An optimal magnetic field difference acquisition method based on electron cyclotron radar disturbance analysis

Abstract

The application discloses an optimal magnetic field difference acquisition method based on electron cyclotron radiation perturbation analysis, and relates to the field of electron cyclotron radiation calibration. The method comprises the following steps: firstly, calculating a first electron temperature distribution and a second electron temperature distribution; secondly, calculating a second radiation signal intensity; thirdly, calculating a calibration coefficient of each channel of the electron cyclotron radiation; and fourthly, using an electron temperature interpolation distribution and a preset standard temperature interpolation distribution to perform radial integration comparison deviation to obtain an accuracy distribution. The distribution magnetic field with an accuracy distribution not less than a threshold value is determined as a target toroidal magnetic field corresponding to a first magnetic field strength, and a target magnetic field strength of the target toroidal magnetic field is obtained. The method can significantly improve the accuracy of the calibration coefficient, quantitatively give the accuracy of the calibration, effectively solve the error problem in the traditional calibration method, provide a strong guarantee for the accurate measurement of the electron cyclotron radiation, and further promote the further development of tokamak plasma diagnosis technology.

Description

Technical Field

[0001] The present invention relates to the field of electron cyclotron radiometer calibration, and more particularly to a method for obtaining an optimal magnetic field difference based on disturbance analysis of an electron cyclotron radiometer. Background Art

[0002] Electron cyclotron radiometers play a crucial role in tokamak plasma diagnostics. Based on microwave radiation receiver technology, they are diagnostic systems that accurately measure the temperature distribution and perturbations of electrons in plasma. Their exceptional local measurement capabilities and high temporal and spatial resolution make them indispensable diagnostic tools in tokamaks. In tokamaks worldwide, electron cyclotron radiometers are widely used to measure electron temperature profiles and perturbation distributions, providing key data for a variety of studies, including magnetohydrodynamic instabilities, microscopic turbulent transport, rupture prediction, identification and location of neoclassical tearing modes, electron thermal transport, and high-energy particle instabilities.

[0003] However, fully utilizing the diagnostic data from an electron cyclotron radiometer requires accurate calibration and the acquisition of corresponding calibration coefficients. Currently, two main calibration methods are commonly used. One is the dual-temperature method. Although widely used, it is complex to implement, and the accuracy of the blackbody source radiation coefficient cannot be guaranteed. In addition, the simulation of microwave radiation in plasma through mirror reflection has a large amount of uncertainty, which often leads to large errors in the calibration results. The other method is the magnetic field difference method, which calculates the relative calibration coefficient between the front and rear channels by varying the strength of the toroidal magnetic field in the discharge. This method is relatively simple to operate. However, for traditional multi-channel electron cyclotron radiometers, the measurement intermediate frequency interval is fixed, while the toroidal magnetic field in the tokamak device decreases inversely along the radial direction. Therefore, when using the magnetic field difference method to calibrate traditional multi-channel electron cyclotron radiometers, the measurement positions of the front and rear channels cannot be completely overlapped between the calibration guns, resulting in inevitable errors in the calibration coefficients. This, to a certain extent, affects the accuracy of electron temperature and disturbance distributions required in various studies and may even adversely affect the accuracy of some important research results. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for obtaining the optimal magnetic field difference based on the perturbation analysis of an electron cyclotron radiometer. Through the perturbation analysis method, the optimal magnetic field difference is found when the measurement positions of adjacent channels between calibration guns do not completely overlap. This solves the problem that the measurement positions of adjacent channels between calibration guns cannot be completely overlapped due to the inconsistency between the change of the tokamak annular magnetic field and the intermediate frequency interval of the traditional multi-channel electron cyclotron radiometer, thereby causing calibration errors. The method can significantly improve the accuracy of the calibration coefficient and quantify the accuracy of the calibration, effectively solving the error problem in the traditional calibration method. It can also provide a strong guarantee for the accurate measurement of the electron cyclotron radiometer, thereby promoting the further development of tokamak plasma diagnostic technology.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions:

[0006] In a first aspect, the present application provides a method for obtaining an optimal magnetic field difference based on electron cyclotron radiometer perturbation analysis, comprising the following specific steps:

[0007] According to a preset first calibration cannon and a preset relative error between a preset second calibration cannon and the first calibration cannon, a first electron temperature distribution of the first calibration cannon in each channel of the electron cyclotron radiometer and a second electron temperature distribution of the second calibration cannon in each channel of the electron cyclotron radiometer are calculated respectively;

[0008] The second radiation signal intensity of each channel of the electron cyclotron radiometer under the first calibration cannon is calculated using the first electron temperature distribution, the second electron temperature distribution, and the first radiation signal intensity of each channel of the electron cyclotron radiometer under the first magnetic field intensity of the first calibration cannon;

[0009] Calculating calibration coefficients of the respective channels of the electron cyclotron radiometer according to the first radiation signal intensity, the second radiation signal intensity, and the measurement positions of the respective channels of the electron cyclotron radiometer in the first calibration gun and the second calibration gun;

[0010] Using the calibration coefficients of each channel and the first radiation signal intensity, the electron temperature interpolation distribution of the electron cyclotron radiometer after calibration is obtained. The radial integral comparison deviation between the electron temperature interpolation distribution and the preset standard temperature interpolation distribution is performed to obtain the accuracy distribution of the distributed magnetic field of the second calibration gun.

