JP2006322886A - Planar thin-film squid differential magnetic flux sensor and non-destructive inspection apparatus using it - Google Patents

Planar thin-film squid differential magnetic flux sensor and non-destructive inspection apparatus using it Download PDF

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JP2006322886A
JP2006322886A JP2005148052A JP2005148052A JP2006322886A JP 2006322886 A JP2006322886 A JP 2006322886A JP 2005148052 A JP2005148052 A JP 2005148052A JP 2005148052 A JP2005148052 A JP 2005148052A JP 2006322886 A JP2006322886 A JP 2006322886A
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JP4635199B2 (en
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Yoshi Hatsukade
好 廿日出
Saburo Tanaka
三郎 田中
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Toyohashi University of Technology NUC
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a planar thin-film SQUID differential magnetic flux sensor having a special structure which makes any magnetic flux trap difficult to occur at a Josephson junction, and to provide a non-destructive inspection apparatus using it. <P>SOLUTION: In the planar thin-film SQUID differential magnetic flux sensor which has a primary or more differential magnetic flux detecting coil for measuring a magnetic field differentiation, a SQUID ring is directly coupled with the magnetic flux detecting coil such that bias current flows in the Josephson junction in the SQUID ring along a direction parallel to a direction of an exciting magnetic field. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、平面薄膜型ＳＱＵＩＤ微分型磁束センサ及びそれを用いた非破壊検査用装置に関するものである。   The present invention relates to a flat thin film type SQUID differential magnetic flux sensor and a nondestructive inspection apparatus using the same.

従来、このような分野の技術として、本願発明者らが、ＳＱＵＩＤ磁束センサを用いた抗原抗体反応装置を提案している（下記特許文献１，２参照）。   Conventionally, the inventors of the present application have proposed an antigen-antibody reaction device using a SQUID magnetic flux sensor as a technology in such a field (see Patent Documents 1 and 2 below).

ところで、測定対象を励磁するために強い磁場を印加し、その磁場中で行うＳＱＵＩＤ磁気センサを用いた磁気計測技術において、従来から用いられている一般的な平面薄膜型ＳＱＵＩＤ微分型磁束センサを用いる場合、その検出原理上、センサのコイル微分方向に対して印加磁場は垂直に印加しなければならない。しかしながら、従来のセンサでは磁場印加方向が必然的にＳＱＵＩＤのジョセフソン接合に流れるバイアス電流の向きと垂直になり、接合に流れる電流にローレンツ力が作用し、磁束ノイズが増大するという不都合があった。大きな磁場を印加したほうが大きな検出信号を得ることができ都合がよいが、磁場増加に伴いこの磁束ノイズが増大するため、大きな磁場を印加することができず、ＳＱＵＩＤ磁気センサの高感度能力を十分に活かすことができていなかった。
特開２００１−１３３４５８号公報 特開２００４−０６１１４４号公報 By the way, in a magnetic measurement technique using a SQUID magnetic sensor applied in a magnetic field in order to excite a measurement object, a conventional flat thin film type SQUID differential magnetic flux sensor that has been conventionally used is used. In this case, due to the detection principle, the applied magnetic field must be applied perpendicular to the coil differential direction of the sensor. However, in the conventional sensor, the magnetic field application direction is inevitably perpendicular to the direction of the bias current flowing through the SQUID Josephson junction, and the Lorentz force acts on the current flowing through the junction, resulting in an increase in magnetic flux noise. . It is convenient to apply a large magnetic field because a large detection signal can be obtained, but this magnetic flux noise increases as the magnetic field increases. Therefore, a large magnetic field cannot be applied, and the high sensitivity capability of the SQUID magnetic sensor is sufficient. I could not make use of it.
JP 2001-133458 A JP 2004-061144 A

上記したように、従来型の平面薄膜型ＳＱＵＩＤ微分型磁束センサを用いる場合、ジョセフソン接合を流れるバイアス電流の向きに対して印加磁場方向が垂直となり、電流にローレンツ力が働く。このローレンツ力によりジョセフソン接合で磁束トラップが生じやすくなり、磁束ノイズ増大の原因となる。このため、印加可能な励磁磁場強度に限界があり、信号・雑音比を向上することが困難であった。   As described above, when a conventional flat thin film SQUID differential magnetic flux sensor is used, the applied magnetic field direction is perpendicular to the direction of the bias current flowing through the Josephson junction, and Lorentz force acts on the current. This Lorentz force tends to cause a magnetic flux trap at the Josephson junction, which causes an increase in magnetic flux noise. For this reason, there is a limit to the intensity of the excitation magnetic field that can be applied, and it has been difficult to improve the signal / noise ratio.

