JPH07142245A - High-temperature superconducting magnet, its designing method, its operating method, and manufacture of high-temperature superconducting tape material - Google Patents

Abstract

PURPOSE:To provide a high-temperature superconducting magnet which can produce a strong magnetic field, its designing method, its operating method and the manufacturing method of a high-temperature superconducting tape material whose critical current is high. CONSTITUTION:The cross-sectional area of a high-temperature superconducting part for conductors 121, 122, 123 is changed for each of individual coil units 111, 112 113, critical currents of the individual coil units 11 to 113 are constituted so as to nearly coincide, and a high-temperature superconducting magnet which produces a strong magnetic field is obtained. In addition, since the edge of a high-temperature superconducting coil which is constituted by winding the conductors 121 to 123 using a high-temperature superconducting material is provided with a ferromagnetic-substance flange, it is possible to obtain the high-temperature superconducting magnet in which a drop in the density of a critical current due to the magnetic field of the conductors 121 to 123 is small and which produces a strong magnetic field. In addition, since heat-conducting members provided with heaters are inserted between the coil units, it is possible to prevent the superconducting coil from being damaged by a fire due to the concentration of energy in a part of the superconducting coil when a superconducting breakdown is caused.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high temperature superconducting magnet device.

[0002]

2. Description of the Related Art FIG. 36 is a block diagram of a conventional superconducting coil disclosed in Japanese Patent Laid-Open No. 188706/1992. In the figure, 101 is a first pancake coil in which a conductor made of a high-temperature superconducting tape material is wound, 102 is a second pancake coil wound in the opposite direction to the first pancake coil 101, and 103 is a second pancake coil. A double pancake coil in which the first pancake coil 101 and the second pancake coil 102 are connected at the winding start portion, 104 is a connecting metal member, and 105
Is a current lead and 106 is a flange.

Further, FIG. 37 is a sectional view of a conventional high temperature superconducting tape material described in a publication (Autumn 1992 Autumn Low Temperature Engineering / Superconducting Society Preliminary Report p. 17). In the figure, 5
32 is a silver sheath as a stabilizing material and has a thickness of 0.05 to
0.1 mm and 533 are high temperature superconductors with a thickness of 0.05 to
It is 0.1 mm. Examples of high-temperature superconductors include (B
i _1-x Pb _x ) Sr ₂ Ca ₂ Cu ₃ O _y is used. 534
Is the interface between the silver sheath 532 and the high temperature superconductor 533.
Such a high-temperature superconducting tape material is produced, for example, by filling a powder of the high-temperature superconductor 533 into a silver pipe, drawing and rolling. The conductor may be composed of a single high-temperature superconducting tape material or a plurality of stacked layers.

[0004]

In the conventional high temperature superconducting superconducting coil configured as described above, since the current density of the high temperature superconducting coil is constant, the pancake coil at the end where the load factor of the conductor is the highest is There was a problem that the magnetic field generated by the coil was low after quenching.

Further, in the case of quenching, since the propagation speed of quenching is slow, there is a problem that heat generation is concentrated in a part of the high temperature superconducting coil and the conductor is burnt out.

Further, the high temperature superconducting tape material has a problem that the high temperature superconducting coil cannot be firmly fixed because the critical current decreases due to strain.

Further, since the conductor made of the high-temperature superconducting tape material is not twisted, when the high-temperature superconducting coil is excited, an induced current flows through the conductor to generate a current distribution between the high-temperature superconducting tape materials, and There was a problem that it was easy to quench. Further, there is a problem that the permanent current is attenuated due to the current distribution between the high temperature superconducting tape materials.

Further, the conventional high temperature superconducting tape material has a problem that the boundary between the silver sheath and the high temperature superconductor is not smooth and the critical current is low.

The present invention has been made to solve the above problems, and a high-temperature superconducting magnet which can obtain a high magnetic field, a designing method and an operating method thereof, and a high-temperature superconducting tape material having a high critical current are manufactured. It is intended to provide a method.

[0010]

According to a first aspect of the present invention, there is provided a high temperature superconducting magnet comprising a high temperature superconducting coil in which a plurality of coil units formed by winding a conductor using a high temperature superconducting material are laminated. , Changing the cross-sectional area of the high temperature superconducting portion of the conductor for each of the coil units,
The configuration is such that the critical currents of the coil units are made to substantially match.

According to a second aspect of the present invention, there is provided a method for designing a high-temperature superconducting magnet, wherein the cross-sectional area of the high-temperature superconducting portion of the conductor according to the first aspect has a critical value of the conductor when the magnetic field strength and direction are changed. From the current density and the magnetic field distribution of the high temperature superconducting coil, the critical current density at the place where the critical current density is the lowest is found for each coil unit, and is calculated in proportion to the reciprocal thereof.

In the high temperature superconducting magnet according to the third aspect of the present invention, a tape material is used as the high temperature superconducting material, and the cross-sectional area of the conductor for each coil unit is changed by changing the number of layers or the width of the tape material. is there.

A high temperature superconducting magnet according to a fourth aspect of the present invention is such that a high temperature superconducting coil formed by winding a conductor made of a high temperature superconducting material is provided with a flange of a ferromagnetic material on an end face thereof.

A high-temperature superconducting magnet according to a fifth aspect of the present invention comprises a high-temperature superconducting coil in which a plurality of coil units formed by winding a conductor using a high-temperature superconducting material are laminated, and between the coil units. A heat conducting member provided with a heater is inserted.

A high temperature superconducting magnet according to a sixth aspect of the present invention comprises a high temperature superconducting coil formed by winding a conductor using a high temperature superconducting material, wherein electrical insulation between the conductors using the high temperature superconducting material is provided. Ceramics fibers are used for the above, and the longitudinal direction of the conductor and the fiber directions of the ceramics fibers are made substantially straight.

A high temperature superconducting magnet according to a seventh aspect of the present invention comprises a high temperature superconducting coil formed by winding a conductor using a high temperature superconducting material, wherein the high temperature superconducting coil is hardened at a temperature of about room temperature or lower. It is impregnated with the impregnating material.

A high-temperature superconducting magnet according to an eighth aspect of the present invention comprises a high-temperature superconducting coil configured by winding a conductor using a high-temperature superconducting material with an insulator interposed between the conductor and the insulator. A stress buffer material is inserted between them.

According to a ninth aspect of the present invention, there is provided a method for operating a high temperature superconducting magnet, which comprises a high temperature superconducting coil formed by winding a conductor obtained by stacking a plurality of high temperature superconducting tape materials with an insulator interposed therebetween. The coil is excited at a temperature at which the coil operating current is a substantially critical current.

In a high temperature superconducting magnet according to a tenth aspect of the present invention, the high temperature superconducting coil is provided with a heater for raising the temperature during excitation, and the heater for raising the temperature during excitation is provided when the high temperature superconducting coil is superconductingly destroyed. It also serves as a heater for forced quench.

In a high temperature superconducting magnet according to an eleventh aspect of the present invention, the high temperature superconducting coil and the permanent current switch are thermally connected, and one or both of the high temperature superconducting coil and the persistent current switch is connected. Is equipped with a heater.

A high-temperature superconducting magnet according to a twelfth aspect of the present invention is a high-temperature superconducting coil in which a plurality of coil units each formed by winding a conductor obtained by stacking a plurality of high-temperature superconducting tape materials with an insulator interposed therebetween are laminated. In the connection of the high-temperature superconducting tape material between the coil units, at least two sets of tape materials are a high-temperature superconducting tape material wound n-th from the inside of one coil unit and the other coil. By connecting the m-th (where n and m are different integers) high-temperature superconducting tape material wound from the inside of the unit, the sum of the magnetic fluxes passing through the loop formed by the high-temperature superconducting tape material becomes approximately zero. It is composed.

A high-temperature superconducting magnet according to a thirteenth aspect of the present invention comprises a high-temperature superconducting coil in which a plurality of coil units formed by winding a conductor using a high-temperature superconducting material are laminated, and between the coil units. The heat conducting member for cooling is installed in the vicinity of the connecting portion of the conductor.

In the high temperature superconducting magnet according to the fourteenth aspect of the present invention, a heat conducting member for cooling is installed at a connecting portion between the high temperature superconducting coil and the coil supporting member.

A high temperature superconducting magnet according to a fifteenth aspect of the present invention is a high temperature superconducting magnet comprising a high temperature superconducting coil and a permanent current switch using a high temperature superconducting material, wherein the permanent current switch is higher than an operating temperature of the superconducting coil. It is arranged in a medium temperature space lower than the critical temperature of the high temperature superconducting material.

A high-temperature superconducting magnet according to a sixteenth aspect of the present invention is configured such that a magnetic field is applied substantially parallel to the c-axis direction of the crystal of the high-temperature superconducting material of the persistent current switch to operate the persistent current switch. Is.

