JPH04276594A - Superconductive magnetic shield device - Google Patents
Superconductive magnetic shield deviceInfo
- Publication number
- JPH04276594A JPH04276594A JP6125291A JP6125291A JPH04276594A JP H04276594 A JPH04276594 A JP H04276594A JP 6125291 A JP6125291 A JP 6125291A JP 6125291 A JP6125291 A JP 6125291A JP H04276594 A JPH04276594 A JP H04276594A
- Authority
- JP
- Japan
- Prior art keywords
- container
- liquid nitrogen
- vessel
- magnetic shielding
- temperature
- 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
- 230000005291 magnetic effect Effects 0.000 title claims abstract description 46
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 56
- 239000007788 liquid Substances 0.000 claims abstract description 30
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 28
- 239000000843 powder Substances 0.000 claims abstract description 10
- 239000000919 ceramic Substances 0.000 claims abstract description 7
- 238000009413 insulation Methods 0.000 claims abstract description 6
- 230000005389 magnetism Effects 0.000 abstract description 8
- 230000015572 biosynthetic process Effects 0.000 abstract 1
- 239000002887 superconductor Substances 0.000 description 8
- 230000037431 insertion Effects 0.000 description 7
- 238000003780 insertion Methods 0.000 description 7
- 241000238366 Cephalopoda Species 0.000 description 5
- 238000001816 cooling Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 230000004907 flux Effects 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 238000009694 cold isostatic pressing Methods 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000010586 diagram Methods 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
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910002480 Cu-O Inorganic materials 0.000 description 1
- 241001465754 Metazoa Species 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 210000004556 brain Anatomy 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000005292 diamagnetic effect Effects 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Landscapes
- Measuring Magnetic Variables (AREA)
- Details Of Measuring And Other Instruments (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は、超電導現象の内、磁束
を排除する性質を利用した磁気シールド装置に関し、特
に超電導体の臨界温度Ｔｃが液体窒素温度７７Ｋを越え
る酸化物高温超電導体で構成された磁気シールド容器を
内含した超電導磁気シールド装置に係る。[Industrial Application Field] The present invention relates to a magnetic shielding device that utilizes the property of excluding magnetic flux among superconducting phenomena, and in particular is constructed of an oxide high-temperature superconductor whose critical temperature Tc exceeds the liquid nitrogen temperature of 77K. The present invention relates to a superconducting magnetic shielding device including a magnetic shielding container.
【０００２】0002
【従来の技術およびその問題点】従来、超電導体は電気
抵抗ゼロと完全反磁性の性質を利用すれば理想的な磁気
シールド材料となることが知られている。しかし、従来
のＮｂやＰｂのような金属系超電導体は高価な液体ヘリ
ウムを冷却媒体として必要とすることから実用に供され
てはいない。また、液体ヘリウム冷却容器は通常２層構
造で外層は液体窒素冷却をしなければならず、また内層
も液体窒素で予冷する必要があり、容器自体も大きくな
り、取扱いも面倒である。このような点から従来の金属
系超電導体は磁気シールドに応用されていない。BACKGROUND OF THE INVENTION Conventionally, it has been known that superconductors can be ideal magnetic shielding materials by utilizing their zero electrical resistance and perfect diamagnetic properties. However, conventional metal-based superconductors such as Nb and Pb are not put into practical use because they require expensive liquid helium as a cooling medium. Furthermore, liquid helium cooling containers usually have a two-layer structure, and the outer layer must be cooled with liquid nitrogen, and the inner layer must also be pre-cooled with liquid nitrogen, making the container itself large and cumbersome to handle. For these reasons, conventional metal-based superconductors have not been applied to magnetic shields.
