Superconductor transmission induced potential processing and parameter calculation system, method and apparatus

Abstract

The application relates to a superconductor transmission induced potential processing and parameter calculation system, method, device, computer equipment, readable storage medium and program product, and relates to the technical field of electromagnetic property measurement. The system can improve signal measurement accuracy. The system comprises a gating and triggering module, a radio frequency signal generation and amplification module, a transmitting coil, a superconducting sample placement area, a receiving coil, a compensation coil, a differential connection or differential amplification module, a filtering and preamplification module, a signal acquisition module and a data processing and magnetic field synchronization module. The differential connection or differential amplification module is connected with the output ends of the receiving coil and the compensation coil respectively, is used for differentially offsetting the magnetic field lifting background induced potential shared by the receiving coil and the compensation coil at the hardware level, and outputs a differential signal retaining the electromagnetic response of the superconducting sample; and the data processing and magnetic field synchronization module is connected with the signal acquisition module, is used for matching the compensated differential signal with a corresponding magnetic field value and calculating superconducting electromagnetic parameters.

Description

Technical Field

[0001] This application relates to the field of electromagnetic property measurement technology, and in particular to a system, method, apparatus, computer equipment, computer-readable storage medium, and computer program product for processing and calculating the transmission induced potential and parameters of a superconductor. Background Technology

[0002] As a core foundational material in cutting-edge modern technologies, the electromagnetic response of superconducting materials under strong magnetic fields—such as critical magnetic field, magnetic flux penetration behavior, surface impedance, AC resistivity, and superconducting transition behavior—is a crucial parameter for evaluating their performance and studying the physical mechanisms of superconductivity. For these parameters, non-contact inductive measurement methods, which eliminate the need for electrodes on the sample surface and avoid issues such as contact resistance, wire bonding, and sample morphology limitations, are particularly suitable for measuring small, brittle, and extreme-environment superconducting samples.

[0003] In traditional non-contact superconductivity measurement methods, a transmitting coil or excitation coil is located on one side of the sample, and a receiving coil is located on the other side, with the superconducting sample positioned between the transmitting and receiving coils. The transmitting coil generates an alternating electromagnetic field, which, after passing through or acting on the superconducting sample, is induced as a voltage signal by the receiving coil. The sample's conductivity, magnetic shielding capability, skin depth, London penetration depth, eddy current response, and superfluid response differ between its normal and superconducting states, thus altering the amplitude, phase, or potential of the signal induced in the receiving coil. By analyzing the changes in the received signal with temperature, magnetic field, or time, the superconducting transition of the sample can be determined, and relevant electromagnetic parameters can be extracted.

[0004] For coil induction measurements, the induced electromotive force in the receiving coil typically satisfies Faraday's law of electromagnetic induction:

[0005]

[0006] In the above formula, V is the induced electromotive force of the coil, N is the number of turns of the coil, and Φ is the magnetic flux through the coil. If the magnetic field is approximately uniform and the effective area of ​​the coil is S, then:

[0007]

[0008] In the above formula, B is the external magnetic induction intensity, and θ is the angle between the magnetic field direction and the coil normal. The background induced electromotive force generated by the rise and fall of the external magnetic field can then be written as:

[0009]

[0010] However, in environments with steady-state strong magnetic fields undergoing rapid sweeps or pulsed strong magnetic fields, the applied magnetic field itself changes rapidly over time. According to the aforementioned electromagnetic induction relationship, increasing or decreasing the magnetic field will generate additional background induced potentials in the receiving coil, connecting wires, and measurement circuit. This background induced potential is superimposed on the sample's superconducting response signal. Especially when the high magnetic field changes rapidly, the background signal may be much larger than the sample response signal, leading to significant baseline drift, low-frequency background, impulse noise, or spurious signals in the received signal. This makes it difficult to accurately extract the true signal generated after penetrating the superconductor, resulting in low signal measurement accuracy. Summary of the Invention

[0011] Therefore, it is necessary to provide a system, method, apparatus, computer equipment, computer-readable storage medium, and computer program product for processing and calculating the transmission induced potential and parameters of superconductors, in order to address the above-mentioned technical problems.

[0012] In a first aspect, this application provides a superconductor transmission induced potential processing and parameter calculation system, the system comprising: a gating and triggering module, a radio frequency signal generation and amplification module, a transmitting coil, a superconducting sample placement area, a receiving coil, a compensation coil, a differential connection or differential amplification module, a filtering and preamplification module, a signal acquisition module, and a data processing and magnetic field synchronization module.

[0013] The transmitting coil and the receiving coil are arranged opposite to each other, and the superconducting sample placement area is located between the transmitting coil and the receiving coil to fix the superconducting sample to be tested; the compensation coil is located near or symmetrically to the receiving coil and is in the same or approximately the same external magnetic field changing environment as the receiving coil.

[0014] The structural parameters of the compensation coil are matched with the background induced potential of the receiving coil. The compensation coil is used to generate a compensation potential that is equal to but opposite in polarity to the background induced potential during the rise and fall of the external magnetic field.

[0015] The differential connection or differential amplification module is connected to the output terminals of the receiving coil and the compensation coil, respectively, and is used to differentially cancel the background induced potential of the magnetic field rise and fall shared by the receiving coil and the compensation coil at the hardware level, and output a differential signal that retains the electromagnetic response of the superconducting sample.

[0016] The output terminal of the radio frequency signal generation and amplification module is connected to the transmitting coil to generate and amplify the radio frequency signal, and to load the amplified radio frequency signal onto the transmitting coil; the gating and triggering module is respectively connected to the control terminal of the radio frequency signal generation and amplification module and the triggering terminal of the signal acquisition module.

[0017] The filtering and preamplification module is connected to the output of the differential connection or differential amplification module, and is used to filter and amplify the differential signal with low noise. The signal acquisition module is connected to the output of the filtering and preamplification module, and is used to acquire the compensated differential signal. The data processing and magnetic field synchronization module is connected to the signal acquisition module, and is used to match the compensated differential signal with the corresponding magnetic field value and calculate the superconducting electromagnetic parameters.

[0018] In one embodiment, the radio frequency (RF) signal generation and amplification module includes: an RF signal source, an RF switch, an RF power amplifier, and a transmitter bandpass filter; the RF signal source is used to output an RF signal at a set frequency; the control terminal of the RF switch is connected to the gate output terminal of the gating and triggering module, and is used to control the on / off state of the RF signal; the RF power amplifier is used to amplify the RF excitation power; the transmitter bandpass filter is used to filter out out-of-band spurious signals; the gating and triggering module includes a pulse signal source, which simultaneously outputs a gating signal and a trigger signal; the gating signal is connected to the control terminal of the RF switch, and is used to control the on / off timing of the RF excitation; the trigger signal is connected to the trigger terminal of the signal acquisition module, and is used to keep the RF excitation and signal acquisition time synchronized.

[0019] In one embodiment, the differential connection or differential amplification module is connected using any of the candidate connection methods; the candidate connection methods include: reverse series connection, differential amplification connection, balanced bridge connection, and adjustable compensation connection.

[0020] In one embodiment, the filtering and preamplification module includes a receiver filter and a low-noise preamplifier connected in sequence; the receiver filter is a bandpass filter used to retain the target radio frequency signal and suppress low-frequency induced interference and spurious signals; the low-noise preamplifier is a differential input amplifier or a single-ended input amplifier; the signal acquisition module includes: a high-resolution oscilloscope, a high-speed data acquisition card, a lock-in amplifier or a phase-sensitive detector; the signal acquisition module is synchronously triggered by the trigger signal of the pulse signal source, and acquires the differentially compensated received waveform in each measurement window.

