Solid conduction cooling structure for superconducting radio frequency cavity

Abstract

The invention relates to the technical field of superconducting accelerators, in particular to a solid conduction cooling structure for a superconducting radio frequency cavity. Comprising a double-cell superconducting cavity body, an equator cold ring, a beam tube cold ring and a thermal bridge structure, and through the ingenious design of the equator cold ring, the beam tube cold ring and the thermal bridge structure and the adoption of oxygen-free copper and other materials with good heat conduction performance and mechanical strength, the efficient and uniform cooling effect is achieved, and the service life of the double-cell superconducting cavity is prolonged. Powerful support is provided for miniaturization and industrial application of the radio frequency superconducting technology; according to the invention, stable operation of the superconducting cavity at a proper low temperature can be realized by adopting a commercial refrigerator, a complex thermostat design, an expensive and huge helium liquefaction low-temperature station and a specialized low-temperature station operation and maintenance team are omitted, and the application difficulty of a radio frequency superconducting technology is reduced; the method has natural advantages in miniaturization and industrial application of the radio frequency superconducting technology.

Description

Technical Field

[0001] The present invention relates to the technical field of superconducting accelerators, and particularly to a solid conduction cooling structure for a superconducting radio frequency cavity. Background Art

[0002] In superconducting accelerator technology, the cooling of superconducting cavities is a key link. Currently, superconducting accelerators based on niobium-based superconducting cavities usually use liquid helium immersion between 2K - 4K to achieve cooling. This cooling method requires large cryogenic refrigeration stations, complex cryostat systems, and professional cryogenic refrigeration maintenance teams, greatly increasing the construction and operation costs of superconducting accelerators and becoming the main obstacle to the popular application of radio frequency superconducting technology.

[0003] In recent years, with the development of high-temperature superconducting materials, the radio frequency performance of high-temperature superconducting cavities with a superconducting transition temperature greater than 15K has reached the level of niobium-based superconducting cavities at 2K even in the state of 4.2K or even cold helium gas. At the same time, industrial refrigeration technology has also made remarkable progress, and a relatively high refrigeration power can be achieved at a low temperature of 4.2K, and the average maintenance cycle of domestic industrial refrigerators is as long as 18 months, which provides the possibility for solid conduction cooling using commercial refrigerators.

[0004] However, despite these technological advancements, how to effectively transfer the cooling capacity of commercial refrigerators to each key part of the superconducting cavity to achieve stable and efficient cooling remains a technical problem faced currently. Existing cooling structures often have problems such as uneven cooling capacity distribution and low cooling efficiency, affecting the working stability and performance of superconducting cavities.

[0005] Therefore, there is an urgent need for a new solid conduction cooling structure for superconducting radio frequency cavities to solve the problems existing in the prior art. Summary of the Invention

[0006] Aiming at the above problems, the present invention aims to provide a cooling solution for superconducting radio frequency cavities that can simplify the cooling system, reduce costs, and improve operating stability, so as to overcome the complexity and high costs brought by relying on liquid helium immersion cooling in the prior art.

[0007] The technical solution adopted by the present invention to solve the technical problems is: a solid conduction cooling structure for a superconducting radio frequency cavity, comprising:

[0008] A double-cell superconducting cavity body, the double-cell superconducting cavity body includes two adjacent accelerating ellipsoidal cavities and beam pipes with inconsistent pipe diameters on both sides of the accelerating unit, and the superconducting cavity body material is made of niobium material;

[0009] The equatorial cold ring, including two equatorial cold rings, is circumferentially arranged in the equatorial region of the accelerating ellipsoidal cavity of the double-cell superconducting cavity. Its inner surface fits against the outer surface of the accelerating ellipsoidal cavity and is connected to the secondary cold source of the refrigerator through a flexible cold chain.

[0010] The beam tube cold ring, including two beam tube cold rings, is respectively circumferentially arranged in the beam pipe region of the superconducting cavity body, and its inner surface fits against the outer surface of the beam pipe of the superconducting cavity.

[0011] The thermal bridge structure includes a thermal bridge structure for connecting the beam tube cold ring and the equatorial cold ring respectively and a thermal bridge structure for connecting the two equatorial cold rings.

[0012] The superconducting cavity material is niobium, with a superconducting transition temperature of 9.25K under zero magnetic field and a critical magnetic field of 0.015T at 4K temperature.

[0013] The equatorial cold ring, the beam tube cold ring and the thermal bridge structure are all made of oxygen-free copper.

[0014] Each equatorial cold ring is connected to the refrigerant of 3 secondary cold sources, and the central angles between the connection regions are all 120°.

