A measuring device for measuring the axial magnetic field distribution of a superconducting magnet in a low-temperature environment

Abstract

The present invention discloses a measuring device for measuring the axial magnetic field distribution of a superconducting magnet in a low-temperature environment. The device includes an axial adjustment system, a fastening and sealing system, a flange conversion system, and a magnetic field measurement system from top to bottom. The device can meet the demand for real-time measurement of the magnetic field size at various locations within a certain axial space of a superconducting magnet in a low-temperature environment. The Hall support rod is locked by the central sleeve and the lifting platform, positioned on the axis of the G-10 sleeve, and the axial movement of the Hall probe is driven by rotating the lifting knob. The copper nut outside the top of the central sleeve can be rotated to squeeze the internal copper ring and then squeeze the O-ring to shrink in the inner diameter direction to achieve the purpose of sealing. At the same time, the Hall support rod can also be fixed for a second time. The device innovatively solves the problem of high-precision measurement of the central axial magnetic field of a superconducting magnet in a low-temperature environment, and is suitable for various low-temperature sealed containers. It has strong versatility, simple operation, and low cost.

Description

Technical Field

[0001] The present invention relates to the technical field of superconducting magnet magnetic field measurement, in particular to a measuring device for measuring the axial magnetic field distribution of a superconducting magnet in a low-temperature environment. Background Art

[0002] In the field of superconducting magnet applications, accurately acquiring axial magnetic intensity data at the center of a superconducting magnet is a crucial step in conducting research related to superconducting magnets. To measure magnetic field strength, a Hall effect element is typically fixed to the center of the magnet using a hoisting system. This method cannot obtain real-time axial magnetic field data at the center of the superconducting magnet. Summary of the Invention

[0003] In order to solve the problem that the axial magnetic field intensity of the center of a superconducting magnet is difficult to measure in real time with high precision, the present invention proposes a measuring device for measuring the axial magnetic field distribution of a superconducting magnet in a low-temperature environment.

[0004] The invention comprises: an axial adjustment system, a fastening and sealing system, a flange conversion system and a magnetic field measurement system.

[0005] The present invention is achieved by adopting the following technical solutions:

[0006] The axial adjustment system includes a support platform, a lifting platform, a lifting knob, a graduated shaft, a locking mechanism, and a fixture. The Hall effect support rod is fixed to the lifting platform by the fixture. Turning the lifting knob drives the axial movement of the Hall effect probe, enabling real-time measurement of the magnetic field at various locations within the axial space.

[0007] In order to prevent the cooling liquid from overflowing from the top when the device is inserted into the closed container in the actual experiment, a sealing design should be made at the top. Therefore, a fastening sealing system is set in the present invention.

[0008] The fastening and sealing system includes a central sleeve, a copper nut, a copper ring, and an O-ring. The copper nut on the top of the central sleeve can be rotated to squeeze the copper ring inside, which in turn squeezes the O-ring, causing it to contract. The copper ring's design limits the outer diameter of the ring, so that it can only move inward when squeezed. This provides a seal and also provides a secondary fixation for the Hall effect support rod.

[0009] The flange conversion system includes a flange, a first adapter block, a second adapter block, a third adapter block, a first G-10 sleeve, a second G-10 sleeve, a third G-10 sleeve, a guide tube, and a stopper. The stopper and adapter block feature a hollow hole design. When the Hall effect probe partially enters the cryogenic liquid helium area, it provides a flow path for the vaporized liquid helium, preventing damage to the sensor caused by excessive local pressure in the Hall effect probe area.

[0010] The magnetic field measurement system includes a Hall support rod, a fixing plate, and a Hall probe. The Hall probe is supported by the fixing plate at the bottom end of the Hall support rod.

[0011] In summary, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0012] When measuring the axial magnetic field strength of a superconducting magnet in a cryogenic environment, the device is hoisted into the interior of the magnet, positioning the Hall probe precisely at the axial center of the superconducting magnet. The height adjustment mechanism of the lifting platform drives the Hall support rod to achieve axial displacement, thereby achieving axial displacement of the Hall probe within the measurement area within the magnet, thereby obtaining the corresponding magnetic field strength and position information. This overcomes the difficulty of real-time measurement of magnetic field strength within a specific axial space within a sealed container.