図５はかかる従来型の平面薄膜型ＳＱＵＩＤ微分型磁束センサを示す模式図であり、図５（ａ）はその全体図、図５（ｂ）はＳＱＵＩＤリング部〔図５（ａ）のＡ部〕の拡大図である。なお、図５（ａ）は３個のＳＱＵＩＤリングを並列に設置したパターンを示しているが、ＳＱＵＩＤを複数個設けたのは歩留まりを増加させるためであり、３個であることに重要な意味はない。実際にＳＱＵＩＤを動作させる場合、そのうちの一つのみを使用する。図５（ｂ）では、３個のＳＱＵＩＤリングのうちの一つを例として示している。   FIG. 5 is a schematic view showing such a conventional flat thin film type SQUID differential type magnetic flux sensor. FIG. 5 (a) is an overall view thereof, FIG. 5 (b) is an SQUID ring portion [A portion of FIG. FIG. FIG. 5 (a) shows a pattern in which three SQUID rings are installed in parallel. The reason why a plurality of SQUIDs are provided is to increase the yield and is important for the fact that three SQUID rings are provided. There is no. When actually operating the SQUID, only one of them is used. In FIG. 5B, one of the three SQUID rings is shown as an example.

これらの図に示すように、従来型の平面薄膜型ＳＱＵＩＤ微分型磁束センサでは、太い二つの矩形コイルからなる微分型磁束検出コイル１０１に対して同量の印加磁界１０７が鎖交するように、図の左から右（もしくは右から左）方向へ印加磁界（印加磁場）１０７を印加する必要がある。この場合、ＳＱＵＩＤリング部Ａのジョセフソン接合部１０５に流れるバイアス電流ＩB と、印加した印加磁界１０７の方向が垂直となるため電流ＩB に対してローレンツ力が働く。このため、印加磁界１０７の強度を増大していくと、ＳＱＵＩＤリング１０２に存在するジョセフソン接合部１０５で磁束のトラップが発生しやすい構造となっている。このため、磁場強度の増大に従い、磁束ノイズも増加してしまう。なお、図５において、１０６はグレインバウンダリーである。 As shown in these figures, in the conventional flat thin film type SQUID differential type magnetic flux sensor, the same amount of applied magnetic field 107 is linked to the differential type magnetic flux detection coil 101 composed of two thick rectangular coils. It is necessary to apply an applied magnetic field (applied magnetic field) 107 from the left to the right (or from right to left) in the figure. In this case, since the bias current I B flowing through the Josephson junction 105 of the SQUID ring portion A and the direction of the applied magnetic field 107 are perpendicular, Lorentz force acts on the current I B. For this reason, when the strength of the applied magnetic field 107 is increased, magnetic flux trapping is likely to occur at the Josephson junction 105 existing in the SQUID ring 102. For this reason, the magnetic flux noise increases as the magnetic field strength increases. In FIG. 5, reference numeral 106 denotes a grain boundary.

このような、現在最も一般的な構造を有する平面薄膜型ＳＱＵＩＤ微分型磁束センサを作製し、バイアス電流ＩB の向きに対して垂直方向に印加した印加磁界強度を増大させていった場合、磁場強度が約２５μＴでＳＱＵＩＤリングが磁束トラップを生じ、磁束ノイズが急激に増加するといった問題があった。 When a flat thin film type SQUID differential magnetic flux sensor having the most general structure as described above is manufactured and the applied magnetic field strength applied in the direction perpendicular to the direction of the bias current I B is increased, There was a problem that the strength was about 25 μT and the SQUID ring caused a magnetic flux trap, and the magnetic flux noise increased rapidly.