【０００３】最近発見された液体窒素温度で超電導にな
る高温酸化物超電導体を磁気シールドに応用することは
本件発明者らが系統的に研究中であり、種々の成果を得
てはいるが、実際に磁気シールド容器に応用できる大き
なゼロ磁場空間を得るだけの大きさの磁気シールド容器
例えば、直径３２ｃｍ以上、深さ６４ｃｍ以上で、重量
が７０Ｋｇ以上もある大きなセラミック体を作製しなけ
ればならず、その作製は非常に困難であり、このような
大型の磁気シールド容器を熱衝撃によるクラックの発生
無しに、しかも地磁気のトラップ無しに冷却することも
極めて困難なことである。The inventors of the present invention are systematically researching the application of the recently discovered high-temperature oxide superconductor, which becomes superconducting at liquid nitrogen temperatures, to magnetic shielding, and have obtained various results. For example, a large ceramic body with a diameter of 32 cm or more, a depth of 64 cm or more, and a weight of 70 kg or more must be made to create a magnetic shield container large enough to obtain a large zero magnetic field space that can be actually applied to a magnetic shield container. , it is extremely difficult to manufacture such a large magnetically shielded container, and it is also extremely difficult to cool such a large magnetically shielded container without generating cracks due to thermal shock and without trapping the earth's magnetic field.
【０００４】本発明は実用に利用できる大きさのゼロ磁
場空間を持つ磁気シールド容器を用い、しかもこの磁気
シールド容器を安価に、クラックの発生及び地磁気のト
ラップ無しに冷却し得る磁気シールド装置を提供するこ
とを目的とするものである。[0004] The present invention uses a magnetically shielded container having a zero magnetic field space of a size that can be practically used, and provides a magnetic shielding device that can cool the magnetically shielded container at low cost without generating cracks or trapping geomagnetism. The purpose is to
【０００５】[0005]
【問題点を解決するための手段】本発明の超電導磁気シ
ールド装置は、一端閉口／一端開口の筒状の超電導磁気
シールド容器と、この磁気シールド容器を収納し内部に
セラミックス粉が充填された温度制御容器と、この温度
制御容器を収納し内部に液体窒素が充填された液体窒素
容器と、この液体窒素容器を収納する二重壁の真空断熱
容器とを具えて成り、真空断熱容器の外側にＸ，Ｙ，Ｚ
方向の地磁気をキャンセルする１対のヘルムホルツコイ
ルからなる地磁気補償コイルを３組設けてなる構成とす
ることにより、前記課題を解決したものである。本発明
において、磁気シールド容器はその閉口端面の中央部に
磁束計の嵌入口を有するものとしても良く、この場合に
は前記磁束計の嵌入口が最外層の真空断熱容器にも設け
られて成るものである。[Means for Solving the Problems] The superconducting magnetic shielding device of the present invention includes a cylindrical superconducting magnetic shielding container with one end closed and one end open, and a temperature-controlled container in which the magnetic shielding container is housed and filled with ceramic powder. It consists of a control container, a liquid nitrogen container that stores the temperature control container and is filled with liquid nitrogen, and a double-walled vacuum insulation container that stores the liquid nitrogen container. X, Y, Z
The above-mentioned problem has been solved by providing a configuration in which three sets of geomagnetic compensation coils each consisting of a pair of Helmholtz coils cancel out the geomagnetism in the direction. In the present invention, the magnetically shielded container may have an inlet for the magnetometer in the center of its closed end surface, and in this case, the inlet for the magnetometer is also provided in the outermost layer of the vacuum insulated container. It is something.
【０００６】本発明装置を図面を参照して以下に説明す
るが、本発明はこれに限定されるものではない。The apparatus of the present invention will be explained below with reference to the drawings, but the present invention is not limited thereto.