According to a seventeenth aspect of the present invention, in the high temperature superconducting magnet according to the sixteenth aspect, the means for applying a magnetic field substantially parallel to the c-axis direction of the crystal of the high temperature superconducting material of the permanent current switch is a coil. Is.

The high-temperature superconducting magnet according to the eighteenth aspect of the present invention comprises a permanent current switch using a film material of the high-temperature superconductor.

In the method for producing a high temperature superconducting tape material according to the nineteenth aspect of the present invention, a high temperature superconducting layer is formed on a metal tape, and another metal tape is formed on the metal tape having the high temperature superconducting layer formed thereon. The above two metal tapes and the high temperature superconductor layer are integrated by stacking and pressing.

According to a twentieth aspect of the present invention, in the method for producing a high temperature superconducting tape material according to the nineteenth aspect, the metal tape has a groove and the high temperature superconductor layer is formed in the groove. is there.

[0030]

According to the first aspect of the present invention, since the cross-sectional area of the high temperature superconducting portion of the conductor is changed for each coil unit so that the critical currents of the coil units are substantially equal to each other, the high temperature superconducting magnetic field having a high magnetic field is generated. You can get a magnet.

According to a second aspect of the present invention, the cross-sectional area of the high temperature superconducting portion of the conductor according to the first aspect is the critical current density of the conductor and the high temperature superconducting coil of the high temperature superconducting coil when the strength and direction of the magnetic field are changed. From the magnetic field distribution, the critical current density at the location where the critical current density is the lowest is found for each coil unit, and is found in proportion to its reciprocal, so that the critical currents of the coil units can be matched well.

According to the third aspect of the present invention, a tape material is used as the high temperature superconducting material, and the cross-sectional area of the conductor is changed for each coil unit by changing the number of layers or the width of the tape material. A high temperature superconducting magnet can be obtained.

In the invention of claim 4, since the high temperature superconducting coil formed by winding the conductor using the high temperature superconducting material is provided with the flange of the ferromagnetic material on the end face, the critical current density due to the magnetic field of the conductor is provided. It is possible to obtain a high temperature superconducting magnet with a small decrease in the magnetic field and a high generated magnetic field.

According to the fifth aspect of the invention, since the heat conducting member provided with the heater is inserted between the coil units,
When the superconducting breakdown occurs, the heat conducting member is heated by the heater to cause the entire high temperature superconducting coil to undergo superconducting destruction, so that the entire superconducting coil absorbs energy, and the energy is concentrated on a part of the superconducting coil, so that the superconducting coil is Prevent burning.

According to the sixth aspect of the present invention, the ceramic fiber is used for electrical insulation between the conductors using the high temperature superconducting material, and the longitudinal direction of the conductor and the fiber direction of the ceramic fiber are substantially oriented. And the coefficient of thermal expansion of the ceramic fibers perpendicular to the fiber direction are substantially the same, so that the critical current of the conductor can be prevented from lowering and a high-temperature superconducting magnet with a high generated magnetic field can be obtained.

In the invention of claim 7, since the high temperature superconducting coil is impregnated with an impregnating material which is hardened at a temperature of about room temperature or lower, the hardening temperature and the temperature are higher than those when an impregnating material which is hardened by raising the temperature is used. A temperature difference from the operating temperature of the superconducting coil can be reduced, distortion after cooling is reduced, and reduction in the critical current of the conductor can be reduced, so that a high-temperature superconducting magnet with a high generated magnetic field can be obtained.

According to an eighth aspect of the present invention, in a high temperature superconducting coil which is formed by winding a conductor using a high temperature superconducting material with an insulator interposed therebetween, a stress buffer is provided between the conductor and the insulator. Since the material is inserted, when the high temperature superconducting coil is cooled, the strain of the conductor is absorbed by the stress cushioning material due to the difference in the coefficient of thermal expansion between the conductor and the insulating material, and the strain is relaxed. It is possible to obtain a high-temperature superconducting magnet that can prevent a decrease in current and generate a high magnetic field.

According to a ninth aspect of the present invention, there is provided a high temperature superconducting coil formed by winding a conductor obtained by stacking a plurality of high temperature superconducting tape materials with an insulator interposed therebetween, and the coil operating current is a substantially critical current. Since the coil is excited at a certain temperature, when the high temperature superconducting coil is completely excited, the current flowing through each high temperature superconducting tape material has almost the same current value. In this state, if the temperature of the high-temperature superconducting coil is lowered to the operating temperature, superconducting breakdown is unlikely to occur even if disturbance occurs in each tape material. Furthermore, when the current value flowing in each tape material is different, the current moves from the larger one to the smaller one,
Since the moving current passes through the normal conducting part, the total current decreases slightly, but when the same amount of current flows, the current does not move and the total current does not decrease.

According to the tenth aspect of the present invention, the heater for raising the temperature during excitation also serves as a heater for forcible quenching when the high temperature superconducting coil is destroyed by superconductivity, so that the number of heaters can be reduced.

In the eleventh aspect of the present invention, the high-temperature superconducting coil and the persistent current switch are thermally connected, and a heater is provided at a connecting portion of either or both of the high-temperature superconducting coil and the persistent current switch. Because
When exciting the high temperature superconducting coil, the temperature of the persistent current switch and the high temperature superconducting coil can be raised simultaneously.

According to a twelfth aspect of the present invention, there is provided a high temperature superconducting coil in which a plurality of coil units each formed by winding a conductor obtained by stacking a plurality of high temperature superconducting tape materials with an insulator interposed therebetween are stacked. In the connection of the above-mentioned high temperature superconducting tape material between the coil units, at least two sets of tape materials include a high temperature superconducting tape material wound n-th from the inside of one coil unit and from the inside of the other coil unit. By connecting the m-th (where n and m are different integers) high-temperature superconducting tape material wound up, the sum of magnetic fluxes passing through the loop made by the high-temperature superconducting tape material is configured to be substantially zero. When the high-temperature superconducting coil is excited, the induced current due to the change in the magnetic field does not occur in the high-temperature superconducting tape materials, and the same size is applied to each of the superposed high-temperature superconducting tape materials. Since the current flows of high-temperature superconducting coil is hard to superconducting destroyed. Furthermore, since no induced current is generated, the excitation speed can be increased.

According to the thirteenth aspect of the present invention, since the heat conduction member for cooling is installed in the vicinity of the connection portion of the conductor between the coil units, the connection portion or the resistance of the connection member during excitation of the high temperature superconducting coil causes connection portion. The heat generated in the high temperature superconducting coil can be quickly removed, the temperature rise of the high temperature superconducting coil can be prevented, and the superconducting breakdown can be prevented.

In the fourteenth aspect of the present invention, since the heat conducting member for cooling is installed at the connecting portion between the high temperature superconducting coil and the coil supporting member, the coil container is usually at room temperature or substantially liquid nitrogen temperature, It is possible to prevent heat from being transferred to the high-temperature superconducting coil via the support member and prevent a temperature rise of the high-temperature superconducting coil, and to obtain a high-temperature superconducting magnet which is hard to quench.

In the invention of claim 15, the permanent current switch is arranged in an intermediate temperature space which is higher than the operating temperature of the superconducting coil and lower than the critical temperature of the high-temperature superconducting material. It suffices to change the temperature of the current switch between the above intermediate temperature and the critical temperature,
As the switch speed increases, the heat quantity of the heater required to operate the permanent current switch can be reduced.

In the sixteenth aspect of the present invention, since the magnetic field is applied substantially parallel to the c-axis direction of the crystal of the high temperature superconducting material of the permanent current switch to operate the permanent current switch, the magnetic field is c When it is parallel to the axis, the decrease in the critical current density due to the magnetic field becomes more remarkable, and the permanent current switch can be operated even when the magnetic field is weak.

In the seventeenth aspect of the present invention, the permanent current can be easily obtained by using the coil to apply the magnetic field substantially parallel to the c-axis direction of the crystal of the high temperature superconducting material of the permanent current switch according to the sixteenth aspect. The switch can be operated.

According to the eighteenth aspect of the invention, since the permanent current switch using the film material of the high temperature superconductor is provided,
Since the critical current density is higher than that of winding a wire as in the past, the cross-sectional area of the film material may be small and the resistance value generated when it is no longer a superconductor is high. Can be made smaller.

In a nineteenth aspect of the present invention, a high temperature superconductor layer is formed on a metal tape, and another metal tape is stacked on the metal tape having the high temperature superconductor layer formed thereon and pressed, whereby Since the high temperature superconducting tape material is manufactured by integrating the two metal tapes and the high temperature superconducting layer, the interface between the metal tape and the high temperature superconducting material is smooth, and the particles of the high temperature superconducting material are thin plates and pressed. Since the azimuths are aligned with each other, the intergranular bonds of the high temperature superconductor are strengthened, and a high temperature superconducting tape material having a high critical current can be obtained.

According to a twentieth aspect of the invention, in the manufacturing method according to the nineteenth aspect, the metal tape has a groove,
Since the high temperature superconductor layer is formed in the groove, in addition to the above effects, the high temperature superconductor layer can be reliably covered with the metal tape, and a high temperature superconducting tape material having a uniform thickness can be obtained.