本発明は、上記状況に鑑みて、ジョセフソン接合での磁束トラップが発生しにくい特殊な構造を有する平面薄膜型ＳＱＵＩＤ微分型磁束センサ及びそれを用いた非破壊検査用装置を提供することを目的とする。   In view of the above situation, the present invention has an object to provide a flat thin film type SQUID differential type magnetic flux sensor having a special structure in which a magnetic flux trap at a Josephson junction is not easily generated, and a nondestructive inspection apparatus using the same. And

本発明は、上記目的を達成するために、
〔１〕平面薄膜型ＳＱＵＩＤ微分型磁束センサにおいて、磁界微分を計測する一次以上の微分型磁束検出コイルを有する平面薄膜型ＳＱＵＩＤ微分型磁束センサにおいて、励磁磁場の方向と、ＳＱＵＩＤリング中のジョセフソン接合部に流れるバイアス電流の方向が平行になるようにＳＱＵＩＤリング部と磁束検出コイルを直接結合させることを特徴とする。 In order to achieve the above object, the present invention provides
[1] In a flat thin film type SQUID differential type magnetic flux sensor, in the flat thin film type SQUID differential type magnetic flux sensor having a primary or higher differential type magnetic flux detection coil for measuring magnetic field differentiation, the direction of the excitation magnetic field and the Josephson in the SQUID ring The SQUID ring part and the magnetic flux detection coil are directly coupled so that the directions of the bias currents flowing in the joint part are parallel.

〔２〕上記〔１〕記載の平面薄膜型ＳＱＵＩＤ微分型磁束センサにおいて、前記バイアス電流を供給するリード線薄膜パターンの、中央部リード線薄膜パターンの方向を励磁磁場の方向と一致させるように配線することを特徴とする。   [2] The flat thin film SQUID differential magnetic flux sensor according to [1] above, wherein the lead thin film pattern for supplying the bias current is wired so that the direction of the central lead thin film pattern coincides with the direction of the excitation magnetic field It is characterized by doing.

〔３〕上記〔１〕又は〔２〕記載の平面薄膜型ＳＱＵＩＤ微分型磁束センサを用いた非破壊検査用装置において、前記励磁磁場を印加する逆向きの極性を持つ２個の電磁石を具備することを特徴とする。   [3] A nondestructive inspection apparatus using the flat thin film type SQUID differential magnetic flux sensor according to [1] or [2], comprising two electromagnets having opposite polarities for applying the excitation magnetic field. It is characterized by that.

〔４〕上記〔１〕又は〔２〕記載の平面薄膜型ＳＱＵＩＤ微分型磁束センサを用いた非破壊検査用装置において、前記検出対象物が板状の検出対象物であり、前記励磁磁場を印加する二対の逆向きの極性を持つ４個の電磁石を具備することを特徴とする。   [4] In the nondestructive inspection apparatus using the flat thin film type SQUID differential magnetic flux sensor according to [1] or [2], the detection target is a plate-shaped detection target, and the excitation magnetic field is applied. And four pairs of electromagnets having opposite polarities.

〔５〕上記〔１〕又は〔２〕記載の平面薄膜型ＳＱＵＩＤ微分型磁束センサを用いた非破壊検査用装置において、前記励磁磁場を印加する逆向きの極性を持つ２個のソレノイドコイルを具備することを特徴とする。   [5] A nondestructive inspection apparatus using the flat thin film type SQUID differential magnetic flux sensor according to [1] or [2], comprising two solenoid coils having opposite polarities for applying the excitation magnetic field. It is characterized by doing.

