A vibration testing device for a cryogenic refrigerator

Abstract

The utility model provides a kind of deep hypothermia refrigerator vibration testing device, including the flange connecting part of being set to the refrigerator cold head outside and being fixedly connected with refrigerator body, the connecting pipe of being set to the refrigerator body outside and being tightly connected with flange connecting part can be adapted to different length cold head, the detection cover of being tightly in the lower end of connecting pipe can be light-transmitting and the laser displacement sensor of being set to the detection cover outside can be passed through detection cover to optical vibration monitoring of machine body, the flange connecting part, connecting pipe and detection cover form sealed cover body, so that refrigerator cold head is located in cover body;It further includes vacuum pump, which can extract gas in the sealed cover body to make the sealed cover body in vacuum state.The utility model clearly reveals the change trend of vibration amplitude, frequency distribution and vibration mode of refrigerator cold head in working process, providing detailed data support for optimizing refrigerator design.

Description

Technical Field

[0001] This utility model relates to the field of quantum computing technology, and in particular to a vibration testing device for cryogenic refrigerators. Background Technology

[0002] The inherent characteristics of quantum technology create a natural symbiotic relationship with cryogenic technology, while the development of cryogenic technology drives the rapid progress of quantum technology. A stable cryogenic environment is crucial for improving the accuracy of weak signal measurements in quantum research, and the liquid helium temperature range is a key bridging temperature gap. Liquid helium temperature refrigeration technology not only meets the temperature requirements of quantum technologies such as spin quantum computing, ion trap quantum computing, and optical quantum computing, but also provides pre-cooling for mK-level dilution refrigerators, thus ensuring the smooth operation of quantum technology research such as superconducting quantum computing, neutral atom simulation, and quantum simulation.

[0003] Liquid helium temperature-range pulse tube refrigerators, with their high reliability, long lifespan, low vibration, and low electromagnetic interference, perfectly meet the needs of quantum technology for liquid helium temperature-range refrigeration. Liquid helium temperature-range pulse tube refrigerators for quantum computing dilution refrigerators provide the necessary support for the pre-cooling of 3He-4He mixtures, enabling the system to quickly reach the initial 4K temperature. At the same time, the low vibration characteristics of pulse tube refrigerators significantly reduce the interference of mechanical vibration on qubits, improving the stability of quantum computing.

[0004] However, even weak vibrations can shorten the coherence time of qubits or introduce noise, thereby affecting the accuracy of quantum computing. Therefore, it is particularly important to accurately measure the vibrations generated during the operation of pulse tube cryostats. By accurately monitoring and analyzing vibration characteristics, cryostat design can be optimized, further reducing the risk of vibrations being transmitted to quantum chips and providing a more stable and reliable ultra-low temperature working environment for quantum computing. Existing detection equipment makes it difficult to accurately detect the vibration characteristics of cryostats. Utility Model Content

[0005] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a vibration testing device for cryogenic refrigerators, which solves the problem that it is difficult to accurately detect the vibration characteristics of cryogenic refrigerators in the prior art.

[0006] To achieve the above and other related objectives, this utility model provides a deep cryogenic refrigerator vibration testing device, including a flange connection part sleeved on the outside of the refrigerator cold head and fixedly connected to the refrigerator body, a connecting pipe sleeved on the outside of the refrigerator body and tightly connected to the flange connection part to adapt to cold heads of different lengths, a light-transmitting detection cover tightly fitted to the lower end of the connecting pipe, and a laser displacement sensor set outside the detection cover to perform optical vibration monitoring of the body through the detection cover. The flange connection part, the connecting pipe, and the detection cover form a sealed cover, so that the refrigerator cold head is located inside the cover. It also includes a vacuum pump that can extract gas from the sealed cover to create a vacuum inside the sealed cover.

