JPH01117004A - Superconducting magnet - Google Patents
Superconducting magnetInfo
- Publication number
- JPH01117004A JPH01117004A JP62273845A JP27384587A JPH01117004A JP H01117004 A JPH01117004 A JP H01117004A JP 62273845 A JP62273845 A JP 62273845A JP 27384587 A JP27384587 A JP 27384587A JP H01117004 A JPH01117004 A JP H01117004A
- Authority
- JP
- Japan
- Prior art keywords
- superconducting
- refrigerant
- superconducting coil
- excitation
- switch
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000003507 refrigerant Substances 0.000 claims abstract description 32
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 18
- 239000000463 material Substances 0.000 claims abstract description 12
- 239000007788 liquid Substances 0.000 claims abstract description 10
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 9
- 230000002085 persistent effect Effects 0.000 claims description 18
- 238000009413 insulation Methods 0.000 claims description 3
- 230000005284 excitation Effects 0.000 abstract description 31
- 230000001747 exhibiting effect Effects 0.000 abstract description 3
- AFYPFACVUDMOHA-UHFFFAOYSA-N chlorotrifluoromethane Chemical compound FC(F)(F)Cl AFYPFACVUDMOHA-UHFFFAOYSA-N 0.000 abstract description 2
- 238000000034 method Methods 0.000 description 18
- 238000010438 heat treatment Methods 0.000 description 6
- 238000010791 quenching Methods 0.000 description 6
- 230000000171 quenching effect Effects 0.000 description 6
- 238000003780 insertion Methods 0.000 description 5
- 230000037431 insertion Effects 0.000 description 5
- 238000001816 cooling Methods 0.000 description 2
- 230000005347 demagnetization Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000002595 magnetic resonance imaging Methods 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
Landscapes
- Magnetic Resonance Imaging Apparatus (AREA)
Abstract
Description
【発明の詳細な説明】
［発明の目的］
（産業上の利用分野）
本発明は、高強度静磁場内に配置した被検体にＲＦパル
スを印加することによって生じる磁気共鳴現象を利用し
て、被検体の断層面内の所定の原子核のスピン密度分布
、緩和時定数分布または化学シフト値の計測を行い、こ
の計測値に基づいて被検体の医用診断情報を得るように
した磁気共＝ １−
鳴イメージング装置の前記高強度静磁場を発生するため
等に用いられる超電導磁石に関し、特に、励磁作業を簡
単に行えるようにした超電導磁石に関する。[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention utilizes a magnetic resonance phenomenon caused by applying an RF pulse to a subject placed in a high-intensity static magnetic field. A magnetic sensor that measures the spin density distribution, relaxation time constant distribution, or chemical shift value of a predetermined atomic nucleus within the tomographic plane of the subject, and obtains medical diagnostic information of the subject based on the measured values = 1- The present invention relates to a superconducting magnet used for generating the high-intensity static magnetic field of a sound imaging device, and particularly relates to a superconducting magnet that allows easy excitation work.
（従来の技術） 超電導磁石の特有な励磁方法に永久電流モードがある。(Conventional technology) Persistent current mode is a unique excitation method for superconducting magnets.
以下、この種の超電導磁石の従来例を第２図を参照して
説明する。Hereinafter, a conventional example of this type of superconducting magnet will be explained with reference to FIG.
第２図に示すように、真空容器１内には、絶対零度に近
い温度で超電導現象を示す超電導材料にて製作された超
電導コイル２と、この超電導コイ、ル２を超電導状態と
するための液体ヘリウム等の絶対零度に近い温度の極低
温冷媒３とが気密にして収容されている。As shown in FIG. 2, inside the vacuum vessel 1 is a superconducting coil 2 made of a superconducting material that exhibits superconducting phenomena at temperatures close to absolute zero, and a superconducting coil 2 made of a superconducting material that exhibits a superconducting phenomenon at a temperature close to absolute zero. A cryogenic refrigerant 3 having a temperature close to absolute zero, such as liquid helium, is housed in an airtight manner.
また、図示はしないが、輻射シールドやこの輻射シール
ドを冷却するための冷媒や他の冷却手段が真空容器１内
に配設されることもある。Further, although not shown, a radiation shield, a refrigerant, or other cooling means for cooling the radiation shield may be provided in the vacuum container 1.