[0011] The distributed magnetic field with an accuracy distribution not less than a threshold is determined as the target toroidal magnetic field corresponding to the first magnetic field intensity, and the target magnetic field intensity of the target toroidal magnetic field is obtained.

[0012] On the basis of the above technical solution, the present invention can also be improved as follows.

[0013] Furthermore, the first electron temperature distribution is specifically:

[0014]

[0015] Where, T ea represents the first electron temperature distribution, T e0 represents the core electron temperature of the first calibration gun, R represents the large radius of the tokamak device, R0 represents the large radius of the core of the first calibration gun, a represents the small radius of the plasma in the tokamak device, σ Represents the peaking parameter.

[0016] Furthermore, the second electron temperature distribution is specifically:

[0017]

[0018] Where, T eb represents the second electron temperature distribution, T e0 represents the core electron temperature of the first calibration gun, R represents the large radius of the tokamak device, R0 represents the large radius of the core of the first calibration gun, a represents the small radius of the plasma in the tokamak device, σ represents the peaking parameter, and x% and y% represent the preset relative error.

[0019] Furthermore, the second radiation signal strength is specifically:

[0020]

[0021] Where, E b，N It represents the second radiation signal intensity of the Nth channel of the electron cyclotron radiometer under the second calibration shot, E a，N It represents the first radiation signal intensity of the Nth channel of the electron cyclotron radiometer under the first calibration shot, T eb，N It represents the electron temperature of the Nth channel of the electron cyclotron radiometer under the second calibration shot, which is obtained through the second electron temperature distribution. ea，N It represents the electron temperature of the Nth channel of the electron cyclotron radiometer under the first calibration shot, obtained from the first electron temperature distribution.

[0022] Furthermore, the above calibration coefficient is specifically:

[0023]

[0024] Where C N+1 Indicates the calibration coefficient of the Nth channel of the electron cyclotron radiometer, E a，N It represents the first radiation signal intensity of the Nth channel of the electron cyclotron radiometer under the first calibration shot, R a，N Indicates the measurement position of the Nth channel of the electron cyclotron radiometer under the first calibration shot, Rb，N Indicates the measurement position of the Nth channel of the electron cyclotron radiometer under the second calibration shot, E b，N It indicates the second radiation signal intensity of the Nth channel of the electron cyclotron radiometer under the second calibration shot, where N is the channel number of the electron cyclotron radiometer.

[0025] Furthermore, the above measurement positions are specifically:

[0026]

[0027] Where R N represents the measurement position of the Nth channel of the electron cyclotron radiometer under one of the calibration guns, e represents the electron charge number, R represents the core maximum radius of the calibration gun, B represents the discharge magnetic field intensity of the calibration gun, m e represents the electron mass, F0 represents the local oscillator frequency of the electron cyclotron radiometer, f N Indicates the intermediate frequency of the Nth channel of the electron cyclotron radiometer.

[0028] Furthermore, the above accuracy distribution is specifically as follows:

[0029]

[0030] Where S Te Represents the preset standard temperature interpolation distribution, S Tea represents the electron temperature interpolation distribution, and D represents the accuracy distribution.

[0031] In a second aspect, the present application provides an optimal magnetic field difference acquisition system based on electron cyclotron radiometer perturbation analysis, which is applied to an optimal magnetic field difference acquisition method based on electron cyclotron radiometer perturbation analysis according to any one of the first aspects, comprising:

[0032] The first module is configured to calculate, based on a preset first calibration cannon and a preset relative error between a preset second calibration cannon and the first calibration cannon, a first electron temperature distribution of the first calibration cannon in each channel of the electron cyclotron radiometer and a second electron temperature distribution of the second calibration cannon in each channel of the electron cyclotron radiometer;

[0033] The second module is configured to calculate the second radiation signal intensity of each channel of the electron cyclotron radiometer under the second calibration cannon by using the first electron temperature distribution, the second electron temperature distribution, and the first radiation signal intensity of each channel of the electron cyclotron radiometer under the first magnetic field intensity of the first calibration cannon;

[0034] A third module is configured to calculate a calibration coefficient for each channel of the electron cyclotron radiometer based on the first radiation signal intensity, the second radiation signal intensity, and the measurement positions of each channel of the electron cyclotron radiometer in the first calibration gun and the second calibration gun, respectively;

[0035] The fourth module is used to obtain the calibrated electron temperature interpolation distribution of the electron cyclotron radiometer using the calibration coefficients of each channel and the first radiation signal intensity, and to compare the deviation of the radial integral of the electron temperature interpolation distribution with the preset standard temperature interpolation distribution to obtain the accuracy distribution of the distributed magnetic field of the second calibration gun;

[0036] The fifth module is used to determine the distributed magnetic field with an accuracy distribution not less than a threshold as the target toroidal magnetic field corresponding to the first magnetic field strength, and obtain the target magnetic field strength of the target toroidal magnetic field.

