JP4067749B2 - Superconducting bulk magnetizer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a superconducting bulk magnetizer.
[0002]
[Prior art]
Conventional superconducting bulk material magnetization methods include field cool, zero field cool, and pulse magnetization. In zero field cool and pulse magnetization, a magnetic field is repeatedly applied to increase the magnetization magnetic field. Although the method has been performed, the temperature of the superconducting bulk body is constant, and the whole is magnetized in the superconducting state.
[0003]
[Problems to be solved by the invention]
In the conventional method as described above, the high-temperature superconducting bulk material must be magnetized by applying a large magnetic field, so that the coil and power supply for the applied magnetic field are increased, and the influence on the surroundings and the outside is increased. There is a problem that a large electromagnetic force is generated in the magnetization.
[0004]
In the present invention, the above-mentioned problems are eliminated, and a relatively small magnetic field is repeatedly applied while gradually expanding the superconducting region of the superconducting bulk body, thereby reducing the applied magnetic field coil and power source and increasing the magnetization process. It is an object of the present invention to provide a superconducting bulk material magnetizing device capable of sufficiently magnetizing without requiring electromagnetic force.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides
[1] In the magnetizing apparatus of the bulk superconductor, and the superconducting bulk body, a plurality of individually controllable heater wire wound concentrically upper and lower surfaces of the bulk superconductors, a center of the superconducting bulk And a means for sequentially applying a magnetic field step by step to sequentially expand the superconducting state.
[0006]
[2] The magnetizing apparatus of the bulk superconductor, and the superconducting bulk body, the superconducting bulk body locally in placed face heater surface, sequentially stepwise repeated field application from the point of the surface heater And means for expanding the superconducting state.
[0007]
[ 3 ] The superconducting bulk body magnetizing apparatus according to [ 2 ], wherein the surface heater is a plurality of individually controllable surface heaters disposed on a surface of the superconducting bulk body.
[0008]
[ 4 ] The superconducting bulk magnetic device according to any one of [1] to [ 3 ], wherein the magnetic field to be applied is a pulsed or stationary magnetic field.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0010]
First, a superconducting bulk magnetizing apparatus according to an embodiment of the present invention will be described.
[0011]
FIG. 1 is a schematic view of a superconducting bulk magnetizing apparatus having a heater wire on the outer periphery of a first reference example of the present invention.
[0012]
In this reference example, a superconducting bulk in which a heater wire 3 is wound around an outer peripheral portion 2 on a cooling device 4 that is attached to a refrigerator head and cooled (may be directly immersed in a refrigerant such as liquid nitrogen for cooling). Place the body 1.
[0013]
Therefore, when the entire superconducting bulk body 1 is cooled by the cooling device 4 and a current is passed from the power supply device 5 whose current value is set in advance through the switch 6 to the heater wire 3, The superconducting bulk body 1 is not heated to be in the superconducting state, and if only a small region inside the superconducting bulk body 1 is in the superconducting state, the entire superconducting state portion can be magnetized even by applying a relatively small magnetic field. . Then, by gradually decreasing the current value of the heater wire 3, the superconducting bulk body 1 is repeatedly superposed on the superconducting region 1 while gradually expanding as shown in FIG. 7 (described later). If magnetization is performed, and finally the current supply to the heater wire is stopped and a magnetic field is applied, the entire superconducting bulk body 1 can be magnetized.
[0014]
FIG. 2 is a schematic diagram of a superconducting bulk body provided with a plurality of concentric heater wires, showing a second reference example of the present invention.
[0015]
As shown in this figure, a plurality of heater wires 12, 13, 14 are wound around a superconducting bulk body 11 concentrically.
[0016]
Therefore, although not shown, using the same cooling device and power supply device as in the first reference example, the current flowing through the plurality of heater wires 12, 13, and 14 is stepwise in the order of the heater wires 12, 13, and 14. By stopping, the superconducting bulk region 11 in the superconducting state region can be repeatedly magnetized while gradually expanding from the center as shown in FIG. 7 (described later).
[0017]
FIG. 3 is a schematic view of a superconducting bulk body provided with a plurality of concentric heater wires on the upper and lower surfaces thereof according to the first embodiment of the present invention.