さらに、超電導コイル２から真空容器１の電流リード挿
入部１ａの近傍に至って超電導コイル２からの導出線２
ａが導出されている。そして、真空容器１外には電源４
ａ、スイッチ４ｂからなる励磁制御部４が設けられてい
る。Furthermore, the lead-out wire 2 from the superconducting coil 2 reaches the vicinity of the current lead insertion part 1a of the vacuum vessel 1.
a has been derived. And, outside the vacuum container 1, there is a power supply 4.
An excitation control section 4 including a switch 4b and a switch 4b is provided.
また、超電導コイル２に対しては並列に永久電流スイッ
チ５のスイッチ用超電導コイル（超電導コイル２と同じ
材質又はほぼ同じ温度で超電導状態を示す材質からなる
）５ａが設けられ、このスイッチ用超電導コイル５ａに
近接して永久電流スイッチ５のヒータ５ｂが設けられ、
このヒータ５ｂは真空容器１外に設けた電源５Ｃ１，ス
イッチ５ｃ２からなるヒータ制御部５Ｃに接続されてい
る。Further, a switch superconducting coil 5a (made of the same material as the superconducting coil 2 or a material exhibiting a superconducting state at approximately the same temperature) of the persistent current switch 5 is provided in parallel with the superconducting coil 2. A heater 5b of the persistent current switch 5 is provided adjacent to the heater 5a,
This heater 5b is connected to a heater control section 5C, which is provided outside the vacuum container 1 and includes a power source 5C1 and a switch 5c2.
以上の構成の従来の超電導磁石の励磁手順について説明
する。すなわち、真空容器１の電流リード挿入部１ａに
対して電流リード６を差込む。次に、永久電流スイッチ
５をオフする。つまり、スイッチ５ｃ２をオンしてヒー
タ５ｂを加熱することにより、スイッチ用超電導コイル
５ａは加熱に伴って超電導状態が失われ、抵抗を示すこ
とになる。これにより、超電導コイル２とスイッチ用超
電導コイル５ａとの回路は、それまで閉回路を形成して
永久電流モードとなっていたものが解除され、電流リー
ド６を介して励磁制御部４と超電導コイル２との閉回路
が形成されることになる。The excitation procedure of the conventional superconducting magnet having the above configuration will be explained. That is, the current lead 6 is inserted into the current lead insertion portion 1a of the vacuum container 1. Next, the persistent current switch 5 is turned off. That is, by turning on the switch 5c2 and heating the heater 5b, the superconducting coil 5a for the switch loses its superconducting state as it is heated and exhibits resistance. As a result, the circuit between the superconducting coil 2 and the superconducting coil 5a for the switch, which had been in the persistent current mode by forming a closed circuit, is released, and the excitation control unit 4 and the superconducting coil are connected via the current lead 6. A closed circuit with 2 will be formed.
ここで、励磁制御部４のスイッチ４Ｃをオンし、電源４
ａから例えば１０Ａ／分で電流を超電導コイル２に通電
する。ここで、設定電流に達したところで、永久電流ス
イッチ５をオンする。つまり、スイッチ５ｃ２をオフし
てヒータ５ｂの加熱を解除することにより、スイッチ用
超電導コイル５ａは加熱解除に伴って超電導状態に復帰
し、抵抗は無くなる。これにより、超電導コイル２とス
イッチ用超電導コイル５ａとの回路は閉回路を形成して
永久電流モードとなる。Here, switch 4C of excitation control section 4 is turned on, and power supply 4C is turned on.
A current is applied to the superconducting coil 2 at a rate of, for example, 10 A/min. Here, when the set current is reached, the persistent current switch 5 is turned on. That is, by turning off the switch 5c2 and canceling the heating of the heater 5b, the switching superconducting coil 5a returns to the superconducting state as the heating is canceled, and the resistance disappears. As a result, the circuit between the superconducting coil 2 and the switching superconducting coil 5a forms a closed circuit and enters the persistent current mode.
以上の状態にした後、電流リード６及び電流リード挿入
部１ａから、極超低温状態となっている真空容器１内へ
の熱侵入を防ぐため、電流を零Ａに下げた後に、電流リ
ード６を電流リード挿入部１ａから抜取り、これにて励
磁作業を終了する。After the above conditions are established, in order to prevent heat from entering the vacuum vessel 1, which is in an extremely low temperature state, from the current lead 6 and the current lead insertion part 1a, the current is lowered to zero A, and then the current lead 6 is removed. The current lead is removed from the insertion part 1a, and the excitation work is completed.
