioning the magnetic probes. It is necessary to consider the surface characteristics of the inner wall of the vacuum chamber in the characteristic triangular magnetic configuration region of the CFQS stellarator, as well as the three-dimensional directional characteristics of the magnetic field lines in this region. When arranging the magnetic probes, the circumferential magnetic perturbation measurement coils of the magnetic probes should be perpendicular to the circumferential magnetic field lines. Attention should be paid to the circumferential distance between the magnetic probes, and the magnetic probes should be arranged along the polar direction to improve the resolution of the circumferential and polar magnetic perturbation mode structures. The distance between the magnetic probes and the window flange should be considered during installation to facilitate the later calibration of the spatial position information of the magnetic probes using a laser tracker. The spatial arrangement of the CFQS high-frequency magnetic probes is as follows: Figure 7 As shown, the magnetic probe array numbered #1, #2, #5, #6, and #8 can be used to study the circumferential propagation of magnetic disturbances. The circumferential angular spacing between adjacent magnetic probes is 17.79°, 11.14°, 9.49°, and 14.15°, respectively. Theoretically, it can resolve magnetic disturbances with a circumferential modulus n equal to 18. Compared with the CFQS low-frequency magnetic probe array, which can only resolve circumferential modulus n = ±6, the high-frequency magnetic probe array has a significantly improved circumferential modulus resolution capability. The vertical spacing between adjacent magnetic probes numbered #2, #3, and #4 is 0.083m and 0.075m, respectively. They can be used to study the poloidal propagation characteristics of magnetic disturbances and have a high poloidal wavenumber resolution capability.

[0074] S300: Using a positioned magnetic probe array, a signal transmission link is constructed from a twisted pair cable inside the vacuum chamber to a 30-meter coaxial cable outside the vacuum chamber. An impedance analyzer is connected to measure the total impedance. The transfer function is calculated by combining the known electrical parameters of the magnetic probe. It is confirmed that the resonant frequency of all channels is >400kHz and changes gradually within 300kHz. The system and transfer function database are output to form a calibrated system.

[0075] It is understood that step S300 includes S301, S302, S303, and S304, wherein:

[0076] S301. Based on the positioned magnetic probe array, place the magnetic probe to be installed and the standard probe side by side at the center of a 100Hz AC excitation solenoid. Simultaneously measure the induced electromotive force of both using a multimeter. The calculation formula is as follows:

[0077]

[0078] In the formula, ε is the induced electromotive force generated by the coil of the magnetic probe to be installed, ε0 is the electromotive force generated by the standard magnetic probe, NS is the effective area of ​​the magnetic probe to be installed, and N0S0 is the effective area of ​​the standard magnetic probe.

[0079] S302. Calculate the effective area in the circumferential / radial direction and the polar direction, and output the calibrated effective area;

[0080] S303. Based on the parameters of the calibrated effective area, connect the end of the signal transmission line to a high-frequency impedance analyzer with a scanning frequency of 1kHz–1MHz to measure the amplitude-frequency and phase-frequency characteristics of the total impedance of the system after installation; combined with the known electrical parameters of the magnetic probe, calculate the frequency response function through the transfer function, and generate a transfer function database. The calculation formula of the transfer function is as follows:

[0081]

[0082] In the formula, H(ω) is the transfer function, and Z... t Z1 is the total output impedance of the magnetic probe diagnostic system circuit, which includes the signal transmission line, and Z2 is the sum of the resistance and inductance of the magnetic probe itself.

[0083] S304. Based on the transfer function database and impedance data, verify that the resonant frequency of all probe channels is >400kHz and the variation within 300kHz is ≤±3dB. After confirming that the high-frequency disturbance measurement requirements are met, output a calibration qualified system including its effective area and transfer function database.

[0084] It should be noted that after the magnetic probe array is constructed, in order to accurately calculate the actual magnetic disturbance information near the magnetic probe through the diagnostic output signal, its key performance parameters must be precisely calibrated before actual use. This calibration process is a crucial bridge connecting hardware design and data interpretation, and specifically includes the calibration of the effective area of ​​the magnetic probe and the calibration of the in-situ frequency response of the magnetic probe.