[0037] In a third aspect, the present application provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements any one of the methods in the first aspect when executing the computer program.

[0038] In a fourth aspect, the present application provides a non-transitory computer-readable storage medium, which stores computer instructions, and the computer instructions enable a computer to execute any one of the methods in the first aspect.

[0039] Compared with the prior art, the present invention has at least the following beneficial effects:

[0040] In the present application, the ultimate goal is to find out the magnetic field strength that needs to be set for the second calibration gun based on the set first calibration gun and the first magnetic field strength set by the first calibration gun, so as to meet the execution conditions of the magnetic field difference method, and complete the calibration of the electron cyclotron radiometer through the set first calibration gun and the second calibration gun, and the magnetic field strength finally set by the second calibration gun is the target magnetic field strength, and the difference between the target magnetic field strength and the first magnetic field strength is the optimal magnetic field difference; first, the second electron temperature distribution of the second calibration gun is calculated based on the first electron temperature distribution of the first calibration gun and the preset relative error, and secondly, the electron temperature distribution is used to calculate the second radiation signal strength of each channel of the electron cyclotron radiometer under the second calibration gun; then, the radiation signal strength and the measurement position of each channel are used to calculate the calibration coefficient of each channel; then, the electronic temperature interpolation distribution is used to perform radial integration with the preset standard temperature interpolation distribution. The accuracy distribution of the distributed magnetic field of the second calibration gun is obtained by comparing the deviation; finally, according to the size of the threshold, the magnetic field with an accuracy distribution not less than the threshold is determined to be the magnetic field most suitable for the first magnetic field strength, that is, the target toroidal magnetic field, and finally the target magnetic field strength of the target toroidal magnetic field is obtained. Through the perturbation analysis method, the optimal magnetic field difference is found when the measurement positions of adjacent channels between the calibration guns do not completely overlap, which solves the problem that the measurement positions of adjacent channels between the calibration guns cannot be completely overlapped due to the inconsistency between the changes in the tokamak toroidal magnetic field and the intermediate frequency interval of the traditional multi-channel electron cyclotron radiometer, thereby causing calibration errors. This can significantly improve the accuracy of the calibration coefficient, and can quantify the accuracy of the calibration, effectively solving the error problem in the traditional calibration method, and can also provide a strong guarantee for the accurate measurement of the electron cyclotron radiometer, thereby promoting the further development of tokamak plasma diagnostic technology.

[0041] In the present application, the method can be used to analyze the optimal discharge magnetic field for the calibration of the electron cyclotron radiometer using the magnetic field difference method according to the actual conditions of different tokamaks, so as to improve the accuracy of the magnetic field difference method calibration, and at the same time, the calibration accuracy can be quantitatively given. Since the typical characteristics of the electron temperature distribution in different tokamaks are not very consistent, and the stability capabilities of the discharge control operation are also different, it is impossible to guarantee the acquisition of a high-accuracy calibration coefficient when the traditional magnetic field difference method is used for calibration. This scheme first starts from the typical electron temperature distribution characteristics of a specific tokamak device, while taking into account the plasma displacement caused by different discharge stabilities. Through mathematical smoothing and the constraint of an unchanged calibration coefficient, the accuracy of the calibration results under different magnetic fields is scanned and calculated in two dimensions: plasma horizontal displacement and core electron temperature. The accuracy distribution of the calibration under different magnetic fields can be given, so as to select the optimal calibration magnetic field, that is, the target toroidal magnetic field, to ultimately obtain a calibration coefficient with higher accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0043] Figure 1 A flowchart of an acquisition method according to an embodiment of the present invention;

[0044] Figure 2 Schematic diagram of electron temperature distribution of two different calibration guns in an embodiment of the present invention;

[0045] Figure 3 Schematic diagram of radiation signal intensities measured in each channel by two different calibration guns in an embodiment of the present invention;

[0046] Figure 4 Schematic diagram of accuracy distribution in an embodiment of the present invention;

[0047] Figure 5 Schematic diagram of the distribution of the target toroidal magnetic field in an embodiment of the present invention;

[0048] Figure 6 The figure is a connection diagram of the acquisition system in an embodiment of the present invention. DETAILED DESCRIPTION

