JPH07321380A - Squid storage container and squid cooling method - Google Patents
Squid storage container and squid cooling methodInfo
- Publication number
- JPH07321380A JPH07321380A JP6128067A JP12806794A JPH07321380A JP H07321380 A JPH07321380 A JP H07321380A JP 6128067 A JP6128067 A JP 6128067A JP 12806794 A JP12806794 A JP 12806794A JP H07321380 A JPH07321380 A JP H07321380A
- Authority
- JP
- Japan
- Prior art keywords
- squid
- magnetic shield
- storage container
- state
- superconducting
- 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
- 241000238366 Cephalopoda Species 0.000 title claims abstract description 79
- 238000001816 cooling Methods 0.000 title claims abstract description 14
- 239000000463 material Substances 0.000 claims abstract description 21
- 239000002826 coolant Substances 0.000 claims description 19
- 230000007704 transition Effects 0.000 claims description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 abstract description 44
- 239000007788 liquid Substances 0.000 abstract description 24
- 229910052757 nitrogen Inorganic materials 0.000 abstract description 22
- 230000004907 flux Effects 0.000 abstract description 11
- 230000000694 effects Effects 0.000 description 6
- 239000010410 layer Substances 0.000 description 6
- 238000005259 measurement Methods 0.000 description 6
- 230000007246 mechanism Effects 0.000 description 6
- 230000008859 change Effects 0.000 description 4
- 239000010949 copper Substances 0.000 description 4
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 4
- NJPPVKZQTLUDBO-UHFFFAOYSA-N novaluron Chemical compound C1=C(Cl)C(OC(F)(F)C(OC(F)(F)F)F)=CC=C1NC(=O)NC(=O)C1=C(F)C=CC=C1F NJPPVKZQTLUDBO-UHFFFAOYSA-N 0.000 description 3
- 229920002799 BoPET Polymers 0.000 description 2
- 239000005041 Mylar™ Substances 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052797 bismuth Inorganic materials 0.000 description 2
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 description 2
- 239000003822 epoxy resin Substances 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 239000001307 helium Substances 0.000 description 2
- 229910052734 helium Inorganic materials 0.000 description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 2
- 239000010955 niobium Substances 0.000 description 2
- 230000000149 penetrating effect Effects 0.000 description 2
- 229920000647 polyepoxide Polymers 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 238000007740 vapor deposition Methods 0.000 description 2
- BTGZYWWSOPEHMM-UHFFFAOYSA-N [O].[Cu].[Y].[Ba] Chemical compound [O].[Cu].[Y].[Ba] BTGZYWWSOPEHMM-UHFFFAOYSA-N 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000004794 expanded polystyrene Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 239000002887 superconductor Substances 0.000 description 1
- 229910052716 thallium Inorganic materials 0.000 description 1
- BKVIYDNLLOSFOA-UHFFFAOYSA-N thallium Chemical compound [Tl] BKVIYDNLLOSFOA-UHFFFAOYSA-N 0.000 description 1
- 229910021521 yttrium barium copper oxide Inorganic materials 0.000 description 1
Landscapes
- Measuring Magnetic Variables (AREA)
- Containers, Films, And Cooling For Superconductive Devices (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、人体あるいは生物体か
ら発生する磁場の計測を行うための医療用診断装置、材
料の透磁率を測定するための物性測定装置、磁気的な信
号伝送のトランスデューサとして用いるＳＱＵＩＤ（Su
perconducting Quantum InterferenceDevice ：超伝導
量子干渉デバイス）を格納することに適したＳＱＵＩＤ
格納容器に関する。ここに、ＳＱＵＩＤとは、液体ヘリ
ウムや液体窒素等により断熱容器（クライオスタット
等）内で低温状態に維持され、ループ内にジョセフソン
接合を含む超伝導ループであるＳＱＵＩＤループに直流
電流をバイアス電流として印加して駆動し、このＳＱＵ
ＩＤループ内に、ピックアップコイルや入力コイル等を
介して外部からの磁束を結合して印加すると、ＳＱＵＩ
Ｄループに周回電流が誘起され、ループ内のジョセフソ
ン接合における量子的な干渉効果により、印加された外
部磁束の微弱な変化を出力電圧の大きな変化に変換する
トランスデューサとして動作することを利用して、微小
磁束変化を測定する素子である。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical diagnostic device for measuring a magnetic field generated from a human body or a living body, a physical property measuring device for measuring magnetic permeability of a material, and a transducer for magnetic signal transmission. SQUID (Su
perconducting quantum interference device: SQUID suitable for storing a superconducting quantum interference device
Concerning the storage container. Here, SQUID is a superconducting loop that is maintained in a low temperature state in a heat-insulating container (such as a cryostat) by liquid helium, liquid nitrogen, etc., and a DC current is used as a bias current in a SQUID loop that is a superconducting loop including a Josephson junction in the loop. Apply and drive this SQU
When a magnetic flux from the outside is coupled and applied to the ID loop via a pickup coil, an input coil, etc., SQUI
A circulating current is induced in the D loop, and it acts as a transducer that converts a weak change in the applied external magnetic flux into a large change in the output voltage due to the quantum interference effect in the Josephson junction in the loop. , An element for measuring a minute magnetic flux change.
