Cryogenic thermoacoustic oscillation detection device and method, and cryostat

Abstract

The present application relates to the technical field of thermoacoustic oscillation suppression, and particularly relates to a low-temperature thermoacoustic oscillation detection device and method and a cryostat. The low-temperature thermoacoustic detection device provided by the present application is used for detecting thermoacoustic oscillation in a sample cavity of a cryostat, and comprises: a resonator arranged in the sample cavity, wherein the resonator comprises a resonant cavity, and the resonant cavity is in communication with the sample cavity; a microwave signal analysis device comprising a microwave signal transmitting module, a microwave signal receiving module and a vector network analyzer; the vector network analyzer is in communication connection with the microwave signal transmitting module and the microwave signal receiving module, and the vector network analyzer is adapted to transmit a microwave signal into the resonant cavity through the microwave signal transmitting module; and a computer in communication connection with the vector network analyzer. The low-temperature thermoacoustic oscillation detection device, method and cryostat provided by the present application can accurately detect thermoacoustic oscillation, and thus provide a reliable basis for suppressing thermoacoustic oscillation.

Description

Technical Field

[0001] This invention relates to the field of thermoacoustic oscillation suppression technology, specifically to a low-temperature thermoacoustic oscillation detection device, method, and low-temperature thermostat. Background Technology

[0002] Low-temperature constant temperature devices are core basic equipment for conducting low-temperature related research. They are used to provide a highly stable low-temperature environment for cutting-edge science, space exploration, quantum technology, large scientific facilities and other fields, and play an important supporting role in scientific discovery and the exploration of new principles.

[0003] In gas pipelines that are open at one end and closed at the other, and where there is a temperature difference, thermoacoustic oscillations usually occur spontaneously. In cryogenic isothermal devices, the temperature gradient between room temperature and cryogenic gas links is large, and the density difference between high and low temperature gases is significant. This leads to pressure and temperature oscillations caused by thermal or mechanical disturbances when the sample chamber of the cryogenic isothermal device is filled with cryogenic gas (especially helium).

[0004] The heat leakage caused by thermoacoustic oscillation is usually several times the system's heat leakage, which can seriously affect the system's temperature and pressure stability. Excessive thermoacoustic oscillation can even damage the system.

[0005] Therefore, it is necessary to detect thermoacoustic oscillations and then take suppression measures to reduce or eliminate them at the detected locations to ensure the normal operation of the system. Summary of the Invention

[0006] This invention provides a low-temperature thermoacoustic oscillation detection device, method, and low-temperature thermostat, which can accurately detect thermoacoustic oscillations, thereby providing a reliable basis for suppressing thermoacoustic oscillations.

[0007] A first aspect of the present invention provides a low-temperature thermoacoustic detection device for detecting thermoacoustic oscillations within the sample chamber of a low-temperature thermostat, comprising:

[0008] A resonator is disposed within the sample cavity, the resonator including a resonant cavity, the resonant cavity being connected to the sample cavity;

[0009] A microwave signal analysis device includes a microwave signal transmitting module, a microwave signal receiving module, and a vector network analyzer; wherein,

[0010] Both the microwave signal transmitting module and the microwave signal receiving module are located on the resonator;

[0011] The vector network analyzer is communicatively connected to the microwave signal transmitting module and the microwave signal receiving module, respectively. The vector network analyzer is adapted to transmit microwave signals into the resonant cavity through the microwave signal transmitting module and obtain scattering parameters S21 by receiving the microwave signals in the resonant cavity through the microwave signal receiving module.

[0012] A computer is communicatively connected to the vector network analyzer. The computer is adapted to control the vector network analyzer to transmit microwave signals point by point within a preset sweep frequency band, determine microwave resonant frequency information and a single sweep frequency according to the scattering parameter S21, and determine thermoacoustic oscillation information according to the scattering parameter S21.

[0013] The low-temperature thermoacoustic detection device provided by the present invention further includes:

[0014] A time standard is communicatively connected to the vector network analyzer, and the time standard is adapted to input standard time information to the vector network analyzer.