[0050]

【Example】

Example 1. FIG. 1 (a) is a perspective view showing a partial cross section of a high temperature superconducting coil according to an embodiment of the invention of claims 1 and 2.
(B) is sectional drawing which expands and shows the cross section of the conductor of (a). In the figure, 121, 122, 123 are conductors having different conductor cross-sectional areas, 111, 112, 113 are coil units produced by winding the conductors 121, 122, 123, respectively, and 110 is a coil unit 111, 11
This is a high temperature superconducting coil produced by laminating 2 and 113 via an insulator 100 made of, for example, an alumina plate, and conductors are connected to each other between coil units. The conductors 121, 122, 123 are wound around an insulator made of alumina fiber, for example.

FIG. 2 is a diagram for explaining the first embodiment, in which (a) is a high temperature superconducting conductor (Bi at a temperature of 5K).
FIG. 3 is a characteristic diagram showing the magnetic field strength and angle dependence of the critical current density of _1-x Pb _x ) Sr ₂ Ca ₂ Cu ₃ O _y , where the angle is perpendicular to the longitudinal direction of the tape and is parallel to the surface of the tape. Case 0
Degrees are 90 degrees when vertical. Further, (b) is an explanatory view showing the magnetic field distribution in the winding portion of the high temperature superconducting coil, showing only one side cross section, and the arrows indicate the strength and direction of the magnetic field. High temperature superconducting coil 1 configured as described above
When electricity is applied to 10, a magnetic field shown in FIG. 2B is generated in the conductor part of the high temperature superconducting coil 110. From the critical current density of the conductor and the magnetic field distribution of the high temperature superconducting coil 110 when the strength and direction of the magnetic field are changed, the coil unit 111,
The critical current density of the place where the critical current density is the lowest is calculated for each 112 and 113, and the conductor 1 is proportional to the reciprocal of the critical current density.
The conductor cross-sectional areas of 21, 122 and 123 are determined. As a result, the critical currents of the conductors 121, 122, 123 become substantially the same, the high temperature superconducting coil 110 exhibits the performance of the conductor, and the magnetic field generated by the high temperature superconducting coil is increased.

For example, the coil unit 1 having an inner diameter of 20 mm, an outer diameter of 80 mm, a coil height of 5 mm, and a constant conductor cross-sectional area.
In a high temperature superconducting coil 110 in which eight 11 are laminated,
The generated magnetic field was 0.6 Tesla. When the ratio of the critical currents of the coil units is from the end coil unit to the center coil unit in the order of, for example, 1: 1.1: 1.3: 1.5, it can be seen that the end coil unit is quenched. . Therefore, the cross-sectional area of the conductor of the coil unit is set to 1: 0.
If it is set to 9: 0.8: 0.7, the ratio of the critical current of each coil unit will be about 1: 1: 1: 1, and the magnetic field generated by the high temperature superconducting coil will be about 0.8 Tesla.

Example 2. FIG. 3A shows claims 1 and 2.
It is another embodiment of the described invention, which is a racetrack type high temperature superconducting coil 153 mounted on a magnetic levitation railway, and as shown in an enlarged view in FIG.
The cross-sectional areas of the conductors 1, 112, 113 are changed to 1: 0.7: 0.5 in the order of the coil units 111, 112, 113. As described above, in the coil 153 mounted on the magnetically levitated railway that is levitating, the conductor capacity can be sufficiently exhibited by changing the conductor cross-sectional area for each coil unit, so that the high temperature superconducting coil 153 can be lightened. In addition,
Reference numeral 151 denotes a thermoelectric conductive member inserted between the coil units, which is shown in FIG.
Will be described in detail.

Example 3. Next, in an embodiment of the invention described in claim 3, when the conductor is composed of a high-temperature superconducting tape material, the case where the cross-sectional area is changed by changing the number of laminated tape materials 130 is shown in FIG. , (B). The critical current density of one high-temperature superconducting tape material 130 is such that the tape thickness of the high-temperature superconducting tape material 130 is 0.1 mm to 0.2 m.
Since the maximum is about m, the tape thickness of the high temperature superconducting tape material 130 cannot be changed greatly. Therefore, if the number of laminated high-temperature superconducting tape materials is changed for each of the conductors 131, 132, 133, the conductor cross-sectional area can be changed for each of the conductors 131, 132, 133 without lowering the critical current density. The effect of can be obtained.

Example 4. FIG. 5 shows another embodiment of the invention described in claim 3 in which the widths of the conductors 141, 142 and 143 are changed. In this example, the conductors 141, 142,
Since the thickness of 143 is constant, the cross-sectional area of the conductor can be changed without changing the outer diameter of the coil.
It can be changed every 2 and 113, and the coil design becomes easy.

Needless to say, the cross-sectional area of the conductor may be changed by changing both the width and the number of layers of the high temperature superconducting tape material.

Example 5. As another embodiment of the invention described in claims 1 and 2, the ratio of the superconductor 533 and the stabilizing material 532 of the conductor as shown in FIG. 37 may be changed. In this case, there is an advantage that the distribution of the magnetic field does not change because the coil shape and the number of turns do not change.

Example 6. FIG. 6 shows an embodiment of the invention as set forth in claim 4, wherein both ends of a high temperature superconducting coil in which a plurality of high temperature superconducting coil units 111 using a high temperature superconducting tape material are laminated are made of iron, such as a silicon steel plate, as a ferromagnetic material. It is a high temperature superconducting magnet with a flange 160 of No. 1 attached.

FIG. 7A shows that when the flange 160 is provided,
(B) is explanatory drawing which shows the mode of the magnetic flux of each coil winding part when there is no flange 160. In the figure, arrows indicate the direction and magnitude of magnetic flux. If there is a flange 160,
Since the magnetic field is directed to the flange 160, the component of the magnetic flux perpendicular to the high temperature superconducting tape material 130 is smaller than in the case without the flange 160. Therefore, the high temperature superconducting tape material 130
The decrease in the critical current density due to the magnetic field is small, and the magnetic field generated by the high temperature superconducting magnet is increased.

Example 7. FIG. 8 (a) is another embodiment of the invention according to claim 4, in which one side of a racetrack type high temperature superconducting coil 153 mounted on a magnetic levitation railway is provided.
As shown in an enlarged view in (b), it is a high temperature superconducting magnet to which an iron flange 160 is attached. This allows
It is possible to reduce locations where the critical current is low.

Example 8. In the seventh embodiment, the flange 160 is a donut type and is installed only near the winding portion of the high temperature superconducting coil 153. However, an elliptical plate shape may be provided on the entire one side of the high temperature superconducting coil. In this case, in addition to the effect of the seventh embodiment, if the side to which the flange 160 is attached is the inside of the vehicle of the magnetic levitation railway, the effect of reducing the magnetic field leaking into the vehicle body can be obtained.

Example 9. FIG. 9 shows an embodiment of the invention described in claim 5, in which a heat conducting member 151 provided with a heater 152 is inserted between coil units. In such a structure, when the superconducting destruction is detected in a part of the high temperature superconducting coil, the heater 152 heats the heat conducting member 151 to cause the entire high temperature superconducting coil 110 to undergo the superconducting destruction. This makes it possible to prevent the energy stored in the high-temperature superconducting coil from being absorbed by the entire superconducting coil and prevent the high-temperature superconducting coil from being burned due to the concentration of energy in a part of the high-temperature superconducting coil.

Example 10. Further, as another embodiment of the invention according to claim 5, in the high temperature superconducting coil 153 operated with a permanent current as shown in FIG. 3A, the energy of the high temperature superconducting coil 153 in the case of superconducting breakdown is transferred to the outside. Since it cannot be taken out, a heat conducting member 151 provided with a heater 152 is inserted between the coil units 111, 112, 113 as shown in FIGS. 3B and 3C, and the high temperature superconducting coil 153 absorbs energy as a whole. This is especially effective.

Example 11. FIG. 10 (a) is a perspective view showing an embodiment of the invention according to claim 6 in a partially cutaway manner, and FIG. 10 (b) is an enlarged perspective view showing a main part of FIG. 10 (a). In this example, alumina fibers 203 are used as ceramic fibers for electrical insulation between the conductors 121, and the fiber direction is the conductor 12
It is fixed with an impregnating material so as to be oriented almost directly in the longitudinal direction of 1.
FIG. 11 shows a conductor 121, an alumina fiber 203, and a resin as an impregnating material (for example, Stycast 126 manufactured by Grace Co.
6) and the coefficient of thermal expansion of the composite material of the alumina fiber 203 and the resin, the coefficient of thermal expansion of the conductor 121 and that of the composite material parallel to the fiber direction are different, so that the critical current of the conductor decreases due to thermal strain during cooling. However, since the coefficient of thermal expansion of the conductor 121 and that of the composite material in the fiber direction are substantially the same, the critical current of the conductor 121 does not decrease.

