A low temperature thermostat assembly

Abstract

The present invention discloses a low-temperature thermostat assembly, comprising a thermostat and a multi-fluid conveying device connected thereto, wherein the multi-fluid conveying device is used to convey refrigerant to the thermostat, the thermostat comprising a thermostat base plate, a cold mass support unit, and a support assembly, the multi-fluid conveying device being fixedly mounted on the top of the cold mass support unit and being used to convey refrigerant to the thermostat, the cold mass support unit being slidably fixed to the top of the thermostat base plate via the support assembly. In the present invention, by pre-offsetting the cold mass support unit at room temperature, the entire low-temperature thermostat returns to a centerline position when contracted at low temperatures, thereby ensuring that the centerline at low temperatures does not deviate and alignment at low temperatures is ensured, and the curved pipe section connected by the bellows can meet its contraction and sliding requirements at low temperatures.

Description

Technical Field

[0001] The present invention relates to the technical field of low-temperature superconducting accelerators, and more particularly to a low-temperature thermostat assembly. Background Art

[0002] As the most important component of a superconducting particle accelerator, the cryostat provides liquid helium and mechanical support for superconducting cavities, superconducting magnets, etc., achieves and maintains the temperature and pressure environment required for the normal operation of superconducting components, and forms thermal shielding and thermal isolation to reduce the overall heat load of the system. Its performance will directly determine the investment and operating costs of the entire accelerator's cryogenic system.

[0003] The cryostat's cold mass consists of several superconducting cavities and superconducting magnets connected in series. To ensure particle acceleration performance, the relative positions of the cavities and magnets must remain fixed. While the cold mass can be aligned at room temperature, the material shrinks at low temperatures, and the amount of shrinkage varies from material to material. Low-temperature alignment of the cold mass is crucial to the cryostat's performance.

[0004] The existing patent document with patent publication number CN 205175896 U discloses an adjustable coupling connector between a spectrometer and a cryostat, an adjustable coupling connector between a spectrometer and a cryostat, comprising a bracket, the bracket comprising an upper support plate, a lower support plate and a support column, a cavity for placing a spectrometer sample cup is formed between the upper support plate and the lower support plate; the lower support plate is provided with a base, the upper end surface of the base is provided with a groove with an upward opening for placing the spectrometer sample cup; the upper support plate is provided with a socket and a reserved observation hole passing through the end surfaces at both ends; the upper support plate is provided with a direction fine-tuning device around the socket, the direction fine-tuning device is used to clamp and adjust the position of the cold head in the cavity; the bracket is provided with a rear baffle on the side, the top of which is connected to the upper support plate, and the bottom of which is connected to the lower support plate, and the connection between the bottom of the rear baffle and the lower support plate is provided with an angle link; the edge of the socket is provided with a flexible material layer.

[0005] However, the material of the cryostat will shrink at low temperatures, and the amount of shrinkage varies from material to material, making it impossible to ensure alignment at low temperatures. Summary of the Invention

[0006] The technical problem to be solved by the present invention is how to ensure the alignment of the cold mass support at low temperatures.

[0007] The present invention solves the above-mentioned technical problems through the following technical means: a low-temperature thermostat assembly, including a thermostat and a multi-fluid conveying device connected thereto, the multi-fluid conveying device is used to convey refrigerant to the thermostat, the thermostat includes a thermostat base plate, a cold mass support unit, and a support assembly, the multi-fluid conveying device is fixedly arranged on the top of the cold mass support unit, and is used to convey refrigerant to the thermostat, the cold mass support unit is slidably fixed to the top of the thermostat base plate through the support assembly, the cold mass support unit is pre-offset installed compared to the thermostat base plate at room temperature, the pre-offset amount of the cold mass support unit is the cold shrinkage amount of its material in a low-temperature state, and the multi-fluid conveying device includes a plurality of curved pipe sections connected by connecting bellows.

[0008] By pre-offsetting the cold mass support unit at room temperature, the entire cryostat returns to the centerline position when shrinking at low temperature, thereby ensuring that the centerline at low temperature is not offset and the alignment at low temperature is guaranteed. The curved pipe section connected by the bellows can meet its shrinkage and sliding at low temperature.

[0009] As a preferred technical solution, the cold mass support unit includes a cold mass support part, on which a plurality of superconducting cavities and superconducting magnets connected in series are installed. The cold mass support part includes two symmetrically distributed cold mass brackets, and the center line of the connecting pipes connecting the plurality of superconducting cavities and superconducting magnets connected in series forms the beam center.

[0010] As a preferred technical solution, the support assembly includes a fixed support and a sliding support. The middle of both sides of the cold mass support part is fixedly connected to the thermostat base plate through a fixed support respectively. The free end of the cold mass bracket is slidingly fixed to the thermostat base plate through two sliding supports respectively. The connecting line between the two fixed supports coincides with the vertical projection of the central axis of the beam. The free end of the cold mass bracket slides toward the fixed support of the cold mass support part at low temperature.

[0011] By setting the fixed support at the center line position and setting sliding supports on both sides, the sliding support point will move toward the fixed support point as the low temperature shrinks, thereby ensuring that the center line does not deviate.

[0012] As an optimal technical solution, the two cold mass brackets are respectively a left cold mass bracket and a right cold mass bracket, the bottom of the left end of the left cold mass bracket and the bottom of the right end of the right cold mass bracket are respectively fixed to the thermostat base plate through fixed supports, and the bottom of the right end of the left cold mass bracket and the bottom of the left end of the right cold mass bracket are respectively slidably fixed to the thermostat base plate through two sliding supports.

