CN216644610U - Nuclear heat insulation demagnetizing refrigerating system - Google Patents
Nuclear heat insulation demagnetizing refrigerating system Download PDFInfo
- Publication number
- CN216644610U CN216644610U CN202220052166.8U CN202220052166U CN216644610U CN 216644610 U CN216644610 U CN 216644610U CN 202220052166 U CN202220052166 U CN 202220052166U CN 216644610 U CN216644610 U CN 216644610U
- Authority
- CN
- China
- Prior art keywords
- rod
- nuclear
- hole
- flange
- refrigeration system
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
Abstract
The utility model provides a nuclear heat insulation demagnetization refrigeration system, which comprises: the device comprises a basic platform, an optical platform, a magnet device, a supporting device, a refrigerating device and a mixed gas recovery pipeline; the foundation platform is arranged on the ground; the optical platform includes: a base and a suspension; the hanging part is provided with a through hole, the bottom of the hanging part is arranged on the base, and the bottom of the inner side of the hanging part is fixedly connected with the top of the magnet device; the magnet device is arranged in the through hole of the suspension part, and the bottom of the magnet device extends into a foundation pit under the ground; the middle part of the magnet device is provided with a through hole; the middle part of the supporting device is provided with a through hole and a clamping device; the upper part of the refrigerating device penetrates through the through hole of the supporting device and is fixedly connected with the clamping device; the lower part of the refrigerating device extends into the bottom of the through hole of the magnet device; the top of the refrigerating device is connected with a mixed gas recovery pipeline; and a damping device is arranged on the mixed gas recovery pipeline. The utility model can realize the temperature lower than 0.1mK and provide the magnetic field of 12T at most for the sample.
Description
Technical Field
The application relates to the technical field of extremely low temperature refrigeration, in particular to a nuclear heat insulation demagnetization refrigeration system.
Background
The extremely-low-temperature high-magnetic-field experimental instrument is an important tool for condensed state physical front research. The performance of quantum properties generally requires a low temperature environment, and more fragile quantum states generally require lower temperatures. Currently, global commercial cryogenic equipment (e.g., commercial dilution refrigerators) can provide temperatures of about 10 millikelvin (mK) at a minimum. Devices that can reach lower temperatures are generally based on the principle of nuclear adiabatic demagnetization, which is well known for a long time, but due to the complexity of design and implementation, no devices are currently commercially available that require the user to design and build themselves.
The main body of a nuclear adiabatic demagnetization refrigeration system can be roughly divided into three main parts: 1) the dilution refrigerator is used for providing low temperature of 10mK magnitude; 2) a section for performing nuclear adiabatic demagnetization; 3) a superconducting magnet. The superconducting magnet can provide a necessary magnetic field for nuclear adiabatic demagnetization on one hand, and measurement of a sample is often carried out in a strong magnetic field environment on the other hand.
Dilution refrigerators in the prior art can be mainly classified into two categories: the classification of "wet" and "dry" refrigerators depends primarily on which device the underlying 4K cryogenic environment is provided by. Among them, the "wet" refrigerator is pre-cooled using liquid helium and is therefore referred to as "wet". Liquid helium at atmospheric pressure can provide a temperature of 4.2 kelvin (K), but maintaining a cryogenic environment requires continuous consumption of liquid helium, which is not commonly available at home and is therefore of limited use; moreover, the cost of using liquid helium is also high; in addition, the design of the liquid helium dewar is limited, the wet adiabatic demagnetization refrigerator cannot be made too large, and the space size is limited. In addition, because liquid helium is consumed continuously, the liquid helium needs to be supplemented manually at intervals during the operation of the equipment. Scientific researchers need to interrupt the experiment when transmitting the liquid helium, so the continuity of the experiment is affected; moreover, manual delivery of liquid helium also prevents the refrigerator from being fully remotely controlled and automatically operated.
The dry type refrigerator is pre-cooled by compressing helium gas by a compressor, and the scheme does not consume liquid helium and helium gas and is driven by common energy power, so the dry type refrigerator is called as a dry type refrigerator. The dry refrigerator is more convenient to use, but can introduce certain vibration, and has great influence on the realization of extremely low temperature.
At present, some laboratories in the world design nuclear heat insulation demagnetization refrigeration systems by themselves, and most of the nuclear heat insulation demagnetization refrigeration systems belong to a wet type. In recent years, dry refrigerators have been vigorously developed for their convenience of use, and some research teams have implemented nuclear adiabatic demagnetization refrigeration systems based on dry dilution refrigerators, but these refrigerators have a minimum temperature of only 0.15mK, cannot achieve a low temperature equal to or lower than 0.1mK, and cannot provide a strong magnetic field required for a sample (for example, a magnetic field of only up to 9T).
SUMMERY OF THE UTILITY MODEL
In view of the above, the present invention provides a nuclear adiabatic demagnetization refrigeration system, which can achieve a temperature lower than 0.1mK and can provide a magnetic field of up to 12T for a sample.