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0050] 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 invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0051] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0052] Example 1: In order to solve the problem of inconsistency between the change of the tokamak annular magnetic field and the intermediate frequency interval of the traditional multi-channel electron cyclotron radiometer, which leads to the inability of the measurement positions of adjacent channels between calibration guns to completely overlap, thereby causing calibration errors, the present application uses a perturbation analysis method to find the optimal magnetic field when the measurement positions of adjacent channels between calibration guns do not completely overlap, which can significantly improve the accuracy of the calibration coefficient and quantify the accuracy of the calibration, effectively solving the error problem in the traditional calibration method, and providing a strong guarantee for the accurate measurement of the electron cyclotron radiometer, thereby promoting the further development of tokamak plasma diagnostic technology; this embodiment provides a method for obtaining the optimal magnetic field difference based on perturbation analysis of the electron cyclotron radiometer, such as Figure 1 As shown, the following specific steps are included:

[0053] S1, based on the preset first calibration gun and the preset relative error between the preset second calibration gun and the first calibration gun, respectively calculate the first electron temperature distribution of the first calibration gun in each channel of the electron cyclotron radiometer and the second electron temperature distribution of the second calibration gun in each channel of the electron cyclotron radiometer.

[0054] S2, using the first electron temperature distribution, the second electron temperature distribution, and the first radiation signal intensity of each channel of the electron cyclotron radiometer under the first magnetic field intensity of the first calibration gun, calculate the second radiation signal intensity of each channel of the electron cyclotron radiometer under the second calibration gun.

[0055] Optionally, the first electron temperature distribution is specifically:

[0056]

[0057] Where, T ea represents the first electron temperature distribution, T e0 represents the core electron temperature of the first calibration gun, R represents the large radius of the tokamak device, R0 represents the large radius of the core of the first calibration gun, a represents the small radius of the plasma in the tokamak device, σ Represents the peaking parameter.

[0058] Optionally, the second electron temperature distribution is specifically:

[0059]

[0060] Where, T eb represents the second electron temperature distribution, T e0 represents the core electron temperature of the first calibration gun, R represents the large radius of the tokamak device, R0 represents the large radius of the core of the first calibration gun, a represents the small radius of the plasma in the tokamak device, σrepresents the peaking parameter, and x% and y% represent the preset relative error.

[0061] S3, calculating the calibration coefficients of each channel of the electron cyclotron radiometer according to the first radiation signal intensity, the second radiation signal intensity, and the measurement positions of each channel of the electron cyclotron radiometer in the first calibration gun and the second calibration gun, respectively.

[0062] Optionally, the second radiation signal strength is specifically:

[0063]

[0064] Where, E b，N It represents the second radiation signal intensity of the Nth channel of the electron cyclotron radiometer under the second calibration shot, E a，N It represents the first radiation signal intensity of the Nth channel of the electron cyclotron radiometer under the first calibration shot, T eb，N It represents the electron temperature of the Nth channel of the electron cyclotron radiometer under the second calibration shot, which is obtained through the second electron temperature distribution. ea，N It represents the electron temperature of the Nth channel of the electron cyclotron radiometer under the first calibration shot, obtained from the first electron temperature distribution.

[0065] Optionally, the above calibration coefficient is specifically:

[0066]

[0067] Where C N+1 Indicates the calibration coefficient of the Nth channel of the electron cyclotron radiometer, E a，N It represents the first radiation signal intensity of the Nth channel of the electron cyclotron radiometer under the first calibration shot, R a，N Indicates the measurement position of the Nth channel of the electron cyclotron radiometer under the first calibration shot, R b，N Indicates the measurement position of the Nth channel of the electron cyclotron radiometer under the second calibration shot, E b，N It indicates the second radiation signal intensity of the Nth channel of the electron cyclotron radiometer under the second calibration shot, where N is the channel number of the electron cyclotron radiometer.

[0068] Optionally, the above measurement positions are specifically:

[0069]

[0070] Where R N represents the measurement position of the Nth channel of the electron cyclotron radiometer under one of the calibration guns, e represents the electron charge number, R represents the core maximum radius of the calibration gun, B represents the discharge magnetic field intensity of the calibration gun, m e represents the electron mass, F0 represents the local oscillator frequency of the electron cyclotron radiometer, fN Indicates the intermediate frequency of the Nth channel of the electron cyclotron radiometer.

[0071] S4. Using the calibration coefficients of each channel and the first radiation signal intensity, the electron temperature interpolation distribution of the electron cyclotron radiometer after calibration is obtained. The radial integral comparison deviation of the electron temperature interpolation distribution and the preset standard temperature interpolation distribution is performed to obtain the accuracy distribution of the distributed magnetic field of the second calibration gun.

[0072] Optionally, the accuracy distribution is specifically:

[0073]

[0074] Where S Te Represents the preset standard temperature interpolation distribution, S Tea represents the electron temperature interpolation distribution, which can be obtained by multiplying the radiation signal intensity received in each channel by the calibration coefficient, and D represents the accuracy distribution; where Figure 4 As shown, Figure 4 In the figure, the bottom curve represents the electronic temperature interpolation distribution, the dotted line represents the preset standard temperature interpolation distribution, and the area where the electronic temperature interpolation distribution curve intersects the preset standard temperature interpolation distribution curve is the accuracy distribution. Figure 4 Indicated by hatching.

