Electron cyclotron radiometer with calibration coefficient compensation function and compensation method

Abstract

The invention relates to the field of plasma diagnosis, in particular to an electron cyclotron radiometer with a calibration coefficient compensation function and a compensation method.The electron cyclotron radiometer comprises a signal generation module, a microwave transmitting and receiving assembly, a signal processing module, an adjustable attenuator and a data acquisition module, and all the modules work cooperatively to achieve dynamic compensation of calibration coefficients; real-time monitoring and dynamic compensation of the calibration coefficient in the diagnosis window coating film forming process are achieved, it is ensured that the calibration coefficient of the electron cyclotron radiometer can still be kept stable in the complex environment, and therefore the accuracy and reliability of electron temperature measurement are effectively improved, and by dynamically adjusting the gain value of the adjustable attenuator, the accuracy and reliability of electron temperature measurement are improved. The problem of transmission signal attenuation caused by window coating can be compensated, so that the measured transmission signal intensity is consistent with an initial calibration state, and the accuracy of a measurement result is ensured.

Description

Technical Field

[0001] The invention relates to the field of plasma diagnosis, and in particular to an electron cyclotron radiometer with a calibration coefficient compensation function and a compensation method. Background Art

[0002] The electron cyclotron radiometer is a plasma diagnostic tool based on microwave receiving technology. It is widely used in magnetic confinement devices such as tokamaks to measure the electron temperature distribution and perturbation information of plasma. This device has become an important experimental means for plasma physics research due to its excellent local measurement capability and high temporal and spatial resolution. Tokamaks around the world generally use electron cyclotron radiometers to obtain electron temperature profiles and perturbation data, providing important experimental support for in-depth research on plasma behavior.

[0003] However, in actual operation, the diagnostic window of the electron cyclotron radiometer will form a coating due to the attachment of impurity ions (such as carbon impurities) during the plasma discharge process. This window coating phenomenon intensifies with the increase in the number of discharges, causing the microwave signal from the plasma to undergo additional reflection or transmission attenuation in the diagnostic window, causing the calibration coefficient to change, which directly affects the measurement accuracy of the electron temperature.

[0004] Although the existing technology attempts to reduce the influence of coating by improving window materials and optimizing microwave antennas, it is difficult to completely solve the interference of window coating on the calibration coefficient. This interference not only causes the electronic temperature measurement value to deviate from the true value, but also reduces the reliability of the measurement data. Therefore, how to effectively compensate for the change in calibration coefficient caused by window coating has become an important technical challenge to improve the measurement accuracy of electron cyclotron radiometers. Summary of the invention

[0005] The technical problem to be solved by the present invention is that the diagnostic window coating causes the calibration coefficient of the electron cyclotron radiometer to be unstable, thereby affecting the accuracy of the electron temperature measurement. The purpose is to provide an electron cyclotron radiometer with a calibration coefficient compensation function and a compensation method, which realizes real-time monitoring and dynamic compensation of the changes in the calibration coefficient, and ensures the accuracy and reliability of the electronic temperature measurement data.

[0006] The present invention is achieved through the following technical solutions:

[0007] An electronic cyclotron radiometer with a calibration coefficient compensation function, comprising:

[0008] A signal generating module, which is used to output a radio frequency signal of a frequency sweep waveform;

[0009] A microwave transmitting and receiving component, which is used to transmit a frequency sweep signal to the diagnostic window and receive a narrowband signal reflected from the diagnostic window and a broadband signal transmitted to the plasma;

[0010] A signal processing module, which is used to perform frequency separation and amplification on the received broadband signal and narrowband signal respectively;

[0011] An adjustable attenuator, which is used to dynamically adjust the gain of the transmission signal according to the change of the intensity of the reflected signal of the diagnostic window;

[0012] A data acquisition module, which is used to collect the compensated transmission signal and adjust the calibration coefficient to keep the calibration coefficient stable;

[0013] The signal input end of the microwave transmitting and receiving component is connected to a signal output end of the signal generating module, the signal output end of the microwave transmitting and receiving component is connected to the signal processing module, and is mixed with the radio frequency signal output from another signal output end of the signal generating module in the signal processing module, and the output end of the signal processing module is connected to the data acquisition module.