The technical scheme of the utility model is realized as follows:
a nuclear adiabatic demagnetization refrigeration system, the nuclear adiabatic demagnetization refrigeration system comprising: the device comprises a basic platform, an optical platform, a magnet device, a supporting device, a refrigerating device and a mixed gas recovery pipeline;
the foundation platform is arranged on the ground, and an opening communicated with a foundation pit under the ground is formed in the foundation platform;
the optical platform includes: a base and a suspension; the hanging part is provided with a through hole corresponding to the opening of the basic platform; the bottom of the base is arranged on the upper surface of the base platform; the bottom of the outer side of the hanging part is arranged on the upper surface of the base; the bottom of the inner side of the suspension part is fixedly connected with the top of the magnet device;
the magnet device is arranged in the through hole of the suspension part, and the bottom of the magnet device extends into a foundation pit under the ground through an opening on the base platform;
the middle part of the magnet device is provided with a through hole;
the bottom of the supporting device is fixedly connected with the upper surface of the optical platform; the middle part of the supporting device is provided with a through hole and a clamping device;
the upper part of the refrigerating device penetrates through the through hole of the supporting device and is fixedly connected with the clamping device of the supporting device;
the lower part of the refrigerating device sequentially penetrates through the through holes of the suspension part of the optical platform and extends into the bottom of the through hole of the magnet device;
the top of the refrigerating device is connected with a mixed gas recovery pipeline;
and the mixed gas recovery pipeline is provided with a damping device.
Preferably, the refrigeration apparatus includes: a dry dilution refrigerator, a thermal connecting rod, a thermal switch and a nuclear heat insulation demagnetizing rod;
the bottom of the dry dilution refrigerator is connected with the top of the thermal connecting rod;
the bottom of the thermal connecting rod is connected with the top of the thermal switch;
the bottom of the thermal switch is connected with the top of the nuclear heat-insulating demagnetizing rod.
Preferably, the hot connecting rod includes: the first flange, the second flange, the connecting copper bar and at least one supporting rod;
the top of the connecting copper rod is connected with the first flange, and the bottom of the connecting copper rod is connected with the second flange;
the middle part of the connecting copper rod is cut into sheets and is annealed;
the support rod is arranged between the first flange and the second flange.
Preferably, the support rod includes: an upper support rod, a lower support rod and a connecting part;
the middle part of the connecting part is provided with a through hole; the through hole is provided with a thread;
the bottom of the upper supporting rod is inserted into the through hole of the connecting part and is connected with the connecting part;
the top of the lower support rod is inserted into the through hole of the connecting part and is connected with the connecting part.
Preferably, the thermal switch comprises: the device comprises a first contact plate, a second contact plate, an aluminum foil, a coil bracket and at least one supporting tube;
the top of the first contact plate is connected with the bottom of the thermal connection rod; the bottom of the first contact plate is connected with the coil bracket and the aluminum foil;
the top of the second contact plate is connected with the aluminum foil; the bottom of the second contact plate is connected with the top of the nuclear heat insulation demagnetizing rod;
the coil support is of a cylindrical structure, and a through hole is formed in the coil support;
the aluminum foil is arranged in the through hole of the coil bracket;
the coil is wound on the coil bracket and is connected with an external power supply;
the support tube surrounds the first contact plate, the second contact plate, and the outside of the coil support.
Preferably, two ends of the supporting tube are respectively provided with one or more heat insulation gaskets.
Preferably, the nuclear adiabatic demagnetization bar includes: a third flange, a fourth flange and a rod body;
the third flange is arranged at the top of the rod body;
the fourth flange is arranged at the bottom of the rod body.
Preferably, the refrigeration apparatus further comprises: a first shield can, a second shield can, and a third shield can;
the first shielding case surrounds the outer surfaces of the middle part and the lower part of the dry dilution refrigerator;
the second shield surrounds the outer surfaces of the thermal connection rod, the thermal switch and the nuclear thermal insulation demagnetizing rod;
the third shielding case is arranged at the bottom of the second shielding case.
Preferably, the refrigeration device further includes: a thermometer;
the thermometer is arranged on the upper surface of the nuclear heat insulation demagnetizing rod and used for measuring temperature.
Preferably, the magnet device includes: the superconducting magnet is arranged in the accommodating cavity;
a through hole is formed in the middle of the accommodating cavity, and the accommodating cavity is in a vacuum state;
the superconducting magnet is arranged in the accommodating cavity;
the compressor is connected with the superconducting magnet through a pipeline and used for refrigerating the superconducting magnet.