【０００２】[0002]
【従来の技術】従来、この種のＳＱＵＩＤ格納容器とし
ては、図２に示すようなものが知られている。このＳＱ
ＵＩＤ格納容器２１は、図２に示すように、高臨界温度
（例えば、液体窒素温度７７Ｋ）で超伝導状態となるイ
ットリウム・バリウム・銅酸化物（ＹＢａ2 Ｃｕ3 Ｏ
7-Y など。）等で構成されたＳＱＵＩＤ２およびその冷
却媒体である液体窒素３を収納可能な内部容器４と、内
部容器４を包囲するとともに内部容器４との間に真空層
５を形成する外部容器６と、内部容器４の首に相当する
部分に挿入された断熱部８と、液体窒素３とその蒸発ガ
スを外部空気と遮断する蓋７と、ＳＱＵＩＤ２を液体窒
素３中に支持するとともにＳＱＵＩＤ２からの計測電流
を容器１の外部に導く計測用導線（図示せず）を止着ま
たは内蔵可能な支持機構９と、を備えて構成される。１
０は計測用導線の引出口である。上記の内部容器４と外
部容器６と蓋７は、例えばガラスエポキシ樹脂等により
形成される。上記の真空層５内には、外部からの輻射熱
の侵入を防止するためアルミニウム蒸着マイラー等の輻
射シールド（図示せず）が設けられる。また、蓋７およ
び断熱部８とを貫通して外部から液体窒素３の給排を行
うための液体窒素給排口（図示せず）も設けられる。上
記のように構成することにより、上記のＳＱＵＩＤ格納
容器１を磁気シールドルーム内等に置き、ＳＱＵＩＤ２
を液体窒素３の内部に支持し、ＳＱＵＩＤ２の臨界温度
Ｔc 以下に冷却すれば、ＳＱＵＩＤ２が超伝導状態で動
作するので、外部容器６の底部に近接して被測定物を配
置すれば、その磁場を測定することができる。2. Description of the Related Art Conventionally, an SQUID storage container of this type is known as shown in FIG. This SQ
As shown in FIG. 2, the UID storage container 21 is a yttrium-barium-copper oxide (YBa 2 Cu 3 O) that becomes a superconducting state at a high critical temperature (for example, liquid nitrogen temperature 77K).
7-Y etc. ) And the like, and an internal container 4 capable of accommodating the liquid nitrogen 3 that is a cooling medium thereof, and an external container 6 that surrounds the internal container 4 and forms a vacuum layer 5 between the internal container 4 and the internal container 4. A heat insulating part 8 inserted into a portion corresponding to the neck of the inner container 4, a lid 7 for blocking the liquid nitrogen 3 and its evaporative gas from the external air, and supporting the SQUID 2 in the liquid nitrogen 3 and measuring current from the SQUID 2. And a support mechanism 9 capable of fixing or incorporating a measuring lead wire (not shown) for guiding the outside of the container 1. 1
Reference numeral 0 is an outlet of the measuring lead wire. The inner container 4, the outer container 6 and the lid 7 are made of, for example, glass epoxy resin or the like. A radiation shield (not shown) such as an aluminum vapor deposition mylar is provided in the vacuum layer 5 in order to prevent radiant heat from entering from the outside. Further, a liquid nitrogen supply / discharge port (not shown) for penetrating the lid 7 and the heat insulating portion 8 to supply / discharge the liquid nitrogen 3 from the outside is also provided. With the above configuration, the SQUID storage container 1 is placed in a magnetically shielded room or the like, and the SQUID 2
SQUID 2 is supported inside liquid nitrogen 3 and cooled below the critical temperature Tc of SQUID 2, SQUID 2 operates in a superconducting state. Can be measured.