[0015] Each equatorial cold ring is connected to 3 thermal bridge structures to be connected to the beam tube cold ring. The central angle between the connection regions is 120°, the angle between the adjacent cold source connection point and the beam tube thermal bridge connection point is 60°, and the two equatorial cold rings are arranged with a 180° rotation relative to the central axis.

[0016] Each beam tube cold ring has three thermal bridge connection regions, and the angles between these thermal bridge connection regions are all 120°.

[0017] The thermal bridges connecting the beam tube cold ring and the equatorial cold ring all adopt an inclined plate structure, with both ends respectively connected to the thermal bridge connection region of the beam tube cold ring and the beam tube thermal bridge connection region of the equatorial cold ring.

[0018] The thermal bridge connecting the two equatorial cold rings adopts a straight plate structure, with both ends respectively connected to the cold source connection region of the equatorial cold ring and the thermal bridge connection region of the next equatorial cold ring.

[0019] The flexible cold chain has sufficient flexibility to adapt to the relative displacement between the secondary cold source of the refrigerator and the equatorial cold ring, and has heat conduction performance.

[0020] The solid conduction cooling structure for the superconducting radio frequency cavity further includes a temperature monitoring system, which is used to monitor the temperatures of the superconducting cavity body, the equatorial cold ring, the beam tube cold ring and the thermal bridge structure to ensure the stable operation of the superconducting cavity at an appropriate low temperature.

[0021] The beneficial effects of the present invention are as follows: The solid conduction cooling structure for superconducting radio frequency cavities of the present invention addresses the complexity and high cost problems brought about by relying on liquid helium immersion cooling in the prior art, and proposes an innovative solution. Its beneficial effects are mainly reflected in the following aspects:

[0022] Through the ingenious design of the equatorial cold ring, beam tube cold ring and heat bridge structure, the present invention constitutes an efficient and compact solid conduction cooling system. This design eliminates the large cryogenic refrigeration station and complex thermostat system required for traditional liquid helium immersion cooling, greatly simplifying the structure and layout of the cooling system.

[0023] The present invention uses a commercial refrigerator as the cold source, combined with the solid conduction cooling structure of the present invention, significantly reducing the construction and operation costs of superconducting accelerators. The average maintenance cycle of domestic industrial refrigerators is up to 18 months, further reducing the maintenance cost and the need for a professional cryogenic refrigeration maintenance team.

[0024] The cooling structure of the present invention realizes the efficient and uniform transfer of cooling capacity through materials with good thermal conductivity and mechanical strength such as oxygen-free copper. The close-fitting design of the equatorial cold ring, beam tube cold ring and heat bridge structure ensures good thermal contact, improves the cooling efficiency, and thus enhances the working stability of the superconducting cavity.

[0025] The addition of a temperature monitoring system enables the temperature of the superconducting cavity to be monitored and controlled in real time, further ensuring the stable operation of the superconducting cavity at an appropriate low temperature.

[0026] The solid conduction cooling structure of the present invention provides strong support for the miniaturization and industrial application of radio frequency superconducting technology. Eliminating the complex thermostat design and expensive and large-scale helium liquefaction cryogenic station reduces the difficulty and threshold of technology application, making radio frequency superconducting technology easier to promote and popularize.

[0027] Through the ingenious design of the heat bridge structure, the present invention effectively solves the problem of uneven cold quantity distribution existing in the existing cooling structure. The heat bridge structure tightly connects the equatorial cold ring and the beam tube cold ring, ensuring that the cold quantity can be evenly and efficiently transferred to each key part of the superconducting cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic structural diagram of the present invention;

[0029] Figure 2 is an axial sectional structural diagram of the present invention.

[0030] Description of the reference numerals:

[0031] In the figure: 1. Dual-cell superconducting cavity body; 1-1. Accelerating ellipsoidal cavity; 1-2. Beam pipe (one side); 1-3. Beam pipe (the other side); 2. Equatorial cold loop; 2-1. The first equatorial cold loop; 2-2. The second equatorial cold loop; 3. Beam tube cold loop; 3-1. The first beam tube cold loop; 3-2. The second beam tube cold loop; 4. Thermal bridge structure; 4-1. Thermal bridge connecting the beam tube cold loop and the equatorial cold loop (the first); 4-2. Thermal bridge connecting the beam tube cold loop and the equatorial cold loop (the second); 4-3. Thermal bridge connecting the two equatorial cold loops. Detailed implementation manners

[0032] In the following description, a detailed implementation manner of a solid conduction cooling structure for a superconducting radio frequency cavity of the present invention will be elaborated. This implementation manner is based on the structure shown in the accompanying drawings and is described in detail in combination with the technical solutions of the claims.