As can be seen from the above, in the nuclear thermal insulation demagnetization refrigeration system of the present invention, since the corresponding base platform, the optical platform and the supporting device are provided, and the damping device is provided on the mixed gas recovery pipeline, the vibration of the nuclear thermal insulation demagnetization refrigeration system caused by the external environment can be effectively reduced, and the additional vibration caused by the air extraction can be reduced, so that the adverse effect on the realization of the extremely low temperature caused by the air extraction or the external vibration can be eliminated as much as possible. In addition, the heat leakage from the outside to the system and the heat generation inside the system are effectively reduced through some corresponding technical means, and finally, the temperature lower than 0.1mK can be realized, and a magnetic field with the maximum 12T can be provided for the sample.
In addition, because the dry dilution refrigerator is used in the refrigerating device, the liquid helium is not continuously consumed, and the device does not depend on the supply of the liquid helium, so that the running cost of the device can be greatly reduced, and the device is not limited by the space size.
Drawings
Fig. 1 is a schematic structural diagram of a nuclear adiabatic demagnetization refrigeration system in an embodiment of the utility model.
Fig. 2 is a schematic view of the internal structure of the refrigeration apparatus in the embodiment of the present invention.
Fig. 3 is a schematic view of a thermal connecting rod according to an embodiment of the present invention.
Fig. 4 is a schematic structural diagram of a thermal switch in an embodiment of the present invention.
Fig. 5 is a schematic view showing the installation of the support pipe in the thermal switch according to the embodiment of the present invention.
FIG. 6 is a schematic diagram of the structure of a nuclear adiabatic demagnetization rod in an embodiment of the utility model.
FIG. 7 is a schematic cross-sectional view of a nuclear adiabatic demagnetization rod in an embodiment of the present invention.
Fig. 8 is an external view of a refrigeration apparatus in an embodiment of the present invention.
Fig. 9 is a magnetic field distribution diagram of a superconducting magnet centerline in an embodiment of the present invention.
Fig. 10 is a schematic diagram of the position of the refrigeration device and the magnetic field distribution in the embodiment of the utility model.
FIG. 11 is a data plot of the minimum temperature that can be achieved by the nuclear adiabatic demagnetization refrigeration system in an embodiment of the present invention.
Detailed Description
In order to make the technical scheme and advantages of the utility model more apparent, the utility model is further described in detail with reference to the accompanying drawings and specific embodiments.
The principle of nuclear adiabatic demagnetization refrigeration is to utilize the spin of atomic nuclei, which are first isothermally magnetized at low temperature; isothermal magnetization gives off heat and spins become relatively ordered, so that entropy decreases. Then, the magnetic field is reduced under the condition that there is no heat exchange with the outside, that is, under the adiabatic condition, the temperature is linearly reduced along with the magnetic field, thereby achieving the temperature drop.
Therefore, the utility model provides a nuclear heat insulation demagnetization refrigeration system.
Fig. 1 is a schematic structural diagram of a nuclear adiabatic demagnetization refrigeration system in an embodiment of the utility model.
As shown in fig. 1, the nuclear adiabatic demagnetization refrigerating system in the embodiment of the present invention includes: a base platform 11, an optical platform 12, a magnet device 13, a support device 14, a refrigeration device 15 and a mixed gas recovery pipeline 16;
the foundation platform 11 is arranged on the ground, and an opening communicated with a foundation pit under the ground is formed in the foundation platform 11;
the optical bench 12 includes: a base 21 and a hanging portion 22; the hanging part 22 is provided with a through hole corresponding to the opening of the basic platform 11; the bottom of the base 21 is arranged on the upper surface of the base platform 11; the bottom outside the hanging part 22 is provided on the upper surface of the base 21; the bottom of the inner side of the hanging part 22 is fixedly connected with the top of the magnet device 13;
the magnet device 13 is arranged in the through hole of the suspension part 22, and the bottom of the magnet device 13 extends into a foundation pit under the ground through an opening on the base platform 11;
a through hole is formed in the middle of the magnet device 13;
the bottom of the supporting device 14 is fixedly connected with the upper surface of the optical platform 12; the middle part of the supporting device 14 is provided with a through hole and a clamping device;
the upper part of the refrigerating device 15 passes through the through hole of the supporting device 14 and is fixedly connected with the clamping device of the supporting device 14;
the lower part of the refrigerating device 15 sequentially passes through the through holes of the hanging parts 22 of the optical platform 12 and extends into the bottom of the through hole of the magnet device 13;
the top of the refrigerating device 15 is connected with a mixed gas recovery pipeline 16;
a damping device is arranged on the mixed gas recovery pipeline 16.