[0085] In this method, a relative calibration is employed, placing the high-frequency magnetic probe under test and a standard magnetic probe with a known effective area side-by-side at the center of a solenoid carrying a 100Hz alternating current. According to Faraday's law of electromagnetic induction:

[0086]

[0087] Where ε is the induced electromotive force generated by the magnetic probe coil, N is the number of turns of the coil, and S is the area of ​​a single turn of the coil. Let be the rate of change of the magnetic field in the normal direction of the coil with time. The induced electromotive forces generated by the standard magnetic probe and the high-frequency magnetic probe under test are measured using a high-precision multimeter as ε0 and ε, respectively. Since the rates of change of the magnetic field through the two magnetic probes are approximately the same, If N0S0 is the known effective area of ​​a standard magnetic probe, then the effective area of ​​the high-frequency magnetic probe to be tested is... Calibration results show that the effective area in the circumferential and radial magnetic disturbance measurement directions is 0.02 m². 2 Nearby, the effective area along the direction of the poloidal magnetic perturbation measurement is 0.018 m². 2 The results are close to the theoretical calculations, with an error of approximately 0.1%.

[0088] Schematic diagram of the equivalent circuit of the magnetic probe after positioning and installation. Figure 6 As shown above, the inductance, resistance, and capacitance of the magnetic probe itself are represented by L. p R p and C p The inductance, resistance, and capacitance of the signal transmission line connected to the magnetic probe are represented by L2, R2, and C2, respectively. The outdoor signal transmission line in the vacuum chamber is 30 meters long, and the initial induced signal of the magnetic probe is represented by V. p The output signal after passing through the signal transmission line is represented by V. out The sum of the inductance and resistance of the magnetic probe is represented by Z1, i.e., Z1 = R. p +iωL p ω is the angular frequency, and i is the imaginary unit; the sum of the magnetic probe capacitance and the impedance of the signal transmission line is denoted by Z3, then the total output impedance of the magnetic probe diagnostic is Z. t Satisfying the relation It can also be written as At the start of the in-situ frequency response calibration of the magnetic probe, the end of the signal transmission line is directly connected to the high-frequency impedance analyzer. First, the total impedance Z of the entire measurement circuit is measured by scanning the frequency (1kHz-1MHz). t The amplitude and phase curves vary with frequency; the R value of the magnetic probe can be measured using an impedance analyzer before installation. p and L p The value is given, therefore Z1 is a known quantity, because the transfer function of the entire magnetic probe circuit is given. Z was measured through a calibration experiment. t Frequency response curve, according to The transfer function of the magnetic probe circuit can be calculated, and then the output signal V can be used in subsequent experiments. out And the transfer function H is used to calculate the induced signal V near the magnetic probe. p In-situ frequency response calibration was performed on all magnetic probes of the CFQS high-frequency magnetic probe array in three measurement directions. The calibration results were similar among the probes. Figure 8The in-situ frequency response calibration results of one of the magnetic probes are shown. It can be seen that the resonant frequencies of the three magnetic disturbance measurement directions of the magnetic probe are all higher than 400kHz, and the transfer function H changes relatively smoothly within 300kHz, which meets the measurement requirements of CFQS high-frequency magnetic disturbance.

[0089] S400, based on the calibrated qualified system, dynamically sets the maximum sampling rate of 1.25MS / s, trigger time, and acquisition duration parameters, and synchronously acquires the original output voltage of all channels during plasma discharge to generate a multi-channel time-domain voltage signal set.

[0090] Understandably, after the precise calibration steps outlined above, the diagnostic system now possesses the foundation for quantitative measurement. In actual plasma discharge experiments, this calibrated system is used for high-fidelity signal acquisition.

[0091] During plasma discharge, a time-varying magnetic field passes through the magnetic probe coil (i.e., there is magnetic disturbance around the magnetic probe). According to Faraday's law of electromagnetic induction, the magnetic probe coil generates an induced electromotive force signal V. p (t). The analog voltage signal is transmitted to the acquisition cabinet via a twisted-pair cable inside the vacuum and a 30-meter coaxial cable outside the vacuum. It then passes through a signal adapter box (the input signal line has a BNC interface, and the output signal line is converted to a D-type interface) to finally output the signal V. out (t) Transmitted to the high-frequency data acquisition card. The acquisition system samples the voltage signal V from all channels at a maximum sampling rate of 1.25 MS / s. out (t) Synchronous digital acquisition is performed. The output of this step is a raw digital voltage signal containing magnetic disturbance information, providing a direct data source for the final physical analysis. The control system of the high-frequency magnetic probe array diagnostics can flexibly control the start time of the diagnostic acquisition, the sampling frequency, and the total acquisition duration, which is very helpful for the smooth conduct of related physical experimental research.

[0092] The S500 combines a multi-channel time-domain voltage signal set with a transfer function database for frequency response correction to restore the true induced voltage. It calculates the magnetic field change rate using the effective area and obtains the magnetic field disturbance through numerical integration. At the same time, it analyzes the disturbance mode structure and propagation direction through time-frequency spectrum analysis and array phase difference analysis, and finally outputs the three-dimensional magnetic disturbance evolution characteristics.

