JP2003037303A - Superconducting coil with permanent current switch using magnesium diboride superconducting wire material and its manufacturing method - Google Patents
Superconducting coil with permanent current switch using magnesium diboride superconducting wire material and its manufacturing methodInfo
- Publication number
- JP2003037303A JP2003037303A JP2001222398A JP2001222398A JP2003037303A JP 2003037303 A JP2003037303 A JP 2003037303A JP 2001222398 A JP2001222398 A JP 2001222398A JP 2001222398 A JP2001222398 A JP 2001222398A JP 2003037303 A JP2003037303 A JP 2003037303A
- Authority
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- Japan
- Prior art keywords
- superconducting
- current switch
- superconducting coil
- coil
- persistent current
- Prior art date
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明はニホウ化マグネシウ
ムを用いた超電導線を使用した永久電流スイッチ付超電
導コイルおよびその製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting coil with a permanent current switch using a superconducting wire made of magnesium diboride and a method for manufacturing the same.
【０００２】[0002]
【従来の技術】超電導マグネットを運転させる方法とし
て、常にコイルに電源から電流を流す方法と、電源に対
して永久電流スイッチと超電導コイルを並列に接続し、
励磁した後はこのスイッチによりコイルを電源から切り
離して永久電流モードに移行させる方法とがある。永久
電流スイッチを用いた永久電流モードの運転法を図１も
ちいて説明する。図に示すように、超電導コイル１の端
子間には短絡スイッチ２が設けられる。この短絡スイッ
チ２は永久電流スイッチと呼ばれ、短絡時の抵抗を低く
するため、通常、超電導体が用いられる。超電導体を用
いたスイッチにおいて、たとえばヒータ加熱によって超
電導体の温度を臨界温度以上とすることにより抵抗が発
生した状態で、電源３から定格電流値まで超電導コイル
１に電流を流し、励磁を行う。次いで、ヒータ加熱を停
止し、スイッチ２を超電導状態に移行させ、短絡を行え
ば、励磁電源を取り外しても一定電流の通電が継続され
ることになる。このようにして永久電流モードの運転が
可能である。2. Description of the Related Art As a method of operating a superconducting magnet, a method of always flowing a current from a power source to a coil, and a permanent current switch and a superconducting coil connected in parallel to the power source,
After excitation, there is a method of disconnecting the coil from the power supply by this switch and shifting to the permanent current mode. A method of operating in the persistent current mode using the persistent current switch will be described with reference to FIG. As shown in the figure, a short-circuit switch 2 is provided between the terminals of the superconducting coil 1. This short-circuit switch 2 is called a permanent current switch, and a superconductor is usually used to reduce the resistance at the time of short circuit. In a switch using a superconductor, a current is caused to flow from the power supply 3 to the superconducting coil 1 up to a rated current value in a state where resistance is generated by heating the temperature of the superconductor to a critical temperature or higher by heating, for example, for excitation. Next, if heating of the heater is stopped, the switch 2 is switched to the superconducting state, and a short circuit is made, energization with a constant current is continued even if the exciting power source is removed. In this way, a permanent current mode operation is possible.
【０００３】永久電流スイッチには、たとえば次のよう
な特性が要求される。
（１）ＯＮ時の抵抗が０であるかまたは小さいこと。
（２）ＯＦＦ時の抵抗が大きいこと。
（３）必要電流を安定に流すことができること。
（４）必要時以外に常電導転移しないこと。For example, the following characteristics are required for the persistent current switch. (1) The resistance when ON is 0 or small. (2) The resistance when off is large. (3) A required current can be stably applied. (4) Do not transfer to normal conduction except when necessary.
【０００４】従来の合金系または化合物系超電導線材を
用いた超電導マグネットに対しては、一般的にはＮｂＴ
ｉ線を使用した永久電流スイッチが用いられている。こ
の場合、永久電流モードに移行させるための温度は、約
９Ｋであり、それより高い温度で使用することはできな
い。臨界温度が低いということは永久電流スイッチにわ
ずかな擾乱エネルギーが入った場合でも、超電導線が臨
界温度以上に上昇してしまい、速やかな常電導転移、す
なわちクエンチを引き起こす場合がある。特にＮｂＴｉ
線を用いた永久電流スイッチはＯＦＦ時の電気抵抗を大
きくするため、安定化材として銅−ニッケル合金を使用
しており、安定化材として銅を用いた超電導線よりクエ
ンチを発生しやすい傾向がある。一旦、永久電流スイッ
チにクエンチが発生すると超電導コイルの電流も失われ
るためマグネットとしての運転を停止せざるを得ないと
いう課題がある。For a conventional superconducting magnet using an alloy-based or compound-based superconducting wire, NbT is generally used.
Permanent current switches using i-line are used. In this case, the temperature for shifting to the persistent current mode is about 9K, and it cannot be used at a higher temperature. The low critical temperature may cause the superconducting wire to rise above the critical temperature even if a small amount of disturbance energy is applied to the persistent current switch, causing a rapid normal conduction transition, that is, quenching. Especially NbTi
Permanent current switches using wires use a copper-nickel alloy as a stabilizer to increase the electrical resistance when they are turned off, and they tend to cause quenching more easily than superconducting wires that use copper as a stabilizer. is there. Once the permanent current switch is quenched, the current in the superconducting coil is also lost, and there is a problem that the operation as a magnet must be stopped.