[0015] According to the low-temperature thermoacoustic detection device provided by the present invention, the resonator is suspended inside the sample cavity, and the resonator is provided with a vent hole, the two ends of which are respectively connected to the sample cavity and the resonator cavity.

[0016] According to the low-temperature thermoacoustic detection device provided by the present invention, the microwave signal transmitting module includes a transmitting antenna, the microwave signal receiving module includes a receiving antenna, and both the transmitting antenna and the receiving antenna are disposed on the resonant cavity.

[0017] According to the low-temperature thermoacoustic detection device provided by the present invention, the vector network analyzer is connected to the microwave signal transmitting module and the microwave signal receiving module respectively via microwave cables and microwave cable connectors.

[0018] A second aspect of the present invention provides a low-temperature thermoacoustic detection method, comprising:

[0019] According to the preset frequency sweep information, the vector network analyzer transmits the first microwave signal point by point to the resonant cavity of the resonator;

[0020] The vector network analyzer determines the first scattering parameter S21 based on the received first microwave signal;

[0021] Based on the first scattering parameter S21, the microwave resonant frequency information is determined, and then the single sweep frequency information is determined.

[0022] Based on the single sweep frequency information, the vector network analyzer repeatedly transmits a second microwave signal to the resonant cavity of the resonator;

[0023] The vector network analyzer determines the second scattering parameter S21 based on the received second microwave signal;

[0024] Thermoacoustic oscillation information is obtained based on the second scattering parameter S21.

[0025] According to the low-temperature thermoacoustic detection method provided by the present invention, the step of the vector network analyzer transmitting a first microwave signal point-by-point to the resonant cavity of the resonator based on preset frequency sweep information includes:

[0026] The computer determines the preset frequency band information based on the user's selection;

[0027] The vector network analyzer receives the preset frequency sweep band information and transmits the first microwave signal point by point within the preset frequency sweep band.

[0028] According to the low-temperature thermoacoustic detection method provided by the present invention, the step of obtaining thermoacoustic oscillation information based on the second scattering parameter S21 includes:

[0029] The resonant frequency is determined by fitting the second scattering parameter S21.

[0030] The thermoacoustic oscillation information is determined by performing Fourier analysis based on the resonant frequency.

[0031] A third aspect of the present invention provides a cryogenic thermostat, comprising:

[0032] Sample chamber;

[0033] A gas supply device, wherein the gas supply device is connected to the sample chamber via a gas supply trunk line;

[0034] The low-temperature thermoacoustic detection device is configured as described in any of the preceding items.

[0035] The low-temperature thermostat provided by the present invention further includes:

[0036] Dewar and multi-level radiation shielding layer, wherein the sample cavity is disposed in the inner cavity of the Dewar and multi-level radiation shielding layer;

[0037] A refrigeration unit is adapted to supply cooling energy to the inner cavity of the Dewar and multi-level radiation shielding layers.

[0038] The technical solution provided by this invention includes a low-temperature thermoacoustic detection device for detecting thermoacoustic oscillations within the sample cavity of a low-temperature thermostat. The device comprises a resonator and a microwave signal analysis device. The resonator is located within the sample cavity and includes a resonant cavity that is connected to the sample cavity. The microwave signal analysis device includes a microwave signal transmitting module, a microwave signal receiving module, and a vector network analyzer. Both the microwave signal transmitting module and the microwave signal receiving module are located within the resonator. The vector network analyzer is communicatively connected to both the microwave signal transmitting module and the microwave signal receiving module. The analysis process of the thermoacoustic oscillations is as follows: First, based on preset frequency sweep information, the vector network analyzer transmits a first microwave signal point-by-point to the resonant cavity of the resonator. The vector network analyzer determines a first scattering parameter S21 based on the received first microwave signal. Based on the first scattering parameter S21, it determines a single frequency sweep information. Based on the single frequency sweep information, the vector network analyzer repeatedly transmits a second microwave signal to the resonant cavity of the resonator. Based on the received second microwave signal, the vector network analyzer determines a second scattering parameter S21. Based on the second scattering parameter S21, Fourier analysis is performed, which can obtain the thermoacoustic oscillation information in the sample cavity in real time, thus providing a reliable basis for suppressing thermoacoustic oscillation. Attached Figure Description