The ceramic fiber 203 is not limited to the alumina fiber as long as it can withstand the temperature at which the high temperature superconducting coil is fired, and any ceramic fiber 203 may be used. And the coefficient of thermal expansion of the composite material are selected to be approximately the same. In addition, the conductor 121 and the composite material 2 when the high temperature superconducting coil 110 is cooled
The strain due to the difference in thermal expansion coefficient of 01 is practically no problem as long as it is about 0.1% or less.

Example 12 Further, as described in claim 7, when the impregnating material is a material that cures at a temperature of about room temperature or lower, such as an epoxy resin, the curing temperature is higher than that when an impregnating material that raises the temperature and cures is used. The temperature difference between the operating temperature of the high temperature superconducting coil can be reduced, the strain after cooling can be reduced, and the decrease in the critical current of the conductor 121 can be reduced, so that the magnetic field generated by the high temperature superconducting coil can be increased.

Example 13 FIG. 12 (a) is a perspective view showing a partially broken superconducting coil according to another embodiment of the present invention, and FIG. 12 (b) is an enlarged perspective view showing an essential part of (a). . In this example, for example, two layers of alumina fibers 203 are arranged all around the conductor 121 made of a high-temperature superconducting tape material for electrical insulation. In the case of this embodiment as well,
As in the case of No. 1, there is an effect that the reduction of the critical current of the conductor can be prevented. In a superconducting coil in which a plurality of coil units 111 are stacked as shown in FIG. 10, by arranging ceramic fibers not only on the side surface of the conductor 121 but also on the entire circumference, the insulating plate 1 inserted between the coil units 111 can be formed.
00 can be omitted.

Example 14 FIG. 13A is a perspective view showing a partially cutaway superconducting coil according to an embodiment of the present invention. In this example, as shown in an enlarged view in FIG. 13B, since the stress buffer material 301 made of, for example, silver, copper, SUS, or the like is inserted between the conductor 121 and the insulating material 202 made of, for example, an alumina plate. When the high-temperature superconducting coil is cooled, the stress buffer material 301 absorbs the strain of the conductor 121 due to the difference in the coefficient of thermal expansion between the conductor 121 and the insulating material 202, and the strain of the conductor 121 is relaxed. The decrease in critical current is eliminated, and the magnetic field generated by the high temperature superconducting coil can be increased. If the stress buffer material 301 is made of silver or copper having excellent thermal conductivity, the heat generated between the conductor 121 and the insulating material 202 is quickly diffused.
The stability of the high temperature superconducting coil is increased.

Example 15 In addition, although the stress buffering material 301 is provided on both sides of the insulating material 202 in the fourteenth embodiment, as another embodiment of the invention described in claim 8, even if the stress buffering material 301 is provided on only one side, the critical current decreases. It is clear that the amount can be reduced.

Example 16. FIG. 14 (a) is a partially cutaway perspective view showing still another embodiment of the present invention. In this example, as shown in an enlarged view of the main part in FIG. 14B, the outer circumference of the conductor 121 is surrounded by the stress buffer material 302, and the outer circumference of the stress buffer material 302 is surrounded by the insulating material 202. Also in this case, the same effect as that of the fourteenth embodiment can be obtained.

Example 17 FIG. 15 is an explanatory view for explaining an operating method of a high temperature superconducting magnet according to an embodiment of the invention described in claim 9, and is a high temperature superconducting coil formed by winding a conductor produced by stacking two high temperature superconducting tape materials. The case of exciting will be described. The two high-temperature superconducting tape materials were designated as tape a and tape b, and the currents flowing through them were designated as current a and current b, respectively. 15 (a), (b)
Indicates a case where the coil is excited at a temperature T ₁ which is higher than the operating temperature of the high temperature superconducting coil by a temperature margin of the conductor, (c),
(D) shows the case of exciting at the operating temperature T ₀ of the high temperature superconducting coil. Here, the difference between the temperature T _{1 at} which the coil operating current becomes a critical current and the coil operating temperature T ₀ is the temperature margin.

As shown in FIGS. 15 (c) and 15 (d), the operating temperature T ₀ of the high temperature superconducting coil, as is generally done.
When excited by, the induced current due to the self-magnetic field of the high temperature superconducting coil flows in the conductor as the total current increases, and a difference occurs between the current a and the current b. The current a corresponds to the operating temperature of the high temperature superconducting coil. Is saturated with the current. This current is larger than half of the operating current value A of the high temperature superconducting coil, which is 2 / 1A.
This causes a difference between the current a and the current b after the high temperature superconducting coil is excited. In this state, even if a slight disturbance is applied to the tape material a, the high temperature superconducting coil will be destroyed by superconductivity. Therefore, as shown in FIGS. 15A and 15B, when excited at a temperature T ₁ higher than the operating temperature of the high temperature superconducting coil by the temperature margin of the conductor, the current value at which the current a saturates is high. Half the operating current value A of 2 / 1A
Becomes When the excitation of the high temperature superconducting coil is completed, the current b has the same current value as the current a. In this state, if the temperature of the high temperature superconducting coil is lowered to the operating temperature, superconducting breakdown is unlikely to occur even if disturbance occurs on both tape a and tape b. In this example, the case where there are two high temperature superconducting tape materials has been described, but the present invention is not limited to this, and the same effect as this example can be obtained even when there are three or more high temperature superconducting tape materials.

Further, FIG. 16 shows the time variation of the current when the high temperature superconducting coil is made a permanent current at time T after the excitation. FIGS. 16 (a) and 16 (b) relate to an embodiment of the invention of claim 9 and show a case where permanent current is applied after excitation at a temperature higher than the operating temperature of the high temperature superconducting coil by a temperature margin of the conductor, ) (D) shows the case where a permanent current was applied after excitation at the operating temperature of the high temperature superconducting coil. FIG.
In (c) and (d), since the current a and the current b are different, the current moves from the tape a to the tape b, and the moving current passes through the normal conducting portion, so that the total current decreases slightly. On the other hand, in FIGS. 16A and 16B, the current a is equal to the current b and the current does not move, so that the total current does not decrease.

Example 18. Next, an embodiment of the invention described in claim 10 will be described. In this example, as shown in FIG. 9, for example, the high temperature superconducting coil is provided with a heater 152 for raising the temperature during excitation, and the heater for raising the temperature during excitation is for forced quench when the high temperature superconducting coil is destroyed by superconductivity. Also serves as a heater. By the heater 152, the temperature of the high temperature superconducting coil can be increased by a temperature margin from the operating temperature of the high temperature superconducting coil during excitation, and a high temperature superconducting magnet which is hard to be broken by superconducting can be obtained without increasing the number of heaters.

Example 19 FIG. 17 is a block diagram for explaining a high temperature superconducting magnet according to an embodiment of the invention as set forth in claim 11, in which 110 is a high temperature superconducting coil,
Reference numeral 404 is a permanent current switch, 360 is a heat conducting member 360, 152 for thermally connecting the permanent current switch 404 and the high temperature superconducting coil 110, and heaters attached to the heat conducting member 360. When the high-temperature superconducting coil 110 is excited in the thus-configured one, the heater 15
By heating the heat conducting member 151 by 2, the temperature of the persistent current switch 404 and the high temperature superconducting coil 110 can be raised simultaneously. In this example, the heater 152 is provided in the heat conducting member 360, but the present invention is not limited to this, and the heater 152 may be provided in the high temperature superconducting coil 110 or the persistent current switch 404.

Example 20. FIG. 18 shows an embodiment of the invention according to claim 12, and as shown in a perspective view in (a),
A coil unit A311 configured by winding a conductor obtained by stacking two high temperature superconducting tape materials 341 and 342 with an insulator interposed therebetween, and the coil unit A311 configured in the same manner.
The present invention relates to a method of connecting the high temperature superconducting tape materials to each other and another coil unit B to be laminated. That is, as shown in (b), in the connection of the above-mentioned high temperature superconducting tape material between the coil units A, B 311, 312, two sets of tape materials were wound first from the inside of one coil unit. High temperature superconducting tape material 3
By connecting 41 and 343 to the high-temperature superconducting tape materials 342 and 344 that are rolled up second from the inside of the other coil unit, the sum of the magnetic fluxes that penetrate through the loop formed by the high-temperature superconducting tape material becomes approximately zero. It is configured as follows. In addition, 105 is an electrode lead and 330 is a connection part. This connection cancels the voltage induced in the regions A and B when the high-temperature superconducting coil is excited, so that the induced current due to the change in the magnetic field does not occur in the high-temperature superconducting tape material. Therefore, since the currents evenly flow through the high temperature superconducting tape 341 and the high temperature superconducting tape 342, and between the high temperature superconducting tape 343 and the high temperature superconducting tape 344, the high temperature superconducting coil is less likely to undergo superconducting breakdown. Moreover, since no induced current is generated, the excitation speed can be increased.