[0014] Specifically, the signal generating module includes a voltage-controlled local oscillator source and a voltage source. The voltage source outputs a periodic voltage waveform to the voltage-controlled local oscillator source through programming, and controls the voltage-controlled local oscillator source to output a radio frequency signal with a swept frequency waveform.

[0015] Optionally, the microwave transmitting and receiving component is a microwave antenna, and the data acquisition module is a high-speed collector.

[0016] Specifically, the signal processing module includes:

[0017] A radio frequency low noise amplifier, whose input end is connected to the signal output end of the microwave transmitting and receiving component;

[0018] A mixer, wherein a first input end thereof is connected to the output end of the radio frequency low noise amplifier, and a second input end thereof is connected to another signal output end of the signal generating module;

[0019] A low-frequency low-pass filter, an input end of which is connected to one output end of the mixer;

[0020] A bandpass filter, an input end of which is connected to another output end of the mixer;

[0021] A first intermediate frequency amplifier, whose input end is connected to the output end of the bandpass filter, and whose output end is connected to the data acquisition module through an adjustable attenuator;

[0022] The second intermediate frequency amplifier has an input end connected to the output end of the low-frequency low-pass filter, and an output end connected to the data acquisition module.

[0023] Optionally, the signal processing module further includes:

[0024] A first isolator, which is arranged between the radio frequency low noise amplifier and the mixer;

[0025] A second isolator, which is arranged between the voltage-controlled local oscillator source and the mixer;

[0026] A detector, whose input end is connected to the output end of the adjustable attenuator;

[0027] A video amplifier, whose input end is connected to the output end of the detector, and whose output end is connected to the data acquisition module.

[0028] Optionally, the operating frequency range of the electron cyclotron radiometer is 60-90 GHz, and the microwave transmitting and receiving assembly includes a rotating standard E-band microwave antenna;

[0029] The signal generation module includes a standard E-band voltage-controlled local oscillator source, whose output sweep frequency is 60-90 GHz and the sweep period is 100 microseconds.

[0030] The radio frequency low noise amplifier, the first isolator, the second isolator and the mixer are all standard E-band devices;

[0031] The passband range of the low-frequency low-pass filter is DC-20MHz, the passband range of the bandpass filter is 100-300MHz, the operating frequency band of the first intermediate frequency amplifier is 100-300MHz, the operating frequency band of the second intermediate frequency amplifier is 1-20MHz, the operating frequency range of the adjustable attenuator is 100-300MHz, and the attenuation range is 0-30dB; the sampling rate of the data acquisition module is 100MSa / s.

[0032] A calibration coefficient compensation method is based on the electron cyclotron radiometer with calibration coefficient compensation function as described above, and the compensation method comprises:

[0033] Before the window coating is formed, the gain of the adjustable attenuator is initialized, and the initial reflection signal intensity and the initial transmission signal intensity are recorded, and the calibration coefficient is determined;

[0034] Real-time acquisition of the reflected signal intensity and the transmitted signal intensity from the diagnosis window;

[0035] Compare the real-time reflected signal strength with the initial calibrated reflected signal strength, and calculate the enhancement ratio of the reflected signal;

[0036] Quantification is performed based on the consistency of the ratio of the reflected signal intensity change to the transmitted signal intensity change, and the attenuation of the transmitted signal is calculated according to the reflected signal enhancement ratio;

[0037] According to the attenuation of the transmission signal, the gain value of the adjustable attenuator is dynamically adjusted to compensate for the loss of the transmission signal until the actual transmission signal intensity is consistent with the initial transmission signal intensity;

[0038] The calibration coefficient is updated according to the real-time reflection signal intensity and the compensated transmission signal intensity.

[0039] Furthermore, different calibration coefficients are determined according to different frequencies.

[0040] Specifically, the enhancement ratio of the reflected signal is: Among them, G r is the reflection signal enhancement coefficient, I r is the voltage amplitude of the reflected signal collected in real time, I r0 is the voltage amplitude of the initially collected reflected signal;

[0041] Attenuation adjustment of adjustable attenuator: Ad r =log 10 (G r 2 )×10, where Ad r It is the attenuation adjustment of the adjustable attenuator.