When the nuclear heat insulation demagnetization refrigeration system is arranged, a foundation pit can be formed on the ground, then a base platform is arranged above the foundation pit, and an opening is formed in the base platform and communicated with the foundation pit under the ground; an optical platform may then be placed on the base platform. The base of the optical platform is arranged on the basic platform, the suspension part is arranged on the base, and a through hole is formed in the middle of the suspension part. In addition, a support device is arranged on the upper surface of the suspension part of the optical platform, and the middle part of the support device is also provided with a through hole. Thus, a magnet arrangement may be fixed at the bottom inside the suspension of the optical platform, which magnet arrangement will extend through the through-hole of the optical platform and the opening in the base platform into the foundation pit below the ground. The middle part of the magnet device is also provided with a through hole, so that the upper part of the refrigerating device can be clamped by the clamping device of the supporting device, and the lower part of the refrigerating device passes through the through hole of the suspension part of the optical platform and extends into the bottom of the through hole of the magnet device. Finally, a mixed gas recovery duct provided with a damping device can be connected to the top of the refrigeration device.
The nuclear adiabatic demagnetization refrigeration system is provided with a series of shock absorption measures, for example, a basic platform and an optical platform are arranged, the magnet device and the refrigeration device are suspended in the air, and the magnet device and the refrigeration device are suspended in a foundation pit under the ground, so that the shock of the external environment on the nuclear adiabatic demagnetization refrigeration system can be effectively weakened, and the adverse effect on realizing extremely low temperature caused by the external shock is eliminated as much as possible.
In addition, as an example, in a preferred embodiment of the present invention, the base 21 includes: a plurality of support columns. For example, the base may specifically include 3 support posts.
In addition, as an example, in a preferred embodiment of the present invention, the shock absorbing device on the mixture recycling pipe 16 includes: universal vibration isolators 61 and sand boxes 62;
the universal vibration isolator 61 is arranged at the front section of the mixed gas recovery pipeline 16;
the sand box 62 is provided at a rear section of the mixture recovery pipe 16.
For example, in a preferred embodiment of the utility model, the sandbox may be secured to the ceiling 64 by means of a screw 63, as an example.
Because the shock absorption device is arranged on the mixed gas recovery pipeline, the extra vibration caused by air extraction can be further effectively weakened, and the adverse effect on the realization of extremely low temperature is avoided as much as possible.
In addition, as an example, in a preferred embodiment of the present invention, the supporting device may be an aluminum supporting structure, or may be a supporting structure made of other suitable materials.
In addition, as an example, in a preferred embodiment of the present invention, the base platform may be a cement platform constructed by using cement, or may be another platform constructed by using another suitable material.
In addition, in the technical solution of the present invention, the above-described refrigeration apparatus can be realized in various ways. The technical solution of the present invention will be described in detail below by taking some specific implementation manners as examples.
For example, as shown in fig. 2, in a preferred embodiment of the present invention, the refrigeration device 15 comprises: a dry dilution refrigerator 51, a thermal connection rod 52, a thermal switch 53 and a nuclear heat insulation demagnetizing rod 54;
the bottom of the dry dilution refrigerator 51 is connected to the top of the thermal connection rod 52;
the bottom of the thermal connection rod 52 is connected with the top of the thermal switch 53;
the bottom of the thermal switch 53 is connected to the top of the nuclear adiabatic demagnetization bar 54.
In the nuclear adiabatic demagnetization refrigeration system, the dry dilution refrigerator is used, so that liquid helium is not continuously consumed, and the system does not depend on liquid helium supply, so that the running cost of the equipment can be greatly reduced, and the system is not limited by the space size.
In addition, in the technical solution of the present invention, the thermal connection rod may be implemented in various ways. The technical solution of the present invention will be described in detail below by taking some specific implementation manners thereof as examples.
For example, as shown in FIG. 3, in a preferred embodiment of the present invention, the hot connection rod 52 may include: a first flange 521, a second flange 522, a connecting copper bar 523 and at least one support bar 524;
the top of the connecting copper rod 523 is connected with the first flange 521, and the bottom of the connecting copper rod is connected with the second flange 522;
the middle part of the connecting copper rod 523 is cut into a sheet shape and is annealed;
the support rod 524 is disposed between the first flange 521 and the second flange 522.
In the thermal connection rod, the copper rod is used, and the connection copper rod is subjected to annealing treatment, so that a better thermal connection effect can be achieved. In addition, since the middle portion of the connecting copper rod is cut into a sheet shape, it is possible to effectively reduce eddy current generated when sweeping the magnetic field. In addition, since the annealed copper rod is softer, one or more (e.g., four) support rods 524 are disposed between the first flange and the second flange for supporting and protecting.
In addition, as an example, in a preferred embodiment of the present invention, the supporting rod may be a phosphor copper supporting rod (i.e., a supporting rod made of a phosphor copper material), so as to provide better supporting and protecting functions.
In addition, as an example, in a preferred embodiment of the present invention, the supporting rod 524 may further include: upper support rod 526, lower support rod 527, and connecting portion 525;
a through hole is formed in the middle of the connecting part 525; the through hole is provided with a thread;
the bottom of the upper support rod 526 is inserted into the through hole of the connecting part 525 and connected with the connecting part 525;
the top of the lower support rod 527 is inserted into the through hole of the connection portion 525, and is connected with the connection portion 525.