[0007] By adopting the above technical solution, the cryogenic cold head can be installed within a sealed enclosure formed by the flange connection, connecting pipe, and detection cover. After installation, calibration is performed using a laser displacement sensor. Then, a vacuum pump is started to evacuate the sealed enclosure to achieve the required high vacuum environment. The cryogenic unit is then turned on to gradually cool down to the target temperature. Finally, the vibration of the cold head is monitored using the laser displacement sensor. This allows for a comprehensive and accurate understanding of the vibration characteristics of cryogenic refrigeration devices under different operating conditions. It not only identifies the main sources of vibration but also provides in-depth analysis of the potential impact of vibration on refrigeration efficiency and stability. It clearly reveals the changing trends of vibration amplitude, frequency distribution, and vibration modes of the cryogenic cold head during operation, providing detailed data support for optimizing cryogenic unit design.

[0008] In one embodiment of this utility model, one end of the flange connection is tightly connected to the refrigeration unit body and a vibration isolation washer is provided at the connection point, and the other end is connected to the connecting pipe through a sealing ring, and the flange connection and the connecting pipe are arranged coaxially.

[0009] By adopting the above technical solution, the cold head of the refrigeration unit can be fixed in the sealed cover through the flange connection. The flange connection adopts a modular design, which can be flexibly replaced according to different models and geometric dimensions of refrigeration units, ensuring the versatility of the test system. At the same time, in order to reduce the interference of external environmental vibration, the flange connection is made of high rigidity material and vibration isolation washers are added at the connection, which improves the stability of the system from the mechanical structure.

[0010] In one embodiment of this utility model, the connecting pipe is a corrugated pipe.

[0011] By adopting the above technical solution, the bellows is made of high-strength, low-temperature compatible metal materials (such as stainless steel or nickel alloy), possessing excellent flexibility and adjustability. It can not only freely adjust its length and angle according to the geometry of the refrigeration unit during system installation, but also ensure the sealing of the cavity, making it compatible with various models of refrigeration units and simplifying the installation process. In addition, the bellows structure can effectively reduce the transmission of vibration during the operation of the refrigeration unit, reduce the impact of vibration noise on the measurement results, and thus improve the accuracy of vibration data.

[0012] In one embodiment of the present invention, the detection cover has optical windows along the X, Y, and Z directions that can be detected by a laser displacement sensor.

[0013] By adopting the above technical solution, the laser displacement sensor can non-contactly measure the vibration characteristics of the cold head through the optical window at the top of the cavity. The measurement angle and position of the laser sensor can be flexibly adjusted along the X, Y, and Z directions. Furthermore, by comprehensively processing the vibration data in the X, Y, and Z directions, the changing trends of the vibration amplitude, frequency distribution, and vibration mode of the refrigeration unit's cold head during operation can be clearly revealed.

[0014] In one embodiment of this utility model, a sealing gasket for sealing connection is provided at the connection between the optical window and the detection cover.

[0015] By adopting the above technical solution, a polytetrafluoroethylene gasket is used to seal the optical window and the stainless steel wall, which provides a good sealing effect during the test.

[0016] In one embodiment of this utility model, a central data acquisition module and an analysis module are further included, which are electrically connected to the laser displacement sensor.

[0017] By adopting the above technical solution, the central data acquisition and analysis module processes the data collected by the sensors in real time. During the experiment, the vibration isolation performance provided by the optical platform, combined with the internal structural design of the cavity, forms a system-level multi-layered anti-vibration mechanism, ensuring the accuracy of the test data. The central controller unit adjusts the sensor acquisition frequency and laser detection path based on the vibration data of the cold head, while managing the vacuum state of the cavity and controlling the opening, closing, and adjustment of the vacuum pop-up windows in the XYZ directions to achieve high-precision, multi-directional vibration characteristic testing and data recording.

[0018] In one embodiment of this utility model, an optical platform for support is further provided on the lower side of the detection cover, and the laser displacement sensor is mounted on the optical platform.

[0019] By adopting the above technical solution, the testing device can be installed on a high-precision optical platform to further reduce the impact of external vibrations on the testing system. The optical platform adopts an anti-vibration design, with high rigidity and excellent vibration isolation performance, which can effectively isolate minor vibrations from the ground and the environment, providing a stable operating foundation for the test bench. The vibration isolation characteristics of the optical platform, combined with the internal design of the test bench, can significantly reduce the interference of external vibration sources on the vibration measurement of the cold head of the refrigerator, thereby improving the reliability and accuracy of the test results.