[0042] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0043] The present invention introduces a calibration coefficient compensation mechanism, sets up a system architecture including key components such as a voltage-controlled local oscillator source, a microwave antenna, an adjustable attenuator and a data acquisition module in the electronic cyclotron radiometer, and outputs a frequency-sweep waveform radio frequency signal through a signal generation module; the microwave antenna is responsible for transmitting the signal to the diagnostic window, and receiving the reflected signal and the transmitted signal at the same time, and the signal processing module performs frequency separation, amplification and mixing processing on the signal. The adjustable attenuator dynamically adjusts the gain value of the transmitted signal according to the changes in the intensity of the reflected signal and the transmitted signal collected in real time, and the data acquisition module further analyzes the compensated transmitted signal, and updates the calibration coefficient in real time to ensure the stability and accuracy of the measured data.

[0044] Through the above technical scheme, the present invention realizes real-time monitoring and dynamic compensation of the calibration coefficient during the diagnostic window coating formation process, ensuring that the calibration coefficient of the electron cyclotron radiometer can remain stable in complex environments, thereby effectively improving the accuracy and reliability of electronic temperature measurement.

[0045] By dynamically adjusting the gain value of the adjustable attenuator, the transmission signal attenuation problem caused by the window coating can be compensated, so that the measured transmission signal intensity is consistent with the initial calibration state, ensuring the accuracy of the measurement results.

[0046] Through the precise acquisition and analysis of real-time signals by the high-speed data acquisition module, the calibration coefficient can be accurately adjusted according to different frequency conditions to adapt to the complex and changeable plasma diagnostic environment, thereby providing high-quality experimental data support for plasma physics research. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings illustrate exemplary embodiments of the present invention and, together with the description thereof, are used to explain the principles of the present invention. These drawings are included to provide a further understanding of the present invention, and the accompanying drawings are included in and constitute a part of this specification and do not constitute a limitation of the embodiments of the present invention.

[0048] Figure 1 It is a structural schematic diagram of an electron cyclotron radiometer with a calibration coefficient compensation function according to the present invention.

[0049] Figure 2 is a schematic diagram of the reflected signal strength according to the present invention.

[0050] Figure 3 is a plasma electron temperature profile diagram measured according to the present invention.

[0051] Figure numerals: 1-microwave antenna, 2-RF low noise amplifier, 3-first isolator, 4-mixer, 5-second isolator, 6-voltage-controlled local oscillator source, 7-voltage source, 8-bandpass filter, 9-first intermediate frequency amplifier, 10-adjustable attenuator, 11-detector, 12-video amplifier, 13-low-frequency low-pass filter, 14-second intermediate frequency amplifier, 15-high-speed collector. DETAILED DESCRIPTION

[0052] To make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and implementation methods. It is understood that the specific implementation methods described herein are only used to explain the relevant content, rather than to limit the present invention.

[0053] It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the drawings.

[0054] In the absence of conflict, the embodiments and features of the embodiments of the present invention may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0055] Embodiment 1

[0056] like Figure 1As shown, an electronic cyclotron radiometer with calibration coefficient compensation function is provided, and its overall design goal is to solve the influence of diagnostic window coating on calibration coefficient stability and measurement accuracy through dynamic compensation technology. The main functional modules of the radiometer include signal generation module, microwave transmitting and receiving component, signal processing module, adjustable attenuator 10 and data acquisition module, and each module works together to realize dynamic compensation of calibration coefficient.

[0057] The signal generation module is used to output a RF signal with a swept frequency waveform; the signal generation module generates a RF signal with a swept frequency waveform and transmits it to the diagnosis window through a microwave transmitting and receiving component, and at the same time sends a part of the signal to the signal processing module for mixing processing.

[0058] The microwave transmitting and receiving component is used to transmit a frequency sweep signal to the diagnostic window, and receive a narrowband signal reflected from the diagnostic window and a broadband signal transmitted to the plasma;

[0059] The signal processing module is used to perform frequency separation and amplification on the received broadband signal and narrowband signal respectively;

[0060] The adjustable attenuator 10 is used to dynamically adjust the gain of the transmission signal according to the change of the intensity of the reflected signal of the diagnostic window;

[0061] The data acquisition module is used to collect the compensated transmission signal and adjust the calibration coefficient to keep the calibration coefficient stable;

[0062] The signal input end of the microwave transmitting and receiving component is connected to a signal output end of the signal generating module, the signal output end of the microwave transmitting and receiving component is connected to the signal processing module, and is mixed with the radio frequency signal output from another signal output end of the signal generating module in the signal processing module, and the output end of the signal processing module is connected to the data acquisition module.