【０００７】図１において、１は酸化物超電導磁気シー
ルド容器であり、その形状は深さ／直径の比が１以上、
好ましくは２とするのがよい。これは開口端からの磁場
が漏れこんでくるために比が大きいほどシールド効果が
よくなる。また、容器底部は曲率を持たせてある。例え
ば、容器直径の１／２の半径の曲率を持たせる。これは
容器を作製する時の応力を緩和するためである。容器は
酸化物超電導体粉末を冷間静水圧プレス（ＣＩＰ）によ
り圧力をかけて成型体を形成し、これを焼結して磁気シ
ールド容器１とする。図２における磁気シールド容器１
はその閉塞端面の中央部に磁束計の嵌入口８が設けられ
たものを示し、この嵌入口８は最外層の真空断熱容器の
嵌入口が磁束計の挿入を可能とするように十分な大きさ
を持たせる必要がある。これにより、上部の嵌入口から
ＳＱＵＩＤ磁束計を挿入し、下部の開口端部から人間の
頭をいれられる構造となる。In FIG. 1, reference numeral 1 denotes an oxide superconducting magnetic shielding container, and its shape has a depth/diameter ratio of 1 or more;
Preferably it is 2. This is because the magnetic field from the open end leaks in, so the larger the ratio, the better the shielding effect. Further, the bottom of the container has a curvature. For example, the radius of curvature is 1/2 of the diameter of the container. This is to relieve stress when manufacturing the container. The container is made by pressurizing oxide superconductor powder by cold isostatic pressing (CIP) to form a molded body, and sintering this to form the magnetically shielded container 1. Magnetic shield container 1 in Figure 2
indicates that a magnetometer insertion opening 8 is provided in the center of the closed end surface, and this insertion opening 8 is large enough so that the insertion opening of the outermost vacuum insulated container can allow insertion of the magnetometer. It is necessary to have a sense of This creates a structure in which a SQUID magnetometer can be inserted through the insertion opening at the top, and a human head can be inserted through the open end at the bottom.
【０００８】磁気シールド容器１は内部にセラミックス
粉２、具体的にはアルミナ粉が充填された温度制御容器
３内に収納され、この温度制御容器３は内部に液体窒素
４が充填された液体窒素容器５内に収納され、さらにこ
の液体窒素容器５は二重壁の真空断熱容器６内に収納さ
れている。なお、二重壁の真空断熱容器６は適用する用
途によっては省略することができる。真空断熱容器の外
側にはＸ，Ｙ，Ｚ方向の地磁気をキャンセルする１対の
ヘルムホルツコイルからなる地磁気補償コイル９が３組
設けられている。温度制御容器３は銅やアルミニウム等
の熱伝導性の良いもので形成する。これにより、その外
側の液体窒素容器５に液体窒素供給孔７より液体窒素を
供給した場合、上部と下部との温度差を減らすことがで
きる。また、この温度制御容器３内に充填するアルミナ
粉は液体窒素供給口から供給される液体窒素に先に接触
する部分の粒径を大きくする。例えば図１の構成のもの
では、底部は２〜３ｍｍの粒子径、開口端側は０．１ｍ
ｍの粒子径にする。このようにすることにより、磁気シ
ールド容器１の冷却に際し、上下部の温度差を減少させ
ることができ、重畳で１００Ｋｇもある大きな磁気シー
ルド容器をクラックの発生無しにしかも地磁気補償コイ
ル９により冷却に際して地磁気の影響を排除することが
でき、磁気シールド容器１内に地磁気がトラップされる
のを防止しつつ臨界温度以下にまで冷却することができ
、これにより装置内を無磁場空間とすることができる。The magnetically shielded container 1 is housed in a temperature-controlled container 3 filled with ceramic powder 2, specifically alumina powder, and this temperature-controlled container 3 is filled with liquid nitrogen 4. The liquid nitrogen container 5 is housed in a double-walled vacuum insulated container 6. Note that the double-walled vacuum insulated container 6 may be omitted depending on the application. Three sets of terrestrial magnetic compensation coils 9 each consisting of a pair of Helmholtz coils for canceling the terrestrial magnetism in the X, Y, and Z directions are provided outside the vacuum insulation container. The temperature control container 3 is made of a material with good thermal conductivity such as copper or aluminum. Thereby, when liquid nitrogen is supplied from the liquid nitrogen supply hole 7 to the liquid nitrogen container 5 on the outside, the temperature difference between the upper part and the lower part can be reduced. Further, the alumina powder filled into the temperature-controlled container 3 has a larger particle size in the portion that first comes into contact with the liquid nitrogen supplied from the liquid nitrogen supply port. For example, in the configuration shown in Figure 1, the particle diameter is 2 to 3 mm at the bottom and 0.1 m at the open end.
