CN114690089A - Vertical measuring system for magnetic field of superconducting undulator - Google Patents

Abstract

The invention discloses a superconducting undulator magnetic field vertical measurement system which comprises a Dewar flask, a superconducting undulator, a first end surface beam, a second end surface beam, a collimating beam, a guide rail, a Hall element, a ski board, a guide pipe, a Dewar top flange and a signal collector. The system can prevent the guide pipe from being bent randomly in the movement process to cause the misalignment of the magnetic field measurement result and damage to other parts.

Description

Vertical measuring system for magnetic field of superconducting undulator

Technical Field

The invention relates to the technical field of accelerator magnetic field measurement, in particular to a superconducting undulator magnetic field vertical measurement system.

Background

In recent years, superconducting undulators have become a hot spot in the accelerator field due to their large excitation current and high peak field strength of the generated magnetic field. In brief, the smaller the magnetic gap of the superconducting undulator, the stronger the peak magnetic field generated, but considering practical applications, the magnetic gap is usually set to 6-9 mm, but the narrow magnetic gap causes difficulties in the magnetic field measurement of the superconducting undulator.

The vertical measurement is a measurement mode of vertically suspending and soaking the superconducting undulator in liquid helium by rotating the superconducting undulator by 90 degrees. The mode of soaking the superconducting undulator in liquid helium can enable the superconducting undulator to be cooled more fully, a vacuum box is not required to be installed, the risk of quench is reduced, a more accurate magnetic field can be obtained, a reference basis is provided for results obtained by horizontal measurement, and whether the superconducting undulator and the cryostat are normal in working state is judged.

At present, the magnetic field vertical measurement technology of some superconducting magnets has been developed, but the technology can only perform the magnetic field measurement of some superconducting dipolar iron or quadrupole iron with larger aperture, and the magnetic field is constant in the longitudinal direction of the magnet, which cannot meet the requirement of the magnetic field vertical measurement of the superconducting undulator.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.

Therefore, the embodiment of the invention provides a superconducting undulator magnetic field vertical measurement system which can prevent the magnetic field measurement result from being misaligned and damaging other parts due to random bending of a guide tube in the movement process.

The superconducting undulator magnetic field vertical measurement system according to an embodiment of the present invention includes: a dewar having liquid helium therein; a superconducting undulator disposed within the dewar and immersed in liquid helium, the superconducting undulator having a magnetic gap; the collimating frame comprises a first end face cross beam, a second end face cross beam and a collimating cross beam, the first end face cross beam and the second end face cross beam are arranged at two ends of the superconducting undulator, and the collimating cross beam is arranged between the first end face cross beam and the second end face cross beam; the guide rail is arranged on the collimation cross beam and is positioned in the magnetic gap; the moving assembly comprises a Hall element, a ski board and a guide pipe, the Hall element is arranged on the ski board, the ski board is arranged on the guide rail, and one end of the guide pipe is connected with the ski board; the Dewar top flange is arranged at the bottleneck of the Dewar bottle and connected with one end of the superconducting undulator, and the other end of the guide pipe penetrates through the Dewar top flange; and the signal collector is connected with the Hall element.

According to the magnetic field vertical measurement system of the superconducting undulator, provided by the embodiment of the invention, the superconducting undulator is vertically arranged in a Dewar flask and immersed in liquid helium, the superconducting undulator is provided with a magnetic gap, the collimation frame is installed on the superconducting undulator, the guide rail is arranged on the collimation cross beam and positioned in the magnetic gap, the collimation frame provides collimation for the guide rail, the sled plate is provided with the Hall element and can freely move on the guide rail, the sled plate can freely move in the magnetic gap, the signal collector is connected with the Hall element, the signal collector obtains a voltage difference signal of the Hall element, and magnetic field data are obtained through a numerical relationship. According to the superconducting undulator magnetic field vertical measurement system disclosed by the embodiment of the invention, the magnetic field measurement result is prevented from being misaligned and other parts are prevented from being damaged due to random bending of the guide pipe in the movement process.

In some embodiments, the superconducting undulator magnetic field vertical measurement system further includes a bearing plate suspended from the dewar top flange by a lead screw, the bearing plate being connected to one end of the superconducting undulator to suspend the superconducting undulator within the dewar.

In some embodiments, the superconducting undulator magnetic field vertical measurement system further includes a vacuum pump, the dewar top flange is provided with a vacuum pump port, and the vacuum pump is adapted to communicate with the dewar through the vacuum pump port.

In some embodiments, the alignment frame further comprises a top block, the alignment beam tensions the guide rail through a lead screw, and the top block is disposed between the guide rail and the alignment beam.

In some embodiments, the moving assembly further includes a roller disposed on the ski board, and the guide rail is provided with a sliding slot, and the roller can freely slide in the sliding slot.

In some embodiments, the movement assembly further comprises a clip and a spring, the roller being disposed in the clip, the clip being resiliently connected to the ski by the spring, the roller being adapted to rest in the runner.

In some embodiments, the lower end of the rail is provided with a stop plate against which the ski is adapted to rest.

In some embodiments, the superconducting undulator magnetic field vertical measurement system further includes a collimating bridge disposed in the guide rail and adjacent to the upper end of the guide rail, the collimating bridge having a through hole, and the guide tube is adapted to pass through the through hole of the collimating bridge.

In some embodiments, the superconducting undulator magnetic field vertical measurement system further includes a convection radiation shield suspended from the dewar top flange by a lead screw.

In some embodiments, the superconducting undulator magnetic field vertical measurement system further includes a collimation patch, the collimation patch is disposed on the convection radiation baffle, a through hole is disposed on the collimation patch, and the guide tube is adapted to pass through the through hole of the collimation patch.

In some embodiments, the motion assembly further comprises a bellows, one end of the bellows is connected to one end of the guide tube, and the other end of the bellows is connected to the servo motor.

In some embodiments, the superconducting undulator magnetic field vertical measurement system further includes a flange exit tube disposed on the dewar top flange, the core tube of the bellows adapted to be inserted into the flange exit tube.

Drawings

FIG. 1 is a schematic diagram of a superconducting undulator magnetic field vertical measurement system according to an embodiment of the present invention.

FIG. 2 is another schematic diagram of a superconducting undulator magnetic field vertical measurement system according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a Dewar of a superconducting undulator magnetic field vertical measurement system of an embodiment of the present invention.

FIG. 4 is a schematic view of a Dewar top flange of a superconducting undulator magnetic field vertical measurement system according to an embodiment of the present invention.

FIG. 5 is a top view of a Dewar top flange of a superconducting undulator magnetic field vertical measurement system of an embodiment of the present invention.

FIG. 6 is a schematic diagram of a collimating frame of a superconducting undulator magnetic field vertical measurement system of an embodiment of the present invention.

Fig. 7 is a partial schematic view of the guide rail 4 of the superconducting undulator magnetic field vertical measurement system according to the embodiment of the present invention.

FIG. 8 is a schematic diagram of the moving components of a superconducting undulator magnetic field vertical measurement system of an embodiment of the present invention.

FIG. 9 is a front view of the moving components of a superconducting undulator magnetic field vertical measurement system of an embodiment of the present invention.

FIG. 10 is a schematic view of a sled of a superconducting undulator magnetic field vertical measurement system according to an embodiment of the present invention.

FIG. 11 is a schematic view of a fixture of a superconducting undulator magnetic field vertical measurement system according to an embodiment of the present invention.

FIG. 12 is a front view of a fixture of the superconducting undulator magnetic field vertical measurement system according to an embodiment of the present invention.

FIG. 13 is a side view of a fixture of a superconducting undulator magnetic field vertical measurement system according to an embodiment of the present invention.

FIG. 14 is a schematic view of a collimating bridge of the superconducting undulator magnetic field vertical measurement system of an embodiment of the present invention.

FIG. 15 is another schematic view of a collimating bridge of the superconducting undulator magnetic field vertical measurement system of an embodiment of the present invention.

FIG. 16 is another schematic view of a measurement platform support of the superconducting undulator magnetic field vertical measurement system according to an embodiment of the present invention.

FIG. 17 is a side view of a superconducting undulator magnetic field vertical measurement system according to an embodiment of the present invention.

Reference numerals are as follows:

the superconducting undulator magnetic field vertical measurement system 100, the Dewar flask 1, the superconducting undulator 2, the alignment frame 3, the first end face cross beam 31, the second end face cross beam 32, the alignment cross beam 33, the top block 34, the guide rail 4, the sliding groove 41, the baffle 42, the alignment bridge 43, the alignment patch 44, the moving assembly 5, the Hall element 51, the sled plate 52, the guide pipe 53, the roller 54, the clamp 55, the corrugated pipe 56, the Dewar top flange 6, the bearing plate 61, the convection radiation baffle 62, the flange leading-out pipe 63, the penetrating piece 64, the signal collector 7, the servo motor 8 and the measurement platform support 81.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

As shown in fig. 1-17, a superconducting undulator magnetic field vertical measurement system 100 according to an embodiment of the present invention includes a dewar 1, a superconducting undulator 2, a collimating frame 3, a guide rail 4, a moving assembly 5, a dewar top flange 6, and a signal collector 7.

Liquid helium is stored in the Dewar flask 1, the superconducting undulator 2 is arranged in the Dewar flask 1 and is immersed in the liquid helium, and the superconducting undulator 2 has a magnetic gap.

Specifically, the longitudinal direction of the superconducting undulator 2 is substantially parallel to the longitudinal direction of the dewar 1, and the superconducting undulator 2 is vertically provided in the dewar 1. The mode of soaking the superconducting undulator 2 in liquid helium can enable the superconducting undulator 2 to be cooled more fully, a vacuum box is not required to be installed, the risk of quench is reduced, a more accurate magnetic field can be obtained, a reference basis is provided for a result obtained by horizontal measurement, and the reference basis is used for judging whether the superconducting undulator 2 is normal or not in a working state.

The collimating frame 3 includes a first end face beam 31, a second end face beam 32, and a collimating beam 33, the first end face beam 31 and the second end face beam 32 are disposed at both ends of the superconducting undulator 2, and the collimating beam 33 is disposed between the first end face beam 31 and the second end face beam 32.

Specifically, the outer circumferential profiles of the first end face beam 31, the second end face beam 32, and the collimating beam 33 are substantially cylindrical, the first end face beam 31 and the second end face beam 32 are arranged in parallel relatively along the length direction of the superconducting undulator 2, and the collimating beam 33 is arranged between the first end face beam 31 and the second end face beam 32, whereby the length direction of the collimating beam 33 is parallel relatively to the length direction of the superconducting undulator 2.

The guide rail 4 is arranged on the collimating beam 33 and the guide rail 4 is located in the magnetic gap.

Specifically, the guide rail 4 is provided on the collimating beam 33, and the longitudinal direction of the guide rail 4 is substantially parallel to the longitudinal direction of the collimating beam 33, that is, the guide rail 4 is located in the magnetic gap and is substantially parallel to the longitudinal direction of the magnetic gap.

The moving assembly 5 includes a hall element 51, a sled 52, and a guide tube 53. The hall element 51 is provided on a ski 52, the ski 52 is provided on the guide rail 4, and one end of a guide tube 53 is connected to the ski 52.

Specifically, the sled plate 52 is slidably disposed on the guide rail 4, the guide tube 53 and the sled plate 52 can further drive the sled plate 52 to freely move along the length direction of the guide rail 4, the sled plate 52 is provided with the hall element 51, and the hall element 51 is used for obtaining the magnitude of the magnetic field in the vertical direction at different positions in the magnetic gap.

The Dewar top flange 6 is arranged at the bottleneck of the Dewar flask 1, the Dewar top flange 6 is connected with one end of the superconducting undulator 2, and the other end of the guide pipe 53 penetrates through the Dewar top flange 6. Specifically, a dewar top flange 6 is provided with the upper end of the superconducting undulator 2 to suspend the superconducting undulator 2 within the dewar 1.

The signal collector 7 is connected with the hall element 51. Specifically, the signal collector 7 includes a constant current source (not shown) for providing an excitation signal to the hall element 51 and a multimeter (not shown) for obtaining a voltage difference signal of the hall element 51, and the signal collector 7 is connected to the hall element 51 through a wire.

Preferably, the superconducting undulator magnetic field vertical measurement system 100 can work in a liquid helium temperature zone (4K), the dewar 1 provides a low-temperature environment for the superconducting undulator 2, the dewar top flange 6 provides a liquid helium channel, various sensor channels and a support for the motion assembly 5, and the motion assembly 5 moves up and down to drive the sled plate 52 carrying the hall element 51 to slide in the magnetic gap of the superconducting undulator 2 to obtain the magnetic field of the superconducting undulator 2.

According to the superconducting undulator magnetic field vertical measurement system 100 provided by the embodiment of the invention, a superconducting undulator 2 is vertically arranged in a Dewar flask 1 and is immersed in liquid helium, the superconducting undulator 2 is provided with a magnetic gap, a collimation frame 3 is installed on the superconducting undulator 2, a guide rail 4 is arranged on a collimation beam and is positioned in the magnetic gap, the collimation frame 3 provides collimation for the guide rail 4, a Hall element 51 is arranged on a sled plate 52, the sled plate 52 can freely move on the guide rail 4, the sled plate 52 can freely move in the magnetic gap, a signal collector 7 is connected with the Hall element 51, the signal collector 7 obtains a voltage difference signal of the Hall element 51, and magnetic field data are obtained through a numerical relationship. According to the superconducting undulator magnetic field vertical measurement system disclosed by the embodiment of the invention, the guide pipe 53 can be prevented from being bent randomly in the movement process, so that the magnetic field measurement result is misaligned and other parts are damaged.

In some embodiments, as shown in fig. 1, the superconducting undulator magnetic field vertical measurement system further includes a bearing plate 61, the bearing plate 61 is suspended on the dewar top flange 6 by a lead screw, and the bearing plate 61 is connected to one end of the superconducting undulator 2 so that the superconducting undulator 2 is suspended in the dewar 1.

It can be understood that the bearing plate 61 is suspended below the dewar top flange 6, and the bearing plate 61 is connected with the upper end of the superconducting undulator 2, so that direct contact between the dewar top flange 6 and the superconducting undulator 2 is avoided, and the bearing plate 61 of the embodiment of the present invention effectively prolongs the service life of the dewar top flange 6.

In some embodiments, the superconducting undulator magnetic field vertical measurement system further comprises a vacuum pump (not shown), the dewar top flange 6 is provided with a vacuum pump port 62, and the vacuum pump is adapted to communicate with the dewar 1 through the vacuum pump port 62.

It will be appreciated that a vacuum pump communicates with dewar 1 via a vacuum pump port 62, the vacuum pump being adapted to reduce the pressure inside dewar 1 to 1 x 10-4Pa and to discharge helium gas and nitrogen gas produced by vaporization of liquid helium and liquid nitrogen out of the vessel prior to injection of the cryogenic liquid.

In some embodiments, as shown in fig. 6, the collimating frame 3 further comprises a top block 34, the collimating beam 33 tensions the guide rail 4 through a lead screw, and the top block 34 is provided between the guide rail 4 and the collimating beam 33.

Specifically, the longitudinal direction of the guide rail 4 is parallel to the longitudinal direction of the collimator beam 33, and the top block 34 is provided between the guide rail 4 and the collimator beam 33 perpendicularly to the longitudinal direction of the guide rail 4, whereby the top block 34 abuts against the guide rail 4 for preventing deformation of the guide rail 4 at low temperature.

In some embodiments, as shown in fig. 7-8, the moving assembly 5 further includes a roller 54, the roller 54 is disposed on the ski board 52, the track 4 is provided with a sliding slot 41, and the roller 54 can freely slide in the sliding slot 41.

Specifically, the skis 52 are disposed within the runners 41 by rollers 54, and the rollers 54 reduce friction between the skis 52 and the rail 4.

Preferably, the rollers 54 are spherical rollers that are mounted to the ski 52 by roller shafts that are thick in the middle and thin at both ends to prevent the roller shafts from falling out of the ski 52, and the flat portions of the spherical rollers are stepped to reduce friction with the ski 52 as the rollers roll.

In some embodiments, as shown in fig. 8, the moving assembly 5 further comprises a clamp 55 and an elastic member (not shown), the roller 54 is disposed in the clamp 55, the clamp 55 is elastically connected to the ski 52 by the elastic member, and the roller 54 is adapted to be stopped in the chute 41.

Specifically, the spherical roller may be mounted on the fixture 55 through a roller shaft, the roller shaft has a thick middle portion and thin middle portions, so as to prevent the roller shaft from coming off the fixture 55, and the flat surface portion of the spherical roller is stepped so as to reduce friction between the roller and the fixture 55 when the roller rolls.

Furthermore, the side of the sled plate 52 is provided with an opening, the fixture 55 is inserted into the opening of the sled plate 52 through the elastic member, the spherical roller is fully contacted with the guide rail 4 under the action of the elastic force, the hall element 51 in the sled plate 52 is ensured to be positioned at the center of the magnetic gap in the superconducting undulator 2, and the fixture 55 limits the maximum range of the movement of the sled plate 52 and prevents the sled plate 52 from falling off under the action of the elastic force.

In some embodiments, as shown in fig. 1, the lower end of the guide rail 4 is provided with a stop plate 42, and the sled 52 is adapted to stop against the stop plate 42.

Specifically, the lowermost end of the guide rail 4 is provided with a stop plate 42, and the stop plate 42 provides initial position calibration of the ski 52 and prevents the ski 52 from sliding out of the guide rail 4 under the force of gravity.

In some embodiments, as shown in fig. 14, the superconducting undulator magnetic field vertical measurement system 100 further includes a collimating bridge 43, the collimating bridge 43 is disposed in the guide rail 4 and adjacent to the upper end of the guide rail 4, the collimating bridge 43 is provided with a through hole, and the guide tube 53 is adapted to pass through the through hole of the collimating bridge 43.

Specifically, a collimating bridge 43 is installed at the upper end of the superconducting undulator 2, and a guide tube 53 is adapted to pass through a through hole in the collimating bridge 43, completing collimation at the end of the superconducting undulator 2. At the same time, the collimating bridge 43 serves as the final position of the ski 52 for measurement.

In some embodiments, as shown in FIG. 1, the superconducting undulator magnetic field vertical measurement system 100 further includes a convection radiation shield 62, the convection radiation shield 62 suspended from the Dewar top flange 6 by a lead screw.

It can be appreciated that the convection radiation baffle 62 is used to prevent the liquid helium from boiling and impacting the dewar top flange 6, and at the same time, to reduce the thermal radiation at the room temperature end to intensify the liquid helium boiling, which effectively improves the safety of the superconducting undulator magnetic field vertical measurement system 100.

Further, the dewar top flange 6 provides support for the superconducting undulator 2 and the convection radiation baffle 62 for preventing boiling impact of liquid helium inside the dewar 1, the dewar top flange 6 provides a passage for liquid helium to be injected into the dewar 1, and the dewar top flange 6 provides a passage for various sensor cables such as a cable of the superconducting undulator 2, a quench protection sensor, and a temperature sensor.

Furthermore, a convection radiation baffle 62, a bearing plate 61 and the superconducting undulator 2 are suspended at the vacuum end of the Dewar top flange 6 through a screw rod, and a measuring platform support 81 of the servo motor 8 is installed at the air end of the Dewar top flange 6.

The Dewar top flange 6 is provided with a penetrating piece 64, and the penetrating piece 64 comprises a vacuum pump port, a temperature sensor interface, a quench protection line interface, a current lead interface, a low-temperature liquid inlet, a safety valve and a magnetic measurement interface.

The temperature sensor interface provides a signal channel to obtain real-time temperature of each position of the superconducting undulator 2, the quench protection line interface provides a signal channel to realize quench protection of the superconducting undulator 2, the current lead interface provides current for the superconducting undulator 2, the low-temperature liquid inlet injects liquid nitrogen and liquid helium into the container to obtain liquid level signals of the liquid helium and the liquid nitrogen, the safety valve protects the pressure in the container from being less than 1.5 atmospheric pressures when the low-temperature liquid is gasified violently, and the magnetic measurement interface provides a channel for the moving component 5.

Wherein, the collimation beam 33 is installed on the superconducting undulator 2, and the precision is 0.01 mm after the collimation is adjusted. The guide rail 4 is a V-shaped guide rail, the thickness of the guide rail is set to be 6mm, the length of the guide rail is processed according to the length of the measured superconducting undulator 2, the material is titanium alloy, the deformation of the long straight guide rail during processing can be resisted in a splicing mode, and the processing precision of parts is 0.01 mm.

In some embodiments, as shown in fig. 1, the superconducting undulator magnetic field vertical measurement system 100 further includes a collimation patch 44, the collimation patch 44 is disposed on the convection radiation shield 62, the collimation patch 44 is provided with a through hole, and the guide tube 53 is adapted to pass through the through hole of the collimation patch 44.

It will be appreciated that the alignment patch 44 ensures that the guide tube 53 does not buckle during up and down movement within the magnetic gap.

Preferably, the alignment patch 44 is two semicircular flat plates, and a circular hole with a diameter of 6mm is formed between the two semicircular alignment patches.

In some embodiments, as shown in fig. 1, the moving assembly 5 further includes a bellows 56, one end of the bellows 56 is connected to one end of the guide tube 53, and the other end of the bellows 56 is connected to the servo motor 8.

In some embodiments, as shown in FIG. 1, superconducting undulator magnetic field vertical measurement system 100 further includes a flange exit 63, flange exit 63 being disposed on top of Dewar flange 6, and the core tube of bellows 56 being adapted to be disposed within flange exit 63.

Further, the moving assembly 5 further comprises a top flange transition pipe and a four-way flange, the sled plate 52 carrying the hall element 51 is an oxygen-free copper plate with the thickness of 5.5 mm, a groove for accommodating the hall element 51 and a lead slot for accommodating the hall element 51 are dug in the sled plate 52, and after the hall element 51 is fixed, the effective area of the hall element is positioned at the center of the transverse section of the sled plate 52.

Three rollers 54 are respectively arranged on the left side and the right side of the ski board 52, and the rollers 54 are matched with the guide rail 4 to realize the longitudinal sliding of the ski board 52 in the magnetic gap of the superconducting undulator 2.

The guide pipe 53 in the magnetic gap needs to move in the magnetic gap of the superconducting undulator 2 and is limited by the magnetic gap between the two poles of the superconducting undulator 2, the outer diameter of the guide pipe 53 is designed to be 5 mm, the guide pipe 53 is 2.5 m long, the guide pipe 53 is in threaded connection with the sled plate 52, the sled plate 52 is driven by the guide pipe 53 to slide on the guide rail 4, and the method is applicable to magnetic field measurement of the superconducting undulator 2 with the length of 1.5 m.

The bellows 56 and the core tube of the bellows 56 are composed of the bellows 56 with a stroke of 1.8 m and a rigid core tube built therein, the bellows 56 is extended or compressed under the driving of the servo motor 8, the rigid core tube enters or extends out of the bellows 56, and the rigid core tube is connected with the magnetic gap inner guide tube 53 to realize the movement of the magnetic gap inner guide tube 53.

The top flange transition pipe connects the magnetic sensing interface of the dewar top flange 6 with the bellows 56, and is used to accommodate the rigid core tube that extends out when the bellows 56 is in a compressed state.

The four-way flange is provided with a penetrating piece 64 to provide a signal channel for reading data of the Hall element 51 and a standby signal channel for subsequent system upgrade, and the corrugated pipe 56 is connected with the servo motor 8 to form a transmission mechanism.

Furthermore, to ensure good measurement repeatability, the superconducting undulator magnetic field vertical measurement system 100 has a plurality of sets of alignment mechanisms, which specifically includes:

a spacing ring is arranged in the corrugated pipe 56 to ensure that the corrugated pipe 56 is not bent in the stretching or compressing process, and the radial movement range of an inner core pipe (with the outer diameter of 22 mm) of the corrugated pipe 56 is limited when the inner core pipe moves longitudinally in a top flange transition pipe (with the inner diameter of 25 mm).

In a preferred embodiment, a successfully assembled prototype of superconducting undulator 2 is 400 mm long with a magnetic gap of 7 mm. The collimating frame 3 on the superconducting undulator 2 is based on two end faces of the superconducting undulator 2.

The flange outlet pipe 63 connected to the top flange magnetic interface serves as a transitional storage conduit for the upward movement of the guide pipe 53 in the magnetic gap and the downward movement of the core pipe in the bellows 56.

The upper end of the inner core tube of the corrugated tube 56 is welded with the upper flange of the corrugated tube 56, and the lower end can realize reciprocating motion under the expansion and contraction of the corrugated tube 56 so as to drive the inner guide tube 53 of the magnetic gap to move. The flange at the upper end of the corrugated pipe 56 is connected with the four-way flange and the motor connecting piece, the motor connecting piece is connected with the servo motor 8, the servo motor 8 is controlled to move, and the corrugated pipe 56 is driven to stretch and retract, so that the power source is the basic power source of the invention.

The signal wire led out from the Hall element 51 passes through the magnetic gap inner guide tube 53 and the corrugated tube 56 inner core tube and is finally connected with the through piece 64 on the four-way flange, the signal wire avoids various consequences caused by signal wire winding due to movement, the four-way flange is provided with three through pieces 64 which can be communicated with signals of at least three Hall elements 51, and the signal wire is continuously led into the signal collector 7 from the through pieces 64.

One specific implementation of the superconducting undulator magnetic field vertical measurement system 100 according to an embodiment of the present invention is as follows:

1. the collimating frame 3, the guide rail 4 and the collimating bridge 43 are mounted in turn in the end face of the superconducting undulator 2 and in the magnetic gap.

2. The assembled ski 52 and hall element 51 are pressed into the rail 4 and the stop plate 42 is mounted on the bottom of the rail 4.

3. Various types of penetrations 64 and sensor leads are mounted to the dewar top flange 6 and the convection radiation shield 62, bearing plate 61 are hoisted to below the dewar top flange 6.

4. And hoisting the alignment frame 3, the guide rail 4 and the moving assembly 5 assembled in the steps 1 and 2 onto a bearing plate 61 through a screw rod.

5. The magnetic gap inner guide tube 53 is connected to the ski board 52 through the magnetic interface of the Dewar top flange 6 and the collimation bridge 43, the lead of the Hall element 51 passes through the magnetic gap inner guide tube 53, and the collimation patch 44 is arranged on the convection radiation baffle plate 62 to limit the radial position of the magnetic gap inner guide tube 53.

6. Welding the current lead of the superconducting undulator 2, the quench protection wire, the temperature sensor and other leads.

7. The installation of the interior of the dewar 1 is completed in steps 1-6, and the dewar top flange 6 is hung into the dewar 1.

8. The corrugated pipe 56 with the overlarge stroke is compressed and then connected with a flange leading-out pipe 63, a core pipe of the corrugated pipe 56 extends out of the bottom end of the flange leading-out pipe 63, a lead of the Hall element 51 penetrates through the core pipe of the corrugated pipe 56 to connect the core pipe of the corrugated pipe 56 with a magnetic gap inner guide pipe 53, and the flange leading-out pipe 63 and a top flange magnetic detection interface are sealed well.

9. The hall element 51 lead wires are welded to the penetration pieces 64, and the bellows 56 is connected to the servo motor 8.

10. Vacuumizing the Dewar flask 1 to 1.0 x 10 < -5 > Pa, injecting liquid nitrogen and liquid helium into the Dewar flask 1, and applying current excitation to the superconducting undulator 2 after the working condition of the superconducting undulator 2 is reached.

11. At the moment, the ski board 52 is positioned at the bottommost end of the guide rail 4, the servo motor 8 is started to pull the corrugated pipe 56, the inner core pipe of the corrugated pipe 56 moves along with the upper flange of the corrugated pipe 56, the inner guide pipe 53 in the magnetic gap is pulled to move upwards in a radial limited range, and therefore the ski board 52 is driven to sweep the longitudinal magnetic field range of the superconducting undulator 2 from bottom to top.

12. In the process that the hall element 51 moves upwards along with the ski board 52, the constant current source meter 2450 provides excitation for the hall element 51, the multimeter DM7510 obtains a voltage difference signal of the hall element 51 in real time, and magnetic field data of the superconducting undulator 2 is obtained according to a numerical relationship between the magnetic field and the voltage difference of the hall element 51.

A specific measurement process of the superconducting undulator magnetic field vertical measurement system 100 according to the embodiment of the present invention is as follows:

1. the alignment frames 3 are arranged on two end surfaces of the superconducting undulator 2, and the end surfaces of the superconducting undulator 2 and the alignment frames 3 are aligned through a measuring articulated arm.

2. A guide rail 4 is arranged in a magnetic gap of the superconducting undulator 2, two ends of the guide rail 4 are fixed on the end surface of the superconducting undulator 2 through connecting pieces, and the middle part of the guide rail 4 is positioned by a collimation cross beam 33 through a screw rod and a top block 34.

3. The sled 52 is grooved and fitted with hall elements 51 or temperature sensors as needed at specific locations.

4. The assembled roller 54 and clamp 55 assembly is mounted on both sides of the ski 52, so that the roller 54 and clamp 55 move well and are subject to a certain elastic force.

5. The combination of the skis 52 is installed in the guide rail 4, and the rollers 54 are in close contact with the sliding grooves 41 of the guide rail 4 under the action of the elastic force, so that the skis 52 can stably slide in the magnetic gap.

6. On the upper end face of the superconducting undulator 2, a collimating bridge 43 is installed, and a sled 52 is closely attached to the lowermost end of the guide rail 4 as a measurement starting position.

7. The convection radiation baffle plate 62 and the bearing plate 61 are sequentially hung below the Dewar top flange 6 through screws, and lines such as a quench protection line, a power line of the superconducting undulator 2 and the like pass through holes in the convection radiation baffle plate 62 and the bearing plate 61 from the Dewar top flange 6 to be ready for connection.

8. The assembled superconducting undulator 2 and the respective components mounted thereon are suspended on the bearing plate 61 by lead screws and aligned.

9. The guide tube 53 in the magnetic gap is connected to the sled 52 via the alignment bridge 43, and after installation, the alignment patch 44 is installed on the convection current baffle 62.

10. The lead wire of the hall element 51 is led out through the magnetic gap inner guide tube 53 by connecting lines such as a power supply line, a temperature sensor line, and a quench protection line of the superconducting oscillator 2.

11. When the corrugated pipe 56 is in a compressed state, the inner core pipe of the corrugated pipe 56 extends out, and the corrugated pipe 56 and the flange lead-out pipe 63 are combined and then suspended on the magnetic measurement interface of the Dewar top flange 6.

12. The lead wire of the Hall element 51 passes through the inner core tube of the corrugated tube 56 to be connected with the penetration piece 64, the upper end of the magnetic gap inner guide tube 53 is connected with the lower end of the inner core tube of the corrugated tube 56 through threads, and the flange eduction tube 63 is folded with the magnetic measuring interface.

13. The upper flange of the corrugated pipe 56, the four-way flange and the three flanges of the motor connecting piece are connected together, so that the continuity of the corrugated pipe 56 is ensured, and the other end of the motor connecting piece is connected with the servo motor 8.

14. Various leads at the air end are connected to corresponding equipment, a power line of the superconducting undulator 2 is connected with a customized power supply, a quench protection line is connected with a quench protection control, a temperature sensor line is connected with a 218S temperature monitor of Lakeshore, an outgoing line of a Hall element 51 is connected with a Gichery 2450 source meter and a 7510 multimeter, and a servo motor 8 is connected with a control cabinet.

15. The dewar 1 and the helium tank are evacuated to 1 x 10-4Pa, and the water vapor therein is discharged to prevent the dewar 1 from freezing.

16. And injecting liquid nitrogen into the Dewar vacuum cavity to provide a layer of cold shield, and then injecting liquid helium into the helium pool to immerse the superconducting undulator 2 in the liquid helium, so that the superconducting undulator 2 is cooled to the working temperature.

17. The superconducting undulator 2 is electrified, measurement starts, the servo motor 8 is controlled to move upwards, the corrugated pipe 56 is extended from the initial compression state, the sled plate 52 is driven to move upwards to sweep a magnetic field region, the servo motor 8 feeds back position signals, and the Hall element 51 feeds back real-time magnetic field signals, so that the magnetic field strength of the superconducting undulator 2 in the vertical direction of each position in the longitudinal direction can be obtained.

18. And (5) recovering liquid helium, reheating the superconducting undulator 2 and finishing the magnetic field measurement.

The superconducting undulator magnetic field vertical measurement system 100 of the embodiment of the present invention has the following advantages:

1. the ski 52 with the thickness of 5.5 mm and the guide rail 4 with the thickness of 6mm are arranged, so that the difficulty of magnetic field measurement under a narrow gap is overcome, and the requirement of magnetic field measurement in the narrow magnetic gap of the superconducting undulator 2 can be met.

2. According to the invention, the sliding of the sled plate 52 on the guide rail 4 is realized, so that the Hall element 51 can sweep the longitudinal magnetic field range of the superconducting undulator 2, and the magnetic field data and the integral field data in the vertical direction of the superconducting undulator 2 at different longitudinal positions can be continuously obtained.