Example 21. 19 and 20 show another embodiment of the invention according to claim 12, and coil units 311, 312, 313, 31 having the same structure as in FIG. 18 (a).
4 is a connection example in the case of 4 pieces, and in these examples as well, the sum of the magnetic fluxes passing through the loop made by the high temperature superconducting tape material is configured to be substantially zero, and there is the same effect as in the above-mentioned Example 20. .

Example 22. 21 and 22 show another embodiment of the invention according to claim 12, which is a coil unit formed by winding a conductor in which three sheets of high temperature superconducting tape materials 341, 342 and 343 are superposed with an insulator interposed therebetween. 21 shows two 311, 312, and FIG. 22 shows three 311, 31
This is a connection example in the case of 2, 313. In FIG. 21,
High temperature superconducting tape material 341 rolled first from the inside of one coil unit, high temperature superconducting tape material 343 rolled third from the inside of the other coil unit, high temperature superconducting tape material rolled second from the inside. 342,
And the third high-temperature superconducting tape material 3 from the inside
43 and the high-temperature superconducting tape material 3 rolled up from the inside 3
In FIG. 22, the high-temperature superconducting tape material 341 rolled from the inside of one coil unit and the other from the inside of the other coil unit are connected to each other in FIG.
Second high temperature superconducting tape material 342, 2 from inside
High-Tc superconducting tape material 342 wrapped around the third and 3 from the inside
The high-temperature superconducting tape material 343 wound in the third order, the high-temperature superconducting tape material 343 wound in the third order from the inside, and the high-temperature superconducting tape material 341 wound in the first order from the inside are respectively connected. Also in these examples, the sum of magnetic fluxes passing through the loop formed by the high temperature superconducting tape material is set to be substantially zero, and the same effect as that of the above-mentioned Example 20 is obtained.

Example 23. 23 and 24 show still another embodiment of the invention according to claim 12, which is constructed by winding a conductor in which four sheets of high temperature superconducting tape materials 341, 342, 343 and 344 are superposed with an insulator interposed therebetween. This is an example of connection when there are two coil units. In FIG. 23, the high-temperature superconducting tape material 341 rolled first from the inside of one coil unit, the high-temperature superconducting tape material 342 rolled second from the inside of the other coil unit, and the second winding roller from the inside. High temperature superconducting tape material 342, high temperature superconducting tape material 341 wound first from the inside, high temperature superconducting tape material 343 wound third from the inner side, high temperature superconducting tape material 344 wound from the fourth inside, and inner side The fourth high temperature superconducting tape material 344 and the third high temperature superconducting tape material 343 wound from the inside are connected to each other, and in FIG. High temperature superconducting tape material 341 and the other coil unit, the high temperature superconducting tape material 344 rolled up from the inside of the other coil unit, the second from the inside High-temperature superconducting tape material 342 wound up, high-temperature superconducting tape material 343 wound third from the inside, high-temperature superconducting tape material 343 wound third from the inside, and high-temperature superconducting tape material 342 wound second from the inside. , And 4 from the inside
High-temperature superconducting tape material 344 wrapped around the second and 1 from the inside
The high-temperature superconducting tape material 341 wound in the second order is connected to each. Also in these examples, the sum of magnetic fluxes passing through the loop formed by the high temperature superconducting tape material is set to be substantially zero, and the same effect as that of the above-mentioned Example 20 is obtained.

As described above in Examples 20 to 23, the high temperature superconducting coil is formed by laminating a plurality of coil units formed by winding a conductor in which a plurality of high temperature superconducting tape materials are superposed with an insulator interposed therebetween. With
In the connection of the high temperature superconducting tape material between the coil units, at least two sets of tape materials include a high temperature superconducting tape material wound nth from the inside of one coil unit and m from the inside of the other coil unit. If the sum of the magnetic fluxes passing through the loop made by the high temperature superconducting tape material is made substantially zero by connecting the second high temperature superconducting tape material (where n and m are different integers), they will be superposed. In addition, since the current flows through each of the high-temperature superconducting tape materials evenly, the high-temperature superconducting coil is less likely to undergo superconducting breakdown, and since no induced current is generated, the exciting speed can be increased.

Example 24. FIG. 25 shows an embodiment of the invention according to claim 13 and is an example in which a heat conduction member for cooling is installed in the vicinity of the connecting portion of the conductor between the coil units. In this example, the connecting portions between the coil units 111 are collected at two places, and the heat conducting member 360 connected to the refrigerator is installed near the connecting member 351. When the high temperature superconducting coil is excited, the connection portion and the resistance of the connecting member 351 generate heat in the connection portion, but since the heat conducting member 360 is installed in the vicinity of the connection portion, the heat generation can be quickly removed and the temperature rise of the high temperature superconducting coil can be prevented. It is possible to prevent it, and the high temperature superconducting coil is hard to be broken by superconductivity.

Example 25. FIG. 26 shows an embodiment of the invention set forth in claim 14, in which 360 is a thermoconductive member, 361 is a coil support member, and 370 is a container for housing the coil. In this example, the heat conducting member 360 connected to the refrigerator is connected to the coil supporting member 361, and the heat conducting member 360 is connected to the high temperature superconducting coil 110. In this way, since the high temperature superconducting coil 110 and the coil supporting member 361 are connected via the heat conducting member 360, normally,
From the coil container 370 at room temperature or substantially liquid nitrogen temperature, the high temperature superconducting coil 1 via the coil supporting member 361.
High-temperature superconducting coil 11 capable of significantly reducing heat transmitted to 10
A high temperature superconducting magnet that can prevent a temperature rise of 0 and is hard to quench is obtained.

Example 26. As another embodiment of the fourteenth aspect of the present invention, the high temperature superconducting coil 110 and the coil supporting member 361 may be connected, and the heat conducting member 360 for cooling may be installed in the vicinity of the connected portion. In this case, in addition to the effect similar to that of Example 25, the high temperature superconducting coil 11
0 and the coil support member 361 can be firmly fixed.

Example 27. 27 shows an embodiment of the invention according to claim 15, wherein 401 is a low temperature space below the liquid nitrogen temperature in which the high temperature superconducting coil 110 is housed, and 402 is a high temperature superconducting material higher than the operating temperature of the superconducting coil 110. Is a medium temperature space lower than the critical temperature, 403 is a room temperature space, 404 is a permanent current switch connected in parallel with the high temperature superconducting coil 110 and made of a high temperature superconductor having a critical temperature of 80K to 150K, and 405 is a high temperature superconducting coil 11.
A power source for exciting 0, 406 is a heater for raising the temperature of the permanent current switch 404. High temperature superconducting coil 1
Reference numeral 10 is a low temperature space 401 below the liquid nitrogen temperature, permanent current switch 404 is a medium temperature space 402, and power source 405 is a room temperature space 403. Thus, the permanent current switch 404 is installed in the medium temperature space higher than the operating temperature of the superconducting coil and lower than the critical temperature of the high temperature superconducting material, that is, in the substantially liquid nitrogen temperature space 402 close to 80K to 150K which is the critical temperature of the high temperature superconductor. Therefore, in order to operate the persistent current switch 404, the temperature of the persistent current switch 404 may be changed between approximately the liquid nitrogen temperature and the critical temperature, and the switch speed becomes faster. Also, the heater 406 required to operate the permanent current switch 404 is
It requires less heat.

FIG. 28 shows the temperature dependence of the critical current density of the Bi type high temperature superconducting tape material. At approximately liquid nitrogen temperature, the critical current density of the high temperature superconducting tape material drops sharply due to the magnetic field and becomes almost zero. The permanent current switch 404 can be operated by the magnetic field. In this case, the permanent current switch 40
Since the temperature of No. 4 has not risen, the operation of the permanent current switch by the magnetic field can be instantaneously performed.

Example 28. FIG. 29 shows claims 16 and 1.
7 shows an embodiment of the invention described in 7, wherein 421 is a coil, 422 is a high temperature superconductor, 423 is a magnetic field, 424.
Is the c-axis of the high temperature superconductor 422. 6 shown in FIG.
As is clear from the change in the critical current density when the magnetic field is applied parallel to and perpendicular to the c-axis 424 of the high temperature superconductor 422 at 3 K, the magnetic field 42 is generated by the coil 421.
When 3 is applied in parallel to the c-axis 424 of the high temperature superconductor 422, the decrease in the critical current density due to the magnetic field 423 becomes more remarkable, and the permanent current switch can be operated even if the magnetic field 423 is weak. Note that FIG. 28 shows the difference in change in the critical current density between when the magnetic field at 63K is applied parallel to the c-axis 424 of the high-temperature superconductor 422 and when it is applied vertically, but the present invention is not limited to 63K and other temperatures are used. But there is a similar tendency.

Example 29. Note that, although the case where the magnetic field is applied by the coil is shown in the 28th embodiment, the 16th embodiment
As another embodiment of the described invention, a permanent magnet may be used and the permanent current switch 404 may be operated by changing the distance between the permanent magnet and the high temperature superconductor.