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

[0040] Figure 1 This is a schematic diagram of the overall structure of the low-temperature thermoacoustic oscillation detection device provided in an embodiment of the present invention;

[0041] Figure 2 This is a flowchart of a low-temperature thermoacoustic oscillation detection method provided according to an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of the magnitude of the scattering parameter S21 obtained by repeatedly measuring the second microwave sweep frequency according to an embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram of the thermoacoustic oscillation analysis results obtained by performing Fourier analysis on the modulus of scattering parameter S21 according to an embodiment of the present invention.

[0044] Figure label:

[0045] 1. Vector network analyzer; 2. Microwave cable; 3. Microwave cable connector; 4. Dewar and multi-level radiation shielding layer; 5. Sample chamber; 6. Microwave signal receiving module; 7. Resonator; 8. Vent; 9. Hanging rod; 10. Microwave signal transmitting module; 11. Time standard; 12. Communication line; 13. Computer; 14. Pressure controller; 15. Electric valve; 16. Valve; 17. Gas pipeline; 18. Gas supply cylinder; 19. Refrigeration unit. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0047] In the description of this invention, it should be understood that the terms "upper", "lower", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0048] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0049] It should be noted that commonly used thermoacoustic oscillation detection methods in the present technology mainly use pressure sensors or commercial instruments (such as Kepler velocimeters, infrared thermal imagers, etc.) to detect changes in pressure or temperature and then infer whether thermoacoustic oscillation has occurred. The detection accuracy of these methods is relatively low. However, the aforementioned existing thermoacoustic oscillation detection methods are only used for thermoacoustic oscillation detection in combustion chambers or gas lines connecting cryogenic liquid systems, and have not yet been applied to thermoacoustic oscillation detection in cryogenic gas systems.

[0050] Because cryogenic isothermal gas systems employ highly stable pressure and temperature control technologies, the occurrence of thermoacoustic oscillations must have minimal impact on the system's internal pressure or temperature; that is, the pressure or temperature fluctuations within the system should be minimal when thermoacoustic oscillations occur. Therefore, thermoacoustic oscillations under these conditions are difficult to detect using commonly used pressure sensors or commercial instruments.

[0051] Based on the discovery of the above-mentioned technical problems, the applicant provides a low-temperature thermoacoustic oscillation detection device, method and low-temperature thermostat, which can accurately detect thermoacoustic oscillations, thereby providing a reliable basis for suppressing thermoacoustic oscillations.

[0052] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0053] Please refer to Figure 1 In the technical solution provided in this embodiment, the low-temperature thermoacoustic detection device is used to detect thermoacoustic oscillations in the sample chamber 5 of the low-temperature thermostat. The low-temperature thermoacoustic detection device includes a resonator 7, a microwave signal analysis device, and a computer 13.

[0054] The microwave signal analysis device includes a microwave signal transmitting module 10, a microwave signal receiving module 6, and a vector network analyzer 1; wherein the microwave signal transmitting module 10 and the microwave signal receiving module 6 are both disposed on the resonator 7. The vector network analyzer 1 is communicatively connected to the microwave signal transmitting module 10 and the microwave signal receiving module 6 respectively. The vector network analyzer 1 is adapted to transmit a first microwave signal or a second microwave signal into the resonant cavity through the microwave signal transmitting module 10, and is adapted to receive the microwave signal according to the microwave signal receiving module 6 and obtain the scattering parameter S21 information.

[0055] Computer 13 is communicatively connected to vector network analyzer 1. Computer 13 is adapted to control vector network analyzer 1 to transmit microwave signals point by point within a preset sweep frequency band, determine a single sweep frequency according to scattering parameter S21, and determine thermoacoustic oscillation information according to scattering parameter S21.