以上の励磁手順は、一つの電流を設定する、つまり一つ
の磁場強度を発生するに至るための手順であるが、近時
に至って、この種の磁気共鳴イメージング装置に用いる
超電導磁石は、可変磁場強度にすることが行われたり、
また、非運転時には減消磁を行ったり、さらに磁性体吸
着事故時の緊急減消磁を行ったりする必要性が出てきた
。このため、上述した励磁手順を頻繁且つ緊急に行うこ
とが想定されている。The excitation procedure described above is a procedure for setting one current, that is, generating one magnetic field strength.However, recently, superconducting magnets used in this type of magnetic resonance imaging apparatus have a variable magnetic field strength. or
In addition, it has become necessary to perform demagnetization during non-operation, and also to perform emergency demagnetization in the event of an accident due to adsorption of a magnetic substance. For this reason, it is assumed that the excitation procedure described above will be performed frequently and urgently.
この場合、上述した励磁手順を頻繁且つ緊急に行うこと
は、電流リード６の電流リード挿入部１ａに対する抜き
差しを頻繁且つ緊急に行うことであるので、この電流リ
ード６の抜き差しに際して真空容器１内へ熱が侵入する
慮れがある。真空容器１内へ熱が侵入すると、クエンチ
ングの発生等の事故を誘発する慮れがあった。In this case, performing the excitation procedure described above frequently and urgently means frequently and urgently inserting and removing the current lead 6 into and out of the current lead insertion portion 1a. There is a risk of heat intrusion. If heat penetrates into the vacuum container 1, there is a possibility that accidents such as quenching may occur.
（発明が解決しようとする問題点）
このように従来の技術においては、一つの磁場強度を設
定するための励磁手順としてその都度電流リードを真空
容器に抜き差しするため、励磁手順を頻繁且つ緊急に行
うときにはクエンチングの発生等の事故を誘発する慮れ
があり、問題であった。(Problems to be Solved by the Invention) In this way, in the conventional technology, the excitation procedure for setting one magnetic field strength involves inserting and removing the current lead into and out of the vacuum container each time, so the excitation procedure is frequently and urgently required. When doing so, there was a risk of causing accidents such as quenching, which was a problem.
そこで本発明の目的は、励磁手順を頻繁且つ緊急に行う
ときであってもクエンチングの発生等の事故を誘発する
慮れが無いようにした超電導磁石を提供することにある
。SUMMARY OF THE INVENTION An object of the present invention is to provide a superconducting magnet that is free from the possibility of causing accidents such as quenching even when excitation procedures are performed frequently and urgently.
［発明の構成］
（問題点を解決するための手段）
本発明は上記問題点を解決し且つ目的を達成するために
次のような手段を講じた構成としている。すなわち、本
発明による超電導磁石は、液体窒素等の高温冷媒を収容
する真空断熱構造を有さない冷媒容器内に、前記高温冷
媒により超電導現象を示す高温超電導材料からなる超電
導コイル及びその冷媒を収容し、且つ永久電流スイッチ
を設けると共に前記超電導コイルから前記冷媒容器の外
に低抵抗を有する電流リードを導出した構成としたこと
を特徴とする。[Structure of the Invention] (Means for Solving the Problems) The present invention has a structure in which the following measures are taken to solve the above problems and achieve the object. That is, the superconducting magnet according to the present invention accommodates a superconducting coil made of a high-temperature superconducting material that exhibits a superconducting phenomenon due to the high-temperature refrigerant and its refrigerant in a refrigerant container that does not have a vacuum insulation structure and stores a high-temperature refrigerant such as liquid nitrogen. The present invention is characterized in that a persistent current switch is provided and a current lead having low resistance is led out from the superconducting coil to the outside of the refrigerant container.
（作用）
このような構成によれば、低抵抗を有する電流リードは
、常に、液体窒素等の高温冷媒により超電導現象を示す
高温超電導材料からなる超電導コイルに接続されている
ので、永久電流スイッチのオン、オフするだけで、励磁
手順を実施することができ、この場合、冷媒容器内には
熱の侵入は無く、たとえ励磁手順を頻繁且つ緊急に行っ
てもクエンチングの発生等の事故を誘発する慮れはない
。(Function) According to this configuration, the current lead having low resistance is always connected to the superconducting coil made of a high temperature superconducting material that exhibits a superconducting phenomenon by a high temperature refrigerant such as liquid nitrogen. The excitation procedure can be performed simply by turning it on and off, and in this case, no heat will enter the refrigerant container, and even if the excitation procedure is performed frequently and urgently, it will cause accidents such as quenching. There is no reason to do so.