Example 30. FIG. 30 is a perspective view showing the structure of a permanent current switch according to an embodiment of the present invention. In the figure, 411 is a substrate, for example, Sr
It is made of TiO ₃ (strontium titanate). 412
Is a film material of a high temperature superconductor, and is made of, for example, YSZ (yttrium stabilized zirconia), and is sputtered or C
It is formed to a thickness of about 1 μm by the VD method or the like. Conventionally, as a permanent current switch, for example, as shown in FIG. 31, a plurality of NbTi wires 413 are cored with CuNi 414 into a linear shape and wound into a coil, and a heater for heating is provided on the outer circumference of the coil. Was used, and the area around this was covered with, for example, an epoxy resin, but it had a large volume as a whole. On the other hand, FIG.
As in the embodiment shown in FIG.
If so, the critical current density is higher than in the case of winding a wire, the cross-sectional area of the film material is small, and the resistance value generated when it is no longer a superconductor is high, so the volume of the permanent current switch is small. it can.

Example 31. 32 is a manufacturing process diagram for explaining a method of manufacturing a high temperature superconducting tape material according to an embodiment of the present invention. In the figure, 511 is a high temperature superconductor layer, 522 is a metal tape or silver tape, and these high temperature superconductor layer 511 and silver tape 522
Both have a thickness of about 0.05 to 1 mm. In the method of manufacturing the high temperature superconducting tape material, first, the high temperature superconductor layer 511 is formed on the silver tape 522 by screen printing, for example. Then, by heating at about 300 ° C., impurities such as a solvent during screen printing are evaporated. Next, another silver tape 522 is overlaid and the two silver tapes 522 and the high temperature superconductor layer 511 are integrated by applying a pressure of about 5 t / cm ² . Further, superconductivity is obtained by heating at about 840 ° C.
The high-temperature superconducting tape material formed in this manner has a silver 522 and a high-temperature superconducting layer 511 in comparison with a conventional high-temperature superconducting powder prepared by filling a high-temperature superconductor powder into a silver pipe, drawing and rolling. Since the boundary surface of the high temperature superconductor layer 511 is smooth, and the grains of the high temperature superconductor layer 511 are thin plates and have the same orientation by pressing, the intergranular bonds of the high temperature superconductor layer 511 become strong.
A high temperature superconducting tape 501 having a high critical current can be obtained.
Therefore, if this high-temperature superconducting tape material 501 is used for a superconducting magnet, a material having a high generated magnetic field can be obtained.

The pressing and heating for obtaining superconductivity may be repeated, or rolling may be performed as a deformation of pressing. Further, a sputtering method or a screen printing method may be used to form the high temperature superconductor layer 511 on the silver tape 523. Further, metal tapes 522, 52
The material of 3 is not limited to silver and may be any metal that does not react during firing.

Example 32. FIG. 33 is a manufacturing process diagram for explaining a method of manufacturing a high temperature superconducting tape material according to an embodiment of the present invention. In this embodiment, the only difference from the above-mentioned embodiment 31 is that one metal tape, that is, the silver tape 523 has a groove. As described above, when the high temperature superconductor layer 511 is formed in the groove, the high temperature superconductor layer 511 does not protrude from the silver tape, and when the high temperature superconductor layer 511 is formed on the flat plate surface as in Example 31, the high temperature superconductor layer 511 is formed. The peripheral portion where the high-temperature superconductor layer 511 is not formed has a smaller thickness than the central portion, and when the tape material is wound to form a coil, inconvenience occurs, but this does not occur.

Example 33. FIG. 34 is a manufacturing process diagram illustrating a method for manufacturing a high temperature superconducting tape material according to another embodiment of the present invention. In this example, a high temperature superconducting tape material 502 is formed by stacking two layers of a silver tape 523 having a groove and a high temperature superconductor layer 511 formed on the groove, and superposing a non-grooved silver tape 522 thereon. According to this embodiment, a high temperature superconducting tape material 502 having a high critical current density and a large thickness can be obtained. Note that the number of layers is not limited to two, but may be multiple.

Example 34. FIG. 35 is a manufacturing process diagram illustrating a method of manufacturing a high temperature superconducting tape material according to still another embodiment of the invention. In this example, the high-temperature superconducting tape material 503 is manufactured by inserting three layers of the high-temperature superconductor layer 511 formed on a grooveless silver tape 522 into a silver tape 523 having a deep groove and then pressing. Also in this case, the same effect as that of the above-mentioned Example 33 can be obtained.

Since the high-temperature superconducting tape materials produced in the above Examples 31 to 34 have high critical current densities, they can be used for bus bars, power transmission cables and the like other than high-temperature superconducting coils.

[0095]

As described above, according to the first aspect of the present invention, the cross-sectional area of the high temperature superconducting portion of the conductor is changed for each coil unit so that the critical currents of the coil units are made substantially equal to each other. Therefore, a high temperature superconducting magnet having a high generated magnetic field can be obtained.

According to the second aspect of the present invention, the cross-sectional area of the high temperature superconducting portion of the conductor according to the first aspect is changed to the critical current density and high temperature of the conductor when the strength and direction of the magnetic field are changed. From the magnetic field distribution of the superconducting coil, find the critical current density where the critical current density is the lowest for each coil unit,
Since it is calculated in proportion to its reciprocal, the critical currents of the coil units can be well matched.

According to the third aspect of the present invention, a tape material is used as the high temperature superconducting material, and the cross-sectional area of the conductor is changed for each coil unit by changing the number of layers or the width of the tape material. A high temperature superconducting magnet having a high magnetic field can be obtained.

According to the fourth aspect of the invention, since the high temperature superconducting coil formed by winding the conductor using the high temperature superconducting material is provided with the flange of the ferromagnetic material on the end surface, It is possible to obtain a high-temperature superconducting magnet with a small decrease in critical current density and a high generated magnetic field.

According to the fifth aspect of the present invention, since the heat conducting member provided with the heater is inserted between the coil units, the superconducting member is heated by the heater when the superconducting breakdown occurs, so that the high temperature superconducting coil is formed. The whole superconducting coil is destroyed by superconducting to absorb energy and prevent the energy from concentrating on a part of the superconducting coil and burning the superconducting coil.

According to the sixth aspect of the present invention, ceramic fibers are used for electrical insulation between the conductors using the high temperature superconducting material, and the longitudinal direction of the conductors and the fiber direction of the ceramic fibers are made substantially straight. Therefore, the coefficient of thermal expansion of the conductor and that of the ceramic fiber perpendicular to the fiber direction are substantially the same, so that it is possible to prevent a decrease in the critical current of the conductor and obtain a high-temperature superconducting magnet with a high generated magnetic field.

Further, according to the invention described in claim 7, since the high temperature superconducting coil is impregnated with the impregnating material which is hardened at a temperature of about room temperature or lower, it is hardened as compared with the case of using the impregnating material which is hardened by raising the temperature. The temperature difference between the temperature and the operating temperature of the high temperature superconducting coil can be reduced, and the distortion after cooling is reduced,
Since the decrease in the critical current of the conductor can be reduced, a high temperature superconducting magnet having a high magnetic field generated can be obtained.

According to the invention of claim 8, there is provided a high-temperature superconducting coil formed by winding a conductor using a high-temperature superconducting material with an insulator interposed between the conductor and the insulator. Since the stress buffer is inserted in the coil, when the high temperature superconducting coil is cooled, the stress buffer absorbs the strain of the conductor due to the difference in the coefficient of thermal expansion between the conductor and the insulating material, and the strain is relaxed in the conductor. It is possible to obtain a high-temperature superconducting magnet that can prevent a decrease in the critical current of the conductor and generate a high magnetic field.

According to the invention of claim 9, there is provided a high temperature superconducting coil constituted by winding a conductor in which a plurality of high temperature superconducting tape materials are superposed with an insulator interposed therebetween, and the coil operating current is substantially the same. Since the coil is excited at a temperature that is a critical current, the current flowing through each high-temperature superconducting tape material has substantially the same current value when the high-temperature superconducting coil is completely excited. In this state, if the temperature of the high-temperature superconducting coil is lowered to the operating temperature, superconducting breakdown is unlikely to occur even if disturbance occurs in each tape material. Furthermore, when the current value flowing in each tape material is different, the current moves from the larger one to the smaller one, and since the moving current passes through the normal conducting part, the total current decreases slightly, but the current of the same magnitude decreases. When flowing, there is no movement of current, so the total current does not decrease.

According to the tenth aspect of the invention, since the heater for raising the temperature during excitation also serves as the heater for the forced quench when the high temperature superconducting coil is destroyed by superconductivity, the number of heaters can be reduced.

According to the eleventh aspect of the present invention, the high temperature superconducting coil and the persistent current switch are thermally connected, and one or both of the high temperature superconducting coil and the persistent current switch is connected. Since the heater is provided, the permanent current switch and the high temperature superconducting coil can be heated at the same time when the high temperature superconducting coil is excited.