[0020] As described above, the vibration testing device for cryogenic refrigerators of this invention has the following beneficial effects: It can install the cryogenic cold head within a sealed enclosure formed by the flange connection, connecting pipe, and detection cover. After installation, calibration is performed using a laser displacement sensor. Then, a vacuum pump is started to evacuate the sealed enclosure to achieve the required high vacuum environment. The cryogenic unit is then turned on, gradually cooling to the target temperature. Finally, the vibration of the cold head is monitored using the laser displacement sensor. This allows for a comprehensive and accurate understanding of the vibration characteristics of cryogenic refrigeration devices under different operating conditions. It not only identifies the main sources of vibration but also provides in-depth analysis of the potential impact of vibration on refrigeration efficiency and stability. It clearly reveals the changing trends of vibration amplitude, frequency distribution, and vibration modes of the cryogenic cold head during operation, providing detailed data support for optimizing cryogenic unit design. Simultaneously, these analytical results can provide higher stability and reliability guarantees for the operating environment of quantum chips in the fields of quantum computing and cryogenic technology, further promoting the precision and engineering application of related technologies. Furthermore, this process can also be used to verify the effectiveness of vibration suppression schemes, laying a solid foundation for the future development of lower-vibration, higher-precision cryogenic refrigeration equipment. Attached Figure Description

[0021] Figure 1 The diagram shown is a schematic representation of the overall structure disclosed in the embodiments of this utility model.

[0022] Component designation explanation

[0023] 1. Flange connection; 2. Connecting pipe; 3. Inspection cover; 4. Refrigeration unit cold head. Detailed Implementation

[0024] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0025] Please see Figure 1It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this invention, should still fall within the scope of the disclosed technical content. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0026] like Figure 1 As shown, this utility model provides a deep cryogenic refrigerator vibration testing device, including a flange connection part 1 sleeved on the outside of the refrigerator cold head and fixedly connected to the refrigerator body, a connecting pipe 2 sleeved on the outside of the refrigerator body and tightly connected to the flange connection part 1 to adapt to cold heads of different lengths, a light-transmitting detection cover 3 tightly attached to the lower end of the connecting pipe 2, and a laser displacement sensor set outside the detection cover 3 to perform optical vibration monitoring of the body through the detection cover 3.

[0027] The flange connection 1, the connecting pipe 2, and the detection cover 3 form a sealed cover. It also includes a vacuum pump that can evacuate the sealed cover, and can install the refrigeration unit cold head 4 inside the sealed cover. The cold head is monitored for vibration by a laser displacement sensor. The refrigeration unit cold head 4 is completely enclosed inside the sealed cover, so that the cold head is in a sealed state for detection.

[0028] One end of the flange connection 1 is tightly connected to the refrigeration unit body, and the other end is connected to the connecting pipe 2 through a sealing ring. The flange connection 1 and the connecting pipe 2 are arranged coaxially. The flange connection 1 adopts a modular design and can be flexibly replaced according to different models and geometric dimensions of refrigeration units. The flange is made of high rigidity material, which improves the stability of the device from a mechanical structure perspective.

[0029] Connecting pipe 2 is a bellows, made of high-strength, low-temperature compatible metal materials (such as stainless steel or nickel alloy), possessing excellent flexibility and adjustability. The bellows not only allows for free adjustment of length and angle according to the geometry of the refrigerator during system installation, but also ensures the sealing of the cavity. This design greatly enhances the adaptability of the testing system, making it compatible with various models of refrigerators and simplifying the installation process. Furthermore, the bellows structure effectively mitigates vibration transmission during refrigerator operation, reducing the impact of vibration noise on measurement results, thereby improving the accuracy of vibration data.

[0030] The detection cover 3 is designed with a square structure. The detection cover 3 has optical windows along the X, Y and Z directions that can be detected by the laser displacement sensor. The optical windows are respectively set on the top and side walls of the detection cover 3. The optical windows are high-precision optical windows made of low-temperature resistant optical transparent materials, which not only ensures the sealing of the vacuum cavity, but also allows the laser signal to pass through without damage, and is used to monitor the vibration of the cold head 4 of the refrigerator.