When the support rod is installed, the upper support rod 526 and the lower support rod 527 may be connected to form a complete support rod through the connecting portion 525, and the total length of the entire support rod may be adjusted through the connecting portion 525, so as to connect the upper support rod 526 and the lower support rod 527 to the first flange 521 and the second flange 522, respectively.
In addition, in the technical solution of the present invention, the thermal switch described above may be implemented in various ways.
For example, as shown in fig. 4 and 5, in a preferred embodiment of the present invention, the thermal switch 53 may include: a first contact plate 531, a second contact plate 532, an aluminum foil 533, a coil (not shown), a coil support 534, and at least one support tube 535;
the top of the first contact plate 531 is connected to the bottom of the hot connection bar 52; the bottom of the first contact plate 531 is connected to the coil bracket 534 and the aluminum foil 533;
the top of the second contact plate 532 is connected with the aluminum foil 533; the bottom of the second contact plate 532 is connected to the top of the nuclear thermally insulating degaussing rod 54;
the coil support 534 is a cylindrical structure, and a through hole is formed in the coil support 534;
the aluminum foil 533 is disposed in the through hole of the coil support 534;
the coil is wound on the coil support 534 and is connected with an external power supply;
the support pipe 535 surrounds the outside of the first contact plate 531, the second contact plate 532, and the coil support 534.
In the above-described thermal switch, the first contact plate and the second contact plate are not directly connected, but are connected through an aluminum foil. Aluminum enters a superconducting state at a temperature below 1.2K, and its free electrons form a schopper pair, so that heat conduction cannot be performed, that is, the thermal conductivity of aluminum entering the superconducting state is very poor. However, aluminum returns to its normal state under a magnetic field of 10.5 milli-tesla (mT). Thus, if current is passed through the coil, thereby applying a magnetic field greater than 10.5mT to the aluminum, the aluminum will become a good thermal conductor. Therefore, in the thermal switch, the magnitude of the supplied magnetic field can be controlled by controlling the magnitude of the current of the coil, so that whether the thermal switch conducts or not in the vertical direction in the drawing can be effectively controlled.
In addition, since the first contact plate and the second contact plate are not used as a support structure, one or more (e.g., four) support tubes are provided in the thermal switch for supporting and protecting the thermal switch.
In addition, as an example, in a preferred embodiment of the present invention, the supporting tube may be a thin-walled stainless steel tube, so as to provide better supporting and protecting functions.
In addition, as shown in fig. 5, in a preferred embodiment of the present invention, one or more heat insulating spacers 536 are further disposed at both ends of the support tube, so as to perform a better heat insulating function.
For example, when the top of the support pipe 535 is coupled to the second flange 522 of the hot connection rod 52 by bolts, heat insulating spacers 536 may be provided at upper and lower ends of the second flange 522, respectively, so that the top of the support pipe 535 is not in direct contact with the second flange 522 of the hot connection rod 52, thereby effectively insulating heat.
For another example, when the bottom of the support pipe 535 is coupled to the flange of the top of the nuclear adiabatic demagnetization bar 54 by bolts, heat insulation spacers 536 may be provided at upper and lower ends of the flange, respectively, so that the bottom of the support pipe 535 is not in direct contact with the flange of the top of the nuclear adiabatic demagnetization bar 54, thereby effectively performing heat insulation.
In addition, in the technical scheme of the utility model, the nuclear heat insulation demagnetizing rod can be realized in various ways.
For example, as shown in FIG. 6, in a preferred embodiment of the present invention, the nuclear thermally insulating degaussing rods 54 may include: a third flange 541, a fourth flange 542 and a rod 543;
the third flange 541 is disposed at the top of the rod 543;
the fourth flange 542 is disposed at the bottom of the rod 543.
In addition, as an example, in a preferred embodiment of the present invention, the rod body of the nuclear thermal insulation demagnetizing rod can be a copper rod (for example, high purity copper with purity of 99.999%), and is subjected to vacuum annealingAnd (6) processing. For example, the vacuum anneal process may be at 10-3Heat to 950 degrees celsius under vacuum in millibar (mbar) and maintain for 60 hours.
In addition, as shown in fig. 6 and 7, in a preferred embodiment of the present invention, a plurality of slots 544 extending along the length direction of the rod body are formed on the rod body of the nuclear adiabatic demagnetization rod, so that eddy currents in the magnetic field can be effectively reduced.
In addition, in the technical scheme of the utility model, the shape of the rod body of the nuclear heat insulation demagnetizing rod can be designed in advance according to the distribution of the magnetic field required to be formed.
For example, in a preferred embodiment of the utility model, the diameter of the central portion of the rod of the nuclear adiabatic demagnetization rod is larger than the diameter of the two ends of the rod.