[0021] In one embodiment, the data processing and magnetic field synchronization module is used to perform the following processing: baseline correction of the acquired waveform and digital phase-sensitive demodulation of the target radio frequency signal; calculation of in-phase component, quadrature component, amplitude and phase based on the demodulated radio frequency signal; matching the signal measured each time with the magnetic field value at the corresponding time to obtain the electromagnetic response curve of the superconducting sample as a function of the magnetic field; and calculating the surface impedance, AC resistivity, critical magnetic field or superconducting transition characteristics of the superconducting sample under test based on the curve, combined with the sample size, coil parameters and electromagnetic model.

[0022] Secondly, this application also provides a method for processing and calculating the transmission induced potential of a superconductor, applied to the superconductor transmission induced potential processing and parameter calculation system described in the above embodiments, the method comprising:

[0023] In the absence of a sample or when the sample does not show a significant superconducting response, background calibration is performed, and the structural parameters of the compensation coil are adjusted so that the background induced potentials of the receiving coil and the compensation coil are differentially canceled at the differential output terminal. The operating parameters of the radio frequency signal source are set, and the pulse signal source outputs a gate signal to the radio frequency switch and triggers the acquisition of the synchronous signal.

[0024] During the start-up of steady-state strong magnetic field rapid sweep or pulsed strong magnetic field, multiple short-time radio frequency measurements are performed at set time intervals; the output of the receiving coil and the output of the compensation coil are reverse-connected, differentially amplified or bridge balanced, and the background induced potential of the magnetic field rise and fall shared by the receiving coil and the compensation coil is differentially canceled at the hardware level, and the compensated differential signal is output.

[0025] The differential signal is acquired, and digital phase-sensitive demodulation is performed on the differential signal. The in-phase component, quadrature component, amplitude, and phase are calculated based on the demodulated differential signal. The signal measured each time is matched with the magnetic field value at the corresponding time to obtain the electromagnetic response curve of the superconducting sample as a function of the magnetic field.

[0026] Based on the aforementioned variation curves, and in conjunction with sample size, coil parameters, and electromagnetic model, the surface impedance, AC resistivity, critical magnetic field, or superconducting transition characteristics of the superconducting sample under test are calculated.

[0027] Thirdly, this application also provides a device for processing and calculating the transmission induced potential of a superconductor, applied to the superconductor transmission induced potential processing and parameter calculation system described in the above embodiments, the device comprising:

[0028] The parameter setting unit is used to perform background calibration and adjust the structural parameters of the compensation coil in the absence of a sample or when the sample does not have a significant superconducting response, so that the background induced potentials of the receiving coil and the compensation coil can be differentially canceled at the differential output terminal; and to set the operating parameters of the radio frequency signal source, so that the pulse signal source outputs a gate signal to the radio frequency switch and triggers the synchronous signal acquisition.

[0029] The signal compensation unit is used to perform multiple short-time radio frequency measurements at set time intervals during the start-up of a steady-state strong magnetic field rapid sweep or pulsed strong magnetic field; it performs reverse series connection, differential amplification or bridge balancing processing on the output of the receiving coil and the output of the compensation coil to differentially cancel the background induced potential of the magnetic field rise and fall shared by the receiving coil and the compensation coil at the hardware level, and outputs the compensated differential signal.

[0030] The phase-sensitive demodulation unit is used to acquire the differential signal, perform digital phase-sensitive demodulation on the differential signal, calculate the in-phase component, quadrature component, amplitude and phase based on the mediated differential signal, match the signal measured each time with the magnetic field value at the corresponding time, and obtain the curve of electromagnetic response of the superconducting sample changing with the magnetic field.

[0031] The result calculation unit is used to calculate the surface impedance, AC resistivity, critical magnetic field, or superconducting transition characteristics of the superconducting sample under test based on the change curve, combined with the sample size, coil parameters, and electromagnetic model.

[0032] Fourthly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0033] In the absence of a sample or with no obvious superconducting response, background calibration is performed, and the structural parameters of the compensation coil are adjusted so that the background induced potentials of the receiving coil and the compensation coil cancel each other out at the differential output. The operating parameters of the radio frequency signal source are set, and a gate signal is output from the pulse signal source to the radio frequency switch to trigger synchronous signal acquisition. During the start-up of steady-state strong magnetic field rapid sweep or pulsed strong magnetic field, multiple short-time radio frequency measurements are performed at set time intervals. The outputs of the receiving coil and the compensation coil are reverse-connected, differentially amplified, or bridged to differentially cancel the background induced potentials of the magnetic field rise and fall shared by the receiving coil and the compensation coil at the hardware level, and the compensated differential signal is output. The differential signal is acquired, and digital phase-sensitive demodulation is performed on the differential signal. The in-phase component, quadrature component, amplitude, and phase are calculated based on the modulated differential signal. The signal of each measurement is matched with the magnetic field value at the corresponding time to obtain the electromagnetic response curve of the superconducting sample as a function of the magnetic field. Based on the curve, combined with the sample size, coil parameters, and electromagnetic model, the surface impedance, AC resistivity, critical magnetic field, or superconducting transition characteristics of the superconducting sample under test are calculated.

[0034] Fifthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0035] In the absence of a sample or with no obvious superconducting response, background calibration is performed, and the structural parameters of the compensation coil are adjusted so that the background induced potentials of the receiving coil and the compensation coil cancel each other out at the differential output. The operating parameters of the radio frequency signal source are set, and a gate signal is output from the pulse signal source to the radio frequency switch to trigger synchronous signal acquisition. During the start-up of steady-state strong magnetic field rapid sweep or pulsed strong magnetic field, multiple short-time radio frequency measurements are performed at set time intervals. The outputs of the receiving coil and the compensation coil are reverse-connected, differentially amplified, or bridged to differentially cancel the background induced potentials of the magnetic field rise and fall shared by the receiving coil and the compensation coil at the hardware level, and the compensated differential signal is output. The differential signal is acquired, and digital phase-sensitive demodulation is performed on the differential signal. The in-phase component, quadrature component, amplitude, and phase are calculated based on the modulated differential signal. The signal of each measurement is matched with the magnetic field value at the corresponding time to obtain the electromagnetic response curve of the superconducting sample as a function of the magnetic field. Based on the curve, combined with the sample size, coil parameters, and electromagnetic model, the surface impedance, AC resistivity, critical magnetic field, or superconducting transition characteristics of the superconducting sample under test are calculated.

[0036] Sixthly, this application also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0037] In the absence of a sample or with no obvious superconducting response, background calibration is performed, and the structural parameters of the compensation coil are adjusted so that the background induced potentials of the receiving coil and the compensation coil cancel each other out at the differential output. The operating parameters of the radio frequency signal source are set, and a gate signal is output from the pulse signal source to the radio frequency switch to trigger synchronous signal acquisition. During the start-up of steady-state strong magnetic field rapid sweep or pulsed strong magnetic field, multiple short-time radio frequency measurements are performed at set time intervals. The outputs of the receiving coil and the compensation coil are reverse-connected, differentially amplified, or bridged to differentially cancel the background induced potentials of the magnetic field rise and fall shared by the receiving coil and the compensation coil at the hardware level, and the compensated differential signal is output. The differential signal is acquired, and digital phase-sensitive demodulation is performed on the differential signal. The in-phase component, quadrature component, amplitude, and phase are calculated based on the modulated differential signal. The signal of each measurement is matched with the magnetic field value at the corresponding time to obtain the electromagnetic response curve of the superconducting sample as a function of the magnetic field. Based on the curve, combined with the sample size, coil parameters, and electromagnetic model, the surface impedance, AC resistivity, critical magnetic field, or superconducting transition characteristics of the superconducting sample under test are calculated.