（実施例）
以下本発明にかかる超電導磁石の一実施例を第１図を参
照して説明する。(Example) An example of a superconducting magnet according to the present invention will be described below with reference to FIG.
第１図に示すように、液体窒素等の高温冷媒を収容する
真空断熱構造を有さない冷媒容器１１内には、液体窒素
等の高温冷媒により超電導現象を示す高温超電導材料か
らなる超電導コイル１２と、超電導コイル１２を超電導
状態とするための液体窒素等の高温冷媒１３とが収容さ
れているまた、超電導コイ／ｌ；１２から冷媒容器１１
の壁近傍に至って超電導コイル１２からの導出線１２ａ
が導出されている。そして、冷媒容器１１外には電源１
４ａ、スイッチ１４ｂからなる励磁−７＝
制御部１４が設けられている。そして、励磁制御部１４
と導出線１２ａとは、冷媒容器１１の壁に貫通して設け
た低抵抗を有する電流リード１６により接続されている
。この場合、電流リード１６をコネクタ構成とし、これ
を冷媒容器１１の壁に内外を貫通してもうける。これに
より、励磁制御部１４と超電導コイル１２とは常時接続
型の電流リード１６により接続されることになる。As shown in FIG. 1, in a refrigerant container 11 that does not have a vacuum insulation structure and accommodates a high-temperature refrigerant such as liquid nitrogen, there is a superconducting coil 12 made of a high-temperature superconducting material that exhibits a superconducting phenomenon due to the high-temperature refrigerant such as liquid nitrogen. and a high-temperature refrigerant 13 such as liquid nitrogen for bringing the superconducting coil 12 into a superconducting state.
The lead wire 12a from the superconducting coil 12 reaches near the wall of
has been derived. A power source 1 is provided outside the refrigerant container 11.
An excitation-7=control unit 14 consisting of a switch 4a and a switch 14b is provided. Then, the excitation control section 14
and the lead-out wire 12a are connected by a current lead 16 having a low resistance and provided through the wall of the refrigerant container 11. In this case, the current lead 16 has a connector configuration and is provided through the wall of the refrigerant container 11 from the inside and outside. Thereby, the excitation control unit 14 and the superconducting coil 12 are connected by the always-connected current lead 16.
ここで、低抵抗を有する電流リード１６の抵抗値をＲａ
とし、後述するスイッチ用超電導コイル１５ａが超電導
状態が失われたときの抵抗値をＲｂとすると、Ｒａ ＞
Ｒｂである。Here, the resistance value of the current lead 16 having low resistance is Ra
If the resistance value when the superconducting coil 15a for a switch, which will be described later, loses its superconducting state is Rb, then Ra >
It is Rb.
また、超電導コイル１２に対しては並列に永久電流スイ
ッチ１５のスイッチ用超電導コイル（超電導コイル１２
と同じ材質又はほぼ同じ温度で超電導状態を示す材質か
らなる）１５ａが設けられ、このスイッチ用超電導コイ
ル１５ａに近接して永久電流スイッチ１５のヒータ１５
ｂが設けられ、このヒータ１５ｂは冷媒容器１１外に設
けた電源１５ｃｌ、スイッチ１５Ｃ２からなるヒータ制
御部１５ｃに接続されている。In addition, the superconducting coil for switching of the persistent current switch 15 (superconducting coil 12
A heater 15a of the persistent current switch 15 is provided in close proximity to the switch superconducting coil 15a.
b is provided, and this heater 15b is connected to a heater control section 15c consisting of a power source 15cl and a switch 15C2 provided outside the refrigerant container 11.
以上の構成の本実施例の超電導磁石の励磁手順について
説明する。すなわち、永久電流スイッチ１５をオフする
。つまり、スイッチ１５Ｃ２をオンしてヒータ１５ｂを
加熱することにより、スイッチ用超電導コイル１５ａは
加熱に伴って超電導状態が失われ、抵抗Ｒｂを示すこと
になる。これにより、ＲＢ ＞ Ｒｈであるので、超電
導コイル１２とスイッチ用超電導コイル１５ａとの回路
は、それまで閉回路を形成して永久電流モードとなって
いたものが解除され、Ｒａ ＞Ｒｂなる関係を有する抵
抗値Ｒａの電流リード１６を介して励磁制御部１４と超
電導コイル１２との閉回路が形成されることになる。The excitation procedure for the superconducting magnet of this embodiment having the above configuration will be explained. That is, the persistent current switch 15 is turned off. That is, by turning on the switch 15C2 and heating the heater 15b, the switching superconducting coil 15a loses its superconducting state as it is heated, and exhibits resistance Rb. As a result, since RB > Rh, the circuit between the superconducting coil 12 and the switching superconducting coil 15a, which had been in a closed circuit and in a persistent current mode, is released, and the relationship Ra > Rb is established. A closed circuit between the excitation control unit 14 and the superconducting coil 12 is formed via the current lead 16 having a resistance value Ra.