[0075] S5, determining the distributed magnetic field with an accuracy distribution not less than the threshold as the target circumferential magnetic field corresponding to the first magnetic field intensity, and obtaining the target magnetic field intensity of the target circumferential magnetic field. The threshold value set may be 0.95, that is, finally, the circumferential magnetic field intensity of another calibration gun (the second calibration gun) other than the first calibration gun is determined based on the area with an accuracy distribution greater than or equal to 0.95; specifically, as Figure 5 As shown, the extension and diffusion of the magnetic field is a three-dimensional structure, so Figure 5 This is a two-dimensional cross-sectional view taken from a three-dimensional diagram. It can be seen that Figure 5 On the right side, the area greater than or equal to 0.95 is the area in the middle of the dotted line. The closer to the middle of the area, the higher the accuracy. The central magnetic field strength of the area within the dotted line is the toroidal magnetic field strength, and the magnetic field in the area within the dotted line is the target toroidal magnetic field.

[0076] Example 2: The traditional magnetic field difference calibration method calibrates by finding the magnetic field at the minimum average deviation of all adjacent channels between calibration guns. The main source of calibration error comes from measurement uncertainty caused by plasma displacement. Therefore, this example proposes an optimal magnetic field difference electron cyclotron radiometer calibration analysis method based on perturbation analysis of the magnetic field difference calibration method. This method includes four specific steps:

[0077] S1. First, a function fitting is performed on the typical electron temperature profile on a specific tokamak device. Before performing the calibration analysis of the optimal magnetic field difference electron cyclotron radiometer, since the typical distribution of electron temperature on different tokamaks is different, in order to improve the accuracy of the analysis, it is necessary to obtain the typical electron temperature distribution on different devices. Thomson scattering diagnostic data or simulation data provided by the integrated simulation analysis platform can be used as a reference. The electron temperature distribution is selected under the condition of pure ohmic heating in a uniform magnetic field. The electron temperature distribution obtained in this way is more reliable and robust. Then, fitting is performed according to the electron temperature distribution fitting function:

[0078]

[0079] In the formula, in the formula, T e represents the electron temperature distribution, T e0 represents the core electron temperature of the calibration gun, R represents the large radius of the tokamak device, R0 represents the large radius of the core of the calibration gun, a represents the small radius of the plasma in the tokamak device, σ represents the peaking parameter; where all parameters can be fitted according to the typical ohmic discharge electron temperature distribution of the actual tokamak as follows Figure 2 The electron temperature distribution of the two different calibration guns is shown in Figure 2 Indicated as T ea and T eb .

[0080] S2, the second step is to define the accuracy of the magnetic field difference method calibration; the magnetic field difference method calibration is based on the premise that other parameters between the two calibration shots remain unchanged, only the magnetic field is changed, so that the measurement positions of adjacent channels of the two calibrations are correlated. Since the toroidal magnetic field in the tokamak device varies nonlinearly along the radial direction, and the intermediate frequency interval of the electron cyclotron radiometer is constant, the measurement positions of adjacent channels between the two calibration shots cannot completely overlap. Therefore, mathematical smoothing can partially reduce the calibration error:

[0081]

[0082] Where C N+1 Indicates the calibration coefficient of the Nth channel of the electron cyclotron radiometer, E a，N It represents the first radiation signal intensity of the Nth channel of the electron cyclotron radiometer under the first calibration shot, R a，N Indicates the measurement position of the Nth channel of the electron cyclotron radiometer under the first calibration shot, R b，N Indicates the measurement position of the Nth channel of the electron cyclotron radiometer under the second calibration shot, E b，NIt represents the second radiation signal intensity of the Nth channel of the electron cyclotron radiometer under the second calibration shot, where N is the channel number of the electron cyclotron radiometer. The measurement position can be calculated by the following formula:

[0083]

[0084] Where R N represents the measurement position of the Nth channel of the electron cyclotron radiometer under one of the calibration guns, e represents the electron charge number, R represents the core maximum radius of the calibration gun, B represents the discharge magnetic field intensity of the calibration gun, m e represents the electron mass, F0 represents the local oscillator frequency of the electron cyclotron radiometer, f N It represents the intermediate frequency of the Nth channel of the electron cyclotron radiometer. It can be assumed that the electron cyclotron radiometer has N+1 channels and the annular magnetic field strength is B a The radiation signal measured in the discharge is expressed as N+1 random signal intensities E a (1, 2, ...N, N+1) means Figure 3 As shown, since the calibration coefficients of different channels do not change with different discharge guns, and the measured electron temperature is equal to the product of the calibration coefficient and the measured radiation signal intensity, for the Nth channel, its toroidal magnetic field intensity is B b The radiation signal intensity measured in the discharge is:

[0085]