[0013] As a preferred technical solution, one end of the superconducting cavity is fixedly connected to the cold mass support, and the other end is movably connected to the cold mass support. One end of the superconducting magnet is fixedly connected to the cold mass support, and the other end is movably connected to the cold mass support. Adjacent superconducting cavities are connected by telescopic bellows, and both ends of the superconducting magnet are connected to the superconducting cavity through the telescopic bellows.

[0014] By setting up the telescopic bellows, the movement of the cold mass support in the X and Y directions during cold contraction can be ensured. By fixing one end of the superconducting cavity and superconducting magnet to the cold mass support and movably connecting the other end, the cold contraction of the superconducting cavity, superconducting magnet and their connecting parts at low temperatures can be ensured.

[0015] As a preferred technical solution, the two ends of the superconducting cavity are respectively fixedly connected with a first connecting plate and a second connecting plate, and the two ends of the cold mass support connected to the superconducting cavity are respectively fixed with connecting pieces adapted to the first connecting plate and the second connecting plate, and the connecting pieces include a first connecting platform and a second connecting platform, the first connecting plate is slidably connected to the first connecting platform through a supporting sliding mechanism, and the second connecting plate is fastened to the second connecting platform by bolts.

[0016] As a preferred technical solution, the second connecting plate is a rectangular plate, which has waist holes on both sides of the top of one end facing the second connecting platform. A guide column is fixed on the top of the second connecting platform, the waist hole is adapted to the guide column, and the bolt is located at the center of the line connecting the two waist holes.

[0017] As a preferred technical solution, the supporting sliding mechanism includes a lower sliding plate and a lower fixed plate. The first connecting plate is a U-shaped plate, and its large end face is fixedly connected to the superconducting cavity. The two small end faces of the first connecting plate are both formed with mounting holes that are compatible with the lower sliding plate. The lower sliding plate is fixedly connected in the mounting holes. The lower fixed plate is fixedly embedded in the top of the cold mass bracket. The lower sliding plate is slidably matched with the lower fixed plate through multiple spheres. The radius of the spheres is greater than the sum of the cold shrinkage of the first connecting plate, the superconducting cavity, and the second connecting plate at low temperatures.

[0018] By setting the lower sliding plate, the lower fixed plate and the sphere therebetween, sliding support can be achieved between the superconducting cavity and the cold mass support. By setting the radius of the sphere to be larger than the sum of the cold shrinkage of the first connecting plate, the superconducting cavity and the second connecting plate at low temperatures, it can be ensured that the first connecting plate will not separate from the first connecting platform during cold shrinkage, and automatic reset can be achieved at room temperature.

[0019] As a preferred technical solution, the two ends of the superconducting magnet are respectively fixedly connected with a third connecting plate and a fourth connecting plate, the top of the cold mass support is fixed with a third connecting platform and a fourth connecting platform adapted to the third connecting plate and the fourth connecting plate, the fourth connecting plate is fixedly connected to the fourth connecting platform, and the third connecting plate is slidably connected to the third connecting platform through a supporting sliding mechanism.

[0020] As an optimal technical solution, the sliding support includes a sliding support cylinder, a second inner flange at the low-temperature end, a second heat sink outer flange, a second inner flange at the room-temperature end, an upper slide rail, a slider, a second cold screen support, and a bottom slide rail. A plurality of bottom slide rails are fixedly connected to the top of the thermostat base plate, a slider is slidably connected to the bottom slide rail, and the top of the slider is slidably connected to the upper slide rail. The vertical projections of the bottom slide rail and the upper slide rail form a cross structure. The top of the upper slide rail is fixedly connected to the sliding support cylinder through the second inner flange at the room-temperature end. The inner wall of the top of the sliding support cylinder is interference-fitted with the second inner flange at the low-temperature end, and is fixedly connected to the cold mass bracket through the second inner flange at the low-temperature end.

[0021] As an optimal technical solution, a cold screen is provided on the outside of the cold mass support, and a second heat sink outer flange is fixedly connected to the outer wall of the sliding support cylinder, and the second heat sink outer flange is fixed to the cold screen through a second cold screen support.

[0022] As an optimal technical solution, the sliding support also includes a second outer flange at the low-temperature end, a second heat sink inner flange, and a second outer flange at the room-temperature end. The second outer flange at the low-temperature end is fixedly arranged on the outer wall of the top of the sliding support cylinder, and the second heat sink inner flange is fixedly arranged on the inner wall of the sliding support cylinder, and its plane is in the same plane as the plane of the second heat sink outer flange. The second outer flange at the room-temperature end is fixedly connected to the outer wall of the bottom of the sliding support cylinder.

[0023] As an optimal technical solution, a vacuum chamber is fixed on the top of the thermostat base plate, a vacuum cavity is opened in the vacuum chamber, the cold screen is located in the vacuum cavity, a vacuum pipeline is also provided in the cold screen, and the cold mass support unit also includes a low-temperature pipeline mounting bracket, which is fixed on the top of the cold mass bracket and provides installation support for the low-temperature pipeline.