ここで、励磁制御部１４のスイッチ１４ｃをオンし、電
源１４ａから電流を超電導コイル１２に通電する。ここ
で、設定電流に達したところで、永久電流スイッチ１５
をオンする。つまり、スイッチ１５Ｃ２をオフしてヒー
タ１５ｂの加熱を解除することにより、スイッチ用超電
導コイル１５ａは加熱解除に伴って超電導状態に復帰し
、抵抗は無くなる。これにより、超電導コイル１２とス
イッチ用超電導コイル１５ａとの回路は閉回路を形成し
て永久電流モードとなり、これにて励磁作業を終了する
。Here, the switch 14c of the excitation control section 14 is turned on, and current is applied to the superconducting coil 12 from the power source 14a. Here, when the set current is reached, the persistent current switch 15
Turn on. That is, by turning off the switch 15C2 and canceling the heating of the heater 15b, the switching superconducting coil 15a returns to the superconducting state as the heating is canceled, and the resistance disappears. As a result, the circuit between the superconducting coil 12 and the switching superconducting coil 15a forms a closed circuit and enters the persistent current mode, thereby ending the excitation work.
以上の励磁手順は、一つの電流を設定する、つまり一つ
の磁場強度を発生するに至るための手順であるが、この
励磁手順を頻繁且つ緊急に行う場合であっても、励磁制
御部１４及び永久電流スイッチ１５をオン・オフするだ
けで、冷媒容器１１内に熱侵入を一切招くことなくして
各々実施することができる。The above excitation procedure is a procedure for setting one current, that is, generating one magnetic field strength, but even if this excitation procedure is performed frequently and urgently, the excitation control unit 14 and By simply turning on and off the persistent current switch 15, each operation can be carried out without any heat intrusion into the refrigerant container 11.
従って、近時に至って、この種の磁気共鳴イメージング
装置に用いる超電導磁石は、可変磁場強度にすることが
行われたり、また、非運転時には減消磁を行ったり、さ
らに磁性体吸着事故時の緊急減消磁を行ったりする必要
性が出てきており、このため、励磁手順を頻繁且つ緊急
に行うことが想定されるが、この場合、上述した励磁手
順を頻繁且つ緊急に行ったとしても、冷媒容器１１内へ
の熱侵入は一切無いので、クエンチングの発生等の事故
は誘発しない。Therefore, in recent years, superconducting magnets used in this type of magnetic resonance imaging equipment have been made to have variable magnetic field strength, are demagnetized when not in operation, and are also required to be demagnetized in case of an accident due to adsorption of magnetic materials. It is expected that the excitation procedure will be performed frequently and urgently.In this case, even if the excitation procedure described above is performed frequently and urgently, the refrigerant container Since there is no heat intrusion into the 11, accidents such as quenching will not occur.
なお、本発明は、その要旨を逸脱しない範囲で種々変形
して実施することができるものである。Note that the present invention can be implemented with various modifications without departing from the gist thereof.
［発明の効果］
以上のように本発明では、液体窒素等の高温冷媒を収容
する真空断熱構造を有さない冷媒容器内に、前記高温冷
媒により超電導現象を示す高温超電導材料からなる超電
導コイル及びその冷媒を収容し、且つ永久電流スイッチ
を設けると共に前記超電導コイルから前記冷媒容器の外
に低抵抗を有する電流リードを導出した構成としたこと
により、低抵抗を有する電流リードは、常に、液体窒素
等の高温冷媒により超電導現象を示す高温超電導材料か
らなる超電導コイルに接続されているので、永久電流ス
イッチのオン、オフするだけで、励磁手順を実施するこ
とができ、この場合、冷媒容器内には熱の侵入は無く、
たとえ励磁手順を頻繁且つ緊急に行ってもクエンチング
の発生等の事故は発生することがない、という効果があ
る。[Effects of the Invention] As described above, the present invention includes a superconducting coil made of a high-temperature superconducting material that exhibits a superconducting phenomenon due to the high-temperature refrigerant, and a By accommodating the refrigerant, providing a persistent current switch, and leading out a current lead having low resistance from the superconducting coil to the outside of the refrigerant container, the current lead having low resistance is always connected to liquid nitrogen. It is connected to a superconducting coil made of high-temperature superconducting material that exhibits superconducting phenomenon with high-temperature refrigerants such as There is no heat intrusion,
This has the effect that accidents such as quenching will not occur even if the excitation procedure is performed frequently and urgently.