【０００５】最近、Nature４１０，６３−６４（２００
１）で報告されたように、ニホウ化マグネシウム（Ｍｇ
Ｂ2 ）が超電導を示すことが発見された。ＭｇＢ2 の特
徴は以下に示す。Recently, Nature 410, 63-64 (200
As reported in 1), magnesium diboride (Mg
It has been discovered that B 2 ) exhibits superconductivity. The characteristics of MgB 2 are shown below.
【０００６】ＭｇＢ2 の臨界温度は３９Ｋである。これ
は従来の金属系超電導材料の最高値である。したがっ
て、この材料を用いて永久電流スイッチを構成した場
合、３９Ｋ以下ではＯＦＦとすること、３９Ｋ以上では
ＯＮとすることができ、他の金属系超電導材料と比較し
て臨界温度が高いことから安定性マージンが高くなるの
で、クエンチを発生しにくい信頼性の高い永久電流スイ
ッチを実現できる。０Ｔにおける臨界磁場は約１８Ｔで
ある。これは従来の金属系超電導材料と比較すると高い
部類に属する。従来の永久電流スイッチ付超電導コイル
における永久電流スイッチでは、その臨界磁場が低くな
る場合があり、永久電流スイッチを超電導コイルから遠
い磁場の小さい場所に配置したり、永久電流スイッチの
外側に磁気シールドを設置したりする制約があった。し
かし、ＭｇＢ2 を用いて永久電流スイッチを構成した場
合、上記のような制約はなくなるため、永久電流スイッ
チの構成が自由となる。The critical temperature of MgB 2 is 39K. This is the highest value of conventional metal-based superconducting materials. Therefore, when a permanent current switch is constructed using this material, it can be turned off below 39K and turned on above 39K, and has a higher critical temperature than other metal-based superconducting materials. Since the performance margin is increased, it is possible to realize a highly reliable persistent current switch that is hard to generate a quench. The critical magnetic field at 0T is about 18T. This belongs to a higher category than the conventional metal-based superconducting materials. The critical magnetic field of a conventional superconducting coil with a persistent current switch may have a low critical magnetic field.Therefore, place the persistent current switch in a place with a small magnetic field far from the superconducting coil, or place a magnetic shield outside the persistent current switch. There was a restriction to install it. However, when the permanent current switch is formed by using MgB 2 , the above-mentioned restrictions are eliminated, so that the structure of the permanent current switch is free.
【０００７】[0007]
【発明が解決しようとする課題】発明者らはＭｇＢ2 の
超電導体としては良好の性質を鑑み、ＭｇＢ2 を永久電
流スイッチに適用できないか検討を続けてきた。本発明
の目的は、ＭｇＢ2 を適用した永久電流スイッチを提供
することにある。In view of the excellent properties of MgB 2 as a superconductor, the inventors have continued to investigate whether MgB 2 can be applied to a persistent current switch. An object of the present invention is to provide a persistent current switch to which MgB 2 is applied.
【０００８】[0008]
【課題を解決するための手段】前記課題を達成するた
め、以下のような手段を適用した。Means for Solving the Problems In order to achieve the above objects, the following means were applied.
【０００９】請求項１記載の発明に係わる永久電流スイ
ッチ付超電導コイルは、超電導コイルと前記超電導コイ
ルを短絡する永久電流スイッチとを備える永久電流スイ
ッチ付超電導コイルにおいて、前記永久電流スイッチは
ニホウ化マグネシウムを含む超電導体とそれを覆う金属
からなる安定化材とからなる超電導線材を備え、前記短
絡のため、前記超電導コイルを構成する超電導線材の超
電導コアと前記永久電流スイッチを構成する前記超電導
線材の超電導コアは接触していることを特徴とする。ニ
ホウ化マグネシウムは他の金属系超電導材料と比較して
臨界温度が高いことから安定性マージンが高くなるの
で、速やかな常電導転移、すなわちクエンチ現象が発生
しにくい信頼性の高い永久電流スイッチを実現できる。
また、超電導コイルと永久電流スイッチ双方の超電導線
材の超電導コアが互いに接触している構造であり、ＯＮ
時の抵抗はゼロとすることができる。A superconducting coil with a persistent current switch according to the present invention is a superconducting coil with a persistent current switch, comprising: a superconducting coil; and a permanent current switch for short-circuiting the superconducting coil, wherein the permanent current switch is magnesium diboride. A superconducting wire comprising a superconductor including a stabilizing material made of a metal covering the superconducting conductor, and for the short circuit, the superconducting core of the superconducting wire constituting the superconducting coil and the superconducting wire constituting the persistent current switch. The superconducting core is in contact with each other. Magnesium diboride has a higher critical temperature than other metal-based superconducting materials, and therefore has a high stability margin, so it realizes a reliable normal current switch in which rapid normal transition, that is, quench phenomenon does not easily occur. it can.