[0063] In this embodiment, the signal generation module provides a unified frequency reference, the microwave antenna 1 transmits signals and receives echoes, and the signal processing module separates and amplifies the reflected and transmitted signals. The adjustable attenuator 10 dynamically compensates the gain of the transmitted signal according to the change in the intensity of the reflected signal, and the data acquisition module further records and adjusts the calibration coefficient in real time. Real-time compensation for the change in the calibration coefficient caused by the window coating is achieved, ensuring the measurement accuracy of the electron cyclotron radiometer in complex environments.

[0064] Embodiment 2

[0065] like Figure 1 The electron cyclotron radiometer is described in detail as shown in FIG. In the whole link of signal generation, reception, processing and acquisition, the electron cyclotron radiometer adopts a multi-module collaborative design to achieve accurate compensation and dynamic adjustment of the calibration coefficient.

[0066] The signal generation module includes a voltage-controlled local oscillator source 6 and a voltage source 7. The voltage source 7 is programmed to output a periodic voltage waveform to the voltage-controlled local oscillator source 6, and controls the voltage-controlled local oscillator source 6 to output a radio frequency signal with a swept frequency waveform. The voltage source 7 is programmed to output a periodic voltage waveform, and controls the voltage-controlled local oscillator source 6 to generate a radio frequency signal with a swept frequency waveform, providing a transmission signal for the microwave antenna 1, and also providing a local oscillator signal for the mixer 4, to ensure the uniformity and accuracy of the signal frequency.

[0067] The microwave transmitting and receiving component is a microwave antenna 1, and the transmitting function is to transmit the swept frequency radio frequency signal to the diagnostic window. The receiving function is to receive the narrowband signal reflected from the window and the broadband signal transmitted to the plasma, and transmit them to the signal processing module for processing.

[0068] The adjustable attenuator 10 dynamically adjusts the gain of the transmission signal according to the change of the intensity of the reflected signal, compensates for the signal attenuation caused by the window coating, and keeps the intensity of the transmission signal consistent.

[0069] The data acquisition module is a high-speed data acquisition device 15, which collects the compensated transmission signal and narrow-band reflection signal.

[0070] The signal processing module includes: a radio frequency low noise amplifier 2, a mixer 4, a filter, an isolator, an amplifier, a detector 11 and a video amplifier 12, etc.

[0071] The input end of the radio frequency low noise amplifier 2 is connected to the signal output end of the microwave transmitting and receiving component; the signal received by the microwave antenna 1 is amplified and the system noise is reduced at the same time.

[0072] The first input end of the mixer 4 is connected to the output end of the RF low noise amplifier 2, and the second input end thereof is connected to another signal output end of the signal generation module; the mixing process is completed and the intermediate frequency signal is output. The mixer 4 generates two outputs: one for the low-frequency low-pass filter 13 to process the narrowband signal, and the other for the bandpass filter 8 to process the broadband signal.

[0073] The input end of the low-frequency low-pass filter 13 is connected to one output end of the mixer 4; a narrowband reflection signal is extracted from the mixed output signal to filter high-frequency interference.

[0074] The input end of the bandpass filter 8 is connected to another output end of the mixer 4; the broadband transmission signal of the mixer output is extracted, and the signal within the target frequency range is retained.

[0075] The input end of the first intermediate frequency amplifier 9 is connected to the output end of the bandpass filter 8, and the output end thereof is connected to the data acquisition module through the adjustable attenuator 10; the first intermediate frequency amplifier 9 amplifies the broadband signal extracted by the bandpass filter 8 and transmits it to the adjustable attenuator 10;

[0076] The second intermediate frequency amplifier 14 has an input end connected to the output end of the low-frequency low-pass filter 13 and an output end connected to the data acquisition module. The second intermediate frequency amplifier 14 amplifies the narrowband signal extracted by the low-frequency low-pass filter 13 and transmits it to the data acquisition module.

[0077] The first isolator 3 is arranged between the RF low noise amplifier 2 and the mixer 4 , and is used to prevent the low noise amplifier output signal from interfering with the mixer 4 .