[0086] Where, E b，N It represents the second radiation signal intensity of the Nth channel of the electron cyclotron radiometer under the second calibration shot, E a，N It represents the first radiation signal intensity of the Nth channel of the electron cyclotron radiometer under the first calibration shot, T eb，N It represents the electron temperature of the Nth channel of the electron cyclotron radiometer under the second calibration shot, which is obtained through the second electron temperature distribution. ea，N It represents the electron temperature of the Nth channel of the electron cyclotron radiometer under the first calibration shot, which is obtained through the first electron temperature distribution. eb，N and T ea，N According to formula (1), formula (3) is substituted into formula (1) to obtain the following: b The radiation signal E measured by all N+1 channels in the discharge b (1, 2, ...N, N+1) Figure 3 As shown, then E a (1, 2, ... N, N + 1), E b(1, 2, ... N, N+1) and the measurement positions of different calibration guns of each channel calculated by formula (3) are put into formula (2) to obtain the calibration coefficients of all N+1 channels.

[0087] Among them, these calibration coefficients are multiplied by the radiation signal intensity received in each channel to obtain the electron temperature interpolation distribution S Tea , and the setting of the toroidal magnetic field strength B a The electron temperature interpolation distribution S Te Compare the deviation by radial integration to get the calibration accuracy D. Figure 3 As shown in , its definition is:

[0088]

[0089] Where S Te Represents the preset standard temperature interpolation distribution, S Tea represents the electron temperature interpolation distribution, and D represents the accuracy distribution.

[0090] S3, based on the discharge stability of the device, evaluates its displacement and electron temperature changes. The error source of the magnetic field difference method is mainly the instability of the electron temperature profile between the calibration guns. Therefore, it is necessary to evaluate the difference in electron temperature profiles between calibration guns according to the conditions of different tokamaks. On the one hand, there is measurement error caused by horizontal displacement of the plasma, and on the other hand, there is change in the core electron temperature caused by vertical displacement. With the toroidal magnetic field strength B a Assume that the circumferential magnetic field strength of another gun is B b The relative errors of the plasma large radius position and core electron temperature of the calibration gun discharge are x% and y%, so T ea and T eb The cross-section of can be expressed as follows:

[0091]

[0092] S4, compare the two-dimensional accuracy distribution under different magnetic field differences to obtain the best magnetic field difference. First, according to different calibration gun magnetic field B a and B b , is brought into formula (3) to calculate the measurement positions of all channels under different magnetic fields, and the radiation signal intensity received by the standard discharge cannon is randomly generated, B a (1, 2, ... N, N+1), and then the electron temperature at different measurement positions of different calibration guns is brought into equation (4) through equations (6) and (7) to obtain the radiation signal intensity E measured by another calibration gun b(1, 2, ... N, N+1), set the calibration coefficient of the first channel to 1, and substitute equations (3) and (4) into equation (2) to recursively obtain the calibration coefficients of all channels; finally, calculate the calibration electron temperature profile and toroidal magnetic field strength according to equation (5) as B a The calibration accuracy between the electron temperature profiles is as follows Figure 4 Finally, the largest B is calculated based on the accuracy greater than 0.95. b As a standard calibration gun B a In addition to the toroidal magnetic field strength of another shot discharge, the above are the specific steps of the optimal magnetic field difference electron cyclotron radiometer calibration analysis method.

[0093] Specifically, before using the optimal magnetic field difference perturbation analysis method to find the optimal calibration magnetic field, it is necessary to first set the basic parameters according to the actual situation of the tokamak device. The maximum radius R0 of the tokamak device can be 178 cm, and the annular magnetic field strength B of the standard calibration gun can be 178 cm. a It can be 1.5T, and its core electron temperature T e0 can be 1 keV, the plasma minimum radius a can be 65 cm, and the peaking parameter σ The electron cyclotron radiometer has 16 channels, a local oscillator frequency of 60 GHz, an intermediate frequency of 1-16 GHz, and an intermediate frequency interval of 1 GHz.

[0094] Furthermore, the radiation signal intensity of the standard calibration gun measured by the 16-channel electron cyclotron radiometer is randomly generated, and equation (3) is substituted into equations (6) and (7) to obtain the electron temperature measured under different magnetic fields in different channels, and then substituted into equation (4) to obtain the radiation signal intensity measured by each channel of another calibration gun. Figure 2 As shown. The calibration coefficient of each channel is calculated by formula (2), and the calibration coefficient is multiplied by the radiation signal intensity to obtain the calibrated electron temperature distribution. The standard electron temperature distribution and the calibrated electron temperature distribution are interpolated and brought into formula (5) to calculate the calibration deviation under the calibration magnetic field intensity of the other gun. Figure 3 shown.

[0095] Specifically, the relative deviation x% of the plasma radius of another gun calibration gun can be 3%, the core radius is scanned from 173 cm to 183 cm, the relative deviation y% of the core electron temperature can be 20%, and the core electron temperature is scanned from 0.8 keV to 1.2 keV. The accuracy distribution is calculated and B is obtained. b is the accuracy disturbance analysis result under a certain magnetic field strength.