【０００３】[0003]
【発明が解決しようとする課題】しかし、上記のＳＱＵ
ＩＤ２を磁気シールドルーム外で冷却し超伝導状態に転
移させたい場合がある。しかし、上記のＳＱＵＩＤに
は、「磁束トラップ現象」という特有の現象が生じる。
これは、ＳＱＵＩＤを冷却していく場合に、ある値以上
の磁場に曝された状態で冷却されると、磁束がＳＱＵＩ
Ｄ上で捕捉され、ＳＱＵＩＤの特性の一時的劣化、例え
ばＳＱＵＩＤの素子感度の一時的低下等を生じる現象で
ある。したがって、図２の状態で、ＳＱＵＩＤ２を液体
窒素３中に挿入すると、そのときの外部磁場をトラップ
してしまい、これがノイズとなってＳＱＵＩＤ２の特性
が著しく低下する。本発明は、上記の問題点を解決する
ためになされたものであり、磁束トラップを生じること
なく精度よく磁場計測行うことができるＳＱＵＩＤ格納
容器およびＳＱＵＩＤ冷却方法を提供することを目的と
する。However, the above-mentioned SQU
There are cases where it is desired to cool ID2 outside the magnetically shielded room and transfer it to the superconducting state. However, the above-mentioned SQUID has a unique phenomenon called “flux trap phenomenon”.
This is because when cooling SQUID, when it is cooled while being exposed to a magnetic field of a certain value or more, the magnetic flux becomes SQUID.
This is a phenomenon that is captured on D and causes a temporary deterioration in the characteristics of the SQUID, for example, a temporary decrease in the element sensitivity of the SQUID. Therefore, when the SQUID 2 is inserted into the liquid nitrogen 3 in the state of FIG. 2, the external magnetic field at that time is trapped, which becomes noise, and the characteristics of the SQUID 2 are remarkably deteriorated. The present invention has been made to solve the above problems, and an object of the present invention is to provide an SQUID storage container and an SQUID cooling method capable of performing accurate magnetic field measurement without causing magnetic flux traps.
【０００４】[0004]
【課題を解決するための手段】上記の課題を解決するた
め、本発明に係るＳＱＵＩＤ格納容器は、ＳＱＵＩＤと
冷却媒体を断熱状態で収納可能なＳＱＵＩＤ格納容器で
あって、前記ＳＱＵＩＤ格納容器内に超伝導材料によっ
て形成された両端開放筒状の磁気シールドを支持し、外
部磁場を遮蔽した状態において当該磁気シールドを前記
冷却媒体によって冷却することにより超伝導状態に転移
させ当該磁気シールド内部に磁気遮蔽空間を発生させ、
次に前記ＳＱＵＩＤを当該磁気遮蔽空間内に移動させ前
記冷却媒体によって冷却することにより超伝導状態に転
移させるように構成される。また、本発明に係るＳＱＵ
ＩＤ冷却方法は、ＳＱＵＩＤと冷却媒体を断熱状態で収
納可能なＳＱＵＩＤ格納容器の内部に超伝導材料によっ
て形成された両端開放筒状の磁気シールドを支持し、外
部磁場を遮蔽した状態において当該磁気シールドを前記
冷却媒体によって冷却することにより超伝導状態に転移
させ当該磁気シールド内部に磁気遮蔽空間を発生させ、
次に前記ＳＱＵＩＤを当該磁気遮蔽空間内に移動させ前
記冷却媒体によって冷却することにより超伝導状態に転
移させるように構成される。In order to solve the above-mentioned problems, an SQUID storage container according to the present invention is an SQUID storage container capable of storing an SQUID and a cooling medium in an adiabatic state. A cylindrical magnetic shield formed of a superconducting material is supported, and the magnetic shield is cooled by the cooling medium in a state in which an external magnetic field is shielded so that the magnetic shield is transformed into a superconducting state. Generate space,
Next, the SQUID is moved into the magnetically shielded space and cooled by the cooling medium so that the SQUID is transformed into a superconducting state. Further, the SQU according to the present invention
In the ID cooling method, a SQUID storage container capable of accommodating a SQUID and a cooling medium in an adiabatic state supports a cylindrical magnetic shield formed by a superconducting material and having open-ended cylinders, and the magnetic shield is shielded against an external magnetic field. By cooling with the cooling medium to a superconducting state to generate a magnetic shielding space inside the magnetic shield,
Next, the SQUID is moved into the magnetically shielded space and cooled by the cooling medium so that the SQUID is transformed into a superconducting state.