[0038] The aforementioned superconductor transmission induced potential processing and parameter calculation system, method, apparatus, computer equipment, computer-readable storage medium, and computer program products, based on the traditional non-contact inductive measurement structure consisting of a transmitting coil, a superconducting sample, and a receiving coil, introduce a compensation coil matched to the receiving coil. Through the design of the coil's turns, area, winding direction, relative position, and connection polarity, the compensation coil generates a compensation potential with an amplitude equal to or close to, but opposite in polarity to, the background induced potential of the receiving coil during the rise and fall of the external magnetic field. Simultaneously, because the compensation coil is positioned to receive little or no effective signal after passing through the superconducting sample, the outputs of the two coils, after differential connection, reverse series connection, or differential amplification, can differentially cancel the background induced potential introduced by the rise and fall of the magnetic field at the hardware level, retaining the effective differential signal caused by electromagnetic shielding, penetration, or changes in the radio frequency response of the superconducting sample. This application can significantly reduce the impact of strong magnetic field rise and fall background on non-contact superconductivity measurement, accurately cancel the background induced potential introduced in the receiving circuit by the change of external magnetic field, and accurately extract the real differential signal generated by the electromagnetic response of the superconducting sample. This improves the signal-to-noise ratio, dynamic range and signal measurement accuracy of superconductor electromagnetic response measurement under steady-state rapid sweep field and pulsed strong magnetic field environment, and realizes high-precision non-contact measurement. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a block diagram of a superconductor transmission induced potential processing and parameter calculation system in one embodiment.

[0041] Figure 2 This is a schematic diagram of the circuit structure of a superconductor transmission induced potential processing and parameter calculation system in one embodiment.

[0042] Figure 3 This is a flowchart illustrating the method for processing and calculating parameters of superconductor transmission induced potential in one embodiment.

[0043] Figure 4 This is a structural block diagram of a superconductor transmission induced potential processing and parameter calculation device in one embodiment.

[0044] Figure 5 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0046] Glossary of terms related to this application:

[0047] Non-contact measurement: refers to the measurement process that does not require the fabrication of electrodes or direct electrical connections on the sample, but instead obtains sample information through coils, electromagnetic coupling, magnetic field transmission, or induction.

[0048] Transmitting coil: A coil used to generate alternating magnetic fields or radio frequency magnetic fields; it can also be called an excitation coil.

[0049] Receiving coil: A coil used to receive electromagnetic signals that pass through or are modulated by a sample and convert them into an induced electromotive force.

[0050] Compensation coil: A coil used to sense the background potential generated by the rise and fall of an external magnetic field and to cancel it out with the background potential in the receiving coil.

[0051] Background induced potential: refers to the non-sample response voltage generated in the receiving coil, compensation coil, or measurement circuit by the change of external magnetic field over time.

[0052] Differential cancellation: This refers to subtracting the receiving coil signal from the compensation coil signal to cancel out the background induced potential of the shared magnetic field rise and fall, leaving only the differential signal of the electromagnetic response.

[0053] Radio frequency (RF): refers to alternating electromagnetic signals with higher frequencies; RF signal source: used to generate RF signals at a set frequency; RF switch: used to control the on / off state of RF signals; RF power amplifier: used to increase the power of RF signals.

[0054] Bandpass filter: Used to allow signals within a specific frequency range to pass through while suppressing signals of other frequencies.

[0055] Preamplifier: Used to amplify weak signals with low noise before signal acquisition.

[0056] Gating signals: used to control the on and off states of radio frequency switches.

[0057] Trigger signal: Used to trigger the oscilloscope or acquisition device to start acquisition.

[0058] Lock-in amplifier: Used to extract the amplitude and phase of a weak periodic signal at a known reference frequency.

[0059] Phase-sensitive detector: used to extract the in-phase and quadrature components of the input signal relative to the reference signal.

[0060] In-phase component I: refers to the signal component that is in phase with the reference radio frequency signal.

[0061] Quadrature component Q: refers to the phase difference relative to the reference RF signal. The signal components.

[0062] Complex conductivity: a complex quantity characterizing the conduction and induction response of a material under an alternating electromagnetic field, usually written as σ (ω,T) = σ1 (ω, T) - iσ2 (ω, T).

[0063] Skin depth: refers to the characteristic depth at which the amplitude of an alternating electromagnetic field attenuates to a certain proportion of the surface value after entering a normal conductor.

[0064] London penetration depth: refers to the characteristic depth to which a magnetic field penetrates the surface of a superconductor, and is an important parameter describing the magnetic field shielding capability of a superconductor.

[0065] Surface impedance: refers to the impedance response of a material surface to an alternating electromagnetic field, and usually includes surface resistance and surface reactance.

[0066] AC resistivity: refers to the equivalent resistivity of a material under the influence of an AC electromagnetic field.

[0067] Current non-contact coil induction measurement technology typically includes a radio frequency (RF) signal source, an RF switch, a power amplifier, a transmitting coil, a receiving coil, a filter, a preamplifier, and an oscilloscope or lock-in amplifier. During measurement, the RF signal source outputs a continuous wave or pulsed RF signal, which is amplified and then input to the transmitting coil. The transmitting coil generates an alternating magnetic field, which acts on a superconducting sample placed between the transmitting and receiving coils. The receiving coil receives the transmitted RF signal and converts it into an induced voltage. Subsequently, the amplitude, phase, or waveform of the received signal is obtained through filtering, amplification, and acquisition equipment.

[0068] In environments with no rapidly changing external magnetic field or with a slow-changing magnetic field, existing technologies can reflect the shielding effect when a sample transitions from a normal state to a superconducting state by measuring changes in the amplitude and phase of the received signal. For example, when a superconducting sample enters the superconducting state, its London penetration depth is much smaller than its skin depth in the normal state, and the radio frequency magnetic field is strongly shielded by the sample, resulting in a significant decrease in the amplitude of the transmitted signal obtained by the receiving coil.

[0069] However, under conditions of steady-state strong magnetic field rapid sweep or pulsed strong magnetic field, existing single-receiving coil measurement schemes are easily affected by the background induced potential caused by the rise and fall of the applied magnetic field. Since both the receiving coil and the signal lead are in a changing magnetic field, the change in magnetic flux will directly generate an induced voltage in the measurement circuit. This voltage mixes with the sample response signal, making it impossible to accurately determine which part of the received signal comes from the change in the superconducting state of the sample and which part comes from the background change of the external magnetic field.

[0070] The most important technical problem to be solved is how to counteract the background induced potential introduced into the receiving circuit by the change of the external magnetic field during the rapid sweeping of the steady-state strong magnetic field and the rise and fall of the pulsed strong magnetic field, so as to extract the real signal generated by the electromagnetic response of the superconducting sample and realize high-precision non-contact measurement.

[0071] In response, the superconductor transmission induced potential processing and parameter calculation system of this application can significantly reduce the influence of strong magnetic field rise and fall background on non-contact superconductivity measurement, and improve the signal-to-noise ratio, dynamic range and measurement accuracy of superconductor electromagnetic response measurement under steady-state rapid sweep field and pulsed strong magnetic field environment.

[0072] In one embodiment, such as Figure 1 and Figure 2 As shown, a superconductor transmission induced potential processing and parameter calculation system 100 is provided. The system includes: a gating and triggering module 101, a radio frequency signal generation and amplification module 102, a transmitting coil 103, a superconducting sample placement area 104, a receiving coil 105, a compensation coil 106, a differential connection or differential amplification module 107, a filtering and pre-amplification module 108, a signal acquisition module 109, and a data processing and magnetic field synchronization module 110.

[0073] The transmitting coil 103 and the receiving coil 105 are arranged opposite to each other. The superconducting sample placement area 104 is located between the transmitting coil 103 and the receiving coil 105 and is used to fix the superconducting sample to be tested. The compensation coil 106 is located near or symmetrically to the receiving coil 105 and is in the same or approximately the same external magnetic field changing environment as the receiving coil 105.

[0074] The structural parameters of the compensation coil 106 are matched with the background induced potential of the receiving coil 105. The compensation coil 106 is used to generate a compensation potential that is equal to and opposite in polarity to the background induced potential during the rise and fall of the external magnetic field.