[0031] The test cover 3 is made of stainless steel. A sealing gasket is installed at the connection between the optical window and the test cover 3 for sealing. The sealing gasket is made of polytetrafluoroethylene and provides a good sealing effect during the test.

[0032] The stable connection of flange connection 1, the high adaptability of bellows, and the multi-directional monitoring capability of square measuring section enable a comprehensive analysis of the vibration characteristics of the cryogenic refrigerator. The flexible structure of the bellows section allows the system to be widely compatible with cryogenic refrigerators with different geometric parameters, while the combination of square measuring section and laser sensor ensures high-precision measurement of vibration data. This not only provides a reliable tool for testing the vibration characteristics of cryogenic refrigerators, but also supports the optimization of refrigerator design through accurate data, providing a higher performance foundation for high-precision technology applications such as quantum computing.

[0033] An optical platform for support is also provided on the lower side of the detection cover 3. The laser displacement sensor is installed on the optical platform, and the testing device is installed on the optical platform. The vibration-resistant structure of the optical platform effectively reduces the transmission of ground and environmental vibrations, providing a highly stable foundation for the testing process. The laser displacement sensor measures the vibration characteristics of the cold head non-contactly through the optical window on the top of the cavity.

[0034] It also includes a central data acquisition module and an analysis module that are electrically connected to the laser displacement sensor. The central data acquisition and analysis module processes the data collected by the sensor in real time. During the experiment, the vibration isolation performance provided by the optical platform, combined with the internal structural design of the cavity, forms a system-level multi-layered anti-vibration mechanism, ensuring the accuracy of the test data. The central controller unit adjusts the sensor's acquisition frequency and laser detection path based on the vibration data of the cold head, while managing the vacuum state of the cavity and controlling the opening, closing, and adjustment of the vacuum pop-up windows in the XYZ directions to achieve high-precision, multi-directional vibration characteristic testing and data recording.

[0035] Before starting the vibration testing system for cryogenic refrigeration devices, the cold head of the cryo-mechanism under test is securely installed in the test chamber via flange connection sections, bellows sections, and square measuring sections, according to experimental requirements. Subsequently, the testing system is connected to a high-precision optical platform to ensure the overall structural stability and vibration isolation effect.

[0036] After installation, the laser displacement sensor needs to be calibrated to ensure its measurement accuracy. Calibration can be achieved using an automated calibration device for displacement sensors based on laser interferometry. This device utilizes a laser interferometer to provide high-precision position feedback signals, enabling automatic calibration of the sensor.

[0037] During calibration, ensure that the sensor's measuring axis is aligned with the vibration direction of the cold head, and adjust the sensor's position and angle to accurately capture minute displacement changes in the cold head.

[0038] Next, the vacuum pump is started to evacuate the test chamber to achieve the required high vacuum environment. Then, the refrigerator is turned on to gradually cool it down to the target temperature. During this process, the vacuum level and temperature changes inside the chamber are continuously monitored to ensure stable system operation. When the refrigerator reaches the predetermined temperature, the laser displacement sensor begins to monitor the vibration of the cold head in real time and collects vibration data in the XYZ directions.

[0039] The collected vibration data needs to be analyzed in depth to assess the vibration characteristics of the refrigerator. By acquiring information such as instantaneous frequency and amplitude, and through comprehensive analysis of the vibration signals, the vibration characteristics of the refrigerator under different operating conditions can be identified, providing a scientific basis for optimizing refrigerator design and reducing the impact of vibration on quantum chips.

[0040] When using the equipment, first install the cold head of the refrigerator under test into the sealed enclosure according to the experimental requirements; then connect the test device to the high-precision optical platform to ensure the stability of the overall structure and the vibration isolation effect; during the installation process, special attention should be paid to the sealing of the flange connection and the compatibility of the bellows to ensure that the system can maintain good sealing and stability under refrigerators of different geometric dimensions.

[0041] After installation, the laser displacement sensor needs to be calibrated to ensure its measurement accuracy. The calibration method can be to use an automated calibration device for displacement sensors based on laser interferometry, which provides a high-precision position feedback signal through a laser interferometer to achieve automatic calibration of the sensor.