[0093] It is understood that step S500 includes S501 and S502, wherein:

[0094] S501: Based on a multi-channel time-domain voltage signal set and transfer function database, the multi-channel time-domain voltage signal set is converted to the frequency domain by Fourier transform, divided by the transfer function to compensate for transmission distortion, and then restored to the true induced voltage by inverse Fourier transform; the magnetic field change rate is calculated using the calibrated effective area, and the three-dimensional magnetic field disturbance is obtained by numerical integration, and the magnetic field disturbance time-domain sequence is output.

[0095] S502. Based on the spatiotemporal distribution of magnetic field disturbances, the frequency-amplitude evolution characteristics are analyzed by short-time Fourier transform; the phase difference between adjacent probe signals is calculated by combining the array spatial coordinates, the circumferential modulus n, the poloidal modulus m and the propagation direction are determined, and a three-dimensional magnetic disturbance evolution model is generated.

[0096] It should be noted that, firstly, the original signal V... out (t) Perform frequency response correction on the time-domain signal V out (t) is subjected to Fourier transform to obtain its frequency domain signal V. out (ω), and then divide by the system transfer function H(ω) measured in the above steps to compensate for the amplitude and phase distortion of the signal during transmission and acquisition, to obtain the true probe induced voltage frequency domain signal V. p (ω). Then, through inverse Fourier transform, the corrected time-domain induced voltage V is obtained. p (t).

[0097] Secondly, calculate the time rate of change of the magnetic field disturbance. According to the formula Using the effective area NS calibrated in step S2, the corrected induced voltage V is... p (t) is converted into the rate of change of the magnetic field over time.

[0098] Finally, a physical analysis is performed, including an analysis of the entire array. The data undergoes time-varying spectral analysis (such as short-time Fourier transform) to identify the time evolution of the frequency and amplitude of magnetic disturbances. Numerical integration of the data yields the absolute magnitude of the magnetic fluctuations. By calculating the phase difference between probe signals at different spatial locations, the poloidal and circumferential propagation directions of the magnetic disturbance mode and the corresponding disturbance mode structure can be determined.

[0099] Example 2:

[0100] like Figure 2 As shown, this embodiment provides a diagnostic system for high-frequency magnetic disturbances in a quasi-toroidal symmetric stellarator. (See also...) Figure 2 The system includes:

[0101] Preparation module 701: Based on the measurement principle and signal transmission path of Faraday's law of electromagnetic induction, it designs the three-dimensional dimensions of the magnetic probe body in combination with the space constraints of the vacuum chamber, optimizes the frequency response characteristics through a layered winding scheme, and selects environmentally resistant protective components to prepare an environmentally resistant magnetic probe entity.

[0102] Verification module 702: Based on the magnetic probe entity, the array spatial layout is designed according to the triangular magnetic configuration characteristics of the CFQS stellarator. The probe is encapsulated in a stainless steel protective box and positioned and installed through the vacuum chamber window. The circumferential measurement coil is perpendicular to the circumferential magnetic lines of force and a space is reserved for laser calibration. The array's circumferential modulus resolution and poloidal wavenumber resolution are verified to obtain the positioned magnetic probe array.

[0103] Confirmation module 703: Used to calibrate the effective area of ​​the magnetic probe in the circumferential, radial and polar directions by using a positioning magnetic probe array, through a 100Hz AC excitation solenoid, and by using a standard probe comparison method. Connect to an impedance analyzer to measure the total impedance, calculate the transfer function by combining the known electrical parameters of the magnetic probe, and confirm that the resonant frequency of all channels is >400kHz and changes smoothly within 300kHz. Output the calibration qualified system and its effective area and transfer function database to form a calibration qualified system.

[0104] Module 704: Used to construct a signal transmission link from a twisted pair in a vacuum to a 30-meter coaxial cable based on a calibrated qualified system. It dynamically sets the sampling rate, trigger time, and acquisition duration parameters up to 1.25 MS / s, and synchronously acquires the original output voltage of all channels during plasma discharge to generate a multi-channel time-domain voltage signal set.

[0105] Calculation module 705: It is used to combine the multi-channel time-domain voltage signal set with the transfer function database for frequency response correction, restore the real induced voltage, calculate the magnetic field change rate using the effective area, and obtain the magnetic field disturbance through numerical integration. At the same time, it analyzes the disturbance mode structure and propagation direction through time-frequency analysis and array phase difference, and finally outputs a three-dimensional magnetic disturbance evolution model.

[0106] Specifically, the verification module 702 includes:

[0107] Design Unit: Based on the triangular magnetic configuration features of the CFQS stellarator, select the characteristic area of ​​the inner wall of the vacuum chamber as the magnetic probe mounting position, and design the magnetic probe array layout according to the three-dimensional direction features of the magnetic field lines, and then output the spatial coordinate scheme.