In addition, the structure is such that the superconducting cores of the superconducting wires of both the superconducting coil and the persistent current switch are in contact with each other.
The time resistance can be zero.
【００１０】請求項２記載の発明に係わる永久電流スイ
ッチ付超電導コイルは、請求項１における永久電流スイ
ッチ付超電導コイルであって、前記超電導コイルを構成
する超電導線材の超電導コアと前記永久電流スイッチを
構成する前記超電導線材の超電導コアは前記安定化材を
介して接続していることを特徴とする。この場合、超電
導線どうしの接続部を長くすることによりＯＮ時の抵抗
を十分小さくすることができる。A superconducting coil with a persistent current switch according to a second aspect of the present invention is the superconducting coil with a persistent current switch according to the first aspect, wherein the superconducting core of the superconducting wire forming the superconducting coil and the persistent current switch are provided. It is characterized in that the superconducting cores of the constituent superconducting wires are connected via the stabilizing material. In this case, the resistance at the time of ON can be sufficiently reduced by lengthening the connecting portion between the superconducting wires.
【００１１】請求項３記載の発明に係わる永久電流スイ
ッチ付超電導コイルは、請求項１における永久電流スイ
ッチ付超電導コイルであって、前記超電導コイルを構成
する超電導線材の超電導コアと前記永久電流スイッチを
構成する前記超電導線材の超電導コアは金属を介して接
続していることを特徴とする。前記金属が超電導体であ
った場合、ＯＮ時の抵抗はゼロとすることができる。一
方、前記金属が常電導体であった場合においてもＯＮ時
の抵抗を十分小さくすることができる。A superconducting coil with a persistent current switch according to a third aspect of the present invention is the superconducting coil with a persistent current switch according to the first aspect, wherein the superconducting core of the superconducting wire forming the superconducting coil and the persistent current switch are provided. It is characterized in that the superconducting cores of the constituent superconducting wires are connected via a metal. When the metal is a superconductor, the resistance when ON can be zero. On the other hand, even when the metal is a normal conductor, it is possible to sufficiently reduce the resistance when ON.
【００１２】請求項４記載の発明に係わる永久電流スイ
ッチ付超電導コイルは、請求項１，２または３における
永久電流スイッチ付超電導コイルであって、前記永久電
流スイッチの前記超電導線は芯材に巻回されており、前
記芯材はその一部にステンレス鋼，ＦＲＰまたはセラミ
ックスを使用していることを特徴とする。芯材として上
記の材料を用いることにより、極低温においても破壊し
にくく、磁場等に影響を受けにくい永久電流スイッチを
実現できる。A superconducting coil with a persistent current switch according to a fourth aspect of the present invention is the superconducting coil with a persistent current switch according to claim 1, 2 or 3, wherein the superconducting wire of the permanent current switch is wound around a core material. The core material is made of stainless steel, FRP or ceramics as a part thereof. By using the above-mentioned materials as the core material, it is possible to realize a permanent current switch that is hard to break even at an extremely low temperature and is hardly affected by a magnetic field or the like.
【００１３】請求項５記載の発明に係わる永久電流スイ
ッチ付超電導コイルは、請求項１，２，３または４にお
ける永久電流スイッチ付超電導コイルであって、前記永
久電流スイッチには前記超電導体を加熱するための発熱
体と前記発熱体を覆う熱絶縁材とをさらに備えることを
特徴とする。これによりＯＮ／ＯＦＦを確実に実施でき
る永久電流スイッチを実現できる。The superconducting coil with a persistent current switch according to the invention of claim 5 is the superconducting coil with a persistent current switch according to claim 1, 2, 3 or 4, in which the superconductor is heated by the permanent current switch. And a heat insulating material that covers the heating element. This makes it possible to realize a permanent current switch that can be reliably turned on and off.
【００１４】請求項６記載の発明に係わる永久電流スイ
ッチ付超電導コイルの製造方法は、超電導線材を用いて
超電導コイルを形成する工程と、ニホウ化マグネシウム
を含む超電導体とそれを覆う金属からなる安定化材とか
らなる超電導線材を用いて永久電流スイッチを形成する
工程と、前記超電導コイルと前記永久電流スイッチを接
続する工程を備えたことを特徴とする。ニホウ化マグネ
シウムを含む超電導体とそれを覆う金属からなる安定化
材とからなる超電導線材を用いて永久電流スイッチを形
成する工程を実施することにより、速やかな常電導転
移、すなわちクエンチ現象が発生しにくい信頼性の高い
永久電流スイッチを製作することができる。According to a sixth aspect of the present invention, there is provided a method of manufacturing a superconducting coil with a persistent current switch, the method comprising the step of forming a superconducting coil using a superconducting wire, a superconductor containing magnesium diboride and a metal covering it. And a step of forming a permanent current switch using a superconducting wire made of a chemical material, and a step of connecting the superconducting coil and the permanent current switch. By carrying out the step of forming a persistent current switch by using a superconducting wire made of a superconductor containing magnesium diboride and a stabilizer made of a metal covering it, a rapid normal transition, that is, a quench phenomenon occurs. It is possible to manufacture a difficult and highly reliable permanent current switch.