[0056] Please refer to Figure 2 In this embodiment, the process of the low-temperature thermoacoustic detection device detecting thermoacoustic oscillation information can be described as follows:

[0057] S1, based on the frequency band information of the sweep frequency input by the user through the computer 13, the computer 13 controls the vector network analyzer 1 to transmit the first microwave signal point by point to the resonant cavity of the resonator; it should be noted that this step transmits multiple first microwave signals of different frequencies point by point to the resonant cavity of the resonator. The frequencies of the multiple microwave signals of different frequencies are within the frequency range of the above-mentioned sweep frequency band. The transmission process can transmit the first microwave signal point by point in a manner from low to high or from high to low frequency.

[0058] S2, the vector network analyzer 1 determines the first scattering parameter S21 based on the received first microwave signal. It should be noted that the multiple transmitted first microwave signals are received by the microwave signal receiving module after resonance within the resonant cavity, and then sent to the vector network analyzer. The network analyzer determines different sweep frequencies f based on the multiple resonant first microwave signals. i The corresponding first scattering parameter S21.

[0059] S3, the computer 13 determines the microwave resonant frequency information based on the first scattering parameter S21, and then determines the single sweep frequency information. In this step, the computer 13 can determine the microwave resonant frequency f and half-width g based on the first scattering parameter S21, and then determine the single sweep frequency f2, that is, the sweep frequency of the second microwave signal, where f2=f±X·g, X=0.6~1.0.

[0060] S4, based on the single sweep frequency information, the computer 13 controls the vector network analyzer 1 to repeatedly transmit the second microwave signal to the resonant cavity of the resonator;

[0061] S5, the vector network analyzer 1 determines the second scattering parameter S21 based on the second microwave signal received multiple times;

[0062] S6, computer 13 obtains thermoacoustic oscillation information based on the second scattering parameter S21. Specifically, computer 13 can obtain thermoacoustic oscillation information in real time through Fourier analysis.

[0063] Unlike pressure sensors or commercial instruments commonly used in the prior art, the technical solution provided in this embodiment can accurately measure the information of thermoacoustic oscillation even when the pressure or temperature fluctuation inside the low-temperature thermostat is very small during thermoacoustic oscillation, thus providing a reliable basis for suppressing thermoacoustic oscillation.

[0064] In this embodiment, for the low-temperature thermoacoustic detection device, the computer 13 communicates with the vector network analyzer 1. Specifically, the connection can be made through the communication line 12, or it can be made through a wireless transmission module.

[0065] In a further embodiment, the low-temperature thermoacoustic detection device also includes a time standard 11, which is communicatively connected to the vector network analyzer 1 and is adapted to input standard time information to the vector network analyzer 1.

[0066] In this embodiment, the time standard 11 in the low-temperature thermoacoustic detection device can communicate with the vector network analyzer 1 and input standard time information to it. The function of the time standard 11 is to provide an accurate time reference to ensure the timing and synchronization of measurements. Specifically, the time standard 11 can perform the following functions:

[0067] 1. Provide a standard time signal: The time standard instrument 11 will output a high-precision standard time signal, such as a time reference based on an atomic clock. This signal can serve as the time base of the measurement system, ensuring that all instruments have a unified time reference during the measurement process.

[0068] 2. Communication connection with vector network analyzer 1: The time standard 11 communicates with the vector network analyzer 1 through a suitable interface. In this way, the time standard 11 can transmit standard time signals to the vector network analyzer 1, ensuring the synchronization of the measurement equipment and the data acquisition process.

[0069] 3. Synchronous Measurement and Data Acquisition: By using the standard time signal provided by the time standard instrument 11, the vector network analyzer 1 can operate synchronously with other measuring devices. This ensures that all instruments perform measurements and data acquisition at the same point in time, avoiding time errors and data inconsistencies.

[0070] The presence of the time standard 11 provides a high-precision time reference, ensuring time synchronization among the various instruments in the cryogenic thermoacoustic detection device. This is crucial for the accurate analysis and interpretation of measurement results, especially in applications requiring time correlation or time series analysis.

[0071] In some embodiments, the resonator 7 is suspended inside the sample cavity 5, and the resonator 7 is provided with a vent 8, the two ends of which are connected to the sample cavity 5 and the resonator cavity, respectively. Specifically, a suspension rod 9 may be provided inside the sample cavity 5, and the resonator 7 is connected to the suspension rod 9.