[0075] The differential connection or differential amplification module 107 is connected to the output terminals of the receiving coil 105 and the compensation coil 106 respectively, and is used to differentially cancel the background induced potential of the magnetic field rise and fall shared by the receiving coil 105 and the compensation coil 106 at the hardware level, and output a differential signal that retains the electromagnetic response of the superconducting sample.

[0076] The output terminal of the radio frequency signal generation and amplification module 102 is connected to the transmitting coil 103 to generate and amplify the radio frequency signal, and load the amplified radio frequency signal onto the transmitting coil 103; the gating and triggering module 101 is connected to the control terminal of the radio frequency signal generation and amplification module 102 and the triggering terminal of the signal acquisition module 109, respectively.

[0077] The filtering and preamplifier module 108 is connected to the output of the differential connection or differential amplifier module 107, and is used to filter and amplify the differential signal with low noise. The signal acquisition module 109 is connected to the output of the filtering and preamplifier module 108, and is used to acquire the compensated differential signal. The data processing and magnetic field synchronization module 110 is connected to the signal acquisition module 109, and is used to match the compensated differential signal with the corresponding magnetic field value and calculate the superconducting electromagnetic parameters.

[0078] The system includes: a gating and triggering module 101 for generating gating signals and acquiring trigger signals; a radio frequency signal generation and amplification module 102 for generating and amplifying radio frequency excitation signals; a transmitting coil 103 for generating an alternating radio frequency magnetic field acting on the superconducting sample; a receiving coil 105 for sensing the effective signal after it has passed through or been modulated by the superconducting sample; a compensation coil 106 for sensing the background induced potential caused by the rise and fall of the external magnetic field; a differential connection or differential amplification module 107 for canceling the background induced potential that exists in both the receiving coil and the compensation coil; a filtering and preamplification module 108 for improving the signal-to-noise ratio of the effective signal; a signal acquisition module 109 for recording the compensated voltage signal; and a data processing and magnetic field synchronization module 110 for matching and analyzing the measured signal with the corresponding magnetic field value.

[0079] To further explain, the transmitting coil 103 is positioned on one side of the superconducting sample under test and is used to generate an alternating radio frequency magnetic field acting on the superconducting sample. The transmitting coil 103 can be a single-turn coil, a multi-turn coil, a solenoid coil, a planar helical coil, or other radio frequency coils suitable for strong magnetic field environments. Preferably, the axis of the transmitting coil 103 is aligned with the axis of the receiving coil 105, allowing the transmitted radio frequency magnetic field to pass through or act on the superconducting sample and be received by the receiving coil 105. A sample placement space is provided between the transmitting coil 103 and the receiving coil 105, with the superconducting sample located between them.

[0080] The superconducting sample placement area 104 is located between the transmitting coil 103 and the receiving coil 105, and is used to fix the superconducting sample to be tested. The sample can be a bulk, sheet, single crystal, polycrystalline, thin film, or other forms of superconducting material. During measurement, the radio frequency magnetic field is emitted from the transmitting coil 103, and reaches the receiving coil after being shielded, attenuated, or phase-modulated by the sample. When the sample is in the normal state and the superconducting state, the radio frequency signal transmitted to the receiving coil changes due to differences in complex conductivity, skin depth, London penetration depth, and superfluid density.

[0081] The receiving coil 105 is disposed on the other side of the superconducting sample, opposite to the transmitting coil 103. The receiving coil 105 is used to sense the radio frequency signal passing through or acting on the superconducting sample and output the received induced potential.

[0082] During the rapid rise and fall of the magnetic field, the output signal of the receiving coil 105 consists of two parts:

[0083] 1. The effective measurement signal generated by modulating the radio frequency signal with the sample;

[0084] 2. Background induced potential caused by changes in external steady-state rapid sweep field or pulsed magnetic field.

[0085] Therefore, the output voltage of the receiving coil 105 can be expressed as:

[0086]

[0087] In the above formula, The electromagnetic response signal of the sample. This is the background induced potential in the receiving coil.

[0088] The compensation coil 106 is the core improved structure of this application. The compensation coil 106 is located near the receiving coil, beside the sample, symmetrically to the receiving coil, or coaxially adjacent to the receiving coil. The compensation coil 106 is in the same or approximately the same external magnetic field changing environment as the receiving coil 105, but its position is set to not receive or to receive as weakly as possible the effective radio frequency transmission signal after passing through the superconducting sample.

[0089] The structural parameters of the compensation coil 106 are matched according to the background induced potential of the receiving coil 105. The structural parameters include, but are not limited to: 1. the number of turns of the compensation coil; 2. the effective area of ​​the compensation coil; 3. the winding direction of the compensation coil; 4. the relative distance between the compensation coil and the receiving coil; 5. the angle between the compensation coil and the direction of the external magnetic field; 6. the connection polarity of the compensation coil; 7. the wire diameter, material and support structure of the compensation coil.

[0090] When the external magnetic field changes, the background induced electromotive force generated in the receiving coil 105 can be expressed as:

[0091]

[0092] Where, N R Φ is the number of turns of the receiving coil. R It represents the external magnetic flux passing through the receiving coil.

[0093] The compensation potential generated in the compensation coil 106 can be expressed as:

[0094]

[0095] Where, N C To compensate for the number of coil turns, Φ C It represents the external magnetic flux passing through the compensation coil.

[0096] If the magnetic field is approximately uniform, and the effective areas of the receiving coil 105 and the compensation coil 106 are respectively S R and SC ,but:

[0097]

[0098]

[0099] By adjusting the number of turns, area, winding direction, and connection polarity of the compensation coil 106, it is made to satisfy:

[0100]

[0101] And implement it at the differential output terminal:

[0102]

[0103] As a result, the rise and fall of the background potential of the magnetic field in the receiving coil 105 and the compensation coil 106 cancel each other out.

[0104] Specifically, refer to Figure 1 and Figure 2 The superconductor transmission induced potential processing and parameter calculation system 100 is used in environments with steady-state strong magnetic field rapid sweep, pulsed strong magnetic field rise and fall, or other magnetic fields that change over time. The transmitting coil 103 generates an alternating radio frequency magnetic field. The superconducting sample is placed between the transmitting coil 103 and the receiving coil 105. The receiving coil 105 receives the effective signal after passing through or acting on the superconducting sample. The compensation coil 106 is positioned adjacent to or symmetrically to the receiving coil 105. Its main function is not to measure the sample response, but to acquire the same or approximately the same background induced potential of the external magnetic field change as the receiving coil 105. By connecting the receiving coil 105 and the compensation coil 106 in reverse series, differential input, or a bridge connection, the common-mode background potential induced by the rise and fall of the external magnetic field cancels each other out, while the sample response signal is retained as a differential signal.

[0105] In the aforementioned superconductor transmission induced potential processing and parameter calculation system 100, a compensation coil 106 matching the receiving coil 105 is introduced based on the traditional non-contact inductive measurement structure. Through the design of the coil's turns, area, winding direction, relative position, and connection polarity, the compensation coil 106 generates a compensation potential with an amplitude equal to or close to the background induced potential of the receiving coil 105, but with opposite polarity, during the rise and fall of the external magnetic field. Simultaneously, since the compensation coil 106 is positioned to receive little or no effective signal after passing through the superconducting sample, the outputs of the two coils, after differential connection, reverse series connection, or differential amplification, can differentially cancel the background induced potential introduced by the rise and fall of the magnetic field at the hardware level, retaining the effective differential signal caused by electromagnetic shielding, penetration, or changes in the radio frequency response of the superconducting sample. This application can significantly reduce the impact of strong magnetic field rise and fall background on non-contact superconductivity measurement, accurately cancel the background induced potential introduced in the receiving circuit by the change of external magnetic field, and accurately extract the real differential signal generated by the electromagnetic response of the superconducting sample. This improves the signal-to-noise ratio, dynamic range and signal measurement accuracy of superconductor electromagnetic response measurement under steady-state rapid sweep field and pulsed strong magnetic field environment, and realizes high-precision non-contact measurement.