【０００５】[0005]
【作用】上記構成を有する本発明によれば、ＳＱＵＩＤ
格納容器内に支持された超伝導材料の両端開放筒状の磁
気シールドを、外部磁場を遮蔽した状態において冷却媒
体によって冷却することにより超伝導状態に転移させ、
この磁気シールド内部に磁気遮蔽空間を発生させること
ができる。次に、ＳＱＵＩＤを上記の磁気遮蔽空間内に
移動させ冷却媒体によって冷却することにより超伝導状
態に転移させることができる。したがって、すでに前段
階において、磁気シールド内部に磁気遮蔽空間が発生し
ているから、磁気遮蔽空間内にＳＱＵＩＤを保持すれ
ば、磁気シールドルーム外部においてＳＱＵＩＤの冷却
を行っても磁束トラップを生じることはない。According to the present invention having the above structure, the SQUID
A cylindrical magnetic shield of both ends of the superconducting material supported in the containment vessel is transformed into a superconducting state by cooling with a cooling medium in a state where an external magnetic field is shielded,
A magnetically shielded space can be generated inside this magnetic shield. Next, the SQUID can be transferred into the superconducting state by moving it into the magnetically shielded space and cooling it with a cooling medium. Therefore, since the magnetic shield space has already been generated inside the magnetic shield in the previous stage, if the SQUID is held in the magnetic shield space, a magnetic flux trap will not occur even if the SQUID is cooled outside the magnetic shield room. Absent.
【０００６】[0006]
【実施例】以下、本発明の実施例を図面にもとづいて説
明する。図１は、本発明の一実施例であるＳＱＵＩＤ格
納容器の構成を示した図である。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of an SQUID storage container which is an embodiment of the present invention.
【０００７】図に示すように、このＳＱＵＩＤ格納容器
１は、高臨界温度（例えば、液体窒素温度７７Ｋ）で超
伝導状態となるＹＢａ2 Ｃｕ3 Ｏ7-Y 等の高臨界温度超
伝導材料で構成されたＳＱＵＩＤ２と架台１１と高臨界
温度超伝導材料で構成された両端開放円筒状の磁気シー
ルド１２とこれらの冷却媒体である液体窒素３を収納可
能な内部容器４と、内部容器４を包囲するとともに内部
容器４との間に真空層５を形成する外部容器６と、内部
容器４の首に相当する部分に挿入された断熱部８と、液
体窒素３とその蒸発ガスを外部空気と遮断する蓋７と、
ＳＱＵＩＤ２を液体窒素３中に支持するとともにＳＱＵ
ＩＤ２からの計測電流を容器１の外部に導く計測用導線
（図示せず）を止着または内蔵可能な支持機構９と、を
備えて構成される。１０は計測用導線の引出口である。
上記の内部容器４と外部容器６と蓋７は、例えばガラス
エポキシ樹脂等により形成される。As shown in the figure, the SQUID storage container 1 is made of a high critical temperature superconducting material such as YBa 2 Cu 3 O 7-Y which is in a superconducting state at a high critical temperature (eg, liquid nitrogen temperature 77K). The SQUID 2, the pedestal 11, the cylindrical magnetic shield 12 made of a high critical temperature superconducting material and open at both ends, the internal container 4 capable of storing the liquid nitrogen 3 as the cooling medium, and the inner container 4 surrounding the internal container 4. In addition, the outer container 6 forming a vacuum layer 5 between the inner container 4 and the inner container 4, the heat insulating portion 8 inserted in the portion corresponding to the neck of the inner container 4, the liquid nitrogen 3 and its evaporative gas are shielded from the outer air. With a lid 7
Support SQUID 2 in liquid nitrogen 3 and
A support mechanism 9 capable of fixing or incorporating a measurement lead wire (not shown) for guiding the measurement current from the ID 2 to the outside of the container 1. Reference numeral 10 is an outlet for the measurement lead wire.
The inner container 4, the outer container 6 and the lid 7 are made of, for example, glass epoxy resin or the like.