[0024] As a preferred technical solution, the cryogenic pipeline includes a main pipe and a branch pipe. The main pipe includes a vertical section and a horizontal section. The vertical section of the main pipe is provided with a telescopic bellows. The bottom of the horizontal section of the main pipe is connected to multiple branch pipes. The tops of the superconducting cavity and the superconducting magnet are both provided with connecting pipes. The branch pipes are respectively connected to the connecting pipes through the telescopic bellows. The arrangement of the telescopic bellows can ensure movement during shrinkage. Horizontal installation is conducive to compensating for large shrinkage displacement in the beam direction, thereby maintaining the stability of the pipeline.

[0025] As an optimal technical solution, valves are provided at both ends of the connecting pipeline, a beam vacuum is contained in the connecting pipeline, a connecting port is provided on the vacuum chamber, a transmission rod is rotatably connected to the connecting port, and the transmission rod is transmission-connected to the telescopic end of the valve through a cross universal joint. By rotating the transmission rod, the valve core in the valve can be moved to achieve the closing or opening of the beam vacuum.

[0026] As a preferred technical solution, the telescopic bellows connecting the branch pipe and the connecting pipe are installed horizontally.

[0027] The advantages of the present invention are:

[0028] (1) In the present invention, the cold mass support unit is pre-offset and installed at room temperature, so that the entire low-temperature thermostat returns to the center line position when it shrinks at low temperature, thereby ensuring that the center line at low temperature is not offset and the alignment at low temperature is ensured. The curved pipe section connected by the bellows can meet its shrinkage and sliding at low temperature.

[0029] (2) In the present invention, the movement of the cold mass support in the X and Y directions during cold contraction can be ensured by setting the telescopic bellows. By fixing one end of the superconducting cavity and the superconducting magnet to the cold mass support and movably connecting the other end, the cold contraction of the superconducting cavity, the superconducting magnet and their connecting parts at low temperatures can be ensured.

[0030] (3) In the present invention, by setting the lower sliding plate and the lower fixed plate and the sphere therebetween, sliding support between the superconducting cavity and the cold mass support can be achieved. By setting the radius of the sphere to be larger than the sum of the shrinkage amounts of the first connecting plate, the superconducting cavity, and the second connecting plate at low temperatures, it can be ensured that the first connecting plate will not separate from the first connecting platform during shrinkage, and automatic reset can be achieved at room temperature.

[0031] (4) In the present invention, the movement during shrinkage can be ensured by setting the telescopic bellows. By installing it horizontally, it is beneficial to compensate for the larger shrinkage displacement in the beam direction, thereby maintaining the stability of the pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of the overall structure of a cryostat assembly provided by an embodiment of the present invention;

[0033] Figure 2 A schematic diagram of the beam center structure of a cryostat assembly provided in an embodiment of the present invention;

[0034] Figure 3 A schematic diagram of a cold mass support structure of a cryostat assembly provided in an embodiment of the present invention;

[0035] Figure 4A schematic structural diagram of a support component of a cryostat assembly provided in an embodiment of the present invention;

[0036] Figure 5 A schematic diagram of a cold shield structure of a cryostat assembly provided in an embodiment of the present invention;

[0037] Figure 6 A schematic diagram of a valve structure of a low-temperature thermostat assembly provided in an embodiment of the present invention;

[0038] Figure 7 A schematic diagram of a top view of a support assembly of a cryostat assembly provided in an embodiment of the present invention;

[0039] Figure 8 A schematic diagram of the three-dimensional structure of a support component of a cryostat assembly provided in an embodiment of the present invention;

[0040] Figure 9 A schematic diagram of a first cold shield support structure of a cryostat assembly provided in an embodiment of the present invention;

[0041] Figure 10 A schematic diagram of a fixed support structure of a cryostat assembly provided in an embodiment of the present invention;

[0042] Figure 11 A low temperature thermostat assembly provided by an embodiment of the present invention Figure 10 BB cross-sectional structure diagram;

[0043] Figure 12 A schematic diagram of a second cold shield support structure of a cryostat assembly provided in an embodiment of the present invention;

[0044] Figure 13 A schematic diagram of a sliding support structure of a cryostat assembly provided in an embodiment of the present invention;

[0045] Figure 14 A low temperature thermostat assembly provided by an embodiment of the present invention Figure 13 AA cross-sectional structural diagram;

[0046] Figure 15 A schematic diagram of a top view of a cold mass support of a cryostat assembly provided in an embodiment of the present invention;

[0047] Figure 16 A schematic diagram of the structure of a mass support of a cryostat assembly provided by an embodiment of the present invention, viewed from top and side;

[0048] Figure 17 A schematic diagram of a low-temperature piping mounting bracket structure of a low-temperature thermostat assembly provided in an embodiment of the present invention;

[0049] Figure 18 A schematic diagram of a top view of a superconducting cavity of a cryostat assembly provided in an embodiment of the present invention;

[0050] Figure 19 A schematic structural diagram of a support sliding mechanism of a cryostat assembly provided in an embodiment of the present invention;

[0051] Figure 20 A schematic structural diagram of a first connecting plate of a cryostat assembly provided in an embodiment of the present invention;

[0052] Figure 21 A schematic diagram of a valve structure of a low-temperature thermostat assembly provided in an embodiment of the present invention;

[0053] Figure 22 A schematic diagram of the internal structure of a valve of a low-temperature thermostat assembly provided in an embodiment of the present invention;

[0054] Figure 23 A schematic diagram of a low-temperature piping structure of a low-temperature thermostat assembly provided in an embodiment of the present invention;

[0055] Figure 24 A schematic diagram of the vacuum chamber structure of a cryostat assembly provided in an embodiment of the present invention;