[0106] In one embodiment, the radio frequency (RF) signal generation and amplification module 102 includes: an RF signal source, an RF switch, an RF power amplifier, and a transmitter bandpass filter; the RF signal source is used to output an RF signal at a set frequency; the control terminal of the RF switch is connected to the gate output terminal of the gate and trigger module, and is used to control the on / off state of the RF signal; the RF power amplifier is used to amplify the RF excitation power; the transmitter bandpass filter is used to filter out out-of-band spurious signals; the gate and trigger module 101 includes a pulse signal source, which simultaneously outputs a gate signal and a trigger signal; the gate signal is connected to the control terminal of the RF switch, and is used to control the on / off timing of the RF excitation; the trigger signal is connected to the trigger terminal of the signal acquisition module 109, and is used to keep the RF excitation and signal acquisition time synchronized.

[0107] Specifically, the radio frequency (RF) signal generation and amplification module 102 includes an RF signal source, an RF switch, an RF power amplifier, and a transmitter bandpass filter. The RF signal source outputs a continuous sinusoidal RF signal at a set frequency, and its output is connected to the input of the RF switch. The control terminal of the RF switch is connected to the gate output of the pulse signal source, and the output of the RF switch is connected to the RF power amplifier. The output of the RF power amplifier is connected to the transmitter bandpass filter, and the output of the transmitter bandpass filter is connected to the transmitter coil. When the gate signal is valid, the RF switch is turned on, and the continuous RF signal output by the RF signal source enters the RF power amplifier through the RF switch. After power amplification and filtering, it is applied to the transmitter coil. When the gate signal ends, the RF switch is turned off, and the RF excitation stops.

[0108] The gating and triggering module 101 includes a pulse signal source, which serves as the system's synchronization control source, simultaneously outputting a gating signal and a trigger signal. The gating signal is connected to the control terminal of the RF switch to control the on / off state of the RF signal. The trigger signal is connected to the external trigger terminal of an oscilloscope, high-speed acquisition card, lockout amplifier, or other acquisition device to ensure synchronization between each RF excitation and signal acquisition. During rapid field sweep or pulsed magnetic field measurement, the pulse signal source repeatedly outputs the gating signal and trigger signal at set time intervals, dividing the entire magnetic field change process into multiple short-time measurement windows, each corresponding to a magnetic field value or magnetic field time point.

[0109] In one embodiment, the differential connection or differential amplification module 107 is connected using any of the candidate connection methods; the candidate connection methods include: reverse series connection, differential amplification connection, balanced bridge connection and adjustable compensation connection.

[0110] Specifically, the output terminals of the receiving coil 105 and the compensation coil 106 can be connected in any of the following ways:

[0111] 1. Reverse series connection: Connect the receiving coil and the compensation coil in series with opposite polarities so that the background induced electromotive force generated by the change of the external magnetic field is opposite in direction and cancels each other out. The remaining voltage after series connection is used as the output signal.

[0112] 2. Differential amplifier connection: The output of the receiving coil is connected to one input terminal of the differential amplifier, and the output of the compensation coil is connected to the other input terminal of the differential amplifier. The differential amplifier outputs the difference signal between the two.

[0113] 3. Balanced bridge connection: The receiving coil and the compensation coil serve as the two sensing arms of the bridge. The background signal of the magnetic field rise and fall is minimized by adjusting the bridge balance.

[0114] 4. Adjustable compensation connection: Add adjustable resistors, capacitors, inductors, attenuators or phase adjusters to the compensation coil branch to adjust the amplitude and phase of the compensation signal so that it can more accurately cancel the background signal in the receiving coil.

[0115] The output signal after differential cancellation can be expressed as:

[0116]

[0117] because

[0118]

[0119] Furthermore, the compensation coil primarily outputs background signals:

[0120]

[0121] Therefore:

[0122]

[0123] when At that time, there were:

[0124]

[0125] That is, the background induced potential induced by the rise and fall of the external magnetic field is canceled at the hardware level, while the real measurement signal caused by the superconducting sample is preserved.

[0126] In one embodiment, the filtering and preamplifier module 108 includes a receiver filter and a low-noise preamplifier connected in sequence; the receiver filter is a bandpass filter used to retain the target radio frequency signal and suppress low-frequency induced interference and spurious signals; the low-noise preamplifier is a differential input amplifier or a single-ended input amplifier; the signal acquisition module 109 includes: a high-resolution oscilloscope, a high-speed data acquisition card, a lock-in amplifier or a phase-sensitive detector; the signal acquisition module 109 is synchronously triggered by the trigger signal of the pulse signal source and acquires the differentially compensated received waveform in each measurement window.

[0127] Specifically, the output differential signal enters a bandpass filter or a low-pass / high-pass combined filter at the receiving end. If the system uses RF transmission measurement, a bandpass filter with the same center frequency as the RF excitation frequency is preferred at the receiving end to retain the target RF signal and suppress low-frequency induced interference and spurious signals. The filtered signal is then input to a low-noise preamplifier. The preamplifier is used to increase the signal amplitude and improve the signal-to-noise ratio of subsequent acquisitions. The preamplifier can be a differential input low-noise amplifier or a single-ended input amplifier.

[0128] The signal acquisition module 109 can employ a high-resolution oscilloscope, a high-speed data acquisition card, a lock-in amplifier, or a phase-sensitive detector. If an oscilloscope or high-speed acquisition card is used, the acquisition device is triggered by a trigger signal output from a pulse signal source, acquiring the differentially compensated received waveform within each measurement window. The acquired waveform is then digitally demodulated to obtain the in-phase component, quadrature component, amplitude, and phase. If a lock-in amplifier or hardware phase-sensitive detector is used, the differentially compensated signal is pre-amplified and directly input to the lock-in amplifier or phase-sensitive detector, which outputs the in-phase and quadrature components.

[0129] In one embodiment, the data processing and magnetic field synchronization module 110 is used to perform the following processing: baseline correction of the acquired waveform and digital phase-sensitive demodulation of the target radio frequency signal; calculation of in-phase component, quadrature component, amplitude and phase based on the mediated radio frequency signal; matching the signal measured each time with the magnetic field value at the corresponding time to obtain the electromagnetic response curve of the superconducting sample as a function of the magnetic field; and calculating the surface impedance, AC resistivity, critical magnetic field or superconducting transition characteristics of the superconducting sample under test based on the curve, combined with the sample size, coil parameters and electromagnetic model.

[0130] Specifically, the data processing and magnetic field synchronization module 110 is used to match the signal acquired each time with the magnetic field value at the corresponding moment. The magnetic field value can come from the magnetic field sensor of the strong magnetic field device, the magnet current signal, the pickup coil signal, or the magnetic field calibration curve.

[0131] The data processing steps include: 1. Baseline correction of the acquired waveform; 2. Digital phase-sensitive demodulation of the radio frequency signal; 3. Calculation of the in-phase component I, quadrature component Q, amplitude A, and phase φ; 4. Matching the signal with the corresponding magnetic field value B; 5. Obtaining the curve of the superconducting sample response as a function of the magnetic field; 6. Calculating the surface impedance, AC resistivity, or superconducting transition characteristics based on the sample size, coil parameters, and electromagnetic model.