【０００８】上記の真空層５内には、外部からの輻射熱
の侵入を防止するためアルミニウム蒸着マイラー等の輻
射シールド（図示せず）が設けられる。また、蓋７およ
び断熱部８とを貫通して外部から液体窒素３の給排を行
うための液体窒素給排口（図示せず）も設けられる。A radiation shield (not shown) such as an aluminum vapor deposition mylar is provided in the vacuum layer 5 in order to prevent radiant heat from entering from the outside. Further, a liquid nitrogen supply / discharge port (not shown) for penetrating the lid 7 and the heat insulating portion 8 to supply / discharge the liquid nitrogen 3 from the outside is also provided.
【０００９】次に、上記のＳＱＵＩＤ格納容器１を用い
てＳＱＵＩＤ２を冷却する方法について説明する。ま
ず、上記のＳＱＵＩＤ格納容器１を磁気シールドルーム
内に置き、上記の内部容器４内の架台１１上に磁気シー
ルド１２を載置し、ＳＱＵＩＤ支持機構９を上方に最大
限引き上げ、ＳＱＵＩＤ２が最も上方に位置するように
する。Next, a method of cooling the SQUID 2 using the SQUID storage container 1 will be described. First, the SQUID storage container 1 is placed in a magnetically shielded room, the magnetic shield 12 is placed on the pedestal 11 in the inner container 4, the SQUID support mechanism 9 is pulled up to the maximum, and the SQUID 2 is the highest. Be located at.
【００１０】この状態で、液体窒素３を静かに注入する
と、磁気シールド１２はその臨界温度Ｔc 以下にまで冷
却され、超伝導状態に転移し、磁気遮蔽効果を発揮する
ようになる。この場合、液体窒素３は、上方に引き上げ
られたＳＱＵＩＤ２を浸すことがないような位置で注入
を停止する。磁気シールド１２の磁気遮蔽効果のある範
囲は、図１における磁気シールド１２内面と図上の鎖線
で囲まれた断面がほぼ鼓状の形状の範囲Ｓである。磁気
遮蔽空間Ｓがこのような形状になるのは、超伝導体であ
る磁気シールド１２の「マイスナー効果」による。In this state, when the liquid nitrogen 3 is gently injected, the magnetic shield 12 is cooled down to its critical temperature Tc or lower, transitions to the superconducting state, and exhibits the magnetic shielding effect. In this case, the liquid nitrogen 3 stops the injection at a position where it does not immerse the SQUID 2 pulled upward. The range in which the magnetic shield 12 has the magnetic shielding effect is a range S in which the inner surface of the magnetic shield 12 in FIG. 1 and a cross section surrounded by a chain line in the drawing have a substantially drum shape. The magnetic shield space S has such a shape due to the “Meissner effect” of the magnetic shield 12 which is a superconductor.
【００１１】この磁気遮蔽空間Ｓの範囲は、磁気シール
ドの内径と円筒長さによって変化する。一般的には、図
１の鎖線のように磁気シールド内に切れ込む深さの円筒
長さ全体に対する比率は、内径が細くなるにしたがって
小さくなる。すなわち換言すれば、円筒が細長くなるほ
ど、磁気シールド内空間全体に対する磁気遮蔽空間の比
率は大きくなる。The range of the magnetic shield space S changes depending on the inner diameter of the magnetic shield and the length of the cylinder. Generally, the ratio of the depth cut into the magnetic shield to the entire cylinder length as shown by the chain line in FIG. 1 becomes smaller as the inner diameter becomes smaller. That is, in other words, the smaller the cylinder, the larger the ratio of the magnetic shield space to the entire space inside the magnetic shield.
【００１２】上記のようにして、磁気シールド１２が磁
気遮蔽効果を発揮すると、このＳＱＵＩＤ格納容器１を
磁気シールドルームの外部へ持ち出しても、上記の磁気
シールド１２内の磁気遮蔽空間Ｓは変化しない。したが
って、次に、ＳＱＵＩＤ支持機構９を静かに降下させ、
ＳＱＵＩＤ２が上記の磁気シールド１２内面の磁気遮蔽
空間Ｓ内に入った時点で停止させ、この磁気遮蔽空間Ｓ
内でＳＱＵＩＤ２の臨界温度Ｔc 以下にまで冷却する
と、ＳＱＵＩＤ２は超伝導状態に転移する。この際、外
部には磁界が存在するが、ＳＱＵＩＤ２は上記の磁気遮
蔽空間Ｓ内に留まっているので、外部磁束はＳＱＵＩＤ
２内に侵入せず、磁束トラップ現象は生じない。When the magnetic shield 12 exerts the magnetic shielding effect as described above, even if the SQUID storage container 1 is taken out of the magnetic shield room, the magnetic shield space S in the magnetic shield 12 does not change. . Therefore, next, gently lower the SQUID support mechanism 9,
The SQUID 2 is stopped when it enters the magnetic shield space S on the inner surface of the magnetic shield 12, and the magnetic shield space S is stopped.