[0108] Calibration unit: Based on the spatial coordinate scheme, the magnetic probe is encapsulated in a stainless steel protective box and installed through the limited window of the vacuum chamber to ensure that the circumferential measuring coil is strictly perpendicular to the circumferential magnetic field lines. A laser tracker is used to calibrate the spatial position and complete the deployment of the positioning array.

[0109] The first computing unit is used to calculate the circumferential modulus resolution and the poloidal wavenumber resolution based on the calibrated array spatial coordinates, and outputs an array performance verification report.

[0110] Specifically, the confirmation module 703 includes:

[0111] The second calculation unit is used to simultaneously measure the induced electromotive force of the magnetic probe to be installed and the standard probe, based on the positioned magnetic probe array, at the center of a 100Hz AC excitation solenoid. The calculation formula is as follows:

[0112]

[0113] In the formula, ε is the induced electromotive force generated by the coil of the magnetic probe to be installed, ε0 is the electromotive force generated by the standard magnetic probe, NS is the effective area of ​​the magnetic probe to be installed, and N0S0 is the effective area of ​​the standard magnetic probe.

[0114] The third calculation unit is used to calculate the effective area of ​​the magnetic probe to be installed in the circumferential, radial, and polar directions, and outputs the calibrated effective area.

[0115] Generation Unit: Based on the parameters of the calibrated effective area, this unit connects the end of the signal transmission line to a high-frequency impedance analyzer with a scanning frequency of 1kHz–1MHz to measure the amplitude-frequency and phase-frequency characteristics of the total impedance of the system after installation. Combining the known electrical parameters of the magnetic probe, it calculates the frequency response function through the transfer function, generating a transfer function database. The calculation formula for the transfer function is as follows:

[0116]

[0117] In the formula, H(ω) is the transfer function, and Z... t Z1 represents the total output impedance of the magnetic probe diagnostic system circuit, including the signal transmission line, and Z1 is the sum of the resistance and inductance of the magnetic probe itself. Verification Unit: Based on the transfer function database and impedance data, this unit verifies that the resonant frequency of all probe channels is >400kHz, and the variation within 300kHz is ≤±3dB. After confirming that the high-frequency disturbance measurement requirements are met, it outputs a calibration-qualified system containing its effective area and transfer function database.

[0118] Specifically, the computing module 705 includes:

[0119] The fourth calculation unit is used to convert the multi-channel time-domain voltage signal set to the frequency domain through Fourier transform based on the multi-channel time-domain voltage signal set and transfer function database, divide by the transfer function to compensate for transmission distortion, and then restore the real induced voltage through inverse Fourier transform; calculate the magnetic field change rate using the calibrated effective area, and obtain the three-dimensional magnetic field disturbance through numerical integration, and output the magnetic field disturbance time-domain sequence.

[0120] The fifth calculation unit is used to analyze the frequency-amplitude evolution characteristics based on the spatiotemporal distribution of magnetic field disturbances through short-time Fourier transform; it also combines the array spatial coordinates to calculate the phase difference between adjacent probe signals, determine the circumferential modulus n, the poloidal modulus m and the propagation direction, and generate three-dimensional magnetic disturbance evolution characteristics.

[0121] It should be noted that the specific methods by which each module performs operations in the system described in the above embodiments have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0122] Example 3:

[0123] Corresponding to the above method embodiments, this embodiment also provides a diagnostic device for high-frequency magnetic disturbances in a quasi-toroidal stellarator. The diagnostic device for high-frequency magnetic disturbances in a quasi-toroidal stellarator described below and the diagnostic method for high-frequency magnetic disturbances in a quasi-toroidal stellarator described above can be referred to in correspondence with each other.

[0124] Figure 3 This is a block diagram illustrating a diagnostic device 800 for high-frequency magnetic disturbances in a quasi-toroidal stellarator, according to an exemplary embodiment. Figure 3 As shown, the diagnostic device 800 for high-frequency magnetic disturbances in the quasi-toroidal stellarator includes a processor 801 and a memory 802. The diagnostic device 800 also includes one or more of a multimedia component 803, an I / O interface 804, and a communication component 805.