[0078] The second isolator 5 is arranged between the voltage-controlled local oscillator source 6 and the mixer 4 , and is used to prevent the signal reflection of the voltage-controlled local oscillator source 6 from interfering with the normal operation of the mixer 4 .

[0079] The input end of the detector 11 is connected to the output end of the adjustable attenuator 10; the detector 11 converts the broadband signal into a low-frequency signal.

[0080] The input end of the video amplifier 12 is connected to the output end of the detector 11 , and the output end of the video amplifier 12 is connected to the data acquisition module.

[0081] This embodiment provides an electronic cyclotron radiometer with a calibration coefficient compensation function, which is based on radiation receiver technology and outputs a periodic voltage waveform to a voltage-controlled local oscillator source 6 by programming a voltage source 7, thereby controlling the voltage-controlled local oscillator source 6 to output a RF signal with a swept frequency waveform.

[0082] The RF signal is divided into two paths, one path is used as the local oscillator signal of the mixer 4 of the electron cyclotron radiometer, and the other path is used as the transmission signal, which is transmitted to the microwave waveguide through the microwave antenna 1 and finally propagates through the diagnostic window. The RF signal is transmitted and reflected in the diagnostic window, wherein the transmission signal enters the plasma and the reflection signal returns to the electron cyclotron radiometer.

[0083] When plasma discharges, it radiates microwave signals, which enter the microwave antenna 1 through the diagnostic window and microwave transmission line and are finally received by the electron cyclotron radiometer. Therefore, the radiation signals received by the electron cyclotron radiometer are divided into two types: (1) broadband signals from the discharge plasma; (2) narrowband signals reflected from the diagnostic window.

[0084] Both signals are within the working range of the RF part of the electron cyclotron radiometer and are amplified by a low-noise RF amplifier. Subsequently, the signal enters the mixer 4 through the isolator and is mixed with the RF signal of the voltage-controlled local oscillator 6 to obtain their respective intermediate frequency signals. Among them, the intermediate frequency of the diagnostic window reflection signal is very fixed and has strong coherence, and its frequency is mainly determined by the transmission line length and the frequency sweep period. Therefore, this signal is easy to separate from the total intermediate frequency signal.

[0085] In order to reduce the interference from the plasma signal, the diagnostic window reflection signal is extracted through a low-frequency low-pass filter 13 after mixing, and is directly collected by a high-speed collector 15 after being amplified by a second intermediate frequency amplifier 14. The electron cyclotron radiation signal from the plasma is filtered by a high-frequency bandpass filter 8, amplified by a first intermediate frequency amplifier 9, and then sent to a detector 11 after adjusting the gain by an adjustable attenuator 10 to obtain the electron cyclotron radiation signal intensity. Finally, the detected signal is amplified by a video amplifier 12 and collected by a high-speed collector 15.

[0086] In this embodiment, the signal is divided into a diagnostic window reflection signal and a plasma electron cyclotron radiation signal by a low-frequency low-pass filter 13 and a bandpass filter 8. When the coating of the diagnostic window gradually increases, the intensity of the diagnostic window reflection signal will increase, while the intensity of the electron cyclotron radiation signal transmitted to the plasma will decrease. This signal intensity change reflects the corresponding behavior characteristics of the same frequency signal on the diagnostic window, that is, the ratio of the reflection signal intensity increase is exactly the same as the ratio of the transmission signal intensity decrease.

[0087] Based on this characteristic, this embodiment records the reflected signal intensity of the electron cyclotron radiometer at different frequencies during the initial calibration phase, and compares it with the reflected signal intensity collected after the diagnostic window is coated, and calculates the enhancement ratio of the reflected signal. The transmission signal intensity is compensated by the adjustable attenuator 10, so that the actual transmission signal intensity is restored to the initial calibration state, thereby achieving the goal of keeping the calibration coefficient of the electron cyclotron radiometer unchanged. This compensation process can effectively eliminate the influence of the window coating on the measurement accuracy of the electron cyclotron radiometer, and ensure the reliability and accuracy of the measurement results.

[0088] Embodiment 3

[0089] The electron cyclotron radiometer of this embodiment is designed with an architecture suitable for an operating frequency range of 60-90 GHz.