When cooled to below the critical temperature Tc of SQUID2, SQUID2 is transformed into a superconducting state. At this time, although a magnetic field exists outside, the SQUID 2 remains in the magnetically shielded space S, so that the external magnetic flux is SQUID.
2 does not enter, and the magnetic flux trap phenomenon does not occur.
【００１３】上記のようにして、超伝導状態に転移させ
た後は、ＳＱＵＩＤ２が超伝導状態で動作するので、Ｓ
ＱＵＩＤ２を内部容器４の底部付近にまで降下させ、外
部容器６の底部付近に被測定物を配置すれば、その磁場
を測定することができる。ただし、磁場測定の場合は、
生体磁場レベルより外部磁場のレベルの方が非常に大き
いので、通常は磁気シールドルーム内で測定することに
なる。After the transition to the superconducting state as described above, SQUID2 operates in the superconducting state.
If the QUID 2 is lowered to near the bottom of the inner container 4 and the object to be measured is placed near the bottom of the outer container 6, the magnetic field can be measured. However, in the case of magnetic field measurement,
Since the level of the external magnetic field is much larger than the level of the biomagnetic field, it is usually measured in the magnetically shielded room.
【００１４】また、同様にして、複数のＳＱＵＩＤセン
サをＳＱＵＩＤ支持機構の先端に取り付けて磁気シール
ド１２内に降下させることにより、磁気シールド１２内
に複数のＳＱＵＩＤセンサを格納することができる。Similarly, a plurality of SQUID sensors can be stored in the magnetic shield 12 by attaching the plurality of SQUID sensors to the tip of the SQUID support mechanism and lowering them into the magnetic shield 12.
【００１５】なお、本発明は、上記実施例に限定される
ものではない。上記実施例は、例示であり、本発明の特
許請求の範囲に記載された技術的思想と実質的に同一な
構成を有し、同様な作用効果を奏するものは、いかなる
ものであっても本発明の技術的範囲に包含される。The present invention is not limited to the above embodiment. The above-mentioned embodiment is an exemplification, has substantially the same configuration as the technical idea described in the scope of the claims of the present invention, and has any similar effect to the present invention. It is included in the technical scope of the invention.
【００１６】例えば、上記の実施例においては、冷却媒
体として液体窒素を用い、ＳＱＵＩＤ材料としてＹＢａ
2 Ｃｕ3 Ｏ7-Y を用い、磁気シールド材料としてビスマ
ス（Ｂｉ）系材料等の高臨界温度の超伝導材料を用いる
例について説明したが、これには限定されず、ＳＱＵＩ
Ｄ又は磁気シールド材料としてＹＢａ2 Ｃｕ3 Ｏ7-Y、
ビスマス（Ｂｉ）系材料、タリウム（Ｔｌ）系材料等の
高臨界温度超伝導材料を用いてもよく、あるいは、冷却
媒体として液体ヘリウムを用い、ＳＱＵＩＤと磁気シー
ルド材料としてニオブ（Ｎｂ）系材料等の超伝導材料を
用いる場合であっても本発明は適用できる。また、上記
実施例においては、磁気シールド１２は、内部容器４内
の底部に載置された架台１１上に載置される例について
説明したが、これは、蓋７あるいは断熱部８の下部に吊
下支持されたり、内部容器の壁面から支持されてもかま
わない。要は、内部容器４内に支持されればよいのであ
る。そして、上記実施例においては、円筒状の磁気シー
ルドを例にとって説明を行ったが、これは他の断面形状
を有する両端開放の筒体、例えば、断面が６角形、８角
形等のｎ角形（ｎはｎ≧３の整数）の両端開放の筒体で
あってもよい。また、上記実施例においては、ＳＱＵＩ
Ｄ格納容器がＳＱＵＩＤと冷却媒体を収納可能な内部容
器と当該内部容器を真空状態に保持しつつ包囲する外部
容器を備えて構成される例について説明したが、これに
は限定されず、内容物を断熱状態で収納できればどのよ
うな格納容器であってもよく、いわゆる「魔法瓶」のよ
うに内部容器と外部容器が一体形成され内部に真空層を
含むような構成であってもよいし、あるいは発砲スチロ
ール製の容器のように内部に細かい空気泡等を含み一層
で構成されるような断熱容器であってもよい。For example, in the above embodiment, liquid nitrogen is used as the cooling medium and YBa is used as the SQUID material.