[0125] The processor 801 controls the overall operation of the diagnostic device 800 for high-frequency magnetic disturbances in the quasi-toroidal stellarator to complete all or part of the steps in the diagnostic method for high-frequency magnetic disturbances in the quasi-toroidal stellarator described above. The memory 802 stores various types of data to support the operation of the diagnostic device 800 for high-frequency magnetic disturbances in the quasi-toroidal stellarator. This data may include, for example, instructions for any application or method operating on the diagnostic device 800 for high-frequency magnetic disturbances in the quasi-toroidal stellarator, as well as application-related data such as contact data, sent and received messages, images, audio, video, etc. The memory 802 can be implemented using any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The multimedia component 803 may include a screen and an audio component. The screen may be, for example, a touchscreen, and the audio component is used to output and / or input audio signals. For example, the audio component may include a microphone for receiving external audio signals. The received audio signals may be further stored in the memory 802 or transmitted via the communication component 805. The audio component also includes at least one speaker for outputting audio signals. I / O interface 804 provides an interface between processor 801 and other interface modules, such as a keyboard, mouse, or buttons. These buttons can be virtual or physical. Communication component 805 is used for wired or wireless communication between the high-frequency magnetic disturbance diagnostic device 800 in the quasi-ring symmetric stellarator and other devices. Wireless communication includes, for example, Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G, or 4G, or a combination thereof. Therefore, the corresponding communication component 805 may include a Wi-Fi module, a Bluetooth module, or an NFC module.

[0126] In an exemplary embodiment, the diagnostic device 800 for high-frequency magnetic disturbances in a quasi-toroidal symmetric stellarator may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the diagnostic method for high-frequency magnetic disturbances in a quasi-toroidal symmetric stellarator described above.

[0127] In another exemplary embodiment, a computer-readable storage medium including program instructions is also provided. When executed by a processor, these program instructions implement the steps of the above-described diagnostic method for high-frequency magnetic disturbances in a quasi-toroidal stellarator. For example, the computer-readable storage medium may be the memory 802 including the program instructions described above. These program instructions may be executed by the processor 801 of the diagnostic device 800 for high-frequency magnetic disturbances in a quasi-toroidal stellarator to complete the above-described diagnostic method for high-frequency magnetic disturbances in a quasi-toroidal stellarator.

[0128] Example 4:

[0129] Corresponding to the above method embodiments, this embodiment also provides a readable storage medium. The readable storage medium described below can be referred to in conjunction with the diagnostic method for high-frequency magnetic disturbances in a quasi-ring symmetric stellarator described above.

[0130] A computer program is stored on a readable storage medium, and when executed by a processor, the computer program implements the steps of the diagnostic method for high-frequency magnetic disturbances in a quasi-annular symmetric stellarator as described in the above method embodiments.

[0131] Specifically, the readable storage medium can be a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, or any other readable storage medium capable of storing program code.

[0132] In summary, this invention aims to design a novel magnetic probe array diagnostic tool with high spatiotemporal resolution, three-dimensional orientation measurement, wide bandwidth response, and strong anti-interference capability for high-frequency magnetic disturbance measurement and analysis in plasma discharge experiments of quasi-ring symmetric stellarator devices (CFQS), thus solving the current problem of lacking a high-frequency magnetic probe array diagnostic tool suitable for quasi-ring symmetric stellarators. These include: designing three-dimensional magnetic probes suitable for CFQS: Considering the characteristics of the three-dimensional magnetic field and magnetic disturbances in the CFQS stellarator, each magnetic probe is designed to simultaneously measure poloidal, circumferential, and radial magnetic disturbances; the size of the magnetic probes must adapt to the characteristics of the CFQS vacuum chamber wall and be smaller than the distance between the outermost closed magnetic surface of the plasma and the vacuum chamber wall during CFQS discharge; meeting the high-frequency magnetic disturbance measurement requirements of CFQS: Addressing the need for CFQS research on 50-300kHz plasma high-frequency magnetic disturbances, the effective area design and resonant frequency design of the magnetic probes are balanced. While ensuring a sufficiently high signal-to-noise ratio, the resonant frequency of the magnetic probes is increased so that the resonant frequency in each measurement direction is higher than 400kHz. A method for calibrating the effective area and in-situ frequency response of each magnetic probe is proposed; and selecting methods suitable for CFQS experimental operation. Materials for fabricating magnetic probes: Considering the high vacuum chamber wall temperature and environment of CFQS, and the susceptibility of magnetic probes to plasma heat, particle bombardment, and plasma radiation, the materials selected for the magnetic probe skeleton and winding are those with high vacuum, low escape rate, high temperature resistance (≥300℃), and radiation resistance. Non-magnetic stainless steel is selected as the protective material for the magnetic probes, and the shape of the protective components needs to be specially designed. Design of the spatial arrangement of magnetic probes suitable for CFQS: Combining the CFQS vacuum chamber wall structure and the three-dimensional directional characteristics of magnetic lines of force near the vacuum chamber wall, magnetic probes are arranged in the characteristic magnetic configuration area of ​​CFQS. Attention is paid to the polar and circumferential distances between magnetic probes to improve the resolution of polar and circumferential magnetic perturbation mode structures. When installing magnetic probes, the distance between the magnetic probes and the window flange is considered to facilitate the later calibration of the spatial position information of the magnetic probes using a laser tracker.