[0018]
As shown in this figure, a plurality of heater wires 23, 24, 25 are concentrically wound around the upper surface 22 of the superconducting bulk body 21, and a plurality of heater wires 27, 28, 29 are wound concentrically around the lower surface 26.
[0019]
Therefore, although not shown, the current flowing through the plurality of heater wires 23, 24, 25 and 27, 28, 29 is stopped stepwise using the same cooling device and power supply device as in the first reference example. As a result, the superconducting bulk body 21 can be repeatedly magnetized while the superconducting region is expanded stepwise from the center as shown in FIG. 7 (described later).
[0020]
FIG. 4 is a schematic diagram (part 1) of a superconducting bulk body provided with a surface heater according to a second embodiment of the present invention, and FIG. 4 (a) is a schematic diagram of the superconducting bulk body provided with a surface heater on the surface thereof. FIG. 4B is a schematic diagram of a superconducting bulk body having a plurality of surface heaters on its surface.
[0021]
First, as shown in FIG. 4A, the surface heaters 62 and 63 are arranged in the local part of the surface of the superconducting bulk body 61.
[0022]
Therefore, although not shown in the figure, by using the same cooling device and power supply device as those in the first reference example, the current flowing in the surface heaters 62 and 63 is reduced stepwise, thereby the superconducting bulk body 61 is in a superconducting state. Magnetization can be repeatedly performed while expanding the region stepwise as shown in FIG. 9 (described later).
[0023]
FIG. 4B is characterized in that a plurality of surface heaters 72, 73, 74, 75 are arranged on the surface of the superconducting bulk body 71.
[0024]
Therefore, although not shown in the figure, the superconducting bulk material is obtained by stepping off the current flowing through the plurality of surface heaters 72, 73, 74, 75 using the same cooling device and power supply device as in the first reference example. Magnetization can be performed while the region of 71 in the superconducting state is expanded stepwise as shown in FIG. 10 (described later).
[0025]
FIG. 5 is a schematic diagram (part 2) of a superconducting bulk body provided with a surface heater according to a second embodiment of the present invention, and FIG. FIG. 5B is a schematic diagram of a superconducting bulk body provided with a plurality of surface heaters on its side surface.
[0026]
First, as shown in FIG. 5A, a surface heater 82 is disposed at a local portion on the side surface of the superconducting bulk body 81.
[0027]
Therefore, although not shown, by using the same cooling device and power supply device as those in the first reference example, the current flowing through the surface heater 82 is decreased stepwise, so that the superconducting state region of the superconducting bulk body 81 is reduced. Magnetization can be repeatedly performed while expanding stepwise.
[0028]
FIG. 5B is characterized in that a plurality of surface heaters 92, 93, 94, 95, 96, 97 are arranged on the side surface of the superconducting bulk body 91.
[0029]
Therefore, although not shown, by using the same cooling device and power supply device as in the first reference example, the current flowing through the plurality of surface heaters 92, 93, 94, 95, 96, and 97 is stopped stepwise. Then, magnetization can be performed while expanding the superconducting region of the superconducting bulk body 91 stepwise.
[0030]
Hereinafter, a specific repeated magnetization method of the superconducting bulk material of the present invention will be described.
[0031]
FIG. 6 is a configuration diagram of a specific repetitive magnetization apparatus for a superconducting bulk material according to the present invention.
[0032]
In this figure, reference numeral 100 denotes a pulse tube refrigerator, and this pulse tube refrigerator is connected to a compressor 102 and an evacuation device 103, and a test high temperature superconducting bulk body 104 is connected to the head 101 of the pulse tube refrigerator. Fixed.
[0033]
The test high-temperature superconducting bulk body 104 is equipped with a heater 105 and connected to a heater power source 106. A temperature element 109 is set on the head 101 of the pulse tube refrigerator so that the temperature can be measured. Further, an electromagnetic coil 107 is disposed around the test high-temperature superconducting bulk body 104, and the electromagnetic coil 107 is connected to an excitation power source 108. The strength of the magnetic field is measured by the Hall element 110.
[0034]
The test high-temperature superconducting bulk body 104 is set in the refrigerator head 101, and the heater 105 is attached by the pulse tube refrigerator 100 when the heater wire is wound around the outer periphery as shown in FIG. The target temperature for cooling the high-temperature superconducting bulk body 104 is kept constant at 80 K, and the current value of the heater wire is decreased stepwise so that the superconducting region is gradually expanded from the central portion and repeatedly pulsed.