An example in which 2 Cu 3 O 7-Y is used and a superconducting material having a high critical temperature such as bismuth (Bi) -based material is used as a magnetic shield material has been described, but the present invention is not limited to this.
D or YBa 2 Cu 3 O 7-Y as a magnetic shield material,
A high critical temperature superconducting material such as bismuth (Bi) -based material or thallium (Tl) -based material may be used, or liquid helium is used as a cooling medium, and SQUID and a magnetic shield material are niobium (Nb) -based material or the like. The present invention can be applied even when the superconducting material is used. In addition, in the above-mentioned embodiment, the magnetic shield 12 is described as being mounted on the pedestal 11 mounted on the bottom of the inner container 4, but this is mounted on the lower portion of the lid 7 or the heat insulating portion 8. It may be suspended or supported from the wall of the inner container. The point is that it may be supported in the inner container 4. In the above embodiments, the description has been given by taking the cylindrical magnetic shield as an example. However, this is a cylindrical body having open-ended ends having another cross-sectional shape, for example, an n-gonal shape having a hexagonal or octagonal cross-section ( n may be a cylindrical body with both ends open, where n ≧ 3. Also, in the above embodiment, SQUI
The example in which the D storage container includes an inner container capable of storing the SQUID and the cooling medium and an outer container that surrounds the inner container while holding the inner container in a vacuum state has been described, but the present invention is not limited to this. May be any storage container as long as it can be stored in a heat-insulated state, and may have a structure in which an internal container and an external container are integrally formed and include a vacuum layer inside, such as a so-called "thermos", or It may be a heat-insulated container such as a container made of expanded polystyrene, which has a single layer containing fine air bubbles and the like.
【００１７】[0017]
【発明の効果】以上説明したように、上記構成を有する
本発明によれば、ＳＱＵＩＤ格納容器内に支持された超
伝導材料の両端開放筒状の磁気シールドを、外部磁場を
遮蔽した状態において冷却媒体によって冷却することに
より超伝導状態に転移させ、この磁気シールド内部に磁
気遮蔽空間を発生させることができる。次に、ＳＱＵＩ
Ｄを上記の磁気遮蔽空間内に移動させ冷却媒体によって
冷却することにより超伝導状態に転移させることができ
る。したがって、すでに前段階において、磁気シールド
内部に磁気遮蔽空間が発生しているから、磁気遮蔽空間
内にＳＱＵＩＤを保持すれば、磁気シールドルーム外部
においてＳＱＵＩＤの冷却を行っても磁束トラップを生
じることはない、という利点がある。As described above, according to the present invention having the above-mentioned structure, the cylindrical magnetic shield of the superconducting material supported in the SQUID storage container, which is open at both ends, is cooled in a state in which the external magnetic field is shielded. By cooling with a medium, it can be transformed into a superconducting state and a magnetically shielded space can be generated inside this magnetic shield. Next, SQUI
By moving D into the magnetically shielded space and cooling it with a cooling medium, it is possible to transition to a superconducting state. Therefore, since the magnetic shield space has already been generated inside the magnetic shield in the previous stage, if the SQUID is held in the magnetic shield space, a magnetic flux trap will not occur even if the SQUID is cooled outside the magnetic shield room. There is an advantage that it does not exist.
【図１】本発明の一実施例であるＳＱＵＩＤ格納容器の
構成を示す断面図である。FIG. 1 is a cross-sectional view showing a configuration of an SQUID storage container which is an embodiment of the present invention.
【図２】従来のＳＱＵＩＤ格納容器の構成を示す断面図
である。FIG. 2 is a cross-sectional view showing a configuration of a conventional SQUID storage container.