According to the twelfth aspect of the present invention, there is provided a high temperature superconducting coil in which a plurality of coil units constituted by winding a conductor in which a plurality of high temperature superconducting tape materials are superposed with an insulator interposed therebetween are laminated. In the connection of the high-temperature superconducting tape material between the coil units, at least two sets of tape materials include a high-temperature superconducting tape material wound n-th from the inside of one coil unit and the other coil unit. By connecting the m-th high-temperature superconducting tape material wound from the inside of n (where n and m are different integers), the sum of the magnetic fluxes passing through the loop formed by the high-temperature superconducting tape material is made substantially zero. Therefore, when exciting the high-temperature superconducting coil, the induced current due to the change in magnetic field does not occur in the high-temperature superconducting tape material, and it is the same for each of the superposed high-temperature superconducting tape materials. Since the can of current flow, the high temperature superconducting coil is hard to superconducting destroyed. Furthermore, since no induced current is generated, the excitation speed can be increased.

According to the thirteenth aspect of the present invention, the heat conducting member for cooling is installed in the vicinity of the connecting portion of the conductor between the coil units. Therefore, the connection resistance and the resistance of the connecting member during the excitation of the high temperature superconducting coil are set. Thus, the heat generated in the connection portion can be quickly removed, the temperature rise of the high temperature superconducting coil can be prevented, and the superconducting breakdown can be prevented.

According to the fourteenth aspect of the invention, since the heat conducting member for cooling is installed at the connecting portion between the high temperature superconducting coil and the coil supporting member, the coil container is usually at room temperature or substantially liquid nitrogen temperature. Therefore, it is possible to prevent heat from being transferred to the high temperature superconducting coil via the coil supporting member and prevent the temperature rise of the high temperature superconducting coil, and to obtain a high temperature superconducting magnet which is hard to quench.

According to the fifteenth aspect of the present invention, since the permanent current switch is arranged in a medium temperature space which is higher than the operating temperature of the superconducting coil and lower than the critical temperature of the high temperature superconducting material, the permanent current switch can be operated. In addition, the temperature of the permanent current switch may be changed between the above-mentioned intermediate temperature and the critical temperature, the switch speed becomes faster, and the amount of heat of the heater required to operate the permanent current switch can be reduced.

Further, according to the sixteenth aspect of the invention, since the magnetic field is applied substantially parallel to the c-axis direction of the crystal of the high temperature superconducting material of the permanent current switch, the permanent current switch is operated. When the magnetic field is parallel to the c-axis, the decrease in the critical current density due to the magnetic field becomes more remarkable, and the permanent current switch can be operated even if the magnetic field is weak.

According to the seventeenth aspect of the invention, it is easy to use a coil to apply a magnetic field substantially parallel to the c-axis direction of the crystal of the high temperature superconducting material of the permanent current switch according to the sixteenth aspect. The permanent current switch can be operated.

According to the eighteenth aspect of the present invention, since the permanent current switch using the film material of the high temperature superconductor is provided, the critical current density is higher than that of the conventional winding of the wire. Since the cross-sectional area of the film material may be small and the resistance value generated when it is not a superconductor is high, the volume of the permanent current switch can be reduced.

According to the nineteenth aspect of the present invention, a high temperature superconductor layer is formed on the metal tape, and another metal tape is stacked and pressed on the metal tape having the high temperature superconductor layer formed thereon. As a result, a high-temperature superconducting tape material is manufactured by integrating the above two metal tapes and the high-temperature superconducting layer, so that the interface between the metal tape and the high-temperature superconducting material is smooth, and the particles of the high-temperature superconducting material are thin plates. Since the orientations are aligned by pressing, the intergranular bonds of the high temperature superconductor are strengthened and a high temperature superconducting tape material having a high critical current can be obtained.

According to the invention of claim 20, in the manufacturing method of claim 19, since the metal tape has a groove and the high temperature superconductor layer is formed in the groove, in addition to the above effects. There is an effect that the high temperature superconducting layer can be surely covered with the metal tape and a high temperature superconducting tape material having a uniform thickness can be obtained.

[Brief description of drawings]

1A and 1B show a high temperature superconducting coil according to Example 1 of the present invention, FIG. 1A is a perspective view showing a partial cross section, and FIG. 1B is a cross sectional view showing an enlarged cross section of a conductor of FIG. 1A.

FIG. 2 is an explanatory diagram for explaining the first embodiment.

FIG. 3 shows a high temperature superconducting coil according to a second embodiment of the present invention, (a) is a perspective view showing a partial cross section, (b) is an enlarged view of a main part of (a), and (c) is a view of (b). FIG.

4A and 4B show a high temperature superconducting coil according to Example 3 of the present invention, FIG. 4A is a perspective view showing a partial cross section, and FIG. 4B is an enlarged cross sectional view of a main part of FIG. 4A.

5A and 5B show a high temperature superconducting coil according to Example 4 of the present invention, FIG. 5A is a perspective view showing a partial cross section, and FIG. 5B is an enlarged cross-sectional view of a main part of FIG. 5A.

FIG. 6 is a perspective view showing a partial cross section of a high temperature superconducting coil according to a sixth embodiment of the present invention.

FIG. 7 is an explanatory view for explaining the action of the high temperature superconducting magnet according to Example 6, where (a) is a case with a flange,
(B) shows the case where there is no flange.

8A and 8B show a high temperature superconducting coil according to Example 7 of the present invention, FIG. 8A is a perspective view showing a partial cross section, and FIG. 8B is an enlarged view of a main part of FIG. 8A.

FIG. 9 is a perspective view showing a partial cross section of a high temperature superconducting coil according to Example 9 of the present invention.

FIG. 10 shows a high temperature superconducting coil according to Example 11 of the present invention, (a) is a perspective view showing a partial cross section, and (b) is an enlarged view of a main part of (a).

FIG. 11 is an explanatory diagram illustrating an operation of the eleventh embodiment.

FIG. 12 shows a high temperature superconducting coil according to Example 13 of the present invention, (a) is a perspective view showing a partial cross section, and (b) is an enlarged view of a main part of (a).

13A and 13B show a high temperature superconducting coil according to Example 14 of the present invention, FIG. 13A is a perspective view showing a partial cross section, and FIG. 13B is an enlarged view of a main part of FIG. 13A.

FIG. 14 shows a high temperature superconducting coil according to Example 16 of the present invention, (a) is a perspective view showing a partial cross section, and (b) is an enlarged view of a main part of (a).

FIG. 15 is an explanatory diagram for explaining an operating method of the high temperature superconducting magnet according to Example 17 of the present invention.

FIG. 16 is an explanatory diagram for explaining an operating method of the high temperature superconducting magnet according to Example 17 of the present invention.

FIG. 17 is a configuration diagram illustrating a high temperature superconducting magnet according to Example 19 of the present invention.

FIG. 18 illustrates a high temperature superconducting coil according to a twentieth embodiment of the present invention, (a) is a perspective view schematically showing how the high temperature superconducting tape material is wound, and (b) is an explanatory diagram illustrating a connecting method. Is.

FIG. 19 is an explanatory diagram for explaining how to connect a high temperature superconducting coil according to a twenty first embodiment of the present invention.

FIG. 20 is an explanatory view illustrating how to connect the high temperature superconducting coils according to the twenty-first embodiment of the present invention.

FIG. 21 is an explanatory diagram for explaining how to connect a high temperature superconducting coil according to a twenty-second embodiment of the present invention.

FIG. 22 is an explanatory diagram for explaining how to connect a high temperature superconducting coil according to a twenty-second embodiment of the present invention.

FIG. 23 is an explanatory view illustrating how to connect a high temperature superconducting coil according to a twenty-third embodiment of the present invention.

FIG. 24 is an explanatory diagram for explaining how to connect a high temperature superconducting coil according to a twenty-third embodiment of the present invention.

FIG. 25 is a structural cross-sectional view showing a high temperature superconducting coil according to Example 24 of the present invention.

FIG. 26 is a structural cross-sectional view showing the main parts of a high temperature superconducting magnet according to Example 25 of the invention.

FIG. 27 is a structural diagram showing a high temperature superconducting magnet according to Example 27 of the present invention.

28 is an explanatory diagram for explaining the operation of the high temperature superconducting magnet according to Example 27. FIG.

FIG. 29 is an explanatory diagram illustrating an operation of the permanent current switch according to the twenty-eighth embodiment of the present invention.

FIG. 30 is a perspective view showing a configuration of a persistent current switch according to a thirtieth embodiment of the present invention.

FIG. 31 is a perspective view showing a partial cross-section of the structure of a conductor used in a conventional persistent current switch.

FIG. 32 is a manufacturing process diagram illustrating the method of manufacturing the high temperature superconducting tape material according to Example 31 of the present invention.