Make the particle size m. By doing so, when cooling the magnetically shielded container 1, the temperature difference between the upper and lower parts can be reduced, and the large magnetically shielded container weighing as much as 100 kg when stacked can be cooled without cracking, and the geomagnetic compensation coil 9 can be cooled. It is possible to eliminate the influence of geomagnetism, prevent geomagnetism from being trapped inside the magnetic shield container 1, and cool it to below the critical temperature, thereby making the inside of the device a magnetic field-free space. .
【０００９】地磁気補償コイル９は１対のヘルムホルツ
コイル、３組からなり、その直径は磁気シールド容器１
の長さの２倍以上必要である。超電導磁気シールド容器
１を冷却する場合に、ＸＹＺ方向の地磁気をキャンセル
するようにそれぞれのコイルに電流を流す。磁気シール
ド容器１が超電導状態になった後は、このコイルを取り
去ることができる。なお、超電導体に地磁気がトラップ
された状態にあると、装置内にＳＱＵＩＤ磁束計を挿入
して極微弱磁場を検出する際に、被検出体、ＳＱＵＩＤ
、シールド容器の相対的な位置のずれ（微少振動）が生
じた場合や、トラップした磁束が熱的に揺らいだ場合、
ＳＱＵＩＤはこれを磁束の変化として検出し、磁気ノイ
ズの原因となる。本発明では、地磁気補償コイルを設け
ることにより、地磁気のトラップは激減し、ノイズを大
幅に減少させることができる。The geomagnetic compensation coil 9 consists of three pairs of Helmholtz coils, the diameter of which is the same as that of the magnetic shielding container 1.
It is necessary to have at least twice the length of . When cooling the superconducting magnetically shielded container 1, current is passed through each coil so as to cancel the earth's magnetism in the XYZ directions. After the magnetic shield container 1 becomes superconducting, this coil can be removed. In addition, if the earth's magnetism is trapped in the superconductor, when inserting a SQUID magnetometer into the device to detect an extremely weak magnetic field, the object to be detected, the SQUID
, when the relative position of the shield container shifts (minor vibration), or when the trapped magnetic flux fluctuates thermally,
The SQUID detects this as a change in magnetic flux, causing magnetic noise. In the present invention, by providing a geomagnetic compensation coil, geomagnetic traps are drastically reduced, and noise can be significantly reduced.
【００１０】0010
【実施例１】超電導磁気シールド容器はＢｉ系酸化物超
電導体の粉末（Ｂｉ−Ｐｂ−Ｓｒ−Ｃａ−Ｃｕ−Ｏ）を
ＣＩＰ成型後、焼成して作製した。この磁気シールド容
器の大きさは直径３２ｃｍ、深さ６４ｃｍ、厚さ２．５
ｃｍであり、その重量は７０Ｋｇであった。また、磁束
計の嵌入口は直径１２ｃｍとした。[Example 1] A superconducting magnetically shielded container was produced by CIP molding a Bi-based oxide superconductor powder (Bi-Pb-Sr-Ca-Cu-O) and then firing it. The size of this magnetically shielded container is 32 cm in diameter, 64 cm in depth, and 2.5 cm in thickness.
cm, and its weight was 70 kg. Moreover, the diameter of the insertion opening of the magnetometer was 12 cm.