[0056] Figure 25 A schematic structural diagram of a multi-fluid delivery device of a cryostat assembly provided in an embodiment of the present invention;

[0057] Figure 26 A schematic diagram of the outer tube structure of a cryostat assembly provided in an embodiment of the present invention;

[0058] Figure 27 A low temperature thermostat assembly provided by an embodiment of the present invention Figure 26 Schematic diagram of the CC local enlarged structure;

[0059] Figure numbers: 1. Thermostat base plate; 2. Base support; 3. Cold mass bracket; 31. Cryogenic pipeline mounting bracket; 4. Superconducting cavity; 401. First connecting plate; 402. Second connecting plate; 403. Waist hole; 404. Bolt; 405. Support sliding mechanism; 4051. Upper sliding plate; 4052. Upper fixed plate; 4053. Lower sliding plate; 4054. Lower fixed plate; 5. Superconducting magnet; 501. Third connecting plate; 502. Fourth connecting plate; 6. Beam center; 7. Support assembly; 71. Fixed support; 711. Fixed support cylinder; 712. First inner flange at low temperature end; 713. First outer flange at low temperature end; 714. First heat sink inner flange; 715. First heat sink outer flange; 716. First inner flange at room temperature end; 717. First outer flange at room temperature end; 718. First cold screen support; 72. Sliding support; 7201. Sliding support cylinder ; 7202, low temperature end second inner flange; 7203, low temperature end second outer flange; 7204, second heat sink inner flange; 7205, second heat sink outer flange; 7206, room temperature end second inner flange; 7207, room temperature end second outer flange; 7208, upper slide rail; 7209, slider; 7210, second cold screen support; 7211, bottom slide rail; 73, connector; 731, first connecting platform; 732, second connecting Platform; 733, guide column; 734, third connecting platform; 735, fourth connecting platform; 8, cryogenic pipeline; 81, main pipe; 82, branch pipe; 9, cold screen; 10, vacuum chamber; 101, connecting port; 1010, transmission rod; 1011, cross universal joint; 1012, sealing ring; 1013, limit retaining ring; 11, valve; 1101, baffle; 12, negative pressure protection device; 19, outer tube; 24,; connecting bellows. DETAILED DESCRIPTION

[0060] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0061] See Figures 1 to 6A low-temperature thermostat assembly includes a thermostat and a multi-fluid conveying device connected thereto, wherein the multi-fluid conveying device is used to convey refrigerant to the thermostat and is fixedly connected to a cold shield 9, wherein the thermostat includes a thermostat base plate 1, a base support 2, a cold mass support unit, a superconducting cavity 4, a superconducting magnet 5, a beam center 6, a support assembly 7, a cryogenic pipeline 8, a cold shield 9, a vacuum chamber 10, a valve 11, and a negative pressure protection device 12. A vacuum chamber 10 is fixedly connected to the top of the thermostat base plate 1, and a vacuum cavity is provided in the vacuum chamber 10. The superconducting cavity 4, the superconducting magnet 5, the beam center 6, the support assembly 7, the cryogenic pipeline 8, the cold shield 9, and the valve 11 are all located in the vacuum cavity. A plurality of base supports 2 are fixedly connected to the bottom of the thermostat base plate 1. The base support 2 is a bottom support structure with adjustable height, which can be a commercially available part. Its specific structure is not repeated here. The cold mass support unit is adjustably arranged on the top of the thermostat base plate 1 through a support assembly 7. The cold mass support unit is provided with a mounting cavity for a superconducting cavity 4 and a superconducting magnet 5. Both the superconducting cavity 4 and the superconducting magnet 5 are adjustably mounted in the mounting cavity of the cold mass support unit, wherein one end of the superconducting cavity 4 is fixed to one end of the cold mass support unit, and the other end is gap-fitted with the other end of the cold mass support unit. The center line of the connecting pipe connecting the multiple superconducting cavities 4 and the superconducting magnets 5 connected in series forms a beam center 6;

[0062] The cold shield 9 is fixedly connected to the cold mass support unit. Valves 11 are fixed at both ends of the connecting pipe connecting the superconducting cavity 4 and the superconducting magnet 5. The beam vacuum is in the connecting pipe. The ion beam runs in the beam vacuum. The beam vacuum can be opened and closed by opening the valve core of the valve 11. The low-temperature pipe 8 is located above the cold shield 9. Figure 24 , the negative pressure protection device 12 is fixedly connected to the top of the vacuum chamber 10, one end of the low-temperature pipeline 8 is connected to the negative pressure protection device 12, and the other end is connected to the superconducting cavity 4 and the superconducting magnet 5;

[0063] In this embodiment, the superconducting cavity 4 is fixed by a sliding support method, so that it can slide freely during the cooling process. According to the different shrinkage coefficients of different materials on the superconducting cavity 4, the installation points on both sides are pre-offset in the X and Y directions. At room temperature, the cold mass support unit is pre-offset relative to the beam center 6, and returns to the beam line position of the beam center 6 at low temperature. At the same time, in the height Z direction, the shrinkage at low temperature is added to the height direction of the cold mass support unit. At room temperature, the height of the cold mass support unit is higher than the height under normal operation, so that at low temperature, the support component 7 shrinks according to its own material properties to reach the normal operating height. After the low-temperature shrinkage is achieved, the thermostat can automatically achieve the collimation effect.