[0090] The operating frequency range of the electron cyclotron radiometer is 60-90 GHz, and the microwave transmitting and receiving assembly includes a rotating standard E-band microwave antenna 1;

[0091] The signal generation module comprises a standard E-band voltage-controlled local oscillator source 6, whose output sweep frequency is 60-90 GHz and whose sweep period is 100 microseconds.

[0092] The radio frequency low noise amplifier 2, the first isolator 3, the second isolator 5 and the mixer 4 are all standard E-band devices, ensuring efficient transmission and processing of signals within the E-band range.

[0093] The passband range of the low-frequency low-pass filter 13 is DC-20MHz, so as to cover the intermediate frequency of the reflected signal of 10MHz and filter out high-frequency interference. The passband range of the bandpass filter 8 is 100-300MHz, which is used to process the plasma electron cyclotron radiation signal to avoid interference from the reflected signal. The working frequency band of the first intermediate frequency amplifier 9 is 100-300MHz, the working frequency band of the second intermediate frequency amplifier 14 is 1-20MHz, the working frequency range of the adjustable attenuator 10 is 100-300MHz, and the attenuation range is 0-30dB; when the diagnostic window coating is aggravated, the reflected signal intensity is enhanced and the transmitted signal intensity is weakened. By real-time acquisition of the enhancement ratio of the reflected signal, calculating the attenuation of the transmitted signal, and adjusting the gain value of the adjustable attenuator 10, signal compensation is achieved to ensure that the transmission signal intensity is consistent with the initial calibration state.

[0094] The sampling rate of the data acquisition module is 100MSa / s, which collects the diagnostic window reflection signal and the plasma electron cyclotron radiation signal for real-time adjustment and analysis of the calibration coefficient.

[0095] The transmission line length from the microwave antenna to the diagnostic window is set to 5 meters, and the frequency sweep rate is output by the voltage-controlled local oscillator source. The round trip time (time delay) from microwave emission to reception in the diagnostic window The intermediate frequency of the reflected signal is f f =v×t=3×10 5 ×3.33×10 -8 =10MHz, therefore, the intermediate frequency of the reflected signal is fixed at 10MHz, which has strong coherence.

[0096] Embodiment 4

[0097] A calibration coefficient compensation method is based on an electron cyclotron radiometer with a calibration coefficient compensation function. By real-time acquisition and analysis of reflection signals and transmission signals, the gain of an adjustable attenuator is dynamically adjusted to compensate for the influence of window coating on the transmission signal, thereby maintaining the stability of the calibration coefficient. The compensation method includes:

[0098] Before the window coating is formed, the gain of the adjustable attenuator is initialized, and the initial reflection signal intensity and initial transmission signal intensity are recorded, and the calibration coefficient is determined, and different calibration coefficients are determined according to different frequencies. The initial reflection signal intensity records the reflection signal intensity of different frequencies when the diagnostic window is not coated; the initial transmission signal intensity records the broadband signal intensity transmitted to the plasma as the reference transmission signal intensity.

[0099] Real-time acquisition of the reflected signal intensity and the transmitted signal intensity from the diagnosis window;

[0100] Compare the real-time reflection signal intensity with the initial calibration reflection signal intensity, and calculate the enhancement ratio of the reflection signal; this reflects the degree of enhancement of the reflection signal by the window coating.

[0101] Quantification is performed based on the consistency of the ratio of the reflected signal intensity change to the transmitted signal intensity change, and the attenuation of the transmitted signal is calculated according to the reflected signal enhancement ratio;

[0102] According to the attenuation of the transmission signal, the gain value of the adjustable attenuator is dynamically adjusted to compensate for the loss of the transmission signal until the actual transmission signal intensity is consistent with the initial transmission signal intensity;

[0103] The calibration coefficient is updated according to the real-time reflection signal intensity and the compensated transmission signal intensity.

[0104] That is, based on the enhancement ratio of the reflected signal, the attenuation of the adjustable attenuator is actively adjusted so that the calibration coefficient is compensated and remains unchanged, wherein the calibration coefficient is obtained by the calibration method, and the calibration coefficient does not change. After the window is coated, the calibration coefficient is kept unchanged by adjusting the adjustable attenuator. The invention compensates the system signal gain by the adjustable attenuator so that the calibration coefficient remains unchanged.