[0042] During calibration, ensure that the sensor's measuring axis is aligned with the vibration direction of the cold head, and adjust the sensor's position and angle to accurately capture minute displacement changes in the cold head.

[0043] Next, the vacuum pump is started to evacuate the test chamber to achieve the required high vacuum environment. Then, the refrigerator is turned on to gradually cool it down to the target temperature. During this process, the vacuum level and temperature changes inside the chamber are continuously monitored to ensure stable system operation. When the refrigerator reaches the predetermined temperature, the laser displacement sensor begins to monitor the vibration of the cold head in real time and collects vibration data in the XYZ directions.

[0044] The collected vibration data needs to be analyzed in depth to assess the vibration characteristics of the refrigerator; information such as its instantaneous frequency and amplitude should be obtained. Through comprehensive analysis of the vibration signals, the vibration characteristics of the refrigerator under different working conditions can be identified, providing a scientific basis for optimizing the refrigerator design and reducing the impact of vibration on quantum chips.

[0045] In summary, this invention enables the cryogenic cooling head 4 to be installed within a sealed enclosure formed by the flange connection 1, connecting pipe 2, and detection cover 3. After installation, calibration is performed using a laser displacement sensor. Then, a vacuum pump is started to evacuate the sealed enclosure to achieve the required high vacuum environment. The cryogenic unit is then turned on to gradually cool down to the target temperature. Finally, the vibration of the cooling head is monitored using a laser displacement sensor. This allows for a comprehensive and accurate understanding of the vibration characteristics of the cryogenic cooling device under different operating conditions. It not only identifies the main sources of vibration but also provides in-depth analysis of the potential impact of vibration on cooling efficiency and stability. It clearly reveals the changing trends of the vibration amplitude, frequency distribution, and vibration mode of the cryogenic cooling head 4 during operation, providing detailed data support for optimizing the cryogenic unit design.

[0046] Meanwhile, these analytical results can provide higher stability and reliability for the operating environment of quantum chips in the fields of quantum computing and cryogenic technology, further promoting the precision and engineering application of related technologies. In addition, this process can also be used to verify the effectiveness of vibration suppression schemes, laying a solid foundation for the future development of low-vibration, high-precision cryogenic refrigeration equipment.

[0047] Therefore, this utility model effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0048] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A vibration testing device for cryogenic refrigerators, characterized in that, The system includes a flange connection part fitted outside the cold head of the refrigerator and fixedly connected to the refrigerator body; a connecting pipe fitted outside the refrigerator body and tightly connected to the flange connection part to adapt to cold heads of different lengths; a light-transmitting detection cover tightly fitted to the lower end of the connecting pipe; and a laser displacement sensor set outside the detection cover to perform optical vibration monitoring of the machine body through the detection cover. The flange connection part, the connecting pipe, and the detection cover form a sealed cover, so that the cold head of the refrigerator is located inside the cover. The system also includes a vacuum pump that can extract gas from the sealed cover to create a vacuum inside the sealed cover.

2. The cryogenic refrigerator vibration testing device according to claim 1, characterized in that: One end of the flange connection is tightly connected to the refrigeration unit body and a vibration isolation washer is provided at the connection point. The other end is connected to the connecting pipe through a sealing ring, and the flange connection and the connecting pipe are arranged on the same axis.

3. The cryogenic refrigerator vibration testing device according to claim 1, characterized in that: The connecting pipe is a corrugated pipe.

4. The cryogenic refrigerator vibration testing device according to claim 1, characterized in that: The detection cover has optical windows along the X, Y, and Z directions that can be detected by a laser displacement sensor.

5. The cryogenic refrigerator vibration testing device according to claim 4, characterized in that: Both the optical window and the detection cover are equipped with sealing gaskets for sealing the connection.

6. The cryogenic refrigerator vibration testing device according to claim 1, characterized in that: It also includes a central data acquisition module and an analysis module that are connected to the electrical signals of the laser displacement sensor.

7. The cryogenic refrigerator vibration testing device according to claim 1, characterized in that: An optical platform for support is also provided on the lower side of the detection cover, and the laser displacement sensor is mounted on the optical platform.

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