[0064] See Figure 7 、 Figure 8The support assembly 7 includes a fixed support 71 and a sliding support 72; the fixed support 71 includes a fixed support cylinder 711, a first inner flange 712 at the low temperature end, a first outer flange 713 at the low temperature end, a first heat sink inner flange 714, a first heat sink outer flange 715, a first inner flange 716 at the room temperature end, a first outer flange 717 at the room temperature end, and a first cold shield support 718;

[0065] See Figure 9 、 Figure 10 、 Figure 11 , the top of the fixed support cylinder 711 is the low-temperature end, and the bottom is the room-temperature end. The outer wall of the top of the fixed support cylinder 711 is interference-fitted with a first outer flange 713 of the low-temperature end, and the inner wall of the top is interference-fitted with a first inner flange 712 of the low-temperature end. The first inner flange 712 of the low-temperature end is fastened to the cold mass support unit through hinged hole bolts. The outer wall of the middle part of the fixed support cylinder 711 is fixedly connected with a first heat sink outer flange 715, and the inner wall is fixedly connected with a first heat sink inner flange 714. The outer wall of the first heat sink outer flange 715 is fixed with a first cold screen support 718. The first cold screen support 718 is used to support the cold screen 9 and obtain cold energy from the cold screen 9 to play a heat sink effect, reducing heat leakage of the cold mass support unit at the low-temperature end. The outer wall of the bottom of the fixed support cylinder 711 is fixedly connected with The first outer flange 717 at the room temperature end has a first inner flange 716 at the room temperature end fixedly connected to the inner wall of its bottom. The first inner flange 716 at the room temperature end is fixedly connected to the thermostat base plate 1 and is positioned by the middle pin hole to ensure installation accuracy. It should be noted that the first inner flange 712 at the low temperature end, the first outer flange 713 at the low temperature end, the first heat sink inner flange 714, the first heat sink outer flange 715, the first inner flange 716 at the room temperature end, and the first outer flange 717 at the room temperature end are all interference fit with the fixed support cylinder 711. They all maintain a stable relative position through the friction force of the interference fit, and have a load-bearing capacity greater than 50KN. The fixed support cylinder 711 is made of G10 / G11 material and has an extremely low thermal conductivity coefficient, which can achieve high load-bearing capacity and low heat leakage within a limited size.

[0066] See Figure 12 、 Figure 13 、 Figure 14 The sliding support 72 includes a sliding support cylinder 7201, a second inner flange 7202 at the low temperature end, a second outer flange 7203 at the low temperature end, a second heat sink inner flange 7204, a second heat sink outer flange 7205, a second inner flange 7206 at the room temperature end, a second outer flange 7207 at the room temperature end, an upper slide rail 7208, a slider 7209, a second cold screen support 7210, and a bottom slide rail 7211; the length direction of the thermostat base plate 1 is the X direction, the width direction is the Y direction, and the height direction is the Z direction;

[0067] See Figure 8 、 Figure 13, the top of the thermostat base plate 1 is fixedly connected to a bottom slide rail 7211, and the bottom slide rail 7211 is arranged along the Y direction. A slider 7209 is slidably connected to the bottom slide rail 7211, and the top of the slider 7209 is slidably connected to the upper slide rail 7208. The upper slide rail 7208 is arranged along the X direction. The upper slide rail 7208 is fixedly connected to the sliding support cylinder 7201 through the second inner flange 7206 at the normal temperature end. The top of the sliding support cylinder 7201 is the low temperature end, and the bottom is the room temperature end. The outer wall of the top of the sliding support cylinder 7201 is interference-fitted with the second outer flange 7203 at the low temperature end, and the inner wall of the top is interference-fitted with the second inner flange 7202 at the low temperature end. The second inner flange 7202 at the low temperature end is connected to the bottom of the cold mass support unit through hinged hole bolts. Then tighten, the outer wall of the middle part of the sliding support cylinder 7201 is fixedly connected with the second heat sink outer flange 7205, and the inner wall is fixedly connected with the second heat sink inner flange 7204. The outer wall of the second heat sink outer flange 7205 is fixed with the second cold screen support 7210. The second cold screen support 7210 is used to support the cold screen 9 and obtain cold energy from the cold screen 9, which plays the role of a heat sink and reduces the heat leakage of the cold mass support unit at the low temperature end. The outer wall of the bottom of the sliding support cylinder 7201 is fixedly connected with the second outer flange 7207 at the room temperature end, and the inner wall of the bottom is fixedly connected with the second inner flange 7206 at the room temperature end. The sliding support cylinder 7201 is made of G10 / G11 material and has extremely low thermal conductivity, which can achieve high load-bearing and low heat leakage effects within a limited size.

