CN-121983355-A - Identification method for rapidly identifying multimode seed magnetic islands and related equipment

CN121983355ACN 121983355 ACN121983355 ACN 121983355ACN-121983355-A

Abstract

The invention discloses a method for rapidly identifying multimode seed magnetic islands and related equipment, relating to the field of magnetic confinement fusion plasma diagnosis, the method is based on two sets of microwave measurement subsystems mounted at different circumferential positions of the tokamak, wherein at least one set switches the observed circumferential positions in different time periods through waveguide switches in the quasi-optical transmission module. The method comprises the steps of synchronously acquiring electronic temperature signals of two groups of microwave measurement subsystems at the same radial channel in time sequence sections corresponding to different circumferential phase differences, carrying out time averaging on the electronic temperature signals, identifying seed magnetic islands corresponding to circumferential moduli based on the same radial temperature difference and normalization judgment, and further extracting a flat area based on the distribution of the electronic temperature along with the radial channel so as to determine the width and boundary position of the magnetic islands. According to the invention, the rapid distinction and high-precision positioning of a plurality of circumferential modulus seed magnetic islands can be realized without adding additional detection channels.

Inventors

JIANG MIN
SHI ZHONGBING
YU XIN
YANG ZENGCHEN
HAN KEXI
YIN ZHIYI

Assignees

核工业西南物理研究院

Dates

Publication Date: 20260505
Application Date: 20260206

Claims (10)

1. The identification method for rapidly identifying the multimode seed magnetic island is characterized by measuring the plasma electron cyclotron radiation signal based on two groups of microwave systems arranged at different annular positions of a tokamak, and comprises the following steps: Controlling waveguide switches in quasi-optical transmission modules of at least one group of microwave systems to switch between a first state and a second state so that the two groups of microwave systems correspondingly form a first annular phase difference and a second annular phase difference in different time sequence sections; In a time sequence section corresponding to the first circumferential phase difference, synchronously acquiring electronic temperature information of two groups of microwave systems at the same radial channel, and carrying out time average processing on the electronic temperature information to obtain average temperatures of the two groups of radial channels; normalizing the temperature difference of the average temperatures of the two groups of radial channels at the same radial channel, and judging whether a seed magnetic island corresponding to the first circumferential modulus is identified or not based on a comparison result of the normalized difference and a preset judgment condition; in a time sequence section corresponding to the second circumferential phase difference, synchronously acquiring electronic temperature information of two groups of microwave systems at the same radial channel, and carrying out time average processing on the electronic temperature information to obtain average temperatures of the other two groups of radial channels; Normalizing the temperature difference of the average temperatures of the other two groups of radial channels at the same radial channel, and judging whether a seed magnetic island corresponding to the second circumferential modulus is identified or not based on a comparison result of the normalized difference and the preset judgment condition; And after the seed magnetic islands of the first circumferential modulus or the second circumferential modulus are identified, extracting an electron temperature flat area based on the distribution of the average temperature of the radial channels along with the radial channels, and determining the width of the magnetic islands and the boundary positions of the magnetic islands according to the radial width corresponding to the flat area.
2. The method for quickly identifying multiple modulus seed magnetic islands according to claim 1, wherein the first state and the second state are two switch states of the waveguide switch, and the first waveguide path and the second waveguide path are selected correspondingly respectively, so that the corresponding observed circumferential positions of the at least one group of microwave systems in the first state and the second state are different, and the first circumferential phase difference and the second circumferential phase difference are formed between the two groups of microwave systems.
3. The method for quickly identifying the multi-modulus seed magnetic island according to claim 1 is characterized in that in a time sequence section corresponding to the circumferential phase difference, electronic temperature signals of two groups of microwave systems at the same radial channel are respectively subjected to time average to obtain two groups of radial channel average temperatures, absolute differences of the two groups of radial channel average temperatures are calculated for each radial channel, one group of radial channel average temperatures is used as a normalization reference to obtain a normalization differential index, when the normalization differential index of at least one radial channel meets a preset judging condition, an identification result corresponding to the circumferential modulus is output, the normalization differential index is not smaller than a preset threshold eta, wherein eta is a threshold interval of 3% -10%, or eta is determined according to the noise fluctuation level of the electronic temperature signals in the time sequence section.
4. The method for quickly identifying multi-module seed magnetic islands according to claim 1, wherein the electronic temperature information comprises N radial channels corresponding to N center frequencies, N is an integer greater than or equal to 4, the two microwave systems synchronously acquire the same center frequency set in the same time sequence section, and the radio frequency parameters corresponding to the center frequencies are consistent and the same frequency bandwidth is adopted 。
5. The method for quickly identifying multiple modulus seed magnetic islands according to claim 1, wherein a preset mapping relationship is satisfied between the center frequency and the radial channel position, and the preset mapping relationship is based at least on a center magnetic field of a tokamak device Large radius Sum point frequency source frequency Determining that the preset mapping relation is Wherein Is the first Center frequency of Corresponding radial positions.
6. The method of claim 1, wherein the first circumferential phase difference is 180 degrees to identify a seed magnetic island with a circumferential modulus of 1, and the second circumferential phase difference is 90 degrees to identify a seed magnetic island with a circumferential modulus of 2.
7. The method for quickly identifying multi-modulus seed magnetic islands according to claim 1 is characterized in that after the seed magnetic islands corresponding to the circumferential modulus are identified, a distribution curve of electron temperature along with radial positions is constructed based on channel average temperatures of two groups of microwave systems at a plurality of radial channels, an electron temperature flat area is determined based on channel sections with temperature change rates between continuous radial channels not exceeding a preset gradient threshold value, the width of the magnetic islands is determined according to the radial width corresponding to the flat area, and the boundary positions of the magnetic islands are determined according to the radial positions of the two ends of the flat area.
8. An identification system for rapidly identifying multimode seed magnetic islands for implementing the method for rapidly identifying multimode seed magnetic islands according to any one of claims 1 to 7, comprising: the two groups of microwave measurement subsystems are respectively arranged at different circumferential positions of the tokamak device and are used for acquiring plasma electron cyclotron radiation signals and outputting corresponding electron temperature information, wherein each group of microwave measurement subsystem comprises a quasi-optical transmission module and a radio frequency receiving module; The waveguide switch is arranged in the quasi-optical transmission module of at least one group of microwave measurement subsystems, and is provided with a first switch state and a second switch state, so that the annular observation positions of the at least one group of microwave measurement subsystems are switched under different switch states, and the two groups of microwave measurement subsystems form a first annular phase difference and a second annular phase difference in different time sequence sections; The synchronous acquisition module is used for synchronously acquiring the electronic temperature information of the two groups of microwave measurement subsystems at the same radial channel in a time sequence section corresponding to the first circumferential phase difference, and synchronously acquiring the electronic temperature information of the two groups of microwave measurement subsystems at the same radial channel in a time sequence section corresponding to the second circumferential phase difference; The data analysis module is used for carrying out time average on the electronic temperature information in the time sequence section to obtain a radial channel average temperature, calculating the temperature difference of the two groups of radial channel average temperatures at the same radial channel, carrying out normalization processing, respectively identifying a seed magnetic island of a first circumferential modulus and a seed magnetic island of a second circumferential modulus based on the comparison result of the normalized difference and a preset judgment condition, extracting an electronic temperature flat area based on the distribution of the radial channel average temperature along with the radial channel after the seed magnetic island is identified, determining the width of the magnetic island according to the radial width corresponding to the flat area, and determining the boundary position of the magnetic island; And the output module is used for outputting the identified circumferential modulus, the magnetic island width and the magnetic island boundary position.
9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the method of identifying multi-modulus seed magnetic islands rapidly as claimed in any of claims 1 to 7 when the program is executed by the processor.
10. A computer-readable storage medium, on which a computer program is stored, characterized in that the program, when being executed by a processor, implements a method of identifying fast multi-modulus seed magnetic islands as claimed in any of claims 1 to 7.