When the rod body of the nuclear heat insulation demagnetizing rod has the shape, most of copper on the rod body can be concentrated in a region with a relatively large and uniform magnetic field.
In addition, as shown in fig. 8, in a preferred embodiment of the present invention, the refrigeration device 15 may further include: a first shield can 55, a second shield can 56, and a third shield can 57;
the first shield case 55 surrounds the outer surfaces of the middle and lower portions of the dry dilution refrigerator 51;
the second shield 56 surrounds the outer surfaces of the hot connection rod 52, the thermal switch 53 and the nuclear adiabatic demagnetization rod 54;
the third shield case 57 is disposed at the bottom of the second shield case 56.
In addition, as an example, in a preferred embodiment of the present invention, the diameter of the first shield can is larger than the diameter of the second shield can; the diameter of the second shield is larger than the diameter of the third shield.
Further, as an example, in a preferred embodiment of the utility model, the second shield 56 and the third shield 57 of the cooling device 15 protrude into the through hole of the magnet device, but do not come into contact with the magnet device. In addition, the first shield cover does not extend into the through hole of the magnet device, but is positioned above the through hole of the magnet device.
In addition, as an example, in a preferred embodiment of the present invention, the magnet device 13 includes: a containment chamber 32, a superconducting magnet and a compressor (not shown in the figures);
a through hole 31 is formed in the middle of the accommodating cavity 32, and the accommodating cavity 32 is in a vacuum state;
the superconducting magnet is arranged in the accommodating cavity 32;
the compressor is connected with the superconducting magnet through a pipeline and used for refrigerating the superconducting magnet.
In addition, as an example, in a preferred embodiment of the present invention, the accommodating cavity may be a cylindrical structure, and may also be other suitable shape structures.
In an embodiment of the present invention, the superconducting magnet in the magnet device may generate a desired magnetic field.
For example, as shown in fig. 9, a superconducting magnet may be used to generate a first low magnetic field region, a first high magnetic field region, a second low magnetic field region, and a second high magnetic field region;
wherein in the first and second low magnetic field regions, the magnetic field strength B does not exceed 10-2T Tesla (T), in the first high magnetic field region, the magnetic field strength for nuclear adiabatic demagnetization is at most 9T, and the range of the magnetic field strength greater than 8T is greater than 25cm (namely the height in the vertical direction is greater than 25 cm); in the second high field region, the magnetic field strength for sample measurement is up to 12T.
In addition, as shown in fig. 10 by way of example, in a preferred embodiment of the present invention, the first low magnetic field region is located in a region in a horizontal direction in which the thermal switch is located; the first high magnetic field region is located substantially in a horizontal region between the top and lower portions of the nuclear adiabatic demagnetization bar; the second low magnetic field region is located substantially in a horizontal region between a lower portion and a bottom of the nuclear adiabatic demagnetization bar; the second high field region is then located substantially in the horizontal region below the nuclear adiabatic demagnetization bar, for example, in the horizontal region of the third shield 57.
This second high magnetic field region is a sample region reserved for mounting a sample so that the sample can be placed in the center of a magnetic field having a magnetic field strength of 12T. Because the sample area is positioned below the nuclear heat insulation demagnetizing rod and at the lowest end of the whole refrigerating device, when the sample is replaced, only the third shielding cover 57 on the refrigerating device needs to be disassembled and assembled, and therefore the operation of replacing and disassembling the sample becomes very convenient.
In addition, in the technical solution of the present invention, the ranges of the first low magnetic field region and the second low magnetic field region (i.e. the heights of the magnetic field regions in the vertical direction) are about 10cm, and the first low magnetic field region and the second low magnetic field region are respectively located at two ends of the nuclear thermal insulation demagnetizing rod, so that the thermal switch, the thermometer and other devices can be normally used, and the thermal conductance of the connection part of different components (for example, the contact surface between the thermal connection rod and the thermal switch, the contact surface between the thermal switch and the nuclear thermal insulation demagnetizing rod, and the like) can be sufficiently good.
In addition, as an example, in a preferred embodiment of the present invention, the refrigeration device 15 may further include: a thermometer;
the thermometer is arranged on the upper surface of the nuclear heat insulation demagnetizing rod and used for measuring temperature.
The thermometer is only in contact with the nuclear adiabatic demagnetization bar and is not in direct contact with other structures such as a thermal switch and the like.
Since the thermometer is disposed on the upper surface of the nuclear adiabatic demagnetization bar, the thermometer is located in the first low magnetic field region described above and can be used to measure the lowest temperature on the nuclear adiabatic demagnetization bar.
In the technical scheme of the utility model, the nuclear heat insulation demagnetization refrigeration system can reach the temperature within 1 mK. As shown in fig. 11, the nuclear adiabatic demagnetization refrigeration system of the present invention can achieve very low temperatures of less than 0.1mk, and as low as 0.09 mk.