[0072] In some embodiments, the microwave signal transmitting module 10 includes a transmitting antenna, and the microwave signal receiving module 6 includes a receiving antenna, both of which are disposed within a resonant cavity. Specifically, the receiving antenna and the transmitting antenna may be disposed on the upper and lower sides of the resonant cavity, respectively. The vector network analyzer 1 is connected to the microwave signal transmitting module 10 and the microwave signal receiving module 6 via a microwave cable 2 and a microwave cable connector 3, respectively.

[0073] This invention also provides a low-temperature thermoacoustic detection method, comprising the following steps:

[0074] S1, based on the frequency band information of the sweep frequency input by the user through the computer 13, the computer 13 controls the vector network analyzer 1 to transmit the first microwave signal point by point to the resonant cavity of the resonator; it should be noted that this step transmits multiple first microwave signals of different frequencies point by point to the resonant cavity of the resonator. The frequencies of the multiple microwave signals of different frequencies are within the frequency range of the above-mentioned sweep frequency band. The transmission process can transmit the first microwave signal point by point in a manner from low to high or from high to low frequency.

[0075] S2, the vector network analyzer 1 determines the first scattering parameter S21 based on the received first microwave signal. It should be noted that the multiple transmitted first microwave signals are received by the microwave signal receiving module after resonance within the resonant cavity, and then sent to the vector network analyzer. The network analyzer determines different sweep frequencies f based on the multiple resonant first microwave signals. i The corresponding first scattering parameter S21.

[0076] S3, computer 13 determines the microwave resonant frequency information based on the first scattering parameter S21, and then determines the single sweep frequency information. Specifically, in this step, the single sweep frequency f2, that is, the sweep frequency of the second microwave signal, can be determined by the microwave resonant frequency f and the half-width g, where f2 = f ± X·g, X = 0.6~1.0.

[0077] S4, based on the single sweep frequency information, the computer 13 controls the vector network analyzer 1 to repeatedly transmit the second microwave signal to the resonant cavity of the resonator;

[0078] S5, the vector network analyzer 1 determines the second scattering parameter S21 based on the second microwave signal received multiple times;

[0079] S6, computer 13 obtains thermoacoustic oscillation information based on the second scattering parameter S21. Specifically, computer 13 can obtain thermoacoustic oscillation information in real time through Fourier analysis.

[0080] In some embodiments, by performing Fourier analysis on the frequency modulus, the following can be obtained: Figure 3 The analysis results shown indicate that although the thermoacoustic oscillations within the system are very small, the frequency changes caused by these oscillations can still be detected using high-precision microwave frequency measurement, thus confirming the occurrence of thermoacoustic oscillations within the system.

[0081] This invention also provides a low-temperature thermostat, including a sample chamber 5, a gas supply device, and a low-temperature thermoacoustic detection device.

[0082] In this embodiment, the sample chamber 5 is located within a cavity composed of a Dewar and a multi-level radiation shielding layer 4 to ensure good thermal insulation. The sample chamber 5 must also be airtight.

[0083] In this embodiment, the gas supply device may specifically include a gas cylinder 18, which is connected to the sample chamber 5 via a gas pipeline 17. A valve 16 and an electric valve 15 are installed on the gas pipeline 17. The electric valve 15 is connected to a pressure controller 14, which controls the opening degree of the electric valve 15, thereby controlling the inlet pressure. The refrigerator 19 inputs cooling energy into the inner cavity of the Dewar and multi-level radiation shielding layer 4, providing a stable low-temperature environment for the sample chamber 5.