Description

Identification method for rapidly identifying multimode seed magnetic islands and related equipment Technical Field The invention relates to the field of magnetic confinement fusion plasma diagnosis, in particular to a method for rapidly identifying multimode seed magnetic islands and related equipment. Background The plasma operation mode with high specific pressure and high constraint performance is an important basis for obtaining continuous fusion power gain of a large-scale magnetic confinement fusion device in the future. The new classical tearing mode is easy to excite in the high specific pressure plasma discharging process, and the magnetic island structure of the new classical tearing mode can cause the change of local magnetic shearing and transportation characteristics, so that the plasma constraint performance is affected. Depending on the discharge conditions, the new classical tear mode may appear as a single circumferential mode or may be accompanied by perturbation of multiple circumferential modes. In order to improve the control efficiency of the tearing die, the seed magnetic islands corresponding to different circumferential moduli need to be identified and positioned rapidly and reliably. The existing magnetic island identification means mostly depend on a traditional electron cyclotron radiation system, and the magnetic island structure is deduced by calculating a flat area in radial distribution of electron temperature. However, this approach generally has the following limitations: (1) The identification capability of the small-scale seed magnetic islands is insufficient, and reliable judgment of the magnetic island structures with smaller widths is difficult; (2) The electron cyclotron radiation system is mostly arranged at the fixed annular position of the tokamak, is limited by observation geometry, and has limited identification capability on the coexistence situation of a magnetic island excited by the non-annular position and a multi-annular module; (3) The method is influenced by factors such as the bandwidth of a rear-end electronic system and signal processing time delay, the width of the magnetic island and the measurement accuracy of the boundary position of the magnetic island are limited, and the boundary positioning accuracy within centimeter level is difficult to realize. Therefore, it is necessary to provide a microwave system and a method for identifying multimode seed magnetic islands under different circumferential observation conditions, which can rapidly identify multimode seed magnetic islands and combine small-scale identification and boundary positioning accuracy. Disclosure of Invention The invention aims to solve the technical problems that the existing magnetic island identification method is difficult to distinguish the seed magnetic islands when a plurality of circumferential moduli exist, and the identification precision of the small-scale magnetic islands and the boundary positions of the magnetic islands is insufficient, the purpose is to provide a recognition method and related equipment for rapidly recognizing multimode seed magnetic islands, which solves the problems of how to realize rapid distinction and recognition of seed magnetic islands with different circumferential moduli and high-precision determination of the width and boundary positions of the magnetic islands. The invention is realized by the following technical scheme: An identification method for rapidly identifying multimode seed magnetic islands, which is based on two groups of microwave systems installed at different annular positions of tokamak to measure plasma electron cyclotron radiation signals, comprises the following steps: Controlling waveguide switches in quasi-optical transmission modules of at least one group of microwave systems to switch between a first state and a second state so that the two groups of microwave systems correspondingly form a first annular phase difference and a second annular phase difference in different time sequence sections; In a time sequence section corresponding to the first circumferential phase difference, synchronously acquiring electronic temperature information of two groups of microwave systems at the same radial channel, and carrying out time average processing on the electronic temperature information to obtain average temperatures of the two groups of radial channels; normalizing the temperature difference of the average temperatures of the two groups of radial channels at the same radial channel, and judging whether a seed magnetic island corresponding to the first circumferential modulus is identified or not based on a comparison result of the normalized difference and a preset judgment condition; in a time sequence section corresponding to the second circumferential phase difference, synchronously acquiring electronic temperature information of two groups of microwave systems at the same radial channel, and carrying out time averag