[0133] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0134] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for diagnosing high-frequency magnetic disturbances in a quasi-toroidal symmetric stellarator, characterized in that, include: Based on the measurement principle and signal transmission path of Faraday's law of electromagnetic induction, the three-dimensional dimensions of the magnetic probe body were designed in combination with the physical research objectives and the spatial constraints of the vacuum chamber. The frequency response characteristics were optimized by a layered winding scheme and protective components adapted to the experimental environment were selected to prepare a magnetic probe body adapted to the experimental environment. The effective area of ​​the magnetic probe in the circumferential, radial and polar directions was calibrated by using a 100Hz AC excitation solenoid and a standard probe comparison method. Based on the magnetic probe entity, the array spatial layout was designed according to the triangular magnetic configuration characteristics of the CFQS stellarator. After the probe was encapsulated in a stainless steel protective box, the circumferential measurement coil was arranged perpendicular to the circumferential magnetic field lines. The magnetic probe was positioned and installed near the window of the vacuum chamber using a laser tracker to obtain the positioned magnetic probe array. The array's circumferential modulus resolution and poloidal wavenumber resolution were verified. Using a positioned magnetic probe array, a signal transmission link is constructed from a twisted pair cable inside the vacuum chamber to a 30-meter coaxial cable outside the vacuum chamber. An impedance analyzer is connected to measure the total impedance. The transfer function is calculated by combining the known electrical parameters of the magnetic probe. It is confirmed that the resonant frequency of all channels is >400kHz and changes gradually within 300kHz. A calibration qualified system and a transfer function database are output to form a calibration qualified system. Based on the calibrated qualified system, the maximum sampling rate of 1.25MS / s, trigger time and acquisition duration parameters are dynamically set to synchronously acquire the original output voltage of all channels during plasma discharge and generate a multi-channel time-domain voltage signal set. The multi-channel time-domain voltage signal set is combined with the transfer function database for frequency response correction to restore the real induced voltage. The magnetic field change rate is calculated using the effective area, and the magnetic field disturbance is obtained through numerical integration. At the same time, the disturbance mode structure and propagation direction are analyzed by time-frequency spectrum analysis and array phase difference analysis, and finally the three-dimensional magnetic disturbance evolution characteristics are output.

2. The diagnostic method for high-frequency magnetic disturbances in a quasi-toroidal stellarator according to claim 1, characterized in that, The magnetic probe array, based on a physical magnetic probe and designed according to the triangular magnetic configuration characteristics of the CFQS stellarator, is encapsulated in a stainless steel protective box. The circumferential measurement coils are arranged perpendicular to the circumferential magnetic field lines. The magnetic probes are positioned and installed near the vacuum chamber window using a laser tracker, resulting in a positioned magnetic probe array, which includes: Based on the triangular magnetic configuration characteristics of the CFQS stellarator, a characteristic area on the inner wall of the vacuum chamber is selected as the magnetic probe mounting position. According to the three-dimensional direction characteristics of the magnetic field lines, the magnetic probe array layout is designed, and then the spatial coordinate scheme is output. Based on the spatial coordinate scheme, the magnetic probe is encapsulated in a stainless steel protective box and installed through a limited window in a vacuum chamber, so that the circumferential measuring coil is perpendicular to the circumferential magnetic field lines. A laser tracker is used to calibrate the spatial position and complete the deployment of the positioning array. Based on the calibrated array spatial coordinates, the circumferential modulus resolution and poloidal wavenumber resolution are calculated, and an array performance verification report is output.