【００１５】[0015]
【発明の実施の形態】本発明では永久電流スイッチにニ
ホウ化マグネシウム（ＭｇＢ2 ）超電導線材を用いる。
ＭｇＢ2 超電導体は、高い臨界温度，臨界磁場および臨
界電流を有する線材を比較的容易に得ることができる。
したがって、特に永久電流スイッチにＭｇＢ2 超電導線
材を用いれば、必要な電流を安定に流すことができ、信
頼性および操作性が高い永久電流スイッチを提供するこ
とができる。BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a magnesium diboride (MgB 2 ) superconducting wire is used for a persistent current switch.
The MgB 2 superconductor can relatively easily obtain a wire having a high critical temperature, a critical magnetic field and a critical current.
Therefore, particularly when the MgB 2 superconducting wire is used for the permanent current switch, a required current can be stably supplied, and a persistent current switch having high reliability and operability can be provided.
【００１６】超電導コイルに用いる超電導材はどのよう
なものでも構わない。例えば、NbTi，Ｎｂ3Ｓｎ ，Ｎｂ
3Ａｌ またはＶ3Ｇａ 等の金属系超電導体、Ｂｉ−２２
１２，Ｂｉ−２２２３，Ｙ−１２３等の酸化物超電導
体、またはＭｇＢ2 でも構わない。Any superconducting material can be used for the superconducting coil. For example, NbTi, Nb 3 Sn, Nb
Metallic superconductor such as 3 Al or V 3 Ga, Bi-22
12, an oxide superconductor such as Bi-2223, Y-123, or MgB 2 may be used.
【００１７】本発明において永久電流スイッチに用いた
ＭｇＢ2 超電導線には、安定化材からなるシース中にＭ
ｇＢ2 超電導体の原料粉末を充填し、塑性加工を施す方
法（いわゆるパウダ・イン・チューブ法）によって作製
されたものをより好ましく用いることができる。このよ
うな方法において、安定化材には銅，銀，アルミ等と比
較して電気抵抗率の高い銅−ニッケル合金またはステン
レス鋼を好ましく用いることができる。この方法におい
て、塑性加工には、伸線加工，静水圧プレス加工，圧延
加工等がある。特に、伸線加工，静水圧プレス加工また
は圧延加工との組合せにより、丸断面線材，角断面線材
またはテープ線材等が得られ、このような線材を好まし
く用いることができる。用いられる超電導線は、単芯線
および多芯線のいずれでもよい。In the MgB 2 superconducting wire used for the permanent current switch in the present invention, M is contained in the sheath made of the stabilizing material.
A material prepared by a method of filling the raw material powder of the gB 2 superconductor and performing plastic working (so-called powder-in-tube method) can be more preferably used. In such a method, a copper-nickel alloy or stainless steel having a higher electric resistivity than copper, silver, aluminum, etc. can be preferably used as the stabilizer. In this method, the plastic working includes wire drawing, isostatic pressing, rolling and the like. In particular, a wire having a round cross section, a wire having a square cross section, a tape wire, or the like can be obtained by a combination with wire drawing, isostatic pressing, or rolling, and such a wire can be preferably used. The superconducting wire used may be either a single-core wire or a multi-core wire.
【００１８】超電導コイルを構成する超電導線と永久電
流スイッチを構成する酸化物超電導線とは電気的に接続
される。接続部ではそれぞれの超電導線のコアどうしが
接触していれば電気抵抗はゼロとすることができる。ま
た、接続部では安定化材どうしを接続したり、別途用意
した金属を介して超電導線どうしを接続したりすること
によっても十分電気抵抗を低くすることができる。前記
金属としては鉛，錫，インジウム，アルミニウム，金，
銀，銅およびそれらを含む合金等を用いることができ
る。The superconducting wire forming the superconducting coil and the oxide superconducting wire forming the permanent current switch are electrically connected. If the cores of the respective superconducting wires are in contact with each other at the connecting portion, the electric resistance can be zero. In addition, the electrical resistance can be sufficiently lowered by connecting the stabilizing materials to each other at the connection portion or connecting the superconducting wires to each other through a metal prepared separately. As the metal, lead, tin, indium, aluminum, gold,
It is possible to use silver, copper and alloys containing them.
【００１９】永久電流スイッチ機構には、熱式，磁気式
等の機構を用いることができる。一般に、熱式のスイッ
チ機構がよく利用される。スイッチングに用いられる発
熱体には、マンガニン線等の電気抵抗により発熱する材
料を好ましく用いることができる。超電導スイッチの使
用時には、発熱体は、電源回路と、発熱を制御する手段
に接続される。発熱体は、超電導線に接触するように設
けられてもよく、電気絶縁材料を介して超電導線上に設
けられてもよい。As the permanent current switch mechanism, a thermal type mechanism or a magnetic type mechanism can be used. Generally, a thermal switch mechanism is often used. As a heating element used for switching, a material that generates heat due to electric resistance such as manganin wire can be preferably used. When using the superconducting switch, the heating element is connected to the power supply circuit and means for controlling heat generation. The heating element may be provided in contact with the superconducting wire, or may be provided on the superconducting wire via an electrically insulating material.