[0013] The present invention features a rational and reliable structural design, adaptable to sealed containers of varying structures, and possesses strong universal performance. Its detachable structure ensures ease of portability, resulting in a simple structure, easy fabrication, and low cost. The device utilizes materials such as G-10 and nylon to construct the superconducting magnet axial magnetic field measurement platform, which is crucial for achieving high-precision measurements across the entire device. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions described in the present invention or in the prior art, the following briefly introduces the drawings required for use in the description of this device or the prior art. Obviously, the drawings described below are merely some structural schematic diagrams of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0016] Figure 2 This is a schematic diagram of the internal structure of the flange conversion system of the present invention;

[0017] Figure 3 This is a schematic diagram of the reserved airway of the present invention;

[0018] Figure 4 For the present invention Figure 1 The enlarged structural diagram at position Ⅰ in the middle;

[0019] Figure 5 It is a structural schematic diagram of the fastening and sealing system of the present invention;

[0020] Figure 6 It is a schematic structural diagram of the axial adjustment system of the present invention.

[0021] In the figure: 1-Hall support rod, 2-bracket platform, 3-guide tube, 4-flange, 5-first adapter block, 6-second adapter block, 7-third adapter block, 8-fixed plate, 9-Hall probe, 10-first G-10 sleeve, 11-second G-10 sleeve, 12-third G-10 sleeve, 13-stopper, 14-O-ring, 15-copper ring, 16-copper nut, 17-center sleeve, 18-lifting platform, 19-lifting knob, 20-scale shaft, 21-locking structure, 22-clamp. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is described in detail below with reference to the actual design process in conjunction with the embodiments. It is necessary to point out that the following description is only used to explain and illustrate the present invention and is not intended to limit the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above invention content still fall within the scope of protection of the present invention.

[0023] like Figure 1 As shown, in this embodiment, the measuring device for measuring the axial magnetic field distribution of a superconducting magnet in a low-temperature environment includes, from top to bottom, an axial adjustment system, a fastening and sealing system, a flange conversion system, and a magnetic field measurement system.

[0024] Among them, such as Figure 4 、 Figure 6 As shown in FIG, the axial adjustment system includes a support platform 2, a lifting platform 18, a lifting knob 19, a scale shaft 20, a locking structure 21, and a clamp 22. The Hall support rod 1 is fixed to the lifting platform 18 by the clamp 22. By rotating the lifting knob 19 to drive the axial movement of the Hall probe 9, the real-time measurement of the magnetic field size at various locations in the axial space is achieved; Figure 5 As shown, the fastening and sealing system includes a central sleeve 17, a copper nut 16, a copper ring 15, and an O-ring 14. The copper nut 16 on the top of the central sleeve 17 can be rotated to squeeze the internal copper ring 15 and thus squeeze the O-ring 14 to shrink. The design of the copper ring 15 limits the displacement of the O-ring 14 in the outer diameter direction, so that the O-ring 14 can only move in the inner diameter direction when squeezed. While achieving sealing, it can also provide a secondary fixation for the Hall effect support rod 1; Figure 2As shown, the flange conversion system includes a flange 4, a first adapter block 5, a second adapter block 6, a third adapter block 7, a first G-10 sleeve 10, a second G-10 sleeve 11, a third G-10 sleeve 12, a guide tube 3, and a stopper 13. Stopper 13, the first adapter block 5, the second adapter block 6, and the third adapter block 7 all feature a hollow hole design. When the Hall probe 9 on the Hall support rod 1 partially enters the cryogenic liquid helium region, it provides an airflow channel for the large amount of vaporized liquid helium, preventing damage to the sensor caused by excessive local pressure in the Hall probe 9 region. The magnetic field measurement system includes a Hall support rod 1, a fixing plate 8, and a Hall probe 9. The Hall probe 9 is supported by the fixing plate 8 at the bottom end of the Hall support rod 1. This device is hoisted into the interior of the magnet, ensuring that the Hall probe 9 at the bottom end of the Hall support rod 1 is accurately positioned at the axial center of the superconducting magnet. The Hall support rod 1 is a whole hollow stainless steel tube, which can be used as a channel to connect the wire of the bottom Hall probe 9. The upper outlet of the Hall support rod 1 is filled with vacuum mud. The bracket platform 2 is assembled with bolts on the upper end face of the flange 4 to support the lifting platform 18. The guide tube 3 is installed with bolts on the outside of the first G-10 sleeve 10 in conjunction with the screw holes on the end face of the flange 4. Small holes are punched on its cylindrical surface for pressure relief.