In summary, in the technical solution of the present invention, because the corresponding base platform, the optical platform and the supporting device are provided, and the damping device is provided on the mixed gas recycling pipeline, the vibration of the nuclear adiabatic demagnetization refrigeration system caused by the external environment can be effectively weakened, and the additional vibration caused by the air extraction can be weakened, so that the adverse effect on the realization of the extremely low temperature caused by the air extraction or the external vibration can be eliminated as much as possible. In addition, the heat leakage from the outside to the system and the heat generation inside the system are effectively reduced through some corresponding technical means, and finally, the temperature lower than 0.1mK can be realized, and a magnetic field with the maximum 12T can be provided for the sample.
In addition, because the dry dilution refrigerator is used in the refrigerating device, the liquid helium is not continuously consumed, and the device does not depend on the supply of the liquid helium, so that the running cost of the device can be greatly reduced, and the device is not limited by the space size.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the utility model, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (10)
1. A nuclear adiabatic demagnetization refrigeration system, the nuclear adiabatic demagnetization refrigeration system comprising: the device comprises a basic platform, an optical platform, a magnet device, a supporting device, a refrigerating device and a mixed gas recovery pipeline;
the foundation platform is arranged on the ground, and an opening communicated with a foundation pit under the ground is formed in the foundation platform;
the optical platform includes: a base and a suspension; the hanging part is provided with a through hole corresponding to the opening of the basic platform; the bottom of the base is arranged on the upper surface of the base platform; the bottom of the outer side of the hanging part is arranged on the upper surface of the base; the bottom of the inner side of the suspension part is fixedly connected with the top of the magnet device;
the magnet device is arranged in the through hole of the suspension part, and the bottom of the magnet device extends into a foundation pit under the ground through an opening on the base platform;
the middle part of the magnet device is provided with a through hole;
the bottom of the supporting device is fixedly connected with the upper surface of the optical platform; the middle part of the supporting device is provided with a through hole and a clamping device;
the upper part of the refrigerating device penetrates through the through hole of the supporting device and is fixedly connected with the clamping device of the supporting device;
the lower part of the refrigerating device sequentially penetrates through the through holes of the suspension part of the optical platform and extends into the bottom of the through hole of the magnet device;
the top of the refrigerating device is connected with a mixed gas recovery pipeline;
and the mixed gas recovery pipeline is provided with a damping device.
2. The nuclear adiabatic demagnetization refrigeration system of claim 1, wherein the refrigeration apparatus comprises: a dry dilution refrigerator, a thermal connecting rod, a thermal switch and a nuclear heat insulation demagnetizing rod;
the bottom of the dry dilution refrigerator is connected with the top of the thermal connecting rod;
the bottom of the thermal connecting rod is connected with the top of the thermal switch;
the bottom of the thermal switch is connected to the top of the nuclear adiabatic demagnetization bar.
3. The nuclear adiabatic demagnetization refrigeration system of claim 2, wherein the thermal connection rod comprises: the first flange, the second flange, the connecting copper bar and at least one supporting rod;
the top of the connecting copper rod is connected with the first flange, and the bottom of the connecting copper rod is connected with the second flange;
the middle part of the connecting copper rod is cut into sheets and is annealed;
the support rod is arranged between the first flange and the second flange.
4. The nuclear adiabatic demagnetization refrigeration system of claim 3, wherein the support rods comprise: an upper support rod, a lower support rod and a connecting part;
the middle part of the connecting part is provided with a through hole; the through hole is provided with a thread;
the bottom of the upper supporting rod is inserted into the through hole of the connecting part and is connected with the connecting part;
the top of the lower support rod is inserted into the through hole of the connecting part and is connected with the connecting part.
5. The nuclear adiabatic demagnetization refrigeration system of claim 2, wherein the thermal switch comprises: the device comprises a first contact plate, a second contact plate, an aluminum foil, a coil bracket and at least one supporting tube;
the top of the first contact plate is connected with the bottom of the thermal connection rod; the bottom of the first contact plate is connected with the coil bracket and the aluminum foil;
the top of the second contact plate is connected with the aluminum foil; the bottom of the second contact plate is connected with the top of the nuclear heat insulation demagnetizing rod;
the coil support is of a cylindrical structure, and a through hole is formed in the coil support;
the aluminum foil is arranged in the through hole of the coil bracket;
the coil is wound on the coil bracket and is connected with an external power supply;
the support tube surrounds the first contact plate, the second contact plate, and the outside of the coil support.
6. The nuclear adiabatic demagnetization refrigeration system of claim 5, wherein:
and one or more heat insulation gaskets are respectively arranged at two ends of the supporting pipe.
7. The nuclear adiabatic demagnetization refrigeration system of claim 2, wherein the nuclear adiabatic demagnetization bar comprises: a third flange, a fourth flange and a rod body;
the third flange is arranged at the top of the rod body;
the fourth flange is arranged at the bottom of the rod body.