[0035]
FIG. 7 is a diagram showing a method (part 1) for expanding the superconducting region of the superconducting bulk material of the present invention.
[0036]
First, as shown in FIG. 7 (a), the central portion of the high-temperature superconducting bulk body 51 is a superconducting region 52, and then, as shown in FIG. 7 (b), the enlarged superconducting region 53, FIG. As shown in FIG. 5B, the superconducting region 54 further expanded and finally the superconducting region 55 covering the entire high-temperature superconducting bulk body 51 is formed, and the magnetization is completed.
[0037]
The measurement result when performing the above stepwise magnetization is shown.
[0038]
FIG. 8 is a diagram showing a measurement result by a method (part 1) of expanding the superconducting region of the superconducting bulk body.
[0039]
In this figure, the horizontal axis is the position (mm), and the vertical axis is the magnetic field (mT). Here, the current values are 0.080A, 0.078A, 0.076A, 0.074A, 0.072A, 0.0. Magnetization was performed over 070A and 0.068A in seven stages.
[0040]
FIG. 9 is a diagram showing a method (part 2) for expanding the superconducting region of the superconducting bulk material of the present invention.
[0041]
In this embodiment, the surface heaters 62 and 63 are provided at the end of the high-temperature superconducting bulk body 61, and the current is decreased stepwise to expand the superconducting region from the end of the high-temperature superconducting bulk body 61. ing. As shown in FIGS. 9A to 9D, the superconducting region is gradually enlarged from the end. That is, the superconducting region 64 → 65 → 66 → 67 can be expanded stepwise.
[0042]
As shown in FIG. 10, many surface heaters 72, 73, 74, and 75 are arranged on the surface of the high-temperature superconducting bulk body 71 to expand the superconducting region of the high-temperature superconducting bulk body 71. That is, as shown in FIGS. 10A to 10D, the superconducting region 76 → 77 → 78 → 79 can be expanded stepwise.
[0043]
The measurement result at the time of performing stepwise magnetization from the edge part of the above superconducting bulk bodies is shown.
[0044]
FIG. 11 is a diagram showing a measurement result by a method (part 2) of expanding the superconducting region of such a superconducting bulk body.
[0045]
When a high-temperature superconducting bulk body is attached to the refrigerator head and one heater is arranged on the surface of the superconducting bulk body 61 shown in FIG. 9 as a heater attachment method, the target temperature for cooling the high-temperature superconducting bulk body by the refrigerator Is a constant value of 80K, and the measurement result when the pulse current is repeatedly magnetized while expanding the superconducting region from the end by decreasing the current value of the heater stepwise is shown.
[0046]
In this figure, the horizontal axis is the position (mm), and the vertical axis is the magnetic field (mT). Here, the current values are 0.055A, 0.053A, 0.051A, 0.049A, 0.047A, 0.0. Magnetization was performed over 045A and 0A stages.
[0047]
For comparison, the temperature of the entire high-temperature superconducting bulk was kept constant at 80K, and pulse magnetization was repeatedly performed without controlling the superconducting region.
[0048]
FIG. 12 shows the measurement results when the superconducting region is kept constant without being controlled. In addition, in FIG. 12, the frequency | count (1-5 times) which applied the pulse magnetic field is shown as a parameter.
[0049]
As described above, when the superconducting region is kept constant without being controlled, an increase in the magnetic field is not observed even when repeated pulse magnetization is attempted, and the maximum value of the magnetic field is 5 mT or less.
[0050]
On the other hand, when pulsed magnetization is repeated while controlling and expanding the superconducting region, an increase in the magnetic field is observed by repetition as shown in FIGS. 8 and 11, and the maximum value of the magnetic field reaches about 30 mT.
[0051]
Note that the shape of the superconducting bulk body is not limited to a cylinder, and can be applied to various shapes such as a rectangular flat plate. Further, the method of expanding the superconducting region can be controlled optimally depending on the characteristics of the superconductor and the magnitude of the applied magnetic field, and the control method is not limited to the example shown.