[0025] like Figure 2 、 Figure 3 、 Figure 4 As shown, the Hall effect support rod 1 is located in the middle, passing through the fastening seal system and the flange conversion system. Along the Hall effect support rod 1, flange 4, first adapter block 5, second adapter block 6, and third adapter block 7 are sequentially arranged. The Hall effect probe 9 is supported at the bottom end of the Hall effect support rod 1 by a fixing plate 8. A center sleeve 17 is welded to the upper end face of flange 4. The screw holes in the lower axial surface of flange 4 mate with the screw holes in the axial surface of the first adapter block 5, and the first G-10 sleeve 10 is bolted to it. A second G-10 sleeve 11 is bolted between the axial surface of the first adapter block 5 and the upper axial surface of the second adapter block 6. A third G-10 sleeve 12 is bolted between the lower axial surface of the second adapter block 6 and the axial surface of the third adapter block 7. A stopper 13 is bolted to the bottom axial surface of the third G-10 sleeve 12. Because a single long sleeve cannot guarantee verticality, while a short sleeve can achieve higher verticality, this device utilizes three short sleeves spliced ​​together.

[0026] Before the Hall support rod 1 is inserted into the magnetic field for measurement, it is pre-cooled to 77K with liquid nitrogen, while the temperature of the magnetic field area is cooled to 4.2K by liquid helium. When the Hall support rod 1 contacts the liquid helium, a large amount of liquid helium will be converted into helium. In order to reserve a drainage channel for the helium and avoid damage to the sensor due to excessive local pressure at the Hall probe 9, such as Figure 3 As shown, the device reserves an air flow channel between the radial areas between the Hall support rod 1 and the first G-10 sleeve 10, the second G-10 sleeve 11, and the third G-10 sleeve 12.

[0027] In order to prevent the coolant from overflowing along the central sleeve 17 when the device is inserted into a closed container in actual experiments, a sealing design should be made at its top.

[0028] Specifically, if Figure 5 As shown, the fastening and sealing system includes a central sleeve 17, a copper ring 15, and an O-ring 14. The copper nut 16 on the top of the central sleeve 17 can be rotated to squeeze the copper ring 15 inside, which in turn squeezes the O-ring 14 inward, thereby closing the air gap and preventing liquid helium leakage. This also provides a secondary fixation for the Hall effect support rod 1.

[0029] like Figure 4 、 Figure 6 As shown, the axial adjustment system includes a support platform 2, a lifting platform 18, a lifting knob 19, a scale shaft 20, a locking structure 21, and a clamp 22. The support platform 2 and the lifting platform 18 are bolted to the upper end surface of the flange 4 in sequence. The lifting knob 19, the scale shaft 20, and the locking structure 21 are mounted on the lifting platform 18. The Hall support rod 1 is fixed to the lifting platform 18 only by two clamps 22 and needs to be moved up and down frequently. To minimize the weight of the Hall support rod 1 and facilitate its axial displacement, a hollow structure is designed for it. The Hall support rod 1 is fixed to the lifting platform 18 by the clamp 22, and the axial movement of the Hall probe 9 is driven by rotating the lifting knob 19.

[0030] In this device, the magnetic field measurement system passes through the axial adjustment system, the fastening and sealing system, and the flange conversion system from top to bottom. The magnetic field measurement system is fixed to the axial adjustment system via the Hall support rod 1 by a fixture 22. The axial adjustment system is bolted to the upper end face of the flange 4 of the flange conversion system via the support platform 2. The fastening and sealing system is welded to the upper end face of the flange 4 of the flange conversion system via the center sleeve 17.

[0031] In this embodiment, the device is inserted into the magnetic field region of a superconducting magnet within a sealed container. The liquid helium in this magnetic field region vaporizes into helium, flows along the bottom stopper 13 and the holes in the first, second, and third adapter blocks 5, 6, and 7 in the middle, and flows into the radial region between the Hall support rod 1 and the first, second, and third G-10 sleeves 10, 11, and 12. The gas is then discharged through the cylindrical surface of the guide tube 3 outside the first G-10 sleeve 10 for pressure relief. Rotating the lift knob 19 on the lift platform 18 causes the Hall support rod 1 to drive the Hall probe 9 at the bottom for axial movement, thereby measuring the magnetic field strength at different axial positions of the superconducting magnet.