8. The nuclear adiabatic demagnetization refrigeration system of claim 2, wherein the refrigeration unit further comprises: a first shield can, a second shield can, and a third shield can;
the first shielding case surrounds the outer surfaces of the middle part and the lower part of the dry dilution refrigerator;
the second shield surrounds the outer surfaces of the thermal connection rod, the thermal switch and the nuclear thermal insulation demagnetizing rod;
the third shielding case is arranged at the bottom of the second shielding case.
9. The nuclear adiabatic demagnetization refrigeration system of claim 8, further comprising: a thermometer;
the thermometer is arranged on the upper surface of the nuclear heat insulation demagnetizing rod and used for measuring temperature.
10. The nuclear adiabatic demagnetization refrigeration system of claim 1, wherein the magnet arrangement comprises: the superconducting magnet is arranged in the accommodating cavity;
a through hole is formed in the middle of the accommodating cavity, and the accommodating cavity is in a vacuum state;
the superconducting magnet is arranged in the accommodating cavity;
the compressor is connected with the superconducting magnet through a pipeline and used for refrigerating the superconducting magnet.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220052166.8U CN216644610U (en) | 2022-01-10 | 2022-01-10 | Nuclear heat insulation demagnetizing refrigerating system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220052166.8U CN216644610U (en) | 2022-01-10 | 2022-01-10 | Nuclear heat insulation demagnetizing refrigerating system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216644610U true CN216644610U (en) | 2022-05-31 |
Family
ID=81726030
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202220052166.8U Active CN216644610U (en) | 2022-01-10 | 2022-01-10 | Nuclear heat insulation demagnetizing refrigerating system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216644610U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114909818A (en) * | 2022-07-18 | 2022-08-16 | 南方科技大学 | Tin separating and combining device for nuclear heat insulation demagnetization refrigeration system |
| CN117287866A (en) * | 2023-11-24 | 2023-12-26 | 中国科学技术大学 | Thermal switch and dilution refrigerator |
-
2022
- 2022-01-10 CN CN202220052166.8U patent/CN216644610U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114909818A (en) * | 2022-07-18 | 2022-08-16 | 南方科技大学 | Tin separating and combining device for nuclear heat insulation demagnetization refrigeration system |
| CN114909818B (en) * | 2022-07-18 | 2022-10-04 | 南方科技大学 | Tin separating and combining device for nuclear heat insulation demagnetization refrigeration system |
| CN117287866A (en) * | 2023-11-24 | 2023-12-26 | 中国科学技术大学 | Thermal switch and dilution refrigerator |
| CN117287866B (en) * | 2023-11-24 | 2024-02-09 | 中国科学技术大学 | Thermal switch and dilution refrigerator |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN216644610U (en) | Nuclear heat insulation demagnetizing refrigerating system | |
| CN101118798B (en) | Superconducting magnet apparatus and magnetic resonance imaging apparatus | |
| US5442928A (en) | Hybrid cooling system for a superconducting magnet | |
| US8429920B2 (en) | Magnetic refrigeration device and refrigeration method | |
| Hasegawa et al. | High-precision temperature control and stabilization using a cryocooler | |
| Ishimoto et al. | Two-stage nuclear demagnetization refrigerator reaching 27 µK | |
| US9927154B2 (en) | Cryogenic cooling apparatus and system | |
| Wang et al. | Development of wide-bore conduction-cooled superconducting magnet system for material processing applications | |
| EP2860781B1 (en) | Cooling container | |
| CN103336212B (en) | A kind of low-temperature superconducting strand Performance Test System | |
| CN102360692B (en) | High temperature superconducting magnet for magnetic resonance imaging system | |
| CN103714935B (en) | A kind of lifting field auxiliary device of superconducting magnet | |
| JPH11337631A (en) | Strong magnetic field low-temperature device for measuring physical property | |
| WO2014203826A1 (en) | Nmr system | |
| Reinders et al. | Novel top-loading 20 mK/15 T cryomagnetic system | |
| JP2004116914A (en) | Cooling pipe and cryogenic cryostat using it | |
| CN219631567U (en) | Superconducting magnet bias thermostat with adjustable center | |
| CN216928214U (en) | Superconducting magnet device | |
| CN114068132B (en) | Nuclear magnetic resonance ultra-high field magnet circulation refrigerating device based on liquid helium circulation | |
| CN217485181U (en) | Superconducting magnet device | |
| CN219303421U (en) | High-tightness adjusting pull rod | |
| Liubiao et al. | An optical cryostat for use in Microscopy cooled by Stirling-type pulse tube cryocooler | |
| Zhang et al. | Sample environment at the China spallation neutron source | |
| Wu et al. | Loading experiment and thermal analysis for conduction cooled magnet of SMES system | |
| Ma et al. | Thermal design and experiment of superconducting electromagnet iron remover |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |