JP2756552B2 - Conduction-cooled superconducting magnet device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conduction cooling type superconducting magnet device, and more particularly to a conduction cooling type superconducting magnet device having an improved structure for cooling a superconducting coil.

[0002]

2. Description of the Related Art In a conventional superconducting magnet apparatus (for example, Japanese Patent Application No. 3-104442), a method is employed in which a superconducting coil is brought into direct contact with a cooling stage of a refrigerator to cool it to an extremely low temperature and obtain a superconducting state. Something you are doing.

[0003] However, there are problems such as that a long time is required for initial cooling for cooling the superconducting coil from room temperature to extremely low temperature, and that the cooling temperature distribution of the superconducting coil is not uniform.

For example, when a refrigerator having a first cooling stage and a second cooling stage lower in temperature than the first cooling stage is used as the cooling stage, the temperature of the first cooling stage having a small heat load is reduced. Is cooled in advance and reaches a predetermined temperature (50 to 70 K of liquid nitrogen temperature), while a superconducting coil having a large heat capacity and a second cooling stage thermally connected to the superconducting coil are cooled by progressive heat transfer. Therefore, there is a problem that it takes a long time to reach a temperature at which a predetermined superconducting state is obtained.

When a superconducting coil employs a good heat conductor such as copper and a superconducting wire wound around a coil winding frame composed of a core and an end flange, the superconducting coil has Because it is cooled from the inner peripheral surface of the coil and the end flange surface of the coil bobbin,
As described above, there is a problem that a long initial cooling is inevitable and a partial temperature deviation inside the superconducting coil is apt to occur.

Although a current lead for supplying power to a superconducting coil has been made of a high-temperature superconductor such as an oxide high-temperature superconductor, the critical current of the oxide superconductor is greatly reduced by an external magnetic field. It is known.

Therefore, when an oxide high-temperature superconductor is used as a current lead for various superconducting coils, it is necessary to prevent the reduction of the critical current by applying some kind of magnetic shield to the leakage magnetic field from the superconducting magnet.

Conventionally, an iron-based metal such as ferrite has been used as a magnetic shield material. However, the metal has a drawback that the metal cannot be completely shielded and the magnetic field is heavy.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems. Particularly, in a conduction cooling type superconducting magnet apparatus which cools a superconducting coil by a conduction heat transfer operation using a refrigerator, the present invention relates to a superconducting magnet. It is an object of the present invention to provide a conduction-cooled superconducting magnet device capable of improving the cooling efficiency by shortening the initial cooling time of a coil and preventing a decrease in critical current of a current lead by applying an effective magnetic shield. .

[0010]

That is, the present invention focuses on a structure which can thermally connect a superconducting coil directly to a cooling stage of a refrigerator and, at the same time, can supplementarily cool the superconducting coil from the outer periphery thereof. The first invention is a conduction cooling type superconducting magnet device having a refrigerator and a superconducting coil that can be cooled by the refrigerator, wherein the superconducting coil is formed by a coil winding frame, and the coil winding frame. And a superconducting wire wound around the superconducting wire, a cooling promoting member is fixed to the outer periphery of the superconducting wire, and the superconducting coil and the cooling promoting member are brought into contact with a cooling stage of the refrigerator. This is a cooled superconducting magnet device.

It is desirable that the cooling promoting member is made of a good heat conductive material.

The cooling promoting member can be divided into an annular shape, and the cooling promoting member can be tightened from the outer peripheral surface of the superconducting wire.

A second invention is a conduction-cooled superconducting magnet device having a refrigerator and a superconducting coil that can be cooled by the refrigerator, wherein liquid nitrogen is introduced into the outer periphery of the superconducting coil. A conduction-cooled superconducting magnet device characterized in that heat can be exchanged with the superconducting coil and the superconducting coil is brought into contact with a cooling stage of the refrigerator.

The superconducting coil comprises a coil winding, a superconducting wire wound around the coil winding, and a cooling promoting member fixed to the outer periphery of the superconducting wire. By providing a cooling copper tube, liquid nitrogen can be introduced into the conduction cooling copper tube.

A third invention relates to a refrigerator having a first stage cooling stage and a second stage cooling stage lower in temperature than the first stage cooling stage, and a superconducting coil which can be cooled by the refrigerator. A conductive cooling type superconducting magnet device having a superconducting coil, which is in contact with the second-stage cooling stage, and which is provided with a contact / separation member that allows the superconducting coil and the first-stage cooling stage to be brought into and out of contact with each other. A conduction cooled superconducting magnet device characterized by the following.

A good heat conductive material plate for bringing the contacting / separating member into and out of contact with the first cooling stage of the refrigerator, and bringing the good heat conductive material plate into and out of contact with the first cooling stage of the refrigerator. separable drive means for movably driving so, can be composed of, and toward and away from heat transfer rod in the greater conductivity coils in accordance with the movement of the good thermal conductive material plate.

[0017] The fourth invention is a refrigerator, a superconducting coil which enables cooled by the refrigerator, a conduction cooling type superconducting magnet apparatus having a current lead, a for supplying power to the the superconducting coil, the Conduction cooling wherein the superconducting coil is brought into contact with a cooling stage of the refrigerator, and a high-temperature superconducting magnetic shield is provided around the current lead, and the high-temperature superconducting magnetic shield is brought into contact with the cooling stage of the refrigerator. Type superconducting magnet device.

A first stage cooling stage and a second stage cooling stage lower in temperature than the first stage cooling stage are provided as a cooling stage of the refrigerator, and the superconducting coil and the high temperature superconducting magnetic shield are provided on the second stage cooling stage. Can be contacted.

The above-mentioned high-temperature superconducting magnetic shield is made of an oxide high-temperature superconductor, and a metal having a high thermal conductivity, such as copper, silver or aluminum, can be combined with the oxide high-temperature superconductor. .

[0020]

In the conduction cooling type superconducting magnet device according to the present invention, since the auxiliary cooling is performed from the outer periphery of the superconducting coil, the initial cooling time until the superconducting state is reached can be shortened, and the superconducting coil can be cooled. Cooling from the inner surface and the outer surface of the coil becomes possible, and a partial temperature deviation accompanying cooling can be eliminated.

In the first aspect of the present invention, since the cooling promoting member composed of a copper block for cooling the outer periphery of a good heat conductive material is arranged on the outer periphery of the superconducting coil, the outer peripheral portion is brought into direct contact with the cooling stage of the refrigerator. Cooling is also possible from the cooling promoting member.

In the second aspect of the present invention, liquid nitrogen is introduced into the outer periphery of the superconducting coil to actively exchange heat with the superconducting coil, so that the cooling efficiency can be further improved.

In the third invention, a refrigerator provided with a first stage cooling stage and a second stage cooling stage lower in temperature than the first stage cooling stage is employed as the cooling stage, and the superconducting coil and the refrigerator are provided. Since the contacting / separating member for contacting / separating the first cooling stage is provided, cooling can be performed from the first cooling stage in the initial cooling in accordance with the cooling of the superconducting coil by the second cooling stage. Time can be reduced.

Further, in the fourth invention, a high-temperature superconducting magnetic shield is provided on the outer periphery of the current lead, and this high-temperature superconducting magnetic shield is cooled together with a superconducting coil by a refrigerator. Magnetic shielding can be performed efficiently.

[0025]

Next, a conduction cooling type superconducting magnet device 1 according to a first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a partial longitudinal sectional view of a conduction cooling type superconducting magnet device 1.
Are a base 2, a vacuum vessel (cryostat) 3, a heat shield plate 4, a superconducting coil 5, a pair of positive and negative high-temperature superconducting current leads 6, a regenerative refrigerator 7, and an external power supply 8.
And

The vacuum vessel 3 is evacuated and has a heat shield plate 4, a superconducting coil 5, a high-temperature superconducting current lead 6, a first cooling stage 7 A and a second cooling stage of a regenerative refrigerator 7. 7B.

The heat shield plate 4 is fixedly in contact with the first cooling stage 7A of the regenerative refrigerator 7 and prevents heat from entering the superconducting coil 5 and the high-temperature superconducting current lead 6 therein.

The superconducting coil 5 is formed by winding a superconducting wire 10 around a coil winding frame 9, and an outer peripheral cooling copper block 11 is fastened to the outer periphery as a cooling promoting member.

The coil winding frame 9 includes a winding core 9A and end flanges 9B integrally formed on both upper and lower ends of the winding core 9A.
Construct this from.

The outer peripheral cooling copper block 11 and the coil winding frame 9 are connected to the second cooling stage 7 B of the regenerative refrigerator 7.
, The superconducting wire 10 can be efficiently cooled to a very low temperature.

FIG. 2 is a longitudinal sectional view showing a specific structure of the outer peripheral cooling copper block 11, and FIG.
FIG. 3 is a cross-sectional view taken along a line III, wherein an outer peripheral cooling copper block 11 is divided at equal angular intervals in a circumferential direction so that an arbitrary number, for example, three arc-shaped unit block portions 11A, 11B,
This is constructed from 1C.

Each of the arc-shaped unit blocks 11A, 11B, 1
At least one eddy current preventing electric insulating material 12 for preventing eddy current at the time of quenching and a copper sheet 13 are interposed between each other, and predetermined tightening is performed from the outer periphery of the superconducting wire 10 by bolts 14. Tighten with force,
The thermal adhesion is improved by increasing the mutual adhesion.

The adhesion can also be adjusted by adjusting the thickness with a shim (not shown).

The space between the outer peripheral cooling copper block 11 and the superconducting wire 10 may be filled with low-temperature grease having good thermal conductivity.

Returning to FIG. 1, the high-temperature superconducting current lead 6 is provided with a pair of positive and negative electrodes.
5 and an external power supply 8 via a normal current flow lead wire 16, the high-temperature end of which is connected to the first cooling stage 7 A of the regenerative refrigerator 7, and the low-temperature end of which is connected to the second cooling stage. 7B.

The regenerative refrigerator 7 is an arbitrary refrigerator such as a GM refrigerator. The first cooling stage 7A can cool the liquid nitrogen to a temperature of around 77K, and the second cooling stage 7B can operate at a very low temperature. It can be cooled to 4-10K.

Therefore, the normal conductive current lead wire 16
Performs power supply in a range from the room temperature (300K) portion of the vacuum vessel 3 to the vicinity of the temperature (70K) of the first cooling stage 7A of the regenerative refrigerator 7, and the high-temperature superconducting current lead 6 is connected to the first cooling stage 7A. From the part of the second cooling stage 7B
The power is supplied in the temperature range.

High-temperature side electrode 17 of high-temperature superconducting current lead 6
Is connected to the normal current flow lead wire 16 and is connected to the first cooling stage 7A of the regenerative refrigerator 7 via the heat anchor copper wire 18 and the high temperature side insulating material 19 such as a high temperature side aluminum nitride plate. This is connected.

The low-temperature side electrode 20 of the high-temperature superconducting current lead 6
Is the second cooling stage 7B of the regenerative refrigerator 7 via the low temperature side insulating material 21 such as a low temperature side aluminum nitride plate.
These are connected and fixed by bolts to form fixed ends, and are connected to the superconducting wire 10 of the superconducting coil 5.

[0041] In conduction cooling type superconducting magnet apparatus 1 of such configuration, the positive electrode current from an external power source 8 first through the current lead terminal 15 is guided to the normal conduction current lead wire 1 6, then sequentially, the high temperature-side electrode 17 The superconducting coil 5 is guided by the high-temperature superconducting current lead 6 and the low-temperature side electrode 20 to excite the superconducting coil 5. Note that the negative electrode current returns to the external power supply 8 in the reverse course.

Thermal contact between the superconducting coil 5 and the second cooling stage 7B of the regenerative refrigerator 7 is performed through the coil winding frame 9. In addition to this heat conduction, the second cooling stage 7B Heat conduction is also performed via the outer peripheral cooling copper block 11 which is in contact with the outer peripheral surface.

Therefore, the heat exchange is performed from the inner surface side of the superconducting coil 5 and also from the entire outer surface of the superconducting coil 5, so that the initial cooling of the superconducting coil 5 is performed promptly and the inside of the superconducting coil 5 is cooled. Is cooled uniformly.

Next, a conduction cooling type superconducting magnet device 30 according to a second embodiment of the present invention will be described with reference to FIG.
However, in the following description, the same parts as those in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 4 is a partial longitudinal sectional view of the conduction cooling type superconducting magnet device 30. The conduction cooling type superconducting magnet device 30 has the same basic structure as the conduction cooling type superconducting magnet device 1 described above. .

In the conduction cooling type superconducting magnet device 30, a conduction cooling copper tube 31 is disposed on the outer peripheral surface of the outer periphery cooling copper block 11 so as to extend therearound. A liquid nitrogen injection pipe 32 and a nitrogen gas discharge pipe 33 made of stainless steel are connected to the outside of the apparatus 3.

A dissimilar material joint 34 is provided at a place where the material changes, and liquid nitrogen is injected into the conduction cooling copper tube 31 from the liquid nitrogen supply source 35 only during initial cooling.

According to the conduction cooling type superconducting magnet device 30 having such a configuration, the outer periphery cooling copper block 11 on the outer periphery of the superconducting coil 5 is formed by the liquid nitrogen in the conduction cooling copper tube 31.
The heat exchange is performed in the portion, and the gasified nitrogen gas is discharged from the liquid nitrogen injection pipe 32 to the outside.

When the superconducting coil 5 to be cooled reaches the predetermined first cooling stage 7A temperature, the injection of liquid nitrogen is stopped, and the conduction cooling copper tube 31, the liquid nitrogen injection tube 32 and the liquid nitrogen The inside of the nitrogen injection tube 32 is evacuated to operate as a heat insulator.

Thus, in cooling the superconducting coil 5, in addition to the cooling effect by the first cooling stage 7A and the second cooling stage 7B of the regenerative refrigerator 7, an auxiliary cooling effect by heat exchange with liquid nitrogen is provided. Thereby, the initial cooling time can be reduced.

Next, a conduction cooled superconducting magnet device 40 according to a third embodiment of the present invention will be described with reference to FIG.

FIG. 5 is a partial longitudinal sectional view of the conduction cooling type superconducting magnet device 40. This conduction cooling type superconducting magnet device 40 has the same basic structure as the above-mentioned conduction cooling type superconducting magnet device 1. .

The conduction cooling type superconducting magnet device 40 is provided with a contact / separation member 41 for allowing the superconducting coil 5 and the first cooling stage 7A of the regenerative refrigerator 7 to come and go.

The contact / separation member 41 includes a good heat conductive material plate 42.
, The contact / separation driving means 43 and the heat transfer copper rod 44.

The good heat conductive material plate 42 is made of a copper plate or the like, and is brought into contact with and separated from the heat shield plate 4 from outside thereof, so that the first refrigerator It comes into contact with and separates from the stage cooling stage 7A.

The contact / separation driving means 43 is composed of an operating rod or the like attached to the vacuum vessel 3 via an O-ring 45, and its tip is formed in a slit or the like formed in the good heat conductive material plate 42. By pressing and engaging and rotating this, it is movably driven so as to come into contact with and separate from the heat shield plate 4.

The heat-transfer copper rod 44 is threaded (male) at one end, and can be engaged with a screw hole 46 (female) formed on the outer periphery of the outer peripheral cooling copper block 11 so as to be good. it is intended to contact and separation on the outer periphery cooling copper block 11 of the outer periphery of the superconducting coil 5 in response to movement of the thermally conductive material plate 42.

Therefore, when the heat transfer copper rod 44 is moved to the outer peripheral cooling copper block 11 by rotating the contact / separation driving means 43, the good heat conductive material plate 42 comes into contact with the heat shield plate 4 and heat is transferred. When the contact and the reverse rotation are made, the good heat conductive material plate 42 is separated from the heat shield plate 4.

According to the conduction cooling type superconducting magnet device 40 having such a configuration, the good heat conduction material plate 42 can be brought into contact with the heat shield plate 4 only at the time of initial cooling, and the heat shield plate 4 and the regenerative refrigerator 7 The first cooling stage 7A and the outer peripheral cooling copper block 11 are in thermal contact with each other via the good heat conductive material plate 42 and the heat transfer copper rod 44 which are good heat conductors.

Therefore, the superconducting coil 5 and the outer peripheral cooling copper block 11 are cooled not only by the second cooling stage 7B of the regenerative refrigerator 7 but also by the first cooling stage 7A, and the cooling action is promoted. You.

After the good heat conductive material plate 42 is brought into contact with the heat shield plate 4 once, the contact / separation driving means 43 is operated in reverse rotation so that the contact / separation drive is performed during cooling by the regenerative refrigerator 7. When the temperature of the superconducting coil 5 reaches a predetermined temperature of the second cooling stage 7B, the contact / separation driving means 43 is rotated forward and reverse to improve the heat conduction. The material plate 42 and the heat shield plate 4 are thermally separated.

FIG. 6 is a graph showing the relationship between the cooling time and the temperature of the object to be cooled in the conduction cooling type superconducting magnet devices 30 and 40. It can be seen that it is shortened as compared with.

However, as shown in the figure, the temperature drop curve of the first cooling stage 7A is represented by the conduction cooling type superconducting magnet device 30.
Is faster than before, and in the case of the conduction cooled superconducting magnet device 40, it is later than before.

Next, a conduction cooled superconducting magnet device 50 according to a fourth embodiment of the present invention will be described with reference to FIGS.

FIG. 7 is a partial longitudinal sectional view of a conduction cooling type superconducting magnet device 50. The conduction cooling type superconducting magnet device 50 has the same basic structure as the above-mentioned conduction cooling type superconducting magnet device 1. .

In the conduction cooled superconducting magnet device 50, a cylindrical high-temperature superconducting magnetic shield 51 is provided around the high-temperature superconducting current lead 6.

Since the high-temperature superconducting current lead 6 has a characteristic that the current carrying capacity (current density) is deteriorated when placed in a strong magnetic field, a function of reducing the magnetism of the lead body is required.

The high-temperature superconducting magnetic shield 51 is made of an oxide high-temperature superconductor or the like, and has a structure in which the high-temperature superconducting current lead 6 is annularly covered outside the high-temperature superconducting current lead 6. By shielding the magnetism, the external magnetic field applied to the high-temperature superconducting current lead 6 is reduced.

The high-temperature superconducting magnetic shield 51 can be conductively cooled to a very low temperature by direct contact with the second cooling stage 7B of the regenerative refrigerator 7.

Specifically, the high-temperature superconducting magnetic shield 51 is fixed to the low-temperature side insulating material 21 which is in contact with the second cooling stage 7B.

With the conduction-cooled superconducting magnet device 50 having such a configuration, the high-temperature superconducting magnetic shield 51 cooled to an extremely low temperature can shield magnetism with better shielding performance.

FIG. 8 is a graph showing the magnetic shield characteristics when the high-temperature superconducting magnetic shield 51 is cooled to a temperature of 4.2K, and FIG. 9 is a graph showing the magnetic shield characteristics when the temperature is cooled to a temperature of 77K. The former completely shields the external magnetic field at 0.091 Tesla, and the latter in 0.0
It can be seen that the external magnetic field is completely shielded at 16 Tesla, and there is an approximately 6-fold difference in the shielding effect between the temperature of 4.2K and 77K.

Although not shown, a high-temperature superconductor is combined with a metal having a high thermal conductivity such as copper, silver, or aluminum to enhance the heat conduction from the cooling stage of the regenerative refrigerator 7. The cooling of the high-temperature superconducting magnetic shield 51 can be promoted, which is effective when the high-temperature superconducting magnetic shield 51 is formed from a high-temperature superconductor having a low thermal conductivity.

[0074]

As described above, according to the present invention, when the superconducting coil is cooled by the refrigerator, an auxiliary cooling mechanism or member is provided, so that the initial cooling time is shortened and the temperature distribution is reduced. It can be made uniform.

Further, since the magnetic shield of the high-temperature superconducting current lead is formed by a high-temperature superconducting magnetic shield having a low temperature, high shielding characteristics can be obtained.

[0076]

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view of a conduction cooling type superconducting magnet device 1 according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of an essential part showing a specific configuration of the outer peripheral cooling copper block 11;

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is a partial longitudinal sectional view of a conduction cooling type superconducting magnet device 30 according to a second embodiment of the present invention.

FIG. 5 is a partial longitudinal sectional view of a conduction cooling type superconducting magnet device 40 according to a third embodiment of the present invention.

FIG. 6 shows a conduction-cooled superconducting magnet device 30 and 40 of the same.
6 is a graph showing the relationship between the cooling time and the temperature of the object to be cooled.

FIG. 7 is a partial longitudinal sectional view of a conduction cooling type superconducting magnet device 50 according to a fourth embodiment of the present invention.

FIG. 8 shows a high-temperature superconducting magnetic shield 51 having a temperature of 4.2.
6 is a graph showing magnetic shield characteristics when cooled to K.

FIG. 9 shows a high-temperature superconducting magnetic shield 51 having a temperature of 77K.
5 is a graph showing the magnetic shield characteristics when cooling is performed.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 conduction cooled superconducting magnet device 2 base 3 vacuum container (cryostat) 4 heat shield plate 5 superconducting coil 6 high temperature superconducting current lead 7 regenerative refrigerator 7A first stage cooling stage of regenerative refrigerator 7A regenerative refrigerator 7 second stage cooling stage 8 external power supply 9 coil winding 9A core of coil winding 9 9B end flange of coil winding 9 10 superconducting wire 11 outer peripheral cooling copper block (cooling promoting member) 11A, 11B, 11C Arc-shaped unit block of outer peripheral cooling copper block 11 12 Electric insulating material for preventing eddy current 13 Copper sheet 14 Bolt 15 Current lead terminal 16 Normal conductive current lead wire 17 High temperature side electrode 18 Heat anchor copper wire 19 High temperature side insulating material (high temperature 20 Low temperature side electrode 21 Low temperature side insulating material (Low temperature side aluminum nitride plate) 3 Conduction cooling type superconducting magnet device 31 conduction cooling copper tube 32 liquid nitrogen injection tube 33 nitrogen gas discharge tube 34 dissimilar material joint 35 liquid nitrogen supply source 40 conduction cooling type superconducting magnet device 41 contacting / separating member 42 good heat conductive material plate 43 contact / separation Driving means (operation rod) 44 Copper rod for heat transfer (rod for heat transfer) 45 O-ring 46 Screw hole (female) formed on the outer periphery of outer peripheral cooling copper block 11 50 Conduction-cooled superconducting magnet device 51 High-temperature superconducting magnet shield

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 39/04 ZAA F25B 9/00 ZAA H01F 6/00 ZAA

Claims (6)

(57) [Claims] 1. A conduction cooling type superconducting magnet device having a refrigerator and a superconducting coil which can be cooled by the refrigerator, wherein the superconducting coil is wound around a coil winding frame and the coil winding frame. And a superconducting wire, and annularly divided cooling promoting members are uniformly arranged on the outer periphery of the superconducting wire .
With at least one eddy current prevention electrical insulator between
By Zaisa, the clamping from the outer peripheral surface of the superconducting wire, and conduction cooling type superconducting magnet apparatus characterized by contacting the superconducting coil and the cooling promoting member to the cooling stage of the refrigerator. 2. A refrigerator provided with a first stage cooling stage and a second stage cooling stage lower in temperature than the first stage cooling stage, a superconducting coil which can be cooled by the refrigerator, and the refrigerator And a heat shield plate that is in contact with and fixed to the first cooling stage and that prevents heat from entering the superconducting coil inside the conduction cooling superconducting magnet device, wherein the superconducting coil is By contacting the second stage cooling stage, and by coming into contact with the heat shield plate from the outside,
A good heat conductive material plate which comes into contact with and separates from the first cooling stage of the refrigerator via the heat shield plate; and a movably drives the good heat conductive material plate so as to come into contact with and separate from the heat shield plate. A contact / separation member comprising: a contact / separation driving means; and a heat transfer rod which contacts / separates the superconducting coil in accordance with the movement of the good heat conductive material plate. A conduction cooling type superconducting magnet device, wherein the first cooling stage and the first cooling stage can be separated from each other. 3. A conduction-cooled superconducting magnet device comprising: a refrigerator; a superconducting coil that can be cooled by the refrigerator; and a current lead that supplies power to the superconducting coil. A conduction-cooled superconducting magnet device, comprising: contacting the superconducting coil; providing a high-temperature superconducting magnetic shield around an outer periphery of the current lead; and bringing the high-temperature superconducting magnetic shield into contact with a cooling stage of the refrigerator. 4. A cooling stage for the refrigerator, comprising a first stage cooling stage and a second stage cooling stage lower in temperature than the first stage cooling stage, wherein the superconducting coil and the high-temperature superconducting magnet are provided on the second stage cooling stage. The conduction-cooled superconducting magnet device according to claim 3, wherein the shield is in contact with the superconducting magnet. 5. The high-temperature superconducting magnetic shield is made of an oxide high-temperature superconductor, and a metal having high thermal conductivity is compounded with the oxide high-temperature superconductor. Conduction cooled superconducting magnet device. 6. The conduction-cooled superconducting magnet device according to claim 5, wherein said metal having a high thermal conductivity is copper, silver, aluminum, or the like.