3. The diagnostic method for high-frequency magnetic disturbances in a quasi-toroidal stellarator according to claim 1, characterized in that, The method utilizes a positioned magnetic probe array to construct a signal transmission link from a twisted-pair cable inside the vacuum chamber to a 30-meter coaxial cable outside the vacuum chamber. The total impedance is measured using an impedance analyzer, and the transfer function is calculated based on the known electrical parameters of the magnetic probes. It is confirmed that the resonant frequency of all channels is >400kHz and changes smoothly within 300kHz. A calibrated system and its effective area and transfer function database are output, forming a calibrated system, including: Before positioning and installing the magnetic probe array, place the magnetic probe to be installed and the standard magnetic probe side by side at the center of the 100Hz AC excitation solenoid, and simultaneously measure the induced electromotive force of both using a multimeter. The induced electromotive force satisfies the following relationship: In the formula, ε is the induced electromotive force generated by the coil of the magnetic probe to be installed, ε0 is the electromotive force generated by the standard magnetic probe, NS is the effective area of ​​the magnetic probe to be installed, and N0S0 is the effective area of ​​the standard magnetic probe. Calculate the effective area of ​​the magnetic probe to be installed in the circumferential, radial, and polar directions, and output the calibrated effective area; Based on the parameters of the calibrated effective area, a high-frequency impedance analyzer with a scanning frequency of 1kHz–1MHz is connected to the end of the signal transmission line to measure the amplitude-frequency and phase-frequency characteristics of the total impedance of the system after installation. Combined with the known electrical parameters of the magnetic probe, the frequency response of the transfer function is calculated using the measured total output impedance of the magnetic probe diagnostic system circuit, generating a transfer function database. The calculation formula for the transfer function is as follows: In the formula, H(ω) is the transfer function, and Z... t Z1 is the total output impedance of the magnetic probe diagnostic system circuit, which includes the signal transmission line, and Z2 is the sum of the resistance and inductance of the magnetic probe itself. Based on the transfer function database and impedance data, verify that the resonant frequency of all probe channels is >400kHz and the variation within 300kHz is ≤±3dB. After confirming that the high-frequency disturbance measurement requirements are met, output a calibration qualified system including its effective area and transfer function database.

4. The diagnostic method for high-frequency magnetic disturbances in a quasi-toroidal symmetric stellarator according to claim 1, characterized in that, The process involves combining a multi-channel time-domain voltage signal set with a transfer function database for frequency response correction to restore the true induced voltage. The magnetic field change rate is calculated using the effective area, and the magnetic field disturbance is obtained through numerical integration. Simultaneously, the disturbance mode structure and propagation direction are analyzed through time-spectrum analysis and array phase difference, ultimately outputting three-dimensional magnetic disturbance evolution characteristics, including: Based on a multi-channel time-domain voltage signal set and transfer function database, the multi-channel time-domain voltage signal set is converted to the frequency domain by Fourier transform, divided by the transfer function to compensate for transmission distortion, and then restored to the true induced voltage by inverse Fourier transform; the magnetic field change rate is calculated using the calibrated effective area, and the three-dimensional magnetic field disturbance is obtained by numerical integration, and the magnetic field disturbance time-domain sequence is output. Based on the spatiotemporal distribution of magnetic field disturbances, the frequency-amplitude evolution characteristics are analyzed by short-time Fourier transform; simultaneously, the phase difference between adjacent probe signals is calculated by combining the array spatial coordinates, and the circumferential modulus n, poloidal modulus m and propagation direction are determined to generate three-dimensional magnetic disturbance evolution characteristics.

5. A diagnostic system for high-frequency magnetic disturbances in a quasi-toroidal stellarator, based on the diagnostic method for high-frequency magnetic disturbances in a quasi-toroidal stellarator as described in claim 1, characterized in that, include: Fabrication module: Based on the measurement principle and signal transmission path of Faraday's law of electromagnetic induction, it designs the three-dimensional dimensions of the magnetic probe body in combination with the physical research objectives and the space constraints of the vacuum chamber, optimizes the frequency response characteristics through a layered winding scheme, and selects protective components adapted to the experimental environment to fabricate a magnetic probe entity adapted to the experimental environment. Verification module: Based on the magnetic probe entity, the array spatial layout is designed according to the triangular magnetic configuration characteristics of the CFQS stellarator. The probe is encapsulated in a stainless steel protective box and positioned and installed through the vacuum chamber window. The circumferential measurement coil is arranged perpendicular to the circumferential magnetic field lines. The magnetic probe is positioned and installed near the vacuum chamber window using a laser tracker to obtain the positioned magnetic probe array. The array's circumferential modulus resolution and poloidal wavenumber resolution are verified. Verification Module: For the magnetic probe array to be installed, the effective area of ​​the magnetic probe to be installed in the circumferential, radial, and polar directions is calibrated using a standard probe comparison method through a 100Hz AC excitation solenoid. A signal transmission link is constructed from the twisted pair inside the vacuum chamber to a 30-meter coaxial cable outside the vacuum chamber. An impedance analyzer is connected to measure the total impedance. The transfer function is calculated based on the known electrical parameters of the magnetic probe. It is confirmed that the resonant frequency of all channels is >400kHz and changes gradually within 300kHz. The system with qualified calibration and its database of effective area and transfer function are output, forming a qualified calibration system. Construction Module: Based on the constructed signal transmission link from the twisted pair cable inside the vacuum chamber to the 30-meter coaxial cable outside the vacuum chamber and the calibrated qualified system, the maximum sampling rate of 1.25MS / s, trigger time and acquisition duration parameters are dynamically set to synchronously acquire the original output voltage of all channels during plasma discharge and generate a multi-channel time-domain voltage signal set; The calculation module is used to combine the multi-channel time-domain voltage signal set with the transfer function database for frequency response correction, restore the real induced voltage, calculate the magnetic field change rate using the effective area, and obtain the magnetic field disturbance through numerical integration. At the same time, it analyzes the disturbance mode structure and propagation direction through time-frequency analysis and array phase difference, and finally outputs the three-dimensional magnetic disturbance evolution characteristics.