FIG. 33 is a manufacturing process diagram illustrating the method of manufacturing the high temperature superconducting tape material according to Example 32 of the present invention.

FIG. 34 is a manufacturing process diagram illustrating a method of manufacturing a high temperature superconducting tape material according to Example 33 of the present invention.

FIG. 35 is a manufacturing process diagram illustrating the method of manufacturing the high temperature superconducting tape material according to Example 34 of the present invention.

FIG. 36 is a configuration diagram of a conventional high temperature superconducting coil.

FIG. 37 is a cross-sectional view of a conventional high temperature superconducting tape material.

[Explanation of symbols]

 101, 102 Pancake coil 103 Double pancake coil 104 Connection metal member 105 Current lead 106 Flange 110 High temperature superconducting coil 111, 112, 113 Coil unit 120, 121, 122, 123 Conductor 130 High temperature superconducting tape material 131, 132, 133 Conductors 141, 142, 143 Conductors 151 Heat-conducting member 152 Heater 153 High-temperature superconducting coil 160 Flange 202 Insulating material 203 Alumina fiber 301 Stress buffering materials 311, 312, 313, 314 Coil unit 330 Connection part 341, 342, 343, 344 High-temperature superconducting Tape material 351 Connection member 360 Heat conduction member 361 Coil support member 370 Coil container 401 Low temperature space below liquid nitrogen temperature 402 Medium temperature space 403 Room temperature space 404 Permanent electricity Switch 405 Power source 406 Heater 411 Substrate 412 High temperature superconductor film material 421 Coil 422 High temperature superconductor 423 Magnetic field 424 c-axis 501, 502, 503 High temperature superconducting tape material 511 High temperature superconductor layer 522, 523, 524 Silver tape 532 Silver sheath 533 High temperature superconductor 534 interface

[Procedure amendment]

[Submission date] January 21, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction content]

According to a ninth aspect of the present invention, there is provided a high temperature superconducting coil formed by winding a conductor obtained by stacking a plurality of high temperature superconducting tape materials with an insulator interposed therebetween, and the coil operating current is a substantially critical current. Since the coil is excited at a certain temperature, when the high temperature superconducting coil is completely excited, the current flowing through each high temperature superconducting tape material has almost the same current value. In this state, if the temperature of the high-temperature superconducting coil is lowered to the operating temperature, superconducting breakdown is unlikely to occur even if disturbance occurs in each tape material. In addition, the high temperature superconducting coil
In the case of current flow, if the current value flowing in each tape material is different, the current moves from the larger one to the smaller one, and since the moving current passes through the normal conducting part, the total current decreases slightly, but the same magnitude. When the current flows, the total current does not decrease because the current does not move.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0088

[Correction method] Change

[Correction content]

Example 30. FIG. 30 is a perspective view showing the structure of a permanent current switch according to an embodiment of the present invention. In the figure, 411 is a substrate, for example, Sr
TiO ₃ (strontium titanate) and YSZ (it )
(Stabilized zirconia) . Reference numeral 412 is a high-temperature superconductor film material, which is made of, for example, YBa ₂ Cu ₃ O ₇ , and is formed to a thickness of about 1 μm by a sputtering method, a CVD method, or the like. Conventionally, as a permanent current switch,
For example, as shown in FIG. 31, a plurality of NbTi wires 413
Was used in which a wire was obtained by containing CuNi414 in the form of a core and winding it into a coil, and a heater for heating was arranged on the outer periphery of this coil, and further around this was covered with, for example, an epoxy resin. It had a large volume overall. On the other hand, when the film material 412 is a high-temperature superconductor as in the embodiment shown in FIG. 30, the critical current density is higher than in the case where a wire is wound, so that the cross-sectional area of the film material is small. Since the resistance value generated when the superconductor is not used is high, the volume of the persistent current switch can be reduced.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 39/20 ZAA 9276-4M

Claims (20)

[Claims] 1. A high-temperature superconducting coil comprising a plurality of coil units laminated by winding a conductor made of a high-temperature superconducting material, wherein a cross-sectional area of a high-temperature superconducting portion of the conductor is set for each coil unit. The high temperature superconducting magnet is characterized in that the critical currents of the coil units are made to substantially match. 2. The cross-sectional area of the high-temperature superconducting portion of the conductor according to claim 1 is determined for each coil unit from the critical current density of the conductor and the magnetic field distribution of the high-temperature superconducting coil when the strength and direction of the magnetic field are changed. A method for designing a high-temperature superconducting magnet, characterized in that the critical current density at the place where the critical current density is the lowest is found, and is found in proportion to the reciprocal thereof. 3. A high-temperature superconducting magnet according to claim 1, wherein a tape material is used as the high-temperature superconducting material, and the cross-sectional area of the conductor for each coil unit is changed by changing the number of layers or the width of the tape material. . 4. A high temperature superconducting magnet, characterized in that a flange of a ferromagnetic material is provided on an end surface of a high temperature superconducting coil formed by winding a conductor using a high temperature superconducting material. 5. A high-temperature superconducting coil comprising a plurality of coil units formed by winding a conductor made of a high-temperature superconducting material, wherein a heat-conducting member provided with a heater is inserted between the coil units. High temperature superconducting magnet. 6. A high-temperature superconducting coil which is formed by winding a conductor using a high-temperature superconducting material, wherein ceramic fibers are used for electrical insulation between the conductors using the high-temperature superconducting material, and the length of the conductor is long. High-temperature superconducting magnet characterized in that the direction of the ceramic fiber and the fiber direction of the ceramic fiber are made substantially direct. 7. A high-temperature superconducting coil that is formed by winding a conductor using a high-temperature superconducting material, wherein the high-temperature superconducting coil is impregnated with an impregnating material that cures at a temperature of about room temperature or lower. High temperature superconducting magnet. 8. A high-temperature superconducting coil which is formed by winding a conductor using a high-temperature superconducting material with an insulator interposed therebetween, wherein a stress buffer is inserted between the conductor and the insulator. High temperature superconducting magnet. 9. A high-temperature superconducting coil constituted by winding a conductor obtained by stacking a plurality of high-temperature superconducting tape materials with an insulator interposed therebetween, wherein the coil operating current is substantially a critical current. A method for operating a high-temperature superconducting magnet, which comprises exciting a coil. 10. The high-temperature superconducting coil comprises a heater for raising the temperature during excitation, and the heater for raising the temperature during excitation also serves as a heater for forced quenching when the high-temperature superconducting coil undergoes superconducting breakdown. Characteristic high temperature superconducting magnet. 11. A high-temperature superconducting coil and a persistent current switch are thermally connected, and a heater is provided at either or both of the high-temperature superconducting coil and the persistent current switch. High temperature superconducting magnet. 12. A high-temperature superconducting coil comprising a plurality of coil units, each of which is formed by winding a conductor in which a plurality of high-temperature superconducting tape materials are superposed with an insulator interposed between the high-temperature superconducting coils. In the connection of the high-temperature superconducting tape material, at least two sets of tape materials include a high-temperature superconducting tape material wound n-th from the inside of one coil unit and an m-th (where n and m are from the inside of the other coil unit). High-temperature superconducting tape material is connected to the high-temperature superconducting tape material, and the sum of the magnetic fluxes passing through the loop formed by the high-temperature superconducting tape material is substantially zero. 13. A high-temperature superconducting coil comprising a stack of a plurality of coil units formed by winding a conductor made of a high-temperature superconducting material, wherein a cooling portion is provided near a connecting portion of the conductors between the coil units. A high temperature superconducting magnet having a heat conducting member installed. 14. A high-temperature superconducting magnet, characterized in that a heat-conducting member for cooling is installed at a connecting portion between the high-temperature superconducting coil and the coil supporting member. 15. A high temperature superconducting magnet comprising a high temperature superconducting coil and a persistent current switch using the high temperature superconducting material, wherein the permanent current switch is a medium temperature space higher than the operating temperature of the superconducting coil and lower than the critical temperature of the high temperature superconducting material. High-temperature superconducting magnet, which is characterized in that it is placed in. 16. The high temperature superconducting device according to claim 15, wherein the permanent current switch is operated by applying a magnetic field substantially parallel to the c-axis direction of the crystal of the high temperature superconducting material of the persistent current switch. magnet. 17. The permanent-current switch according to claim 16, wherein the means for applying a magnetic field substantially parallel to the c-axis direction of the crystal of the high temperature superconducting material is a coil.
6. The high temperature superconducting magnet according to 6. 18. A high-temperature superconducting magnet, comprising a permanent current switch using a film material of the high-temperature superconductor. 19. A high-temperature superconductor layer is formed on a metal tape, and another metal tape is placed on the metal tape on which the high-temperature superconductor layer is formed and pressure is applied to the two metal tapes and the high temperature. A method for producing a high-temperature superconducting tape material which integrates a superconducting layer. 20. The method for producing a high temperature superconducting tape material according to claim 19, wherein the metal tape has a groove, and the high temperature superconductor layer is formed in the groove.