[0105] The algorithm formula for each step is:

[0106] Calculate the enhancement ratio of the reflected signal: G r is the reflection signal enhancement coefficient, I r is the voltage amplitude of the reflected signal collected in real time, I r0 is the voltage amplitude of the initially collected reflected signal.

[0107] Calculate the attenuation adjustment of the adjustable attenuator: Ad r =log 10 (G r 2 )×10dB. r It is the attenuation adjustment of the adjustable attenuator, in dB.

[0108] Embodiment 5

[0109] This embodiment provides a specific example.

[0110] The attenuation value of the adjustable attenuator is set to 20dB to ensure that the signal link is in the calibration reference state. The reflected link signal is collected, and the result is as follows Figure 2 The blue line in the figure shows the reflected voltage signal when the diagnostic window is not coated. Under this baseline condition, the measured plasma electron temperature profile is as follows: Figure 3 The black dashed line in FIG is used as the initial calibration profile.

[0111] After a period of plasma discharge, the reflected signal is enhanced due to the influence of the diagnostic window coating. The collected reflected link signal is as follows: Figure 2 As shown by the orange line in the figure, the voltage signal intensity is twice that of the calibration. If the transmission signal is not compensated and the electron temperature profile is measured directly, the following will be obtained: Figure 3 As shown by the yellow line in the figure, its intensity is only 1 / 4 of that during calibration, resulting in serious distortion of the measured data.

[0112] According to the reflection signal intensity enhancement ratio (2 times), the attenuation value of the adjustable attenuator is dynamically adjusted from 20dB to 14dB to compensate for the gain of the transmission signal link. After compensation, the electron temperature profile is measured again, and the results are as follows: Figure 3 As shown by the orange line in , it is completely consistent with the black dotted line profile during calibration.

[0113] By adjusting the adjustable attenuator, the calibration coefficient is stabilized. After the window is coated, dynamic compensation is used to maintain the balance of the reflection signal and transmission signal links, ensuring that the calibration coefficient does not drift. The electron temperature profile remains consistent with the calibration in the coating state, avoiding measurement errors caused by window coating.

[0114] In addition, the application scenarios of this invention are not limited to tokamak devices, but can also be applied to any device that can be diagnosed by an electron cyclotron radiation receiver, such as a stellarator device.

[0115] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments / methods or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments / methods or examples described in this specification and the features of the different embodiments / methods or examples, unless they are contradictory.

[0116] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0117] It should be understood by those skilled in the art that the above embodiments are only for the purpose of clearly illustrating the present invention, and are not intended to limit the scope of the present invention. For those skilled in the art, other changes or modifications may be made based on the above invention, and these changes or modifications are still within the scope of the present invention.

Claims

1. An electron cyclotron radiometer with calibration coefficient compensation function, characterized in that: include: A signal generating module, which is used to output a radio frequency signal of a frequency sweep waveform; A microwave transmitting and receiving component, which is used to transmit a frequency sweep signal to the diagnostic window and receive a narrowband signal reflected from the diagnostic window and a broadband signal transmitted to the plasma; A signal processing module, which is used to perform frequency separation and amplification on the received broadband signal and narrowband signal respectively; An adjustable attenuator (10) is used to dynamically adjust the gain of the transmission signal according to the change in the intensity of the reflected signal of the diagnostic window; A data acquisition module, which is used to collect the compensated transmission signal and adjust the calibration coefficient to keep the calibration coefficient stable; The signal input end of the microwave transmitting and receiving component is connected to a signal output end of the signal generating module, the signal output end of the microwave transmitting and receiving component is connected to the signal processing module, and is mixed with the radio frequency signal output from another signal output end of the signal generating module in the signal processing module, and the output end of the signal processing module is connected to the data acquisition module.

2. The electron cyclotron radiometer with calibration coefficient compensation function according to claim 1, characterized in that: The signal generation module comprises a voltage-controlled local oscillator source (6) and a voltage source (7). The voltage source (7) outputs a periodic voltage waveform to the voltage-controlled local oscillator source (6) through programming, thereby controlling the voltage-controlled local oscillator source (6) to output a radio frequency signal with a swept frequency waveform.

3. The electron cyclotron radiometer with calibration coefficient compensation function according to claim 2, characterized in that: The microwave transmitting and receiving component is a microwave antenna (1), and the data acquisition module is a high-speed data collector (15).