第１図は本発明にかかる超電導磁石の一実施例の構成を
示す図、第２図は従来例の構成を示す図である。
１１・・・冷媒容器、１２・・・超電導コイル、１３・
・・冷媒、１４・・・励磁制御部、１５・・・永久電流
スイッチ、１６・・・低抵抗を有する電流リード。
出願人代理人 弁理士 鈴江武彦FIG. 1 is a diagram showing the configuration of an embodiment of a superconducting magnet according to the present invention, and FIG. 2 is a diagram showing the configuration of a conventional example. 11... Refrigerant container, 12... Superconducting coil, 13.
... Refrigerant, 14... Excitation control unit, 15... Persistent current switch, 16... Current lead having low resistance. Applicant's agent Patent attorney Takehiko Suzue
Claims (1)
ない冷媒容器内に、前記高温冷媒により超電導現象を示
す高温超電導材料からなる超電導コイル及びその冷媒を
収容し、且つ永久電流スイッチを設けると共に前記超電
導コイルから前記冷媒容器の外に低抵抗を有する電流リ
ードを導出した構成としたことを特徴とする超電導磁石
。A superconducting coil made of a high-temperature superconducting material that exhibits a superconducting phenomenon due to the high-temperature refrigerant and the refrigerant are housed in a refrigerant container that does not have a vacuum insulation structure and contains a high-temperature refrigerant such as liquid nitrogen, and a persistent current switch is provided. A superconducting magnet characterized in that a current lead having low resistance is led out from the superconducting coil to the outside of the refrigerant container.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62273845A JPH01117004A (en) | 1987-10-29 | 1987-10-29 | Superconducting magnet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62273845A JPH01117004A (en) | 1987-10-29 | 1987-10-29 | Superconducting magnet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01117004A true JPH01117004A (en) | 1989-05-09 |
Family
ID=17533347
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62273845A Pending JPH01117004A (en) | 1987-10-29 | 1987-10-29 | Superconducting magnet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01117004A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004037081A1 (en) * | 2002-10-24 | 2004-05-06 | Hitachi Medical Corporation | Superconducting magnet device and magnetic resonance imaging system employing it |
| US6809618B2 (en) * | 2002-01-15 | 2004-10-26 | Siemens Aktiengesellschaft | Switching device for superconducting technology |
| JP2009090127A (en) * | 2008-12-03 | 2009-04-30 | Hitachi Medical Corp | Magnetic resonance imaging device and superconducting magnet device |
| JP2012148073A (en) * | 2011-01-19 | 2012-08-09 | General Electric Co <Ge> | Apparatus and method for protecting magnetic resonance imaging magnet during quench |
-
1987
- 1987-10-29 JP JP62273845A patent/JPH01117004A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6809618B2 (en) * | 2002-01-15 | 2004-10-26 | Siemens Aktiengesellschaft | Switching device for superconducting technology |
| WO2004037081A1 (en) * | 2002-10-24 | 2004-05-06 | Hitachi Medical Corporation | Superconducting magnet device and magnetic resonance imaging system employing it |
| US7304478B2 (en) | 2002-10-24 | 2007-12-04 | Hitachi Medical Corporation | Magnetic resonance imaging apparatus provided with means for preventing closed loop circuit formation across and between inside and outside of cryostat |
| CN100413465C (en) * | 2002-10-24 | 2008-08-27 | 株式会社日立医药 | Superconducting magnet device and magnetic resonance imaging system employing it |
| JP2009090127A (en) * | 2008-12-03 | 2009-04-30 | Hitachi Medical Corp | Magnetic resonance imaging device and superconducting magnet device |
| JP2012148073A (en) * | 2011-01-19 | 2012-08-09 | General Electric Co <Ge> | Apparatus and method for protecting magnetic resonance imaging magnet during quench |
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