[0084] The low-temperature thermoacoustic detection device in this embodiment can be any of the low-temperature thermoacoustic detection devices described in the previous embodiments. With this configuration, the low-temperature thermostat provided in this embodiment can accurately detect thermoacoustic oscillation information, providing a reliable basis for suppressing thermoacoustic oscillations.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-temperature thermoacoustic detection method, characterized in that, A low-temperature thermoacoustic detection device is used to detect thermoacoustic oscillations in the sample cavity (5) of the low-temperature thermostat. The device includes a resonator (7) disposed in the sample cavity (5). The resonator (7) includes a resonant cavity and is connected to the sample cavity (5). The low-temperature thermoacoustic detection method includes: According to the preset frequency sweep information, the vector network analyzer (1) transmits the first microwave signal point by point to the resonant cavity of the resonator (7); The vector network analyzer (1) determines the first scattering parameter S21 based on the received first microwave signal; Based on the first scattering parameter S21, the microwave resonant frequency information is determined, and then the single sweep frequency information is determined. According to the single sweep frequency information, the vector network analyzer (1) repeatedly transmits a second microwave signal to the resonant cavity of the resonator (7); The vector network analyzer (1) determines the second scattering parameter S21 based on the received second microwave signal; Thermoacoustic oscillation information is obtained based on the second scattering parameter S21.

2. The low-temperature thermoacoustic detection method according to claim 1, characterized in that, According to the preset frequency sweep information, the vector network analyzer (1) transmits a first microwave signal point by point to the resonant cavity of the resonator (7), including: The computer determines the preset frequency band information based on the user's selection; The vector network analyzer (1) receives the preset frequency sweep band information and transmits the first microwave signal point by point within the preset frequency sweep band.

3. The low-temperature thermoacoustic detection method according to claim 2, characterized in that, The step of obtaining thermoacoustic oscillation information based on the second scattering parameter S21 includes: The resonant frequency is determined by fitting the second scattering parameter S21. The thermoacoustic oscillation information is determined by performing Fourier analysis based on the resonant frequency.

4. A cryogenic thermoacoustic detection device for performing the cryogenic thermoacoustic detection method as described in any one of claims 1 to 3, characterized in that, Also includes: The microwave signal analysis device includes a microwave signal transmitting module (10), a microwave signal receiving module (6), and a vector network analyzer (1); wherein, The microwave signal transmitting module (10) and the microwave signal receiving module (6) are both located on the resonator (7); The vector network analyzer (1) is communicatively connected to the microwave signal transmitting module (10) and the microwave signal receiving module (6) respectively. The vector network analyzer (1) is adapted to transmit microwave signals into the resonant cavity through the microwave signal transmitting module (10) and obtain scattering parameters S21 from the microwave signals in the resonant cavity received by the microwave signal receiving module (6). A computer (13) is communicatively connected to the vector network analyzer (1). The computer (13) is adapted to control the vector network analyzer (1) to transmit microwave signals point by point within a preset sweep frequency band, determine microwave resonant frequency information and single sweep frequency according to the scattering parameter S21, and determine thermoacoustic oscillation information according to the scattering parameter S21.

5. The low-temperature thermoacoustic detection device according to claim 4, characterized in that, Also includes: A time standard instrument (11) is communicatively connected to the vector network analyzer (1), and the time standard instrument (11) is adapted to input standard time information to the vector network analyzer (1).

6. The low-temperature thermoacoustic detection device according to claim 4, characterized in that, The resonator (7) is suspended inside the sample cavity (5), and the resonator (7) is provided with a vent (8), the two ends of which are connected to the sample cavity (5) and the resonator cavity respectively.

7. The low-temperature thermoacoustic detection device according to claim 4, characterized in that, The microwave signal transmitting module (10) includes a transmitting antenna, and the microwave signal receiving module (6) includes a receiving antenna. Both the transmitting antenna and the receiving antenna are disposed on the resonant cavity.

8. The low-temperature thermoacoustic detection device according to claim 4, characterized in that, The vector network analyzer (1) is connected to the microwave signal transmitting module (10) and the microwave signal receiving module (6) via microwave cable (2) and microwave cable connector (3), respectively.

9. A low-temperature thermostat, characterized in that, include: Sample chamber (5); A gas supply device is connected to the sample chamber (5) via a gas supply trunk line; The low-temperature thermoacoustic detection device is configured as described in any one of claims 4-8.

10. The low-temperature thermostat according to claim 9, characterized in that, Also includes: The sample chamber (5) is located in the inner cavity of the Dewar and multi-level radiation shielding layer (4); A refrigeration unit (19) is adapted to supply cooling energy to the inner cavity of the Dewar and the multi-level radiation shielding layer (4).

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