[0068] See Figure 15 、 Figure 16 、 Figure 17The cooling mass support unit includes two cooling mass support parts, each cooling mass support part includes two symmetrical cooling mass supports 3, namely the left cooling mass support 3 and the right cooling mass support 3. The four cooling mass supports 3 are respectively counted as the first, second, third and fourth cooling mass supports 3 from left to right, respectively, the first cooling mass support part and the second cooling mass support part. The bottom of the first cooling mass support part is fixedly connected to two fixed supports 71 and four sliding supports 72. The cooling mass support 3 is a rectangular structure, and its Y-direction length is greater than its X-direction length. The two fixed supports 71 are respectively fixed at the middle of the two cooling mass supports 3, one of the fixed supports 71 is fixedly connected to the left bottom of the first cooling mass support 3, and the other fixed support 71 is fixedly connected to the right bottom of the second cooling mass support 3. The two sliding supports 72 are fixedly connected to the right bottom of the first cooling mass support 3 and are symmetrically arranged along the Y-direction midline of the first cooling mass support 3. The second cooling mass support part has the same structure as the first cooling mass support part. The second cooling mass support part includes the third cooling mass support 3 and the fourth cooling mass support 3 arranged in sequence along the direction of the beam center 6. The third cooling mass support A fixed support 71 is fixedly connected to the center of the bottom left side of the frame 3 and the center of the bottom right side of the fourth cold mass support 3. Two sliding supports 72 are fixedly connected to the center of the bottom right side of the third cold mass support 3 and the bottom left side of the fourth cold mass support 3, and are symmetrically arranged along the Y-direction midline of the third cold mass support 3. The four fixed supports 71 are all located on the same straight line. The four cold mass supports 3 can be limited by the four fixed supports 71. At low temperatures, the sliding support 72 shrinks and there are X- and Y-direction offsets. When the X-direction offset occurs, the sliding support cylinder 72 01 drives the upper slide rail 7208 to slide along the X direction of the slider 7209. When the Y direction offset occurs, the sliding support cylinder 7201 drives the slider 7209 to slide along the bottom slide rail 7211 (i.e., the Y direction) through the upper slide rail 7208. Therefore, during installation, the cold mass bracket 3 is pre-offset installed according to the offset of cold shrinkage at low temperature. On the mass-produced thermostat, since the pre-offset in the three directions is based on theoretical calculations, an alignment measurement can be performed at low temperature to check and make necessary corrections to the pre-offset, thereby further improving the alignment at low temperature.

[0069] See Figure 17 The cold mass support unit also includes a low-temperature pipeline mounting bracket 31, which is fixedly connected to the top of the cold mass support 3 and is used to support the low-temperature pipeline 8.

[0070] See Figure 18, one end of the superconducting cavity 4 is fixedly connected to the first connecting plate 401, and the other end is fixedly connected to the second connecting plate 402. The two ends of the cold mass bracket 3 are respectively fixedly connected to the connecting pieces 73 adapted to the first connecting plate 401 and the second connecting plate 402. The connecting piece 73 includes a first connecting platform 731, a second connecting platform 732, and a guide column 733. The first connecting platform 731 and the first connecting plate 401 are located on the same side of the superconducting cavity 4, and the second connecting platform 732 and the second connecting plate 402 are located on the same side of the superconducting cavity 4. The second connecting plate 402 is a rectangular plate, and a hole is provided on both sides of the top of the end close to the second connecting platform 732. A waist hole 403 is formed, and a guide column 733 is fixed at the corresponding position of the second connecting platform 732 and the waist hole 403. The waist hole 403 is adapted to the shape of the guide column 733 and limits it. The middle of the top of one end of the second connecting plate 402 close to the second connecting platform 732 is fastened to the second connecting platform 732 by a bolt 404. At low temperatures, since the middle of the second connecting platform 732 is fixed, the two ends of the second connecting plate 402 shrink toward the middle. The second connecting plate 402 is a U-shaped plate, and its large end face is fixedly connected to the superconducting cavity 4, and the two small end faces are slidably fixed to the first connecting platform 731 through the support sliding mechanism 405. Figure 19 、 Figure 20 The supporting sliding mechanism 405 includes an upper sliding plate 4051, an upper fixed plate 4052, a lower sliding plate 4053, and a lower fixed plate 4054. The two small end surfaces of the second connecting plate 402 are provided with mounting holes. The mounting holes are through holes with steps. The step size is adapted to the size of the upper sliding plate 4051, the upper fixed plate 4052, the lower sliding plate 4053, and the lower fixed plate 4054. The lower fixed plate 4054 is located at the bottom of the lower sliding plate 4053 and is slidably connected to the lower sliding plate 4053 through a plurality of balls with the same ball diameter. The top of the lower fixed plate 4054 is circumferentially connected to the lower sliding plate 4053. Grooves that are compatible with the spheres are arranged at equal angles. The grooves can limit the spheres to prevent them from sliding out of the grooves. It should be noted that the radius of the spheres is greater than the total shrinkage of the superconducting cavity 4, the first connecting plate 401, and the second connecting plate 402. The lower sliding plate 4053 is clamped in the mounting hole, and the lower fixed plate 4054 is fixedly connected to the second connecting platform 732, thereby realizing sliding support between the first connecting platform 731 and the superconducting cavity 4; wherein, the upper fixed plate 4052 is fixedly connected in the mounting hole, and the upper sliding plate 4051 slides with the upper fixed plate 4052 through multiple spheres.