[0132] The amplitude and phase can be expressed as:

[0133]

[0134]

[0135] In one embodiment, such as Figure 3 As shown, a method for processing and calculating parameters of transmission induced potential in superconductors is provided, which is then applied to... Figure 1 The following steps are used as an example to illustrate the superconductor transmission induced potential processing and parameter calculation system 100:

[0136] Step S301: In the absence of a sample or with no obvious superconducting response, perform background calibration, adjust the structural parameters of the compensation coil so that the background induced potentials of the receiving coil and the compensation coil are differentially canceled at the differential output end; set the operating parameters of the radio frequency signal source, and output a gate signal from the pulse signal source to the radio frequency switch to trigger the synchronous signal acquisition.

[0137] Step S302: During the start-up of steady-state strong magnetic field rapid sweep or pulsed strong magnetic field, perform multiple short-time radio frequency measurements at set time intervals; perform reverse series connection, differential amplification or bridge balancing on the output of the receiving coil and the output of the compensation coil, and differentially cancel the background induced potential of the magnetic field rise and fall shared by the receiving coil and the compensation coil at the hardware level, and output the compensated differential signal.

[0138] Step S303: Acquire differential signal, perform digital phase-sensitive demodulation on differential signal, calculate in-phase component, quadrature component, amplitude and phase based on the demodulated differential signal, match the signal measured each time with the magnetic field value at the corresponding time, and obtain the curve of electromagnetic response of superconducting sample as a function of magnetic field.

[0139] Step S304: Based on the change curve, combined with the sample size, coil parameters and electromagnetic model, calculate the surface impedance, AC resistivity, critical magnetic field or superconducting transition characteristics of the superconducting sample to be tested.

[0140] Specifically, the superconductor transmission induced potential processing and parameter calculation method in this embodiment may include the following steps:

[0141] Step 1: Install the coil and sample:

[0142] The transmitting coil is positioned on one side of the superconducting sample, and the receiving coil is positioned on the other side, with the superconducting sample located between the transmitting and receiving coils. A compensation coil is positioned near or symmetrically to the receiving coil, placing the compensation coil in the same or approximately the same external magnetic field environment as the receiving coil.

[0143] Step 2: Adjust the compensation coil:

[0144] Background calibration is performed with no sample or when the sample is in a state where it does not produce a significant superconducting response. An external magnetic field is applied to increase, decrease, or simulate changes, and the background induced potentials of the receiving coil and the compensation coil are recorded. The number of turns, effective area, winding direction, position, connection polarity, or compensation branch parameters of the compensation coil are adjusted so that the background induced potentials generated by the receiving coil and the compensation coil cancel each other out at the differential output terminal.

[0145] The adjustment target is:

[0146]

[0147] Step 3: Set the radio frequency excitation and acquisition parameters:

[0148] Configure the frequency, power, gate pulse width, repetition frequency, sampling rate, and trigger mode of the RF signal source. The pulse signal source outputs a gate signal to the RF switch and a trigger signal to an oscilloscope or data acquisition device.

[0149] Step 4: Activate the strong magnetic field to raise or lower the field:

[0150] Initiate a steady-state strong magnetic field rapid sweep or pulsed strong magnetic field process. The external magnetic field changes over time, and the system performs multiple short-duration radio frequency measurements at set time intervals.

[0151] Step 5: Transmit radio frequency signal:

[0152] When the gating signal is valid, the RF switch is turned on, and the RF signal is amplified and filtered before being input to the transmitting coil. The transmitting coil generates an alternating RF magnetic field, which acts on the superconducting sample.

[0153] Step Six: Synchronize the induced signals of the receiving coil and the compensation coil:

[0154] The receiving coil senses the effective radio frequency signal passing through or acting on the superconducting sample, and also senses the background potential caused by the rise and fall of the external magnetic field. The compensation coil mainly senses the background potential caused by the rise and fall of the external magnetic field.

[0155] Step 7: Background potential cancellation:

[0156] The output of the receiving coil and the output of the compensation coil are connected in reverse series, differentially amplified, or balanced by a bridge circuit to cancel out the background induced potential caused by the rise and fall of the magnetic field, and the compensated measurement signal is output.

[0157] Step 8: Filtering, Amplification, and Acquisition

[0158] The compensated output signal passes through a receiver filter and a low-noise preamplifier before entering an oscilloscope, high-speed acquisition card, or lock-in amplifier. The acquisition device records the waveform or demodulated value within each measurement window under the control of a trigger signal.

[0159] Step 9: Signal Demodulation and Data Processing

[0160] The acquired signal is subjected to digital phase-sensitive demodulation or hardware phase-sensitive detection to obtain the amplitude and phase of the received signal. Each measurement result is matched with the corresponding magnetic field value to obtain the relationship between the electromagnetic response of the superconducting sample and the magnetic field.

[0161] Step 10: Calculate the superconducting electromagnetic parameters:

[0162] Based on the amplitude and phase changes of the received signal, combined with the coil geometry, sample thickness, sample size, and electromagnetic transmission model, the sample surface impedance, AC resistivity, critical magnetic field, or superconducting transition characteristics are calculated.

[0163] To further explain, without a compensation coil, the output signal of the receiving coil can be expressed as:

[0164]

[0165] In the above formula, The effective signal is generated by the radio frequency magnetic field passing through the superconducting sample. This is the background induced potential caused by changes in the external magnetic field.

[0166] In steady-state rapid sweep field and pulsed magnetic field, dB / dt is relatively large, leading to The potential for this to increase significantly could overwhelm the valid signal. This application incorporates a compensation coil to generate a compensation potential:

[0167]

[0168] By matching the structure and reversing the polarity, we can achieve the following:

[0169]

[0170] The differential output is:

[0171]

[0172] When the background signal matches:

[0173]

[0174] Thus, the background potential induced by the rise and fall of the external magnetic field is canceled out at the hardware level, while the real signal caused by the superconducting sample is preserved.

[0175] For radio frequency transmission measurements, a radio frequency current is passed through transmitting coil A:

[0176]

[0177] In the above formula, I0 is the amplitude of the radio frequency current, and ω is the radio frequency angular frequency.

[0178] If there is no sample, the induced voltage received by receiving coil B is:

[0179]

[0180] In the above formula, M0 is the mutual inductance between the transmitting coil and the receiving coil in free space.

[0181] After the sample is added, it shields and dissipates the radio frequency magnetic field, causing the effective mutual inductance to become:

[0182]

[0183] In the above formula, This represents the change in mutual inductance caused by the electromagnetic response of the sample.

[0184] At this time, the radio frequency voltage of the receiving coil is:

[0185]

[0186] The amplitude of the received signal is:

[0187]

[0188] The response of a sample in a radio frequency field can be represented by complex conductivity:

[0189]

[0190] In the above formula, σ₁ represents the dissipative part, which mainly corresponds to the contribution of normal electrons; σ₂ represents the dissipationless inductive part, which mainly corresponds to the contribution of superfluid density.

[0191] In the normal state T>Tc, the complex conductivity can generally be approximated as:

[0192]

[0193] In the above formula, is the normal state conductivity.

[0194] In the superconducting state T<Tc, the imaginary part of the complex conductivity can be expressed as:

[0195]

[0196] In the above formula, is the superfluid density, e is the electron charge, and m is the electron mass.

[0197] The skin depth in normal metals is:

[0198]

[0199] After the sample enters the superconducting state, the penetration depth of the radio frequency magnetic field is mainly governed by the London penetration depth:

[0200]

[0201] If the sample thickness is d, the amplitude of the received signal can be approximately expressed as:

[0202]

[0203] In the above formula, Λ(ω,T) is the effective radio frequency penetration length.

[0204] In the normal state:

[0205]

[0206] In the superconducting state:

[0207]

[0208] Since generally:

[0209]

[0210] Therefore, the radio frequency magnetic field is more strongly shielded by the sample in the superconducting state, and the amplitude of the received signal decreases significantly compared to the normal state.