[0052]
Moreover, although the thing with thickness was shown as said superconducting bulk body, even if it is a thin shape, it is contained in the superconducting bulk body of this invention.
[0053]
Further, as a heating means, although not shown, a hot air device may be disposed in the vicinity of the superconducting bulk body to heat the local portion of the superconducting bulk body.
[0054]
In addition, this invention is not limited to the said Example, A various deformation | transformation is possible based on the meaning of this invention, and these are not excluded from the scope of the present invention.
[0055]
【The invention's effect】
As described above in detail, according to the present invention, since the magnetic field applied when magnetizing the superconducting bulk body can be reduced, the coil and power source for the applied magnetic field can be reduced in size and weight, and the surrounding and external The influence can be reduced.
[0056]
Further, the electromagnetic force generated in the superconducting bulk body and the applied magnetic field coil when magnetized can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a superconducting bulk magnetizing device provided with a heater wire on the outer peripheral portion according to a first reference example of the present invention.
FIG. 2 is a schematic diagram of a superconducting bulk body provided with a plurality of concentric heater wires according to a second reference example of the present invention.
FIG. 3 is a schematic view of a superconducting bulk body provided with a plurality of concentric heater wires on the upper and lower surfaces according to the first embodiment of the present invention.
FIG. 4 is a schematic diagram (No. 1) of a superconducting bulk body including a surface heater according to a second embodiment of the present invention.
FIG. 5 is a schematic diagram (No. 2) of a superconducting bulk body including a surface heater according to a second embodiment of the present invention.
FIG. 6 is a configuration diagram of a specific repetitive magnetization apparatus for a superconducting bulk material according to the present invention.
FIG. 7 is a diagram showing a method (part 1) of expanding the superconducting region of the superconducting bulk material according to the present invention.
FIG. 8 is a diagram showing a measurement result by a method (part 1) of expanding a superconducting region of a superconducting bulk body according to the present invention.
FIG. 9 is a diagram showing a method (part 2) of expanding the superconducting region of the superconducting bulk material of the present invention.
FIG. 10 is a diagram showing a method of arranging a plurality of heaters on the superconducting bulk body of the present invention and expanding the superconducting region of the high-temperature superconducting bulk body.
FIG. 11 is a diagram showing a measurement result by a method (part 2) of expanding a superconducting region of a superconducting bulk body according to the present invention.
FIG. 12 is a diagram showing a measurement result when the superconducting region is kept constant without being controlled.
[Explanation of symbols]
1, 11, 21, 51, 61, 71, 81, 91 Superconducting bulk body 2 Outer peripheral part 3, 12, 13, 14, 23, 24, 25, 27, 28, 29 Heater wire 4 Cooling device (refrigerator head)
5 Power supply device 6 Switch 22 Upper surface 26 Lower surface 62, 63, 72, 73, 74, 75, 82, 92, 93, 94, 95, 96, 97 Surface heater 52, 53, 54, 55, 64, 65, 66, 67, 76, 77, 78, 79 Superconducting region 100 Pulse tube refrigerator 101 Refrigerator head 102 Compressor 103 Evacuating device 104 High temperature superconducting bulk body 105 Heater 106 Heater power supply 107 Electromagnetic coil 108 Excitation power supply 109 Temperature element 110 Hall element

Claims (4)

(A) the superconducting bulk body,
(B) a plurality of individually controllable heater wires concentrically wound around the upper and lower surfaces of the superconducting bulk body;
(C) A superconducting bulk magnetizing device comprising means for repeatedly applying a magnetic field stepwise from the center of the superconducting bulk body to sequentially expand the superconducting state. (A) the superconducting bulk body,
(B) a surface heater disposed locally on the surface of the superconducting bulk body;
( C ) A superconducting bulk body magnetizing apparatus comprising: ( c ) means for repeatedly applying a magnetic field in a stepwise manner from the surface heater and sequentially expanding the superconducting state. 3. The superconducting bulk body magnetizing apparatus according to claim 2 , wherein the surface heater is a plurality of individually controllable surface heaters disposed on a surface of the superconducting bulk body. Magnetic device. In magnetizer superconducting bulk body of any one of claims 1 to 3, magnetizing apparatus of bulk superconductor, wherein the magnetic field to be the application is a pulsed or steady magnetic field.

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