[0033] This embodiment provides a solid conduction cooling structure for a superconducting radio frequency cavity, as Figure 1 and Figure 2 shown, this structure mainly includes the following parts:

[0034] Dual-cell superconducting cavity body 1: The dual-cell superconducting cavity body 1 includes two adjacent accelerating ellipsoidal cavities 1-1, and these two accelerating ellipsoidal cavities 1-1 are designed for particle acceleration. Beam pipes 1-2 and 1-3 with different diameters are arranged on both sides of the accelerating unit for guiding the particle flow. The superconducting cavity body material is made of niobium, whose superconducting transition temperature at zero magnetic field is 9.25K, and the critical magnetic field at 4K temperature is 0.015T (as Figure 1 and Figure 2 marked 1).

[0035] Equatorial cold loop 2: It includes two equatorial cold loops 2-1 and 2-2, which are arranged circumferentially in the equatorial region of the accelerating ellipsoidal cavity of the dual-cell superconducting cavity. The inner surface of the equatorial cold loop is in contact with the outer surface of the accelerating ellipsoidal cavity to ensure good thermal contact. The equatorial cold loop is connected to the secondary cold source of the refrigerator through a flexible cold chain to transfer cold (as Figure 1 and Figure 2 marked 2, 2-1, 2-2).

[0036] Beam tube cold loop 3: It includes two beam tube cold loops 3-1 and 3-2, which are respectively arranged circumferentially in the beam pipe region of the superconducting cavity body. The inner surface of the beam tube cold loop is in contact with the outer surface of the superconducting cavity beam pipe to ensure effective cooling of the beam pipe (as Figure 1 and Figure 2 marked 3, 3-1, 3-2).

[0037] Thermal bridge structure 4: includes thermal bridge structures 4-1 and 4-2 for connecting the bundle tube cold ring and the equatorial cold ring, and a thermal bridge structure 4-3 for connecting two equatorial cold rings. The thermal bridges 4-1 and 4-2 connecting the bundle tube cold ring and the equatorial cold ring both adopt an inclined plate structure, with the two ends respectively connected to the thermal bridge connection area of the bundle tube cold ring and the bundle tube thermal bridge connection area of the equatorial cold ring. The thermal bridge 4-3 connecting the two equatorial cold rings adopts a straight plate structure, with the two ends respectively connected to the cold source connection area of the equatorial cold ring 2-1 and the thermal bridge connection area of the next equatorial cold ring 2-2 (such as Figure 1 and Figure 2 Marks 4, 4-1, 4-2, 4-3 in it).

[0038] Specific connection and layout: In this embodiment, each equatorial cold ring is connected to the refrigerants of three secondary cold sources, and the center angles between the connection areas are all 120°. Each equatorial cold ring is connected to three thermal bridge structures and is connected to the bundle tube cold ring. The center angles between the connection areas are also 120°, and the angles between adjacent cold source connection points and bundle tube thermal bridge connection points are 60°. The relative central axes of the two equatorial cold rings are rotated 180° to ensure that the angles of the secondary cold source connection points of different equatorial cold rings differ by 60° and do not overlap in space. Each bundle tube cold ring has three thermal bridge connection areas, and the angles between these thermal bridge connection areas are all 120°.

[0039] Material selection: In this embodiment, the equatorial cold ring 2, the bundle tube cold ring 3 and the thermal bridge structure 4 are all made of oxygen-free copper to ensure good thermal conductivity and mechanical strength.

[0040] Working principle: In this embodiment, the equatorial cold ring 2 is connected to the secondary cold source of the refrigerator through a flexible cold chain to provide cold energy for the entire structure. The cold energy is distributed to various parts of the superconducting cavity through the equatorial cold ring 2, the beam tube cold ring 3 and the thermal bridge structure 4, so that the superconducting cavity body is maintained in a low-temperature superconducting working state. The flexible cold chain has sufficient flexibility to adapt to the relative displacement between the secondary cold source of the refrigerator and the equatorial cold ring, and has good thermal conductivity.

[0041] The simulation results show that this embodiment is the simulation result of the overall temperature distribution of the superconducting cavity under normal operation. The secondary cold source temperature of the refrigerator is set to 3.02K, and the contact thermal resistance is set to 1000K·cm 2 / W, contact cooling and radiation cooling are both 0.05W, and the heat generation of the superconducting cavity wall is 1.38W. The overall maximum temperature of the superconducting cavity is 3.15K, which is at a very good superconducting temperature and can operate normally without quenching.

[0042] Temperature monitoring system: The structure may further include a temperature monitoring system for monitoring the temperature of the superconducting cavity body, the equatorial cold ring, the beam tube cold ring and the thermal bridge structure to ensure that the superconducting cavity operates stably at a suitable low temperature.