[0071] See Figure 2 、 Figure 18Two superconducting cavities 4 are placed on the first cold mass support 3, one superconducting cavity 4 and a superconducting magnet 5 are placed on the second cold mass support 3, two superconducting cavities 4 are placed on the third cold mass support 3, and one superconducting cavity 4 and a superconducting magnet 5 are placed on the fourth cold mass support 3. Adjacent superconducting cavities 4 are connected in sequence through telescopic bellows. Both ends of the superconducting magnet 5 are connected to the adjacent superconducting cavities 4 through telescopic bellows respectively. The right end of the superconducting magnet 5 on the fourth cold mass support 3 is connected to the beam center 6 through the telescopic bellows. Figure 21 、 Figure 22 , a valve 11 is provided on the beam center 6. The cold mass needs to be assembled in the clean room. After the assembly is completed, it is transferred to the outside for the overall assembly of the thermostat. Before leaving the clean room, the beam vacuum needs to be sealed and protected. Therefore, a valve 11 is provided at both ends of the first cold mass bracket 3 and the fourth cold mass bracket 3. After the thermostat is installed, the valve 11 is fixedly connected to the inside of the vacuum chamber 10. A connection port 101 is fixedly connected to the vacuum chamber 10. A transmission rod 1010 is rotatably connected to the connection port 101, and a sealing ring 1012 is used to achieve rotational sealing. The valve 11 is movably connected with a baffle 1101, which is coaxial with the axis of the beam center 6. The valve 11 is a commercially available part, and has an input end on its right side. Rotating the input end can drive the baffle 1101 to slide in the valve 11, thereby closing or opening the beam vacuum. A hexagonal screw is formed at one end of the transmission rod 1010, and the other end is connected to the input end of the valve 11 through a cross universal joint 1011. Eccentric transmission can be achieved without the cross universal joint 1011. A limiting retaining ring 1013 is fixedly connected to the transmission rod 1010 to prevent the transmission rod 1010 from being sucked into the vacuum.

[0072] See Figure 18 The superconducting magnet 5 is movably fixed on the second cold mass support 3, one end of the superconducting magnet 5 is fixedly connected to the third connecting plate 501, and the other end is fixedly connected to the fourth connecting plate 502. The third connecting platform 734 and the fourth connecting platform 735 are fixed on the second cold mass support 3, the third connecting platform 734 and the third connecting plate 501 are located on the same side, and the fourth connecting platform 735 and the fourth connecting plate 502 are located on the same side. The fourth connecting platform 735 is fixedly connected to the fourth connecting plate 502 by two bolts, and the third connecting plate 501 is slidably fixed to the third connecting platform 734 through the support sliding mechanism 405.

[0073] See Figure 23The cryogenic pipeline 8 provides refrigerant for the cold mass. The cryogenic pipeline 8 includes a main pipe 81 and a branch pipe 82. The main pipe 81 includes a horizontal section and a vertical section. The vertical section of the main pipe 81 is provided with a telescopic bellows to take into account the shrinkage in the height direction. The bottom of the horizontal section of the main pipe 81 is connected to multiple branch pipes 82. The tops of the superconducting cavity 4 and the superconducting magnet 5 are both provided with connecting pipes. The branch pipes 82 are respectively connected to the connecting pipes through a telescopic bellows. The compensation for cryogenic shrinkage can be achieved by setting the bellows. The bellows are installed horizontally, which is conducive to compensating for the larger shrinkage displacement in the beam direction. The fixed point of the cryogenic pipeline 8 is set in the middle position, and the two sides of the main pipe 81 are placed symmetrically. Regardless of whether it is negative pressure or positive pressure operation, the forces of the bellows will offset each other and will not cause impact on the main pipe 81, thereby maintaining the stability of the pipeline.

[0074] See Figure 26 、 Figure 27 The multi-fluid conveying device includes a multi-fluid conveying device connecting pipeline, which includes a plurality of curved pipe sections connected in sequence. The central pipes of adjacent curved pipe sections are welded and fixed by connecting bellows 24. One end of the multi-fluid conveying device is fixedly connected to the cold screen 9, and the other end is connected to the external cold source. The curved pipe section includes an outer pipe 19 and a plurality of conveying pipelines arranged in the outer pipe 19. The connecting bellows 24 is located in the outer pipe 19.

[0075] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A low-temperature thermostat assembly, comprising a thermostat and a multi-fluid delivery device connected thereto, wherein the multi-fluid delivery device is used to deliver refrigerant to the thermostat, characterized in that: The thermostat includes a thermostat base plate, a cold mass support unit, and a support assembly. The multi-fluid conveying device is fixed on the top of the cold mass support unit and is used to convey refrigerant to the thermostat. The cold mass support unit is slidably fixed to the top of the thermostat base plate through the support assembly. At room temperature, the cold mass support unit is pre-offset compared to the thermostat base plate. The pre-offset amount of the cold mass support unit is the amount of cold shrinkage of its material in a low-temperature state. The multi-fluid conveying device includes a plurality of curved pipe sections connected by connecting bellows. The cold mass support unit includes a cold mass support part on which a plurality of superconducting cavities and superconducting magnets are installed in series. The cold mass support part includes two symmetrically distributed cold masses. A measurement bracket, one end of the superconducting cavity is fixedly connected to the cold mass bracket, and the other end is movably connected to the cold mass bracket, one end of the superconducting magnet is fixedly connected to the cold mass bracket, and the other end is movably connected to the cold mass bracket, adjacent superconducting cavities are connected by telescopic bellows, and both ends of the superconducting magnet are connected to the superconducting cavity through the telescopic bellows; the two ends of the superconducting cavity are respectively fixedly connected with a first connecting plate and a second connecting plate, and the two ends of the cold mass bracket connected to the superconducting cavity are respectively fixed with connecting pieces adapted to the first connecting plate and the second connecting plate, and the connecting pieces include a first connecting platform and a second connecting platform, the first connecting plate is slidably connected to the first connecting platform through a support sliding mechanism, and the second connecting plate is fastened to the second connecting platform by bolts.

2. A cryostat assembly according to claim 1, characterized in that: A center line of a connecting pipeline connecting a plurality of the superconducting cavities and the superconducting magnets connected in series forms a beam center.