【００２０】本発明における永久電流スイッチが液体ヘ
リウム，気体ヘリウム等の冷媒に接触させられる場合、
発熱体は熱絶縁材によって覆われる。熱絶縁材は、冷却
のための環境と、超電導線材および発熱体との間に適当
な温度勾配を形成し、発熱体および線材が急激に冷却さ
れないよう熱緩衝材としての役割を果たす。また熱絶縁
材は、スイッチのＯＦＦ時に超電導線を十分加熱するこ
とができるよう、発熱体を保護する。熱絶縁材には、た
とえば、エポキシ樹脂等の樹脂材料，樹脂コンパウン
ド，シリコン系コンパウンド等を用いることができる。
熱絶縁材には、使用する温度において好ましくは１０-3
Ｗ／cm・Ｋ〜１０-5Ｗ／cm・Ｋの熱伝導率を有する材料
を用いることができる。When the permanent current switch of the present invention is brought into contact with a refrigerant such as liquid helium or gaseous helium,
The heating element is covered with a heat insulating material. The heat insulating material forms an appropriate temperature gradient between the environment for cooling and the superconducting wire and the heating element, and acts as a heat buffering material so that the heating element and the wire are not rapidly cooled. The heat insulating material protects the heating element so that the superconducting wire can be sufficiently heated when the switch is turned off. As the heat insulating material, for example, a resin material such as an epoxy resin, a resin compound, a silicon compound, or the like can be used.
The heat insulating material preferably has a temperature of 10 −3 at the use temperature.
A material having a thermal conductivity of W / cm · K to 10 −5 W / cm · K can be used.
【００２１】本発明における超電導コイルの形状は特に
限定されるものではない。必要に応じてソレノイドコイ
ル，パンケーキコイル等が用いられる。超電導コイルお
よびスイッチは、液体ヘリウム，液体窒素等の冷媒によ
り直接的に冷却することができる。また、冷凍機によっ
て冷却を行ってもよい。冷凍機を用いる場合、永久電流
スイッチの発熱体上に熱絶縁材を設けなくともよい。The shape of the superconducting coil in the present invention is not particularly limited. A solenoid coil, a pancake coil, etc. are used as needed. The superconducting coil and switch can be directly cooled by a coolant such as liquid helium or liquid nitrogen. Moreover, you may cool with a refrigerator. When a refrigerator is used, it is not necessary to provide a heat insulating material on the heating element of the permanent current switch.
【００２２】（実施例１）図２に本発明の実施例１を示
す。(Embodiment 1) FIG. 2 shows Embodiment 1 of the present invention.
【００２３】超電導コイルに用いた超電導線は超電導材
としてＮｂＴｉ、安定化材として銅を用いた直径１mmの
ＮｂＴｉ超電導線１１である。これをアルミニウム合金
製ボビン１２に巻き、内径５２mmφ，外径７５mmφ，高
さ８０mmのソレノイドコイルとした。巻線間の絶縁は、
エナメル絶縁によって行った。ソレノイドコイルのター
ン数は８００ターン，２０Ａの電流を流したときの中心
磁場は０.１Ｔ であった。The superconducting wire used for the superconducting coil is NbTi superconducting wire 11 having a diameter of 1 mm and using NbTi as a superconducting material and copper as a stabilizing material. This was wound around an aluminum alloy bobbin 12 to form a solenoid coil having an inner diameter of 52 mmφ, an outer diameter of 75 mmφ and a height of 80 mm. The insulation between the windings is
Made by enamel insulation. The number of turns of the solenoid coil was 800, and the central magnetic field when a current of 20 A was passed was 0.1T.
【００２４】永久電流スイッチに用いた超電導線は超電
導材としてＭｇＢ2 、安定化材として銅−ニッケル合金
を用いた直径１.２mm のＭｇＢ2 超電導線２１である。
これをステンレス鋼製芯材２２に巻いた。このときのＭ
ｇＢ2 超電導線の長さは約５０ｍである。ＭｇＢ2 超電
導線を巻いた上からエポキシ系樹脂を用いた絶縁材２３
を塗り、その上にマンガニン線２４を巻回している。マ
ンガニン線には銅線２５ａ，２５ｂを接続し、銅線には
外部のヒータ電源を接続できる構造である。ＭｇＢ2超
電導線２１，ＮｂＴｉ超電導線１１，電流リード線１３
ａ，１３ｂは超電導線接続部３１ａ，３１ｂにおいて接
続されている。本実施例においては、超電導線接続部１
３ａ，１３ｂではそれぞれの超電導線の安定化材が除去
され超電導コアどうしが接触している。接続部の機械的
強度を増加するため、接続部の上にはハンダおよびエポ
キシ樹脂が塗りこまれている。The superconducting wire used for the permanent current switch is MgB 2 as a superconducting material and a MgB 2 superconducting wire 21 having a diameter of 1.2 mm and using a copper-nickel alloy as a stabilizing material.