[0043] The present invention aims to achieve the stable operation of a superconducting cavity at an appropriate low temperature through an innovative cooling structure design, while simplifying the cooling system, reducing costs, and improving operational stability. In this embodiment, the conduction cooling heat bridge structure for an ellipsoidal superconducting cavity, through the ingenious design of the equatorial cold ring, beam tube cold ring, and heat bridge structure, and by using materials such as oxygen-free copper with good thermal conductivity and mechanical strength, achieves an efficient and uniform cooling effect, providing strong support for the miniaturization and industrial application of radio frequency superconducting technology; through the above specific embodiments, the conduction cooling heat bridge structure for an ellipsoidal superconducting cavity of the present invention can use a commercial refrigerator to achieve the stable operation of the superconducting cavity at an appropriate low temperature, eliminating the need for a complex cryostat design, an expensive and bulky helium liquefaction cryogenic station, and a professional cryogenic station operation and maintenance team, reducing the application difficulty of radio frequency superconducting technology, and having natural advantages in the miniaturization and industrial application of radio frequency superconducting technology.

Claims

1. A solid conduction cooling structure for a superconducting radio frequency cavity, characterized in that, Comprising: A double-cell superconducting cavity body, which includes two adjacent accelerating ellipsoidal cavities and beam pipes with inconsistent pipe diameters on both sides of the accelerating unit, and the superconducting cavity body material is made of niobium; Equatorial cold rings, including two equatorial cold rings, which are arranged circumferentially in the equatorial region of the accelerating ellipsoidal cavity of the double-cell superconducting cavity, with the inner surface fitting the outer surface of the accelerating ellipsoidal cavity and connected to the secondary cold source of the refrigerator through a flexible cold chain; Beam tube cold rings, including two beam tube cold rings, which are respectively arranged circumferentially in the beam pipe region of the superconducting cavity body, with the inner surface fitting the outer surface of the superconducting cavity beam pipe; Heat bridge structures, including heat bridge structures for connecting the beam tube cold rings and the equatorial cold rings respectively and heat bridge structures for connecting the two equatorial cold rings.

2. The solid conduction cooling structure for a superconducting radio frequency cavity according to claim 1, wherein The superconducting cavity material is niobium, with a superconducting transition temperature of 9.25K under zero magnetic field and a critical magnetic field of 0.015T at 4K temperature.

3. The solid conduction cooling structure for a superconducting radio frequency cavity according to claim 1 or 2, characterized in that, The equatorial cold rings, beam tube cold rings and heat bridge structures are all made of oxygen-free copper.

4. The solid conduction cooling structure for a superconducting radio frequency cavity according to claim 1, characterized in that Each of the equatorial cold rings is connected to the refrigerant of 3 secondary cold sources, and the central angles between the connection regions are all 120°.

5. The solid conduction cooling structure for a superconducting radio frequency cavity according to claim 4, wherein Each of the equatorial cold rings is connected to 3 heat bridge structures to be connected to the beam tube cold rings, the central angle between the connection regions is 120°, the angle between the adjacent cold source connection points and the beam tube heat bridge connection points is 60°, and the two equatorial cold rings are arranged with a 180° rotation relative to the central axis.

6. The solid conduction cooling structure for a superconducting radio frequency cavity according to claim 1, wherein Each of the beam tube cold rings has three heat bridge connection regions, and the angles between these heat bridge connection regions are all 120°.

7. The solid conduction cooling structure for a superconducting radio frequency cavity according to claim 1, wherein The heat bridges connecting the beam tube cold rings and the equatorial cold rings all adopt an inclined plate structure, with both ends respectively connected to the heat bridge connection region of the beam tube cold ring and the beam tube heat bridge connection region of the equatorial cold ring.

8. The solid conduction cooling structure for a superconducting radio frequency cavity according to claim 1, characterized in that, The heat bridge connecting the two equatorial cold rings adopts a straight plate structure, with both ends respectively connected to the cold source connection region of the equatorial cold ring and the heat bridge connection region of the next equatorial cold ring.

9. The solid conduction cooling structure for a superconducting radio frequency cavity according to claim 1, characterized in that, The flexible cold chain has sufficient flexibility to adapt to the relative displacement between the secondary cold source of the refrigerator and the equatorial cold ring, and has heat conduction performance.

10. The solid conduction cooling structure for a superconducting radio frequency cavity according to any one of claims 1 to 9, characterized in that, It further includes a temperature monitoring system, which is used to monitor the temperatures of the superconducting cavity body, equatorial cold rings, beam tube cold rings and heat bridge structures to ensure the stable operation of the superconducting cavity at an appropriate low temperature.

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