[0211] If a two-fluid model is used, the superfluid density can be approximated as:

[0212]

[0213] The corresponding penetration depth through London is:

[0214]

[0215] Therefore, the received amplitude in the superconducting state can be written as:

[0216]

[0217] Under normal conditions:

[0218]

[0219] Therefore, we can obtain the segmented form:

[0220]

[0221] The compensation coil structure of this application can accurately obtain the signal change caused by the sample during the rise and fall of a strong magnetic field, rather than being masked by the background of magnetic field change.

[0222] Furthermore, the areas in this technical solution that can be substituted or expanded include:

[0223] 1. The arrangement of the compensation coil can be replaced by:

[0224] The compensation coil can be placed next to the receiving coil, on the side of the receiving coil facing away from the sample, coaxially adjacent to the receiving coil, symmetrical to the receiving coil, or placed near the sample but not directly receiving the transmitted signal from the sample.

[0225] 2. The structure of the compensation coil can be replaced by:

[0226] The compensation coil can be a single-turn coil, a multi-turn coil, a planar coil, a solenoid coil, a printed circuit board coil, a miniature wound coil, or a flexible coil. The number of turns, area, and shape of the compensation coil can be designed according to the background potential of the receiving coil.

[0227] 3. Alternative compensation methods are available:

[0228] Background cancellation can be achieved by using reverse series connection, differential amplification, bridge balancing, analog subtraction circuit, or digital differential subtraction between the receiving coil and the compensation coil. Hardware reverse series connection or differential amplification is preferred to avoid excessive background signal causing saturation of the back-end amplifier.

[0229] 4. Compensation and adjustment methods can be used as alternatives:

[0230] The compensation amount can be optimized by changing the position of the compensation coil, changing the number of turns of the compensation coil, changing the effective area, reversing the winding direction, adding adjustable resistors, adjustable capacitors, adjustable inductors, variable attenuators, or phase adjusters.

[0231] 5. Signal acquisition methods can be replaced by:

[0232] The signal acquisition module can use a high-speed oscilloscope, a high-speed data acquisition card, a lock-in amplifier, a phase-sensitive detector, a digitizer, or a spectrum analyzer.

[0233] 6. Demodulation methods can be replaced by:

[0234] The amplitude and phase of the received signal can be extracted using methods such as digital phase-sensitive demodulation, hardware phase-sensitive detection, phase-locked amplification, Fourier transform, envelope detection, or amplitude-phase demodulation.

[0235] 7. Incentive methods can be substituted:

[0236] Radio frequency excitation can be continuous wave gating excitation, pulse radio frequency excitation, sweep frequency excitation, multi-frequency excitation, or AC low-frequency excitation.

[0237] 8. The magnetic field environment can be expanded:

[0238] This technical solution is not only applicable to rapid sweeping of steady-state strong magnetic fields and pulsed strong magnetic fields, but can also be used for the measurement of electromagnetic response of superconductors in low-temperature, high-pressure, high-frequency, rotating magnetic field, or other external field coupling environments.

[0239] 9. Sample types can be expanded:

[0240] The sample to be tested can be a superconducting thin film, a bulk superconductor, a single crystal superconductor, a polycrystalline superconductor, a wire, a strip, a heterojunction sample, or other materials with magnetic shielding or electromagnetic transmission variation.

[0241] 10. Filters and amplifiers can be substituted:

[0242] The transmitter and receiver filters can be selected as bandpass, high-pass, low-pass, or notch filters depending on the measurement frequency. The preamplifier can be a low-noise voltage amplifier, differential amplifier, instrumentation amplifier, or RF amplifier.

[0243] This invention achieves the following technical effects by placing a compensation coil near the receiving coil and making the compensation coil generate a compensation signal with the same amplitude but opposite polarity as the background induced potential of the receiving coil:

[0244] 1. Effectively counteracts the background induced potential caused by the rise and fall of the magnetic field:

[0245] Under conditions of steady-state strong magnetic field rapid sweep and pulsed strong magnetic field, the compensation coil can synchronously sense the background potential generated by the change of external magnetic field, and cancel the background induced potential in the receiving coil through reverse series connection, differential amplification or bridge balancing.

[0246] 2. Improve the extraction accuracy of the true response signal of superconducting samples:

[0247] After the background potential is canceled out, the output signal mainly reflects the shielding, transmission and phase modulation effects of the superconducting sample on the radio frequency magnetic field or alternating magnetic field, which makes it easy to accurately extract the electromagnetic response change of the sample from the normal state to the superconducting state.

[0248] 3. Improve signal-to-noise ratio and measurement sensitivity:

[0249] By canceling common-mode background at the hardware level, baseline drift, low-frequency induction interference, and spurious signals from magnetic field changes can be reduced, making weak sample response signals easier to detect.

[0250] 4. Reduce reliance on software post-processing for background removal:

[0251] This invention cancels the background potential before the signal enters the amplifier and acquisition device, avoiding excessive background signal from causing preamplifier saturation or insufficient dynamic range of acquisition, while reducing errors caused by subsequent data subtraction.

[0252] 5. Applicable to rapid sweeping of steady-state strong magnetic fields and pulsed strong magnetic field measurements:

[0253] This scheme can adapt to environments with continuous changes, rapid rises and falls, and high magnetic field strength, and is particularly suitable for non-contact measurement of superconducting materials in large scientific facilities with strong magnetic fields.

[0254] 6. Improve the consistency and repeatability of data from different magnetic field ranges;

[0255] Since the background induced potential is suppressed, the measurement results are less affected by the rate of change of the magnetic field, the lead arrangement and the coil loop area, thereby improving the stability and repeatability of the experimental data.

[0256] 7. Maintain the advantages of non-contact measurement:

[0257] This invention eliminates the need to fabricate electrodes or leads on the surface of superconducting samples, and does not introduce contact resistance, solder joint thermal effects, or sample damage. It is suitable for measuring brittle, small-sized, or extreme superconducting materials.

[0258] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0259] Based on the same inventive concept, this application also provides a device for processing and calculating the superconductor transmission induced potential and parameters, used to implement the superconductor transmission induced potential processing and parameter calculation method described above. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more embodiments of the superconductor transmission induced potential processing and parameter calculation device provided below can be found in the limitations of the superconductor transmission induced potential processing and parameter calculation method described above, and will not be repeated here.

[0260] In one exemplary embodiment, such as Figure 4 As shown, a device for processing and calculating parameters of superconductor transmission induced potential is provided. This device may include:

[0261] The parameter setting unit 401 is used to perform background calibration and adjust the structural parameters of the compensation coil in the absence of a sample or when the sample has no obvious superconducting response, so that the background induced potentials of the receiving coil and the compensation coil can be differentially canceled at the differential output end; and to set the operating parameters of the radio frequency signal source, so that the pulse signal source outputs a gate signal to the radio frequency switch and triggers the synchronous signal acquisition.

[0262] Signal compensation unit 402 is used to perform multiple short-time radio frequency measurements at set time intervals during the start-up of steady-state strong magnetic field rapid sweep or pulsed strong magnetic field; it performs reverse series connection, differential amplification or bridge balancing processing on the output of the receiving coil and the output of the compensation coil to differentially cancel the background induced potential of the magnetic field rise and fall shared by the receiving coil and the compensation coil at the hardware level, and outputs the compensated differential signal.

[0263] The phase-sensitive demodulation unit 403 is used to acquire the differential signal, perform digital phase-sensitive demodulation on the differential signal, calculate the in-phase component, quadrature component, amplitude and phase based on the mediated differential signal, match the signal measured each time with the magnetic field value at the corresponding time, and obtain the curve of electromagnetic response of superconducting sample changing with magnetic field.

[0264] The result calculation unit 404 is used to calculate the surface impedance, AC resistivity, critical magnetic field, or superconducting transition characteristics of the superconducting sample under test based on the change curve, combined with the sample size, coil parameters, and electromagnetic model.