3. The invention sets four sets of alignment mechanisms for the motion equipment of the measuring system, controls the alignment accuracy of the alignment frame within 0.01 mm, ensures the accuracy of the longitudinal position, simultaneously, the spherical roller can adapt to the contraction deformation of the guide rail 4 at low temperature and the discontinuity of the splicing position under the action of the elasticity, ensures that the effective area of the Hall element 51 is positioned at the transverse center of the magnetic gap, and ensures the accuracy of the transverse position, therefore, the invention has high accuracy of the measuring position and good repeatability.

4. The invention leads the lead of the Hall element 51 out of the vacuum from the inside of the measuring device moving equipment, can ensure that the lead can not be wound in the magnetic gap of the superconducting undulator 2 along with the movement of the Hall element 51, and effectively protects the experimental equipment.

5. The extra-large-stroke corrugated pipe 56 with the stroke of 1.8 meters and the magnetic gap inner guide pipe 53 with the length of 2.5 meters, which are configured in the invention, can meet the vertical measurement requirement of the superconducting undulator magnetic field 2 with the maximum length of 1.5 meters, and for the superconducting undulators 2 with different lengths, the matched collimating frame 3 and the guide rail 4 are only needed to be reconfigured for installation and measurement, and the liquid helium level can be controlled according to the different lengths of the superconducting undulators 2, so that the liquid helium cost is effectively controlled.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise explicitly stated or limited, the terms "mounted," "connected," "fixed," and the like are to be construed broadly, e.g., as being permanently connected, detachably connected, or integral; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the present disclosure, the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" and the like mean that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are exemplary and not to be construed as limiting the present invention, and that changes, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims (12)

1. A superconducting undulator magnetic field vertical measurement system, comprising:

a dewar having liquid helium therein;

a superconducting undulator disposed within the dewar and immersed in liquid helium, the superconducting undulator having a magnetic gap;

the collimating frame comprises a first end face cross beam, a second end face cross beam and a collimating cross beam, the first end face cross beam and the second end face cross beam are arranged at two ends of the superconducting undulator, and the collimating cross beam is arranged between the first end face cross beam and the second end face cross beam;

the guide rail is arranged on the collimation cross beam and is positioned in the magnetic gap;

the moving assembly comprises a Hall element, a ski board and a guide pipe, the Hall element is arranged on the ski board, the ski board is arranged on the guide rail, and one end of the guide pipe is connected with the ski board;

the Dewar top flange is arranged at the bottle mouth of the Dewar bottle and connected with one end of the superconducting undulator, and the other end of the guide pipe penetrates through the Dewar top flange;

and the signal collector is connected with the Hall element.

2. The superconducting undulator magnetic field vertical measurement system of claim 1, further comprising a bearing plate suspended from the dewar top flange by a lead screw, the bearing plate being connected to one end of the superconducting undulator to suspend the superconducting undulator within the dewar.

3. The superconducting undulator magnetic field vertical measurement system of claim 1, further comprising a vacuum pump, the dewar top flange having a vacuum pump port thereon, the vacuum pump adapted to communicate with the dewar through the vacuum pump port.

4. The superconducting undulator magnetic field vertical measurement system of claim 1, wherein the collimating frame further includes a top block, the collimating beam tensions the guide rail through a lead screw, and the top block is disposed between the guide rail and the collimating beam.

5. The superconducting undulator magnetic field vertical measurement system of claim 1, wherein the motion assembly further comprises a roller, the roller is disposed on the ski board, the guide rail is provided with a sliding slot, and the roller can freely slide in the sliding slot.

6. The superconducting undulator magnetic field vertical measurement system of claim 5, wherein the motion assembly further includes a jig and a resilient member, the roller being disposed within the jig, the jig being resiliently coupled to the sled plate via the resilient member, the roller being adapted to rest within the chute.

7. The superconducting undulator magnetic field vertical measurement system of claim 1, wherein the lower end of the rail is provided with a baffle, and the ski is adapted to rest against the baffle.

8. The superconducting undulator magnetic field vertical measurement system of claim 1, further comprising a collimating bridge disposed within the guide rail and adjacent to the upper end of the guide rail, the collimating bridge having a through hole, the guide tube adapted to pass through the through hole of the collimating bridge.

9. The superconducting undulator magnetic field vertical measurement system of claim 1, further comprising a convection radiation shield suspended from the dewar top flange by a lead screw.

10. The superconducting undulator magnetic field vertical measurement system of claim 9, further comprising a collimation patch, wherein the collimation patch is disposed on the convection radiation baffle, a through hole is disposed on the collimation patch, and the guide tube is adapted to pass through the through hole on the collimation patch.

11. The superconducting undulator magnetic field vertical measurement system of claim 1, wherein the motion assembly further includes a bellows, one end of the bellows is connected to one end of the guide tube, and the other end of the bellows is connected to a servo motor.

12. The superconducting undulator magnetic field vertical measurement system of claim 11, further comprising a flange exit tube disposed on the dewar top flange, the core tube of the bellows adapted to be disposed within the flange exit tube.

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