【００１１】図２に示される装置を用い、上記した大型
の磁気シールド容器を冷却した。冷却に要した液体窒素
の量は約５００リッターであり、室温から液体窒素温度
まで冷却するのに１２時間を要した。また、容器の上部
と開口端に熱電対を貼付て測温した。その結果、上部と
開口端との温度差は３０Ｋ以下であった。The large magnetically shielded container described above was cooled using the apparatus shown in FIG. The amount of liquid nitrogen required for cooling was approximately 500 liters, and it took 12 hours to cool from room temperature to liquid nitrogen temperature. Additionally, thermocouples were attached to the top and open end of the container to measure the temperature. As a result, the temperature difference between the upper part and the open end was 30K or less.
【００１２】このようにして冷却した超電導磁気シール
ド装置のシールド効果をＳＱＵＩＤ磁束計を用いて測定
した。その結果、外部磁界強度０．５ガウス、周波数０
．２Ｈｚの時、深さ／直径＝１の位置で外部磁界は千分
の１に減少した。The shielding effect of the superconducting magnetic shield device cooled in this manner was measured using a SQUID magnetometer. As a result, the external magnetic field strength is 0.5 Gauss, and the frequency is 0.
．． At 2 Hz, the external magnetic field was reduced by a factor of 1,000 at the depth/diameter=1 position.
【００１３】[0013]
【発明の効果】以上のように、本発明によれば、人の脳
から発する微少磁気の検出、小動物等の発する生体磁気
の検出、極めて微弱な磁性体の磁化率等を計測するのに
極めて好適な超電導磁気シールド装置が得られ、しかも
簡単な構成により磁気シールド容器をクラック及び地磁
気のトラップ無しに臨界温度以下にまで容易に冷却する
ことができ、初めて実用に供し得る磁気シールド装置が
提供される。[Effects of the Invention] As described above, the present invention is extremely useful for detecting minute magnetism emitted from the human brain, detecting biological magnetism emitted from small animals, and measuring the magnetic susceptibility of extremely weak magnetic materials. A suitable superconducting magnetic shielding device is obtained, and the magnetic shielding container can be easily cooled down to below the critical temperature without cracking or geomagnetic traps due to its simple configuration, and a magnetic shielding device that can be put to practical use for the first time is provided. Ru.
【図１】本発明に係る超電導磁気シールド装置の一例を
示す概略説明図である。FIG. 1 is a schematic explanatory diagram showing an example of a superconducting magnetic shielding device according to the present invention.
【図２】本発明に係る超電導磁気シールド装置の他の例
を示す概略説明図である。FIG. 2 is a schematic explanatory diagram showing another example of the superconducting magnetic shielding device according to the present invention.
１ 磁気シールド容器 ２ セラミックス粉 ３ 温度制御容器 ４ 液体窒素 ５ 液体窒素容器 ６ 真空断熱容器 ７ 液体窒素供給孔 ８ 磁束計の嵌入口 ９ 地磁気補償コイル 1 Magnetic shield container 2 Ceramic powder 3 Temperature controlled container 4. Liquid nitrogen 5. Liquid nitrogen container 6 Vacuum insulation container 7 Liquid nitrogen supply hole 8 Magnetometer insertion hole 9 Geomagnetic compensation coil
Claims (2)
気シールド容器と、この磁気シールド容器を収納し内部
にセラミックス粉が充填された温度制御容器と、この温
度制御容器を収納し内部に液体窒素が充填された液体窒
素容器と、この液体窒素容器を収納する二重壁の真空断
熱容器とを具えて成り、真空断熱容器の外側にＸ，Ｙ，
Ｚ方向の地磁気をキャンセルする１対のヘルムホルツコ
イルからなる地磁気補償コイルを３組設けてなる超電導
磁気シールド装置。Claim 1: A cylindrical superconducting magnetically shielded container with one end closed and one end open, a temperature-controlled container that stores the magnetically shielded container and is filled with ceramic powder, and a temperature-controlled container that stores the temperature-controlled container and has a liquid inside. It consists of a liquid nitrogen container filled with nitrogen and a double-walled vacuum insulated container that houses the liquid nitrogen container.