This was wound around a stainless steel core material 22. M at this time
The length of the gB 2 superconducting wire is about 50 m. Insulation material 23 using epoxy resin on the MgB 2 superconducting wire
Is applied, and a manganin wire 24 is wound on it. The manganin wire is connected to the copper wires 25a and 25b, and the copper wire is connected to an external heater power source. MgB 2 superconducting wire 21, NbTi superconducting wire 11, current lead wire 13
a and 13b are connected at superconducting wire connection portions 31a and 31b. In the present embodiment, the superconducting wire connecting portion 1
In 3a and 13b, the stabilizing material of each superconducting wire is removed and the superconducting cores are in contact with each other. To increase the mechanical strength of the connection, solder and epoxy resin are coated on the connection.
【００２５】また、電流リード線１３ａ，１３ｂの他端
には励磁用電源を接続できる構造である。Further, the other ends of the current lead wires 13a and 13b are connected to an exciting power source.
【００２６】以上のように構成された構造体を液体ヘリ
ウムに浸漬し、銅線２５ａ，２５ｂを介してマンガニン
線２４に電流を流して加熱を行い、永久電流スイッチと
して働く部分のＭｇＢ2 超電導線を常電導状態(４０Ｋ
以上の温度)に転移させた。その状態で電流リード線１
３ａ，１３ｂを介してソレノイドコイルに電源より電流
を流した。ソレノイドコイルが励磁されたら、マンガニ
ン線２４による加熱をやめ、スイッチの部分のＭｇＢ2
超電導線２１を超電導状態に戻した。この状態で励磁電
源を取り外した結果、永久電流モードの状態が得られ
た。このときの接合部の電気抵抗は０.１ｎΩ 以下であ
った。一方、超電導線接続部１３ａ，１３ｂにおいて超
電導コアどうしの接続に鉛−錫ハンダを用いた場合、電
気抵抗の測定値は約１０ｎΩであった。このように本発
明によれば、接合による電気抵抗を顕著に低減すること
ができた。The structure constructed as described above is immersed in liquid helium, and an electric current is applied to the manganin wire 24 through the copper wires 25a and 25b to heat it, and the MgB 2 superconducting wire of the portion which functions as a permanent current switch is heated. In the normal conduction state (40K
(Temperature above). Current lead wire 1 in that state
A current was supplied from a power supply to the solenoid coil via 3a and 13b. When the solenoid coil is excited, heating by the manganin wire 24 is stopped, and MgB 2 in the switch part
The superconducting wire 21 was returned to the superconducting state. As a result of removing the exciting power supply in this state, a state of a permanent current mode was obtained. The electrical resistance of the joint at this time was 0.1 nΩ or less. On the other hand, when lead-tin solder was used to connect the superconducting cores in the superconducting wire connecting portions 13a and 13b, the measured electric resistance was about 10 nΩ. As described above, according to the present invention, the electric resistance due to the bonding can be remarkably reduced.
【００２７】（実施例２）実施例１では、図２における
超電導線接続部３１ａ，３１ｂでは、接続する超電導コ
アどうしを直接接続していた。しかしながら、超電導コ
アどうしを接続しなくても、すなわち超電導線の安定化
材を残したままで接続長さを十分長くすることにより接
続抵抗を十分低くすることができた。この時、２本の超
電導線の間には厚さ０.１mm のインジウムシートを挿入
している。例えば、ＭｇＢ2 超電導線２１，ＮｂＴｉ超
電導線１１の接続長さを１ｍとすることにより、接続部
の電気抵抗を０.２ｎΩ とすることができた。また、実
施例と同様の手順により永久電流モード状態を実現でき
ることも確認した。(Embodiment 2) In Embodiment 1, in the superconducting wire connecting portions 31a and 31b in FIG. 2, the superconducting cores to be connected were directly connected. However, even if the superconducting cores were not connected to each other, that is, by making the connecting length sufficiently long while leaving the stabilizing material for the superconducting wire, the connecting resistance could be made sufficiently low. At this time, an indium sheet having a thickness of 0.1 mm is inserted between the two superconducting wires. For example, by setting the connection length of the MgB 2 superconducting wire 21 and the NbTi superconducting wire 11 to 1 m, the electric resistance of the connecting portion could be set to 0.2 nΩ. It was also confirmed that the permanent current mode state could be realized by the same procedure as in the example.
【００２８】[0028]
【発明の効果】上述したように、本発明によれば以下の
ような特性を備えた永久電流スイッチ付超電導コイルを
提供することができる。
（１）永久電流スイッチのＯＮ時において電気抵抗が顕
著に小さい。
（２）永久電流スイッチのＯＦＦ時において電気抵抗は
十分に大きい。
（３）永久電流スイッチに十分な電流を安定に流すこと
ができる。
（４）永久電流スイッチにおいて必要時以外に常電導転
移しない
本発明はエネルギ貯蔵用マグネット，ＮＭＲ用マグネッ
ト，ＭＲＩ用マグネット等に利用すると効果的である。As described above, according to the present invention, it is possible to provide a superconducting coil with a persistent current switch having the following characteristics. (1) The electric resistance is remarkably small when the permanent current switch is ON. (2) The electric resistance is sufficiently large when the permanent current switch is OFF. (3) A sufficient current can be stably supplied to the permanent current switch. (4) The present invention, which does not cause a normal conduction transition in a permanent current switch except when necessary, is effectively applied to an energy storage magnet, an NMR magnet, an MRI magnet, and the like.