本発明の平面薄膜型ＳＱＵＩＤ微分型磁束センサを用いることにより、数ｐＴ程度の極微弱磁場計測を必要とする非破壊検査、食品中異物検出装置、バイオ活動計測などにおいて、計測する印加磁場強度を従来の約１０倍以上に増大できることが見込まれる。また、本発明によれば、従来技術を大きく上回る高い信号・雑音比を得ることが可能となる。したがって、上記技術の高度化、実用化が促進されるだけでなく、これまで計測ができなかった微小な対象からの磁気信号が計測可能となり、微小磁気計測応用分野のさらなる開拓が期待できる。   By using the flat thin film type SQUID differential type magnetic flux sensor of the present invention, the applied magnetic field strength to be measured in the non-destructive inspection, the foreign matter detection apparatus in food, the bioactivity measurement, etc. that require the measurement of the extremely weak magnetic field of about several pT can be obtained. It is expected that it can be increased to about 10 times or more than the conventional one. In addition, according to the present invention, it is possible to obtain a high signal / noise ratio that greatly exceeds the prior art. Therefore, not only the advancement and practical application of the above-described technology are promoted, but also a magnetic signal from a minute object that could not be measured so far can be measured, and further development of the field of application of minute magnetic measurement can be expected.

本発明は、平面薄膜型ＳＱＵＩＤ微分型磁束センサにおいて、印加磁界の方向と、ＳＱＵＩＤリング中のジョセフソン接合部に流れるバイアス電流の方向が平行になるようにＳＱＵＩＤリング部と磁束検出コイルを直接結合させた特殊な構造とする。これにより、ＳＱＵＩＤリングでの磁束トラップ発生が抑制され、ＳＱＵＩＤに対して強い磁場の印加が可能となる。   In the flat thin film type SQUID differential magnetic flux sensor, the present invention directly couples the SQUID ring part and the magnetic flux detection coil so that the direction of the applied magnetic field is parallel to the direction of the bias current flowing through the Josephson junction in the SQUID ring. Special structure. Thereby, magnetic flux trap generation in the SQUID ring is suppressed, and a strong magnetic field can be applied to the SQUID.

以下、本発明を実施するための最良の形態を図を参照しながら詳細に説明する。   Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

図１は本発明の実施例を示す平面薄膜型ＳＱＵＩＤ微分型磁束センサの模式図であり、図１（ａ）はその全体図、図１（ｂ）はＳＱＵＩＤリング部〔図１（ａ）のＢ部〕の拡大図である。   FIG. 1 is a schematic diagram of a flat thin film type SQUID differential type magnetic flux sensor showing an embodiment of the present invention. FIG. 1A is an overall view thereof, FIG. 1B is a SQUID ring portion [of FIG. FIG.

これらの図に示すように、１は微分型磁束検出コイル、２はＳＱＵＩＤリング、３はジョセフソン接合部へバイアス電流ＩB を供給するための垂直方向に延びる上部リード線薄膜パターン、４はその上部リード線薄膜パターン３に接続され、水平方向へ延びる中央部リード線薄膜パターン、５はその中央部リード線薄膜パターン４に接続され、垂直方向に延びる下部リード線薄膜パターン、６はジョセフソン接合部、７はグレインバウンダリー、８は中央部リード線薄膜パターン４と平行な方向に印加される印加磁界（印加磁場）である。 As shown in these figures, 1 is a differential magnetic flux detection coil, 2 is a SQUID ring, 3 is a vertically extending upper lead thin film pattern for supplying a bias current I B to the Josephson junction, A central lead wire thin film pattern 5 connected to the upper lead thin film pattern 3 and extending in the horizontal direction, 5 is connected to the central lead thin film pattern 4, and a lower lead thin film pattern 6 extending in the vertical direction, and 6 is a Josephson junction. Reference numeral 7 denotes a grain boundary, and reference numeral 8 denotes an applied magnetic field (applied magnetic field) applied in a direction parallel to the central lead wire thin film pattern 4.

このように、本発明のＳＱＵＩＤリング２のジョセフソン接合部６に流れるバイアス電流ＩB と、外部から印加した印加磁界（印加磁場）８の向きが平行となる構造となるようにした。このため、印加磁界８に対するローレンツ力がゼロとなる。この構造により、励磁磁場の強度を増大しても、ジョセフソン接合部で磁束トラップが発生しにくく、磁束ノイズの増加無しに検出信号を増大できる。 As described above, the bias current I B flowing through the Josephson junction 6 of the SQUID ring 2 of the present invention and the direction of the applied magnetic field (applied magnetic field) 8 applied from the outside are parallel to each other. For this reason, the Lorentz force with respect to the applied magnetic field 8 becomes zero. With this structure, even if the intensity of the excitation magnetic field is increased, magnetic flux traps are hardly generated at the Josephson junction, and the detection signal can be increased without increasing magnetic flux noise.