6. The diagnostic system for high-frequency magnetic disturbances in a quasi-toroidal symmetric stellarator according to claim 5, characterized in that, The verification module includes: Design Unit: Based on the triangular magnetic configuration features of the CFQS stellarator, select the characteristic area of ​​the inner wall of the vacuum chamber as the magnetic probe mounting position, and design the magnetic probe array layout according to the three-dimensional direction features of the magnetic field lines, and then output the spatial coordinate scheme. Calibration unit: Based on the spatial coordinate scheme, the magnetic probe is encapsulated in a stainless steel protective box and installed through the limited window of the vacuum chamber, so that the circumferential measuring coil is perpendicular to the circumferential magnetic field lines. The spatial position is calibrated using a laser tracker to complete the deployment of the positioning array. The first computing unit is used to calculate the circumferential modulus resolution and poloidal wavenumber resolution based on the calibrated array spatial coordinates, and outputs an array performance verification report.

7. The diagnostic system for high-frequency magnetic disturbances in a quasi-toroidal symmetric stellarator according to claim 5, characterized in that, The confirmation module includes: The second calculation unit is used to place the magnetic probe to be installed and the standard probe side by side at the center of a 100Hz AC excitation solenoid before positioning and installing the magnetic probe array. The induced electromotive force of both is measured synchronously using a multimeter. The calculation formula is as follows: In the formula, ε is the induced electromotive force generated by the coil of the magnetic probe to be installed, ε0 is the electromotive force generated by the standard magnetic probe, NS is the effective area of ​​the magnetic probe to be installed, and N0S0 is the effective area of ​​the standard magnetic probe. The third calculation unit is used to calculate the effective area of ​​the magnetic probe to be installed in the circumferential, radial, and polar directions, and outputs the calibrated effective area. Generation Unit: Based on the parameters of the calibrated effective area, this unit connects the end of the signal transmission line to a high-frequency impedance analyzer with a scanning frequency of 1kHz–1MHz to measure the amplitude-frequency and phase-frequency characteristics of the total impedance of the system after installation. Combining the known electrical parameters of the magnetic probe, it calculates the frequency response of the transfer function using the measured total output impedance of the system circuit, generating a transfer function database. The calculation formula for the transfer function is as follows: In the formula, H(ω) is the transfer function, and Z... t Z1 is the total output impedance of the magnetic probe diagnostic system circuit, which includes the signal transmission line, and Z2 is the sum of the resistance and inductance of the magnetic probe itself. Verification Unit: Based on the transfer function database and impedance data, this unit verifies that the resonant frequency of all probe channels is >400kHz and the variation within 300kHz is ≤±3dB. After confirming that the high-frequency disturbance measurement requirements are met, it outputs a calibration qualified system containing the calibration qualified system, its effective area, and the transfer function database.

8. The diagnostic system for high-frequency magnetic disturbances in a quasi-toroidal symmetric stellarator according to claim 5, characterized in that, The computing module includes: The fourth calculation unit is used to convert the multi-channel time-domain voltage signal set to the frequency domain through Fourier transform based on the multi-channel time-domain voltage signal set and transfer function database, divide by the transfer function to compensate for transmission distortion, and then restore the real induced voltage through inverse Fourier transform; calculate the magnetic field change rate using the calibrated effective area, and obtain the three-dimensional magnetic field disturbance through numerical integration, and output the magnetic field disturbance time-domain sequence. The fifth calculation unit is used to analyze the frequency-amplitude evolution characteristics based on the spatiotemporal distribution of magnetic field disturbances through short-time Fourier transform; it also combines the array spatial coordinates to calculate the phase difference between adjacent probe signals, determine the circumferential modulus n, the poloidal modulus m and the propagation direction, and generate three-dimensional magnetic disturbance evolution characteristics.

9. A diagnostic device for high-frequency magnetic disturbances in a quasi-toroidal symmetric stellarator, characterized in that, include: Memory, used to store computer programs; A processor, configured to implement, when executing the computer program, a method for diagnosing high-frequency magnetic disturbances in a quasi-toroidal stellarator as described in any one of claims 1 to 4.

10. A readable storage medium, characterized in that: The readable storage medium stores a computer program that, when executed by a processor, implements a diagnostic method for high-frequency magnetic disturbances in a quasi-annular stellarator as described in any one of claims 1 to 4.

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