[0096] Among them, the annular magnetic field strength B of the other gun is calibrated b Analyze and calculate every 0.001 Tesla from 1.51 to 1.8T, Bb The results of the magnetic field difference disturbance analysis of 1.532 and 1.75 T are as follows Figure 4 The figure shows the other shot calibration magnetic field (1.532T) selected by the traditional magnetic field difference method and the optimal B given by the magnetic field difference perturbation analysis method. b Calibration magnetic field (1.75T); specifically, B b The area where the calibration accuracy is greater than 0.95 at 1.75 T is significantly larger than that at 1.532 T. Therefore, the calibration magnetic field given by the optimal magnetic field difference perturbation analysis method can greatly increase the probability of a high-accuracy calibration coefficient.

[0097] The paper presents an optimal magnetic field selection analysis method for calibrating multi-channel electron cyclotron radiometers using the magnetic field difference method, derived from theoretical perturbation analysis. This analysis method can be used to design optimal magnetic field differences for electron cyclotron radiometer calibration for different tokamaks and discharge control states, while also quantitatively determining the calibration accuracy. This inventive method is applicable not only to calibrating electron cyclotron radiometers using the magnetic field difference method on tokamaks, but also to any device using the magnetic field difference method for electron cyclotron radiometer calibration, such as stellarators.

[0098] Example 3: This embodiment of the present application provides an optimal magnetic field difference acquisition system based on electron cyclotron radiometer perturbation analysis, which is applied to an optimal magnetic field difference acquisition method based on electron cyclotron radiometer perturbation analysis in any one of Example 1 or Example 2, such as Figure 6 As shown, including:

[0099] The first module is used to calculate the first electron temperature distribution of the first calibration gun in each channel of the electron cyclotron radiometer and the second electron temperature distribution of the second calibration gun in each channel of the electron cyclotron radiometer based on the preset first calibration gun and the preset relative error between the preset second calibration gun and the first calibration gun.

[0100] The second module is used to calculate the second radiation signal intensity of each channel of the electron cyclotron radiometer under the second calibration gun by using the first electron temperature distribution, the second electron temperature distribution, and the first radiation signal intensity of each channel of the electron cyclotron radiometer under the first magnetic field intensity of the first calibration gun.

[0101] The third module is used to calculate the calibration coefficient of each channel of the electron cyclotron radiometer according to the first radiation signal intensity, the second radiation signal intensity, and the measurement positions of each channel of the electron cyclotron radiometer in the first calibration gun and the second calibration gun respectively.

[0102] The fourth module is used to use the calibration coefficients of each channel and the first radiation signal intensity to obtain the electron temperature interpolation distribution of the electron cyclotron radiometer after calibration, and use the radial integral comparison deviation of the electron temperature interpolation distribution and the preset standard temperature interpolation distribution to obtain the accuracy distribution of the distributed magnetic field of the second calibration gun.

[0103] The fifth module is used to determine the distributed magnetic field with an accuracy distribution not less than a threshold as the target toroidal magnetic field corresponding to the first magnetic field strength, and obtain the target magnetic field strength of the target toroidal magnetic field.

[0104] Example 4: An embodiment of the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method of any one of Example 1 or Example 2 is implemented.

[0105] Example 5: The embodiment of the present application provides a non-transitory computer-readable storage medium, which stores computer instructions, and the computer instructions enable a computer to execute the method of any one of Example 1 or Example 2.