このように、特殊な構造を有する図１に示すような平面薄膜型ＳＱＵＩＤ微分型磁束センサを作製し、上記と同じ設定で印加磁場８を増大させていった場合、印加磁場強度が約２５０μＴになっても磁束ノイズの増加は見られなかった。   As described above, when the flat thin film type SQUID differential type magnetic flux sensor as shown in FIG. 1 having a special structure is manufactured and the applied magnetic field 8 is increased with the same setting as described above, the applied magnetic field strength is about 250 μT. However, no increase in magnetic flux noise was observed.

このように、微分型ＳＱＵＩＤにおいて、印加磁場８の方向と、ＳＱＵＩＤリング中のジョセフソン接合部６に流れるバイアス電流の方向が平行になるようにＳＱＵＩＤリング２と微分型磁束検出コイル１を直接接合させると、磁場と電流の間に働くローレンツ力がゼロとなる。このため、感度に何ら影響を与えることなく、強い磁場中でもＳＱＵＩＤリング２での磁束トラップ発生を抑制することができ、結果的に磁束ノイズの増大を抑制することができる。これにより、印加する励磁磁場強度を従来の一桁以上増大させることができる。この結果、励磁信号強度が増加して、微小磁場計測において高い信号・雑音比を達成することができる。   In this way, in the differential SQUID, the SQUID ring 2 and the differential magnetic flux detection coil 1 are directly joined so that the direction of the applied magnetic field 8 and the direction of the bias current flowing through the Josephson junction 6 in the SQUID ring are parallel. As a result, the Lorentz force acting between the magnetic field and the current becomes zero. For this reason, generation | occurrence | production of the magnetic flux trap in SQUID ring 2 can be suppressed also in a strong magnetic field, without affecting a sensitivity at all, As a result, the increase in magnetic flux noise can be suppressed. Thereby, the excitation magnetic field strength to be applied can be increased by an order of magnitude or more. As a result, the excitation signal intensity increases, and a high signal / noise ratio can be achieved in the measurement of a minute magnetic field.

図２は上記した本発明の平面薄膜型ＳＱＵＩＤ微分型磁束センサとこの微分磁束センサの微分方向と垂直な方向から励磁磁場を印加することができる励磁用磁場印加機構を備えたＳＱＵＩＤ非破壊検査用装置を示す図である。   FIG. 2 shows a flat thin film SQUID differential magnetic flux sensor according to the present invention and a SQUID nondestructive inspection equipped with an excitation magnetic field applying mechanism capable of applying an excitation magnetic field from a direction perpendicular to the differential direction of the differential magnetic flux sensor. It is a figure which shows an apparatus.

この図において、１０は上記した本発明の平面薄膜型ＳＱＵＩＤ微分型磁束センサ、１１，１２は電磁石、１３は検出対象物、１４はクライオスタット（低温冷媒保持容器）、１５は励磁磁場、１６はバイアス電流ＩB である。 In this figure, 10 is the above-described flat thin film type SQUID differential type magnetic flux sensor of the present invention, 11 and 12 are electromagnets, 13 is a detection object, 14 is a cryostat (low temperature refrigerant holding container), 15 is an excitation magnetic field, and 16 is a bias. Current I B.