4. The electron cyclotron radiometer with calibration coefficient compensation function according to claim 1, characterized in that: The signal processing module comprises: A radio frequency low noise amplifier (2), the input end of which is connected to the signal output end of the microwave transmitting and receiving component; A mixer (4), a first input end of which is connected to the output end of the radio frequency low noise amplifier (2), and a second input end of which is connected to another signal output end of the signal generating module; A low-frequency low-pass filter (13), an input end of which is connected to one output end of the mixer (4); A bandpass filter (8), an input end of which is connected to another output end of the mixer (4); A first intermediate frequency amplifier (9), whose input end is connected to the output end of the bandpass filter (8), and whose output end is connected to the data acquisition module via an adjustable attenuator (10); The second intermediate frequency amplifier (14) has an input end connected to the output end of the low-frequency low-pass filter (13), and an output end connected to the data acquisition module.

5. The electron cyclotron radiometer with calibration coefficient compensation function according to claim 4, characterized in that: The signal processing module also includes: A first isolator (3) arranged between the radio frequency low noise amplifier (2) and the mixer (4); A second isolator (5), which is arranged between the signal generating module and the mixer (4); A detector (11), the input end of which is connected to the output end of the adjustable attenuator (10); A video amplifier (12) has an input end connected to the output end of the detector (11), and an output end of the video amplifier (12) connected to the data acquisition module.

6. The electron cyclotron radiometer with calibration coefficient compensation function according to claim 3, characterized in that: The operating frequency range of the electron cyclotron radiometer is 60-90 GHz, and the microwave transmitting and receiving component comprises a rotating standard E-band microwave antenna (1); The signal generation module comprises a standard E-band voltage-controlled local oscillator source (6), whose output frequency sweeping frequency is 60-90 GHz and whose frequency sweeping period is 100 microseconds.

7. The electron cyclotron radiometer with calibration coefficient compensation function according to claim 5, characterized in that: The radio frequency low noise amplifier (2), the first isolator (3), the second isolator and the mixer (4) are all standard E-band devices; The passband range of the low-frequency low-pass filter (13) is DC-20 MHz, the passband range of the band-pass filter (8) is 100-300 MHz, the working frequency band of the first intermediate frequency amplifier (9) is 100-300 MHz, the working frequency band of the second intermediate frequency amplifier (14) is 1-20 MHz, the working frequency range of the adjustable attenuator (10) is 100-300 MHz, and the attenuation range is 0-30 dB; the sampling rate of the data acquisition module is 100 MSa / s.

8. A method for compensating a calibration coefficient, characterized in that: Based on the electron cyclotron radiometer with calibration coefficient compensation function as described in any one of claims 1 to 7, the compensation method comprises: Before the window coating is formed, the gain of the adjustable attenuator is initialized, and the initial reflection signal intensity and the initial transmission signal intensity are recorded, and the calibration coefficient is determined; Real-time acquisition of the reflected signal intensity and the transmitted signal intensity from the diagnosis window; Compare the real-time reflected signal strength with the initial calibration reflected signal strength, and calculate the enhancement ratio of the reflected signal; Quantification is performed based on the consistency of the ratio of the reflected signal intensity change to the transmitted signal intensity change, and the attenuation of the transmitted signal is calculated according to the reflected signal enhancement ratio; According to the attenuation of the transmission signal, the gain value of the adjustable attenuator is dynamically adjusted to compensate for the loss of the transmission signal until the actual transmission signal intensity is consistent with the initial transmission signal intensity; The calibration coefficient is updated according to the real-time reflection signal intensity and the compensated transmission signal intensity.

9. A calibration coefficient compensation method according to claim 8, characterized in that: Different calibration coefficients are determined according to different frequencies.

10. A calibration coefficient compensation method according to claim 8, characterized in that: Enhancement ratio of reflected signal: Among them, G r is the reflection signal enhancement coefficient, I r is the voltage amplitude of the reflected signal collected in real time, I r0 is the voltage amplitude of the initially collected reflected signal; Attenuation adjustment of adjustable attenuator: Ad r =log 10 (G r 2 )×10, where Ad r It is the attenuation adjustment of the adjustable attenuator.

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