[0106] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for obtaining an optimal magnetic field difference based on electron cyclotron radiometer disturbance analysis, characterized in that: The specific steps include: According to a preset first calibration cannon and a preset relative error between a preset second calibration cannon and the first calibration cannon, a first electron temperature distribution of the first calibration cannon in each channel of the electron cyclotron radiometer and a second electron temperature distribution of the second calibration cannon in each channel of the electron cyclotron radiometer are calculated respectively; Calculating the second radiation signal intensity of each channel of the electron cyclotron radiometer under the first calibration cannon using the first electron temperature distribution, the second electron temperature distribution, and the first radiation signal intensity of each channel of the electron cyclotron radiometer under the first magnetic field intensity of the first calibration cannon; Calculating calibration coefficients for each channel of the electron cyclotron radiometer based on the first radiation signal intensity, the second radiation signal intensity, and measurement positions of each channel of the electron cyclotron radiometer in the first calibration gun and the second calibration gun, respectively; Using the calibration coefficients of each channel and the first radiation signal intensity, an interpolated electron temperature distribution of the electron cyclotron radiometer after calibration is obtained, and radially integrating and comparing the deviations between the interpolated electron temperature distribution and a preset standard interpolated temperature distribution to obtain an accuracy distribution of the distributed magnetic field of the second calibration gun; Determining a distributed magnetic field with an accuracy distribution not less than a threshold as a target toroidal magnetic field corresponding to the first magnetic field intensity, and obtaining a target magnetic field intensity of the target toroidal magnetic field; The first electron temperature distribution is specifically: Where, T ea represents the first electron temperature distribution, T e0 represents the core electron temperature of the first calibration gun, R represents the large radius of the tokamak device, R0 represents the large radius of the core of the first calibration gun, a represents the small radius of the plasma in the tokamak device, σ represents the peaking parameter; The second electron temperature distribution is specifically: Where, T eb represents the second electron temperature distribution, T e0 represents the core electron temperature of the first calibration gun, R represents the large radius of the tokamak device, R0 represents the large radius of the core of the first calibration gun, a represents the small radius of the plasma in the tokamak device, σ represents the peaking parameter, x% and y% represent the preset relative error; The measurement positions are specifically: Where R N represents the measurement position of the Nth channel of the electron cyclotron radiometer under one of the calibration guns, e represents the electron charge number, R represents the core maximum radius of the calibration gun, B represents the discharge magnetic field intensity of the calibration gun, m e represents the electron mass, F0 represents the local oscillator frequency of the electron cyclotron radiometer, f N Indicates the intermediate frequency of the Nth channel of the electron cyclotron radiometer; The accuracy distribution is specifically: Where S Te Represents the preset standard temperature interpolation distribution, S Tea represents the electron temperature interpolation distribution, and D represents the accuracy distribution.

2. The method for obtaining the optimal magnetic field difference based on electron cyclotron radiometer perturbation analysis according to claim 1, characterized in that: The second radiation signal strength is specifically: Where, E b，N It represents the second radiation signal intensity of the Nth channel of the electron cyclotron radiometer under the second calibration shot, E a，N It represents the first radiation signal intensity of the Nth channel of the electron cyclotron radiometer under the first calibration shot, T eb，N It represents the electron temperature of the Nth channel of the electron cyclotron radiometer under the second calibration shot, which is obtained through the second electron temperature distribution. ea，N It represents the electron temperature of the Nth channel of the electron cyclotron radiometer under the first calibration shot, obtained from the first electron temperature distribution.

3. The method for obtaining the optimal magnetic field difference based on electron cyclotron radiometer perturbation analysis according to claim 1, characterized in that: The calibration coefficient is specifically: Where C N+1 Indicates the calibration coefficient of the Nth channel of the electron cyclotron radiometer, E a，N It represents the first radiation signal intensity of the Nth channel of the electron cyclotron radiometer under the first calibration shot, R a，N Indicates the measurement position of the Nth channel of the electron cyclotron radiometer under the first calibration shot, R b，N Indicates the measurement position of the Nth channel of the electron cyclotron radiometer under the second calibration shot, E b，N It indicates the second radiation signal intensity of the Nth channel of the electron cyclotron radiometer under the second calibration shot, where N is the channel number of the electron cyclotron radiometer.

4. A system for obtaining an optimal magnetic field difference based on electron cyclotron radiometer perturbation analysis, applied to an optimal magnetic field difference obtaining method based on electron cyclotron radiometer perturbation analysis according to any one of claims 1 to 3, characterized in that: include: The first module is configured to calculate, based on a preset first calibration cannon and a preset relative error between a preset second calibration cannon and the first calibration cannon, a first electron temperature distribution of the first calibration cannon in each channel of the electron cyclotron radiometer and a second electron temperature distribution of the second calibration cannon in each channel of the electron cyclotron radiometer; a second module, configured to calculate the second radiation signal intensity of each channel of the electron cyclotron radiometer under the first calibration cannon using the first electron temperature distribution, the second electron temperature distribution, and the first radiation signal intensity of each channel of the electron cyclotron radiometer under the first magnetic field intensity of the first calibration cannon; a third module, configured to calculate a calibration coefficient for each channel of the electron cyclotron radiometer based on the first radiation signal intensity, the second radiation signal intensity, and the measurement positions of each channel of the electron cyclotron radiometer in the first calibration gun and the second calibration gun, respectively; a fourth module, configured to obtain an interpolated electron temperature distribution of the calibrated electron cyclotron radiometer using the calibration coefficients of each channel and the first radiation signal intensity, and to perform radial integral comparison of the deviation between the interpolated electron temperature distribution and a preset standard temperature interpolated distribution to obtain an accuracy distribution of the distributed magnetic field of the second calibration gun; The fifth module is used to determine the distributed magnetic field with an accuracy distribution not less than a threshold as the target toroidal magnetic field corresponding to the first magnetic field strength, and obtain the target magnetic field strength of the target toroidal magnetic field.

5. An electronic device, characterized in that: The method comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the method according to any one of claims 1 to 3 is implemented when the processor executes the computer program.

6. A non-transitory computer-readable storage medium, characterized in that The non-transitory computer-readable storage medium stores computer instructions, and the computer instructions enable a computer to execute the method according to any one of claims 1 to 3.

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