この図に示すように、ＳＱＵＩＤ微分型磁束センサ１０の下にある検出対象物１３を励磁するために、逆向きの極性をもつ２個の電磁石１１，１２を用いて、平面薄膜型ＳＱＵＩＤ微分型磁束センサ１０のコイル微分方向に対して垂直に磁場を印加するように設置している、この場合、本発明の平面薄膜型ＳＱＵＩＤ微分型磁束センサ１０を用いると、励磁磁場１５の方向と、ジョセフソン接合部を流れるバイアス電流ＩB の方向が平行となり、強い強度の磁場を印加して、大きな検査信号を得ることができる。 As shown in this figure, in order to excite the detection target 13 under the SQUID differential magnetic flux sensor 10, two thin film type SQUID differential types are used by using two electromagnets 11 and 12 having opposite polarities. The magnetic field sensor is installed so as to apply a magnetic field perpendicular to the coil differential direction of the magnetic flux sensor 10. In this case, when the flat thin film type SQUID differential type magnetic flux sensor 10 of the present invention is used, the direction of the excitation magnetic field 15, the Joseph It becomes parallel direction of the bias current I B flowing through the Son joints, by applying a high intensity magnetic field, it is possible to obtain a large test signal.

図３は図２と同じ原理で４個の電磁石を用いて、板状の検査対象物の傷検出に適用したＳＱＵＩＤ非破壊検査用装置を示す図である。   FIG. 3 is a view showing a SQUID nondestructive inspection apparatus applied to the detection of scratches on a plate-like inspection object using four electromagnets based on the same principle as FIG.

この図において、１０は上記した本発明の平面薄膜型ＳＱＵＩＤ微分型磁束センサ、２１，２２；２３，２４は電磁石、２５は板状の検査対象物、２６はその板状の検査対象物２５の欠陥部、２７はクライオスタット（低温冷媒保持容器）、２８は励磁磁場、２９はバイアス電流ＩB である。 In this figure, 10 is the above-described flat thin film type SQUID differential magnetic flux sensor of the present invention, 21, 22; 23 and 24 are electromagnets, 25 is a plate-like inspection object, and 26 is the plate-like inspection object 25. defect, 27 cryostat (low-temperature refrigerant storage container), the 28 excitation magnetic field, the 29 is the bias current I B.

この図に示すように、本発明の平面薄膜型ＳＱＵＩＤ微分型磁束センサ１０を用いて板状の検査対象物２５の傷（欠陥部２６の有無）の検査を行うことができる。   As shown in this figure, the flat thin film type SQUID differential type magnetic flux sensor 10 of the present invention can be used to inspect a scratch (presence or absence of the defective portion 26) of the plate-like inspection object 25.

図４は図２と同じ原理で電磁石に代えて、ソレノイドコイル２個を用いた場合のＳＱＵＩＤ非破壊検査用装置を示す図である。   FIG. 4 is a view showing a SQUID nondestructive inspection apparatus when two solenoid coils are used instead of an electromagnet based on the same principle as FIG.

この図において、１０は上記した本発明の平面薄膜型ＳＱＵＩＤ微分型磁束センサ、３１，３２は励磁用ソレノイドコイル、３３は検出対象物、３４はクライオスタット（低温冷媒保持容器）、３５は励磁磁場、３６はバイアス電流ＩB である。 In this figure, 10 is the above-described flat thin film type SQUID differential type magnetic flux sensor of the present invention, 31 and 32 are excitation solenoid coils, 33 is a detection object, 34 is a cryostat (low temperature refrigerant holding container), 35 is an excitation magnetic field, Reference numeral 36 denotes a bias current I B.

このように、２個の対向する励磁用ソレノイドコイル３１，３２を配置して、簡便に検出対象物３３の非破壊検査を行うことができる。   As described above, the two opposing exciting solenoid coils 31 and 32 can be arranged to easily perform the nondestructive inspection of the detection target 33.