【図１】永久電流スイッチ付超電導コイルの回路図。FIG. 1 is a circuit diagram of a superconducting coil with a persistent current switch.
【図２】実施例２の概念図。FIG. 2 is a conceptual diagram of a second embodiment.
１…超電導マグネット、２…短絡スイッチ（永久電流ス
イッチ）、３…電源、１１…ＮｂＴｉ超電導線、１２…
アルミニウム合金製ボビン、１３ａ，１３ｂ…電流リー
ド線、２１…ＭｇＢ2 超電導線、２２…ステンレス鋼製
芯材、２３…絶縁材、２４…マンガニン線、２５ａ，２
５ｂ…銅線、３１ａ，３１ｂ…超電導線接続部。1 ... Superconducting magnet, 2 ... Short-circuit switch (permanent current switch), 3 ... Power supply, 11 ... NbTi superconducting wire, 12 ...
Aluminum alloy bobbin, 13a, 13b ... Current lead wire, 21 ... MgB 2 superconducting wire, 22 ... Stainless steel core material, 23 ... Insulating material, 24 ... Manganin wire, 25a, 2
5b ... Copper wire, 31a, 31b ... Superconducting wire connection part.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 鈴木 保夫 茨城県日立市大みか町七丁目１番１号 株 式会社日立製作所日立研究所内 (72)発明者 岡田 道哉 茨城県日立市大みか町七丁目１番１号 株 式会社日立製作所日立研究所内 Ｆターム(参考） 4M114 AA15 AA29 CC03 CC11 CC16 CC18 DB13 DB14 DB16 DB62 DB63 DB64 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Yasuo Suzuki 7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Michiya Okada 7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture Inside the Hitachi Research Laboratory, Hitachi Ltd. F term (reference) 4M114 AA15 AA29 CC03 CC11 CC16 CC18 DB13 DB14 DB16 DB62 DB63 DB64
Claims (6)
る永久電流スイッチとを備える永久電流スイッチ付超電
導コイルにおいて、前記永久電流スイッチはニホウ化マ
グネシウムを含む超電導体とそれを覆う金属からなる安
定化材とからなる超電導線材を備え、前記短絡のため、
前記超電導コイルを構成する超電導線材の超電導コアと
前記永久電流スイッチを構成する前記超電導線材の超電
導コアは接触していることを特徴とする永久電流スイッ
チ付超電導コイル。1. A superconducting coil with a permanent current switch, comprising: a superconducting coil; and a permanent current switch for short-circuiting the superconducting coil, wherein the permanent current switch is a stabilizing material made of a superconductor containing magnesium diboride and a metal covering the superconductor. And a superconducting wire consisting of, due to the short circuit,
A superconducting coil with a persistent current switch, wherein a superconducting core of a superconducting wire forming the superconducting coil and a superconducting core of the superconducting wire forming the persistent current switch are in contact with each other.
導コイルであって、前記超電導コイルを構成する超電導
線材の超電導コアと前記永久電流スイッチを構成する前
記超電導線材の超電導コアは前記安定化材を介して接続
していることを特徴とする永久電流スイッチ付超電導コ
イル。2. The superconducting coil with a persistent current switch according to claim 1, wherein the superconducting core of the superconducting wire forming the superconducting coil and the superconducting core of the superconducting wire forming the persistent current switch are made of the stabilizing material. A superconducting coil with a persistent current switch, characterized in that it is connected via.
導コイルであって、前記超電導コイルを構成する超電導
線材の超電導コアと前記永久電流スイッチを構成する前
記超電導線材の超電導コアは金属を介して接続している
ことを特徴とする永久電流スイッチ付超電導コイル。3. The superconducting coil with a persistent current switch according to claim 1, wherein the superconducting core of the superconducting wire forming the superconducting coil and the superconducting core of the superconducting wire forming the persistent current switch are connected via a metal. A superconducting coil with a permanent current switch, which is characterized by
イッチ付超電導コイルであって、前記永久電流スイッチ
の前記超電導線は芯材に巻回されており、前記芯材はそ
の一部にステンレス鋼，ＦＲＰまたはセラミックスを使
用していることを特徴とする永久電流スイッチ付超電導
コイル。4. The superconducting coil with a persistent current switch according to claim 1, 2 or 3, wherein the superconducting wire of the persistent current switch is wound around a core material, and the core material is made of stainless steel. A superconducting coil with a permanent current switch characterized by using steel, FRP or ceramics.