3. A cryostat assembly according to claim 2, characterized in that: The support assembly includes a fixed support and a sliding support. The middle of both sides of the cold mass support part is fixedly connected to the thermostat base plate through a fixed support respectively. The free end of the cold mass bracket is slidingly fixed to the thermostat base plate through two sliding supports respectively. The connecting line between the two fixed supports coincides with the vertical projection of the central axis of the beam. The free end of the cold mass bracket slides toward the fixed support of the cold mass support part at low temperature.

4. A cryostat assembly according to claim 3, characterized in that: The two cold mass brackets are respectively a left cold mass bracket and a right cold mass bracket. The bottom of the left end of the left cold mass bracket and the bottom of the right end of the right cold mass bracket are fixed to the thermostat base plate through fixed supports, and the bottom of the right end of the left cold mass bracket and the bottom of the left end of the right cold mass bracket are slidably fixed to the thermostat base plate through two sliding supports.

5. The cryostat assembly according to claim 1, wherein: The second connecting plate is a rectangular plate, and waist holes are respectively opened on both sides of the top of one end facing the second connecting platform. A guide column is fixed on the top of the second connecting platform. The waist hole is adapted to the guide column, and the bolt is located at the center of the line connecting the two waist holes.

6. A cryostat assembly according to claim 5, characterized in that: The supporting sliding mechanism includes a lower sliding plate and a lower fixed plate. The first connecting plate is a U-shaped plate, and its large end face is fixedly connected to the superconducting cavity. The two small end faces of the first connecting plate are both formed with mounting holes adapted to the lower sliding plate. The lower sliding plate is fixedly connected in the mounting holes. The lower fixed plate is fixedly embedded in the top of the cold mass bracket. The lower sliding plate is slidably matched with the lower fixed plate through a plurality of spheres.

7. A cryostat assembly according to claim 1, characterized in that: The two ends of the superconducting magnet are respectively fixedly connected with a third connecting plate and a fourth connecting plate, and the top of the cold mass support is fixed with a third connecting platform and a fourth connecting platform adapted to the third connecting plate and the fourth connecting plate. The fourth connecting plate is fixedly connected to the fourth connecting platform, and the third connecting plate is slidably connected to the third connecting platform through a supporting sliding mechanism.

8. A cryostat assembly according to claim 4, characterized in that: The sliding support includes a sliding support cylinder, a second inner flange at the low-temperature end, a second heat sink outer flange, a second inner flange at the room-temperature end, an upper slide rail, a slider, a second cold screen support, and a bottom slide rail. A plurality of bottom slide rails are fixedly connected to the top of the thermostat base plate, a slider is slidably connected to the bottom slide rail, and the top of the slider is slidably connected to the upper slide rail. The vertical projections of the bottom slide rail and the upper slide rail form a cross-shaped structure. The top of the upper slide rail is fixedly connected to the sliding support cylinder through the second inner flange at the room-temperature end. The inner wall of the top of the sliding support cylinder is interference-fitted with the second inner flange at the low-temperature end, and is fixedly connected to the cold mass bracket through the second inner flange at the low-temperature end.

9. A cryostat assembly according to claim 8, characterized in that: A cold screen is provided on the outside of the cold mass support, and a second heat sink outer flange is fixedly connected to the outer wall of the sliding support cylinder. The second heat sink outer flange is fixed to the cold screen through a second cold screen support.

10. A cryostat assembly according to claim 8, characterized in that: The sliding support also includes a second outer flange at the low-temperature end, a second heat sink inner flange, and a second outer flange at the room-temperature end. The second outer flange at the low-temperature end is fixedly arranged on the outer wall of the top of the sliding support cylinder. The second heat sink inner flange is fixedly arranged on the inner wall of the sliding support cylinder, and its plane is in the same plane as the plane of the second heat sink outer flange. The second outer flange at the room-temperature end is fixedly connected to the outer wall of the bottom of the sliding support cylinder.

11. A cryostat assembly according to claim 9, characterized in that: A vacuum chamber is fixed on the top of the thermostat base plate, a vacuum cavity is opened in the vacuum chamber, the cold screen is located in the vacuum cavity, a vacuum pipeline is also provided in the cold screen, and the cold mass support unit also includes a low-temperature pipeline mounting bracket, the low-temperature pipeline mounting bracket is fixed on the top of the cold mass bracket, and provides installation support for the low-temperature pipeline.

12. A cryostat assembly according to claim 11, characterized in that: The cryogenic pipeline includes a main pipe and a branch pipe. The main pipe includes a vertical section and a horizontal section. A telescopic bellows is provided on the vertical section of the main pipe. A plurality of branch pipes are connected to the bottom of the horizontal section of the main pipe. Connecting pipes are provided at the top of the superconducting cavity and the superconducting magnet. The branch pipes are respectively connected to the connecting pipes through the telescopic bellows.

13. The cryostat assembly according to claim 11, wherein: Valves are provided at both ends of the connecting pipeline. A beam vacuum is provided in the connecting pipeline. A connecting port is provided on the vacuum chamber. The connecting port is rotatably connected to a transmission rod. The transmission rod is transmission-connected to the telescopic end of the valve through a cross universal joint. By rotating the transmission rod, the valve core in the valve can be moved to achieve the closing or opening of the beam vacuum.

14. A cryostat assembly according to claim 12, characterized in that: The telescopic bellows connecting the branch pipe and the connecting pipe are installed horizontally.

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