A superconducting magnetic shielding device equipped with three sets of geomagnetic compensation coils each consisting of a pair of Helmholtz coils that cancel geomagnetism in the Z direction.
端面の中央部に磁束計の嵌入口を有する超電導磁気シー
ルド容器と、この磁気シールド容器を収納し内部にセラ
ミックス粉が充填された温度制御容器と、この温度制御
容器を収納し内部に液体窒素が充填された液体窒素容器
と、この液体窒素容器を収納する二重壁の真空断熱容器
とを具えて成り、前記磁束計の嵌入口が最外層の真空断
熱容器にも設けられ、真空断熱容器の外側にＸ，Ｙ，Ｚ
方向の地磁気をキャンセルする１対のヘルムホルツコイ
ルからなる地磁気補償コイルを３組設けてなる超電導磁
気シールド装置。Claim 2: A superconducting magnetically shielded container having a cylindrical shape with one end closed and one end open and having a magnetometer fitting opening in the center of the closed end surface, and a temperature in which the magnetically shielded container is housed and the inside is filled with ceramic powder. A control container, a liquid nitrogen container that stores the temperature control container and is filled with liquid nitrogen, and a double-walled vacuum insulation container that stores the liquid nitrogen container; is also provided on the outermost layer of the vacuum insulated container, and X, Y, Z
A superconducting magnetic shielding device equipped with three sets of geomagnetic compensation coils each consisting of a pair of Helmholtz coils that cancel the geomagnetism in the direction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6125291A JPH04276594A (en) | 1991-03-02 | 1991-03-02 | Superconductive magnetic shield device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6125291A JPH04276594A (en) | 1991-03-02 | 1991-03-02 | Superconductive magnetic shield device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04276594A true JPH04276594A (en) | 1992-10-01 |
Family
ID=13165861
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6125291A Pending JPH04276594A (en) | 1991-03-02 | 1991-03-02 | Superconductive magnetic shield device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04276594A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1829476A1 (en) * | 2004-12-20 | 2007-09-05 | National Institute of Information and Communications Technology | Measuring structure of superconducting magnetic shield brain field measuring equipment |
| WO2009052635A1 (en) * | 2007-10-22 | 2009-04-30 | D-Wave Systems Inc. | Systems, methods, and apparatus for superconducting magnetic shielding |
| JP2009216424A (en) * | 2008-03-07 | 2009-09-24 | Kobe Steel Ltd | Magnet position measuring method and magnetic field measuring instrument |
| US8228688B2 (en) | 2007-10-31 | 2012-07-24 | D-Wave Systems Inc. | Systems, methods, and apparatus for combined superconducting magnetic shielding and radiation shielding |
-
1991
- 1991-03-02 JP JP6125291A patent/JPH04276594A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1829476A1 (en) * | 2004-12-20 | 2007-09-05 | National Institute of Information and Communications Technology | Measuring structure of superconducting magnetic shield brain field measuring equipment |
| EP1829476A4 (en) * | 2004-12-20 | 2012-03-28 | Nat Inst Inf & Comm Tech | Measuring structure of superconducting magnetic shield brain field measuring equipment |
| WO2009052635A1 (en) * | 2007-10-22 | 2009-04-30 | D-Wave Systems Inc. | Systems, methods, and apparatus for superconducting magnetic shielding |
| US7990662B2 (en) | 2007-10-22 | 2011-08-02 | D-Wave Systems Inc. | Systems, methods, and apparatus for superconducting magnetic shielding |
| US8228688B2 (en) | 2007-10-31 | 2012-07-24 | D-Wave Systems Inc. | Systems, methods, and apparatus for combined superconducting magnetic shielding and radiation shielding |
| JP2009216424A (en) * | 2008-03-07 | 2009-09-24 | Kobe Steel Ltd | Magnet position measuring method and magnetic field measuring instrument |
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