上記したように、微分型ＳＱＵＩＤにおいて、励磁用磁場の方向と、ＳＱＵＩＤリング中のジョセフソン接合部に流れるバイアス電流の方向が平行になるようにＳＱＵＩＤリング部と磁束検出コイルを直接結合させると、磁場と電流の間に働くローレンツ力がゼロとなる。このため、感度になんら影響を与えることなく、強い磁場中でもＳＱＵＩＤリング部での磁束トラップ発生を抑制することができ、結果的に磁束ノイズの増大を抑制することができる。これにより、印加する励磁磁場強度を従来の一桁以上増大することが見込まれる。この結果、励磁信号強度が増加して、微小磁場計測において高い信号・雑音比を達成することができる。   As described above, in the differential SQUID, when the SQUID ring unit and the magnetic flux detection coil are directly coupled so that the direction of the exciting magnetic field and the direction of the bias current flowing through the Josephson junction in the SQUID ring are parallel, The Lorentz force acting between the magnetic field and the current becomes zero. For this reason, it is possible to suppress the generation of magnetic flux traps in the SQUID ring portion even in a strong magnetic field without affecting the sensitivity, and as a result, it is possible to suppress an increase in magnetic flux noise. As a result, it is expected that the excitation magnetic field strength to be applied is increased by an order of magnitude or more. As a result, the excitation signal intensity increases, and a high signal / noise ratio can be achieved in the measurement of a minute magnetic field.

なお、本発明は上記実施例に限定されるものではなく、本発明の趣旨に基づき種々の変形が可能であり、これらを本発明の範囲から排除するものではない。   In addition, this invention is not limited to the said Example, Based on the meaning of this invention, a various deformation | transformation is possible and these are not excluded from the scope of the present invention.

本発明の平面薄膜型ＳＱＵＩＤ微分型磁束センサ及びそれを用いた装置は、ＳＱＵＩＤ磁気センサを用いた非破壊検査や、異物検査装置や、バイオ計測（ＤＮＡ検査や抗原抗体反応検査など）に利用可能である。   The flat thin film type SQUID differential type magnetic flux sensor of the present invention and the apparatus using the same can be used for non-destructive inspection using a SQUID magnetic sensor, foreign matter inspection apparatus, bio-measurement (DNA inspection, antigen-antibody reaction inspection, etc.) It is.

本発明の実施例を示す平面薄膜型ＳＱＵＩＤ微分型磁束センサの模式図である。It is a schematic diagram of the plane thin film type SQUID differential type magnetic flux sensor which shows the Example of this invention. 本発明の平面薄膜型ＳＱＵＩＤ微分型磁束センサとこの微分磁束センサの微分方向と垂直な方向から励磁磁場を印加することができる励磁用磁場印加機構を備えたＳＱＵＩＤ非破壊検査用装置を示す図である。FIG. 2 is a diagram showing a SQUID nondestructive inspection apparatus equipped with a planar thin film type SQUID differential magnetic flux sensor of the present invention and an excitation magnetic field applying mechanism capable of applying an excitation magnetic field from a direction perpendicular to the differential direction of the differential magnetic flux sensor. is there. 図２と同じ原理で４個の電磁石を用いて、板状の検査対象物の傷検出に適用したＳＱＵＩＤ非破壊検査用装置を示す図である。It is a figure which shows the apparatus for SQUID nondestructive inspection applied to the detection of the damage | wound of a plate-shaped test object using four electromagnets by the same principle as FIG. 図２と同じ原理で励磁コイル（電磁石）に代えて、ソレノイドコイル２個を用いた場合のＳＱＵＩＤ非破壊検査用装置を示す図である。It is a figure which shows the apparatus for SQUID nondestructive inspection at the time of using two solenoid coils instead of an excitation coil (electromagnet) on the same principle as FIG. 従来の平面薄膜型ＳＱＵＩＤ微分型磁束センサを示す模式図である。It is a schematic diagram showing a conventional flat thin film type SQUID differential type magnetic flux sensor.

符号の説明Explanation of symbols

１ 微分型磁束検出コイル
２ ＳＱＵＩＤリング
３ 上部リード線薄膜パターン
４ 中央部リード線薄膜パターン
５ 下部リード線薄膜パターン
６ ジョセフソン接合部
７ グレインバウンダリー
８ 印加磁界（印加磁場）
１０ 平面薄膜型ＳＱＵＩＤ微分型磁束センサ
１１，１２，２１，２２；２３，２４ 電磁石
１３，３３ 検出対象物
１４，２７，３４ クライオスタット（低温冷媒保持容器）
１５，２８，３５ 励磁磁場
１６，２９，３６ バイアス電流ＩB
２５ 板状の検査