流スイッチ付超電導コイルであって、前記永久電流スイ
ッチには前記超電導体を加熱するための発熱体と前記発
熱体を覆う熱絶縁材とを備えることを特徴とする永久電
流スイッチ付超電導コイル。5. The superconducting coil with a persistent current switch according to claim 1, 2, 3 or 4, wherein the permanent current switch has a heating element for heating the superconductor and a heat insulating material covering the heating element. A superconducting coil with a persistent current switch, characterized by comprising:
る工程と、ニホウ化マグネシウムを含む超電導体とそれ
を覆う金属からなる安定化材とからなる超電導線材を用
いて永久電流スイッチを形成する工程と、前記超電導コ
イルと前記永久電流スイッチを接続する工程を備えたこ
とを特徴とする永久電流スイッチ付超電導コイルの製造
方法。6. A step of forming a superconducting coil using a superconducting wire, and a step of forming a persistent current switch using a superconducting wire made of a superconductor containing magnesium diboride and a stabilizer made of a metal covering the superconductor. And a step of connecting the superconducting coil and the persistent current switch, and a method of manufacturing a superconducting coil with a persistent current switch.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001222398A JP2003037303A (en) | 2001-07-24 | 2001-07-24 | Superconducting coil with permanent current switch using magnesium diboride superconducting wire material and its manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001222398A JP2003037303A (en) | 2001-07-24 | 2001-07-24 | Superconducting coil with permanent current switch using magnesium diboride superconducting wire material and its manufacturing method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2003037303A true JP2003037303A (en) | 2003-02-07 |
Family
ID=19055879
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001222398A Pending JP2003037303A (en) | 2001-07-24 | 2001-07-24 | Superconducting coil with permanent current switch using magnesium diboride superconducting wire material and its manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2003037303A (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003273415A (en) * | 2002-01-15 | 2003-09-26 | Siemens Ag | Superconducting switching device |
| US6957480B2 (en) * | 2002-05-10 | 2005-10-25 | Edison S.P.A.. | Method for the production of superconductive wires based on hollow filaments made of MgB2 |
| JP2006228797A (en) * | 2005-02-15 | 2006-08-31 | Hitachi Ltd | Permanent current switch using magnesium diboride and its manufacturing method |
| JP2007221013A (en) * | 2006-02-20 | 2007-08-30 | Hitachi Ltd | Persistent current switch |
| JP2009004794A (en) * | 2008-07-10 | 2009-01-08 | Hitachi Ltd | Persistent current switch |
| JP2009267182A (en) * | 2008-04-28 | 2009-11-12 | Hitachi Ltd | Superconducting magnet |
| US7684839B2 (en) | 2004-12-14 | 2010-03-23 | Hitachi, Ltd. | Connecting structure for magnesium diboride superconducting wire and a method of connecting the same |
| JP2011187524A (en) * | 2010-03-05 | 2011-09-22 | Hitachi Ltd | High-temperature superconducting parallel conductor, high-temperature superconducting coil using the same, and high-temperature superconducting magnet |
| JP2013122981A (en) * | 2011-12-12 | 2013-06-20 | Hitachi Ltd | Superconducting magnet and method for connecting superconducting wire rod |
| JP2019096648A (en) * | 2017-11-17 | 2019-06-20 | 株式会社東芝 | Operational method of superconducting magnet device and the superconducting magnet device |
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2001
- 2001-07-24 JP JP2001222398A patent/JP2003037303A/en active Pending
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6809618B2 (en) * | 2002-01-15 | 2004-10-26 | Siemens Aktiengesellschaft | Switching device for superconducting technology |
| JP2003273415A (en) * | 2002-01-15 | 2003-09-26 | Siemens Ag | Superconducting switching device |
| JP4612991B2 (en) * | 2002-01-15 | 2011-01-12 | シーメンス アクチエンゲゼルシヤフト | Superconducting switch device |
| US6957480B2 (en) * | 2002-05-10 | 2005-10-25 | Edison S.P.A.. | Method for the production of superconductive wires based on hollow filaments made of MgB2 |
| US7684839B2 (en) | 2004-12-14 | 2010-03-23 | Hitachi, Ltd. | Connecting structure for magnesium diboride superconducting wire and a method of connecting the same |
| JP2006228797A (en) * | 2005-02-15 | 2006-08-31 | Hitachi Ltd | Permanent current switch using magnesium diboride and its manufacturing method |
| JP4728007B2 (en) * | 2005-02-15 | 2011-07-20 | 株式会社日立製作所 | Persistent current switch using magnesium diboride and method of manufacturing the same |
| US7602269B2 (en) | 2006-02-20 | 2009-10-13 | Hitachi, Ltd. | Permanent current switch |
| JP2007221013A (en) * | 2006-02-20 | 2007-08-30 | Hitachi Ltd | Persistent current switch |
| JP2009267182A (en) * | 2008-04-28 | 2009-11-12 | Hitachi Ltd | Superconducting magnet |
| US8077001B2 (en) | 2008-04-28 | 2011-12-13 | Hitachi, Ltd. | Superconducting magnet |
| JP2009004794A (en) * | 2008-07-10 | 2009-01-08 | Hitachi Ltd | Persistent current switch |
| JP2011187524A (en) * | 2010-03-05 | 2011-09-22 | Hitachi Ltd | High-temperature superconducting parallel conductor, high-temperature superconducting coil using the same, and high-temperature superconducting magnet |
| JP2013122981A (en) * | 2011-12-12 | 2013-06-20 | Hitachi Ltd | Superconducting magnet and method for connecting superconducting wire rod |
| JP2019096648A (en) * | 2017-11-17 | 2019-06-20 | 株式会社東芝 | Operational method of superconducting magnet device and the superconducting magnet device |
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