１ ＳＱＵＩＤ格納容器 ２ ＳＱＵＩＤ ３ 液体窒素 ４ 内部容器 ５ 真空層 ６ 外部容器 ７ 蓋 ８ 断熱部 ９ ＳＱＵＩＤ支持機構 １０ 計測用導線引出口 １１ 架台 １２ 磁気シールド ２１ ＳＱＵＩＤ格納容器 Ｓ 磁気遮蔽空間 1 SQUID Storage Container 2 SQUID 3 Liquid Nitrogen 4 Inner Container 5 Vacuum Layer 6 Outer Container 7 Lid 8 Heat Insulation Section 9 SQUID Support Mechanism 10 Measurement Lead Outlet 11 Frame 12 Magnetic Shield 21 SQUID Storage Container S Magnetic Shielding Space
Claims (2)
可能なＳＱＵＩＤ格納容器であって、 前記ＳＱＵＩＤ格納容器内に超伝導材料によって形成さ
れた両端開放筒状の磁気シールドを支持し、外部磁場を
遮蔽した状態において当該磁気シールドを前記冷却媒体
によって冷却することにより超伝導状態に転移させ当該
磁気シールド内部に磁気遮蔽空間を発生させ、次に前記
ＳＱＵＩＤを当該磁気遮蔽空間内に移動させ前記冷却媒
体によって冷却することにより超伝導状態に転移させる
ことを特徴とするＳＱＵＩＤ格納容器。1. A SQUID storage container capable of storing an SQUID and a cooling medium in an adiabatic state, wherein a magnetic shield having an open-ended cylindrical shape made of a superconducting material is supported in the SQUID storage container, and an external magnetic field is applied. In the shielded state, the magnetic shield is cooled by the cooling medium to transition to a superconducting state to generate a magnetically shielded space inside the magnetic shield, and then the SQUID is moved into the magnetically shielded space. A SQUID storage container characterized by being transformed into a superconducting state by being cooled by.
可能なＳＱＵＩＤ格納容器の内部に超伝導材料によって
形成された両端開放筒状の磁気シールドを支持し、外部
磁場を遮蔽した状態において当該磁気シールドを前記冷
却媒体によって冷却することにより超伝導状態に転移さ
せ当該磁気シールド内部に磁気遮蔽空間を発生させ、次
に前記ＳＱＵＩＤを当該磁気遮蔽空間内に移動させ前記
冷却媒体によって冷却することにより超伝導状態に転移
させることを特徴とするＳＱＵＩＤ冷却方法。2. A magnetic shield, which is open at both ends and is formed of a superconducting material, is supported inside a SQUID storage container capable of storing the SQUID and a cooling medium in an adiabatic state, and the magnetic shield is shielded against an external magnetic field. Is transformed into a superconducting state by being cooled by the cooling medium to generate a magnetically shielded space inside the magnetic shield, and then the SQUID is moved into the magnetically shielded space and cooled by the cooling medium to superconduct. A SQUID cooling method characterized by transferring to a state.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6128067A JPH07321380A (en) | 1994-05-19 | 1994-05-19 | Squid storage container and squid cooling method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6128067A JPH07321380A (en) | 1994-05-19 | 1994-05-19 | Squid storage container and squid cooling method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07321380A true JPH07321380A (en) | 1995-12-08 |
Family
ID=14975645
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6128067A Pending JPH07321380A (en) | 1994-05-19 | 1994-05-19 | Squid storage container and squid cooling method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07321380A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002353528A (en) * | 2001-05-25 | 2002-12-06 | Furukawa Electric Co Ltd:The | Magnetic shield and method of manufacturing the same |
| CN115585400A (en) * | 2022-09-28 | 2023-01-10 | 中国科学院上海微系统与信息技术研究所 | A liquid cryogenic medium delivery device, method, and superconducting device working system |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03248069A (en) * | 1990-02-26 | 1991-11-06 | Shimadzu Corp | Squid probe |
-
1994
- 1994-05-19 JP JP6128067A patent/JPH07321380A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03248069A (en) * | 1990-02-26 | 1991-11-06 | Shimadzu Corp | Squid probe |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002353528A (en) * | 2001-05-25 | 2002-12-06 | Furukawa Electric Co Ltd:The | Magnetic shield and method of manufacturing the same |
| CN115585400A (en) * | 2022-09-28 | 2023-01-10 | 中国科学院上海微系统与信息技术研究所 | A liquid cryogenic medium delivery device, method, and superconducting device working system |
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