[0265] Specific limitations regarding the device for processing and calculating the transmission induced potential of superconductors can be found in the limitations of the method for processing and calculating the transmission induced potential of superconductors described above, and will not be repeated here. Each module in the aforementioned device for processing and calculating the transmission induced potential of superconductors can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independently of the processor, or they can be stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0266] In one exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 5 As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When executed by the processor, the computer program implements a method for processing and calculating parameters of a superconductor transmission induced potential. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0267] Those skilled in the art will understand that Figure 5The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0268] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0269] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0270] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0271] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0272] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0273] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0274] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A superconductor transmission induced potential processing and parameter calculation system, characterized by, The system includes: a gating and triggering module, a radio frequency signal generation and amplification module, a transmitting coil, a superconducting sample placement area, a receiving coil, a compensation coil, a differential connection or differential amplification module, a filtering and preamplification module, a signal acquisition module, and a data processing and magnetic field synchronization module. The transmitting coil and the receiving coil are arranged opposite to each other, and the superconducting sample placement area is located between the transmitting coil and the receiving coil to fix the superconducting sample to be tested; the compensation coil is located near or symmetrically to the receiving coil and is in the same or approximately the same external magnetic field changing environment as the receiving coil. The structural parameters of the compensation coil are matched with the background induced potential of the receiving coil. The compensation coil is used to generate a compensation potential that is equal to but opposite in polarity to the background induced potential during the rise and fall of the external magnetic field. The differential connection or differential amplification module is connected to the output terminals of the receiving coil and the compensation coil, respectively, and is used to differentially cancel the background induced potential of the magnetic field rise and fall shared by the receiving coil and the compensation coil at the hardware level, and output a differential signal that retains the electromagnetic response of the superconducting sample. The output terminal of the radio frequency signal generation and amplification module is connected to the transmitting coil to generate and amplify the radio frequency signal, and to load the amplified radio frequency signal onto the transmitting coil; the gating and triggering module is respectively connected to the control terminal of the radio frequency signal generation and amplification module and the triggering terminal of the signal acquisition module. The filtering and preamplification module is connected to the output of the differential connection or differential amplification module, and is used to filter and amplify the differential signal with low noise. The signal acquisition module is connected to the output of the filtering and preamplification module, and is used to acquire the compensated differential signal. The data processing and magnetic field synchronization module is connected to the signal acquisition module, and is used to match the compensated differential signal with the corresponding magnetic field value and calculate the superconducting electromagnetic parameters.

2. The system of claim 1, wherein, The radio frequency (RF) signal generation and amplification module includes: an RF signal source, an RF switch, an RF power amplifier, and a transmitter bandpass filter; the RF signal source is used to output an RF signal at a set frequency; the control terminal of the RF switch is connected to the gate output terminal of the gating and triggering module, and is used to control the on / off state of the RF signal; the RF power amplifier is used to amplify the RF excitation power; the transmitter bandpass filter is used to filter out out-of-band spurious signals; the gating and triggering module includes a pulse signal source, which simultaneously outputs a gating signal and a trigger signal; the gating signal is connected to the control terminal of the RF switch, and is used to control the on / off timing of the RF excitation; the trigger signal is connected to the trigger terminal of the signal acquisition module, and is used to keep the RF excitation and signal acquisition time synchronized.

3. The system of claim 2, wherein, The differential connection or differential amplification module is connected using any of the candidate connection methods; the candidate connection methods include: reverse series connection, differential amplification connection, balanced bridge connection, and adjustable compensation connection.

4. The system of claim 3, wherein, The filtering and preamplifier module includes a receiver filter and a low-noise preamplifier connected in sequence; the receiver filter is a bandpass filter used to retain the target radio frequency signal and suppress low-frequency induced interference and spurious signals; the low-noise preamplifier is a differential input amplifier or a single-ended input amplifier. The signal acquisition module includes: a high-resolution oscilloscope, a high-speed data acquisition card, a lock-in amplifier or a phase-sensitive detector; The signal acquisition module is synchronously triggered by the trigger signal of the pulse signal source, and acquires the received waveform after differential compensation within each measurement window.

5. The system of claim 4, wherein, The data processing and magnetic field synchronization module is used to perform the following processing: baseline correction of the acquired waveform and digital phase-sensitive demodulation of the target radio frequency signal; calculation of in-phase component, quadrature component, amplitude and phase based on the demodulated radio frequency signal; matching the signal measured each time with the magnetic field value at the corresponding time to obtain the electromagnetic response curve of the superconducting sample as a function of the magnetic field; and calculating the surface impedance, AC resistivity, critical magnetic field or superconducting transition characteristics of the superconducting sample under test based on the curve, combined with the sample size, coil parameters and electromagnetic model.

6. A method for processing and parameter calculation of superconductor transmission induced potential, characterized in that, The method, applied to the superconductor transmission induced potential processing and parameter calculation system as described in any one of claims 1 to 5, comprises: In the absence of a sample or when the sample does not show a significant superconducting response, background calibration is performed, and the structural parameters of the compensation coil are adjusted so that the background induced potentials of the receiving coil and the compensation coil are differentially canceled at the differential output terminal. The operating parameters of the radio frequency signal source are set, and the pulse signal source outputs a gate signal to the radio frequency switch and triggers the acquisition of the synchronous signal. During the start-up of steady-state strong magnetic field rapid sweep or pulsed strong magnetic field, multiple short-time radio frequency measurements are performed at set time intervals; the output of the receiving coil and the output of the compensation coil are reverse-connected, differentially amplified or bridge balanced, and the background induced potential of the magnetic field rise and fall shared by the receiving coil and the compensation coil is differentially canceled at the hardware level, and the compensated differential signal is output. The differential signal is acquired, and digital phase-sensitive demodulation is performed on the differential signal. The in-phase component, quadrature component, amplitude, and phase are calculated based on the demodulated differential signal. The signal measured each time is matched with the magnetic field value at the corresponding time to obtain the electromagnetic response curve of the superconducting sample as a function of the magnetic field. Based on the aforementioned variation curves, and in conjunction with sample size, coil parameters, and electromagnetic model, the surface impedance, AC resistivity, critical magnetic field, or superconducting transition characteristics of the superconducting sample under test are calculated.

7. A device for processing and calculating parameters of superconductor transmission induced potential, characterized in that, The apparatus, used in the superconductor transmission induced potential processing and parameter calculation system as described in any one of claims 1 to 5, comprises: The parameter setting unit is used to perform background calibration and adjust the structural parameters of the compensation coil in the absence of a sample or when the sample does not have a significant superconducting response, so that the background induced potentials of the receiving coil and the compensation coil can be differentially canceled at the differential output terminal; and to set the operating parameters of the radio frequency signal source, so that the pulse signal source outputs a gate signal to the radio frequency switch and triggers the synchronous signal acquisition. The signal compensation unit is used to perform multiple short-time radio frequency measurements at set time intervals during the start-up of a steady-state strong magnetic field rapid sweep or pulsed strong magnetic field; it performs reverse series connection, differential amplification or bridge balancing processing on the output of the receiving coil and the output of the compensation coil to differentially cancel the background induced potential of the magnetic field rise and fall shared by the receiving coil and the compensation coil at the hardware level, and outputs the compensated differential signal. The phase-sensitive demodulation unit is used to acquire the differential signal, perform digital phase-sensitive demodulation on the differential signal, calculate the in-phase component, quadrature component, amplitude and phase based on the mediated differential signal, match the signal measured each time with the magnetic field value at the corresponding time, and obtain the curve of electromagnetic response of the superconducting sample changing with the magnetic field. The result calculation unit is used to calculate the surface impedance, AC resistivity, critical magnetic field, or superconducting transition characteristics of the superconducting sample under test based on the change curve, combined with the sample size, coil parameters, and electromagnetic model.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method of claim 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method of claim 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method of claim 6.

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