[0032] In summary, in a measuring device for measuring the axial magnetic field distribution of a superconducting magnet in a low-temperature environment provided by the present invention, when the device is inserted into the magnetic field region where the superconducting magnet is located in a sealed container, rotating the lifting knob can cause the Hall support rod to move axially. After locking, the corresponding axial magnetic field strength and position information can be obtained in real time by cooperating with the scale shaft on the lifting platform and the Hall probe at the bottom of the Hall support rod. At the same time, the hollow design of the device can reserve space for helium to prevent excessive pressure, and the design of the center sleeve, copper nut, copper ring, and O-ring sealing rubber ring structure can prevent the leakage of liquid helium and perform secondary fixation on the Hall support rod.

Claims

1. A measuring device for measuring the axial magnetic field distribution of a superconducting magnet in a cryogenic environment, characterized by: Including axial adjustment system, fastening and sealing system, flange conversion system and magnetic field measurement system; The axial adjustment system includes: a support platform, a lifting platform, a lifting knob, a scale shaft, a locking structure, and a clamp. In the axial adjustment system, the support platform and the lifting platform are sequentially assembled on the upper end surface of the flange with bolts. The lifting platform is provided with a lifting knob, a scale shaft, and a locking structure. The Hall support rod is fixed to the lifting platform by a clamp, and the axial movement of the Hall probe is driven by rotating the lifting knob. The fastening and sealing system includes: a central sleeve, a copper nut, a copper ring, and an O-ring. In the fastening and sealing system, the copper nut on the top of the central sleeve can be rotated to squeeze the internal copper ring, which in turn squeezes the O-ring in the direction of the inner diameter to achieve the purpose of sealing, and can also perform secondary fixation on the Hall effect support rod. The flange conversion system includes: a flange, a first adapter block, a second adapter block, a third adapter block, a first G-10 sleeve, a second G-10 sleeve, a third G-10 sleeve, a guide tube, and a stopper; The magnetic field measurement system includes: a Hall support rod, a fixing plate, and a Hall probe; The Hall support rod passes through the center sleeve, flange, first adapter block, second adapter block, and third adapter block from top to bottom in sequence. The center sleeve is welded to the upper end face of the flange. The screw hole on the lower axial surface of the flange cooperates with the screw hole on the axial surface of the first adapter block to install the first G-10 sleeve with bolts. The second G-10 sleeve is installed between the axial surface of the first adapter block and the upper axial surface of the second adapter block with bolts. The third G-10 sleeve is installed between the lower axial surface of the second adapter block and the axial surface of the third adapter block with bolts. The Hall probe is supported at the bottom end of the Hall support rod by a fixing plate, and the stop block is installed at the bottom of the axial surface of the third G-10 sleeve with bolts. The guide tube is installed with bolts on the outside of the first G-10 sleeve in cooperation with the screw hole on the end face of the flange.

2. The measuring device for measuring the axial magnetic field distribution of a superconducting magnet in a low-temperature environment according to claim 1, characterized in that: The Hall support rod is a whole hollow stainless steel tube, which can be used as a channel to connect the bottom Hall probe wire. The upper outlet of the Hall support rod is filled with vacuum sealing mud.

3. The measuring device for measuring the axial magnetic field distribution of a superconducting magnet in a low-temperature environment according to claim 1, characterized in that: The block and adapter block both have holes as airflow channels. Since the probe temperature after liquid nitrogen pre-cooling is still higher than 4.2K, when the Hall probe part enters the low-temperature liquid helium area, the liquid helium is rapidly vaporized in large quantities. The provision of an airflow channel can prevent the sensor from being damaged by excessive local pressure in the Hall probe area. The block and adapter block are made of nylon.

4. The measuring device for measuring the axial magnetic field distribution of a superconducting magnet in a low-temperature environment according to claim 1, wherein: The sleeve and guide tube are both made of G-10 material.

5. The measuring device for measuring the axial magnetic field distribution of a superconducting magnet in a low-temperature environment according to claim 1, wherein: A copper ring is installed at the top of the central sleeve, and an O-shaped sealing rubber ring is installed inside the copper ring. By rotating the copper nut outside the top of the central sleeve, the copper ring is squeezed, and then the internal O-shaped sealing rubber ring is squeezed to shrink in the inner diameter direction, which plays an overall sealing role for the measurement system. At the same time, the squeezing effect between the rubber ring and the Hall support rod can also play a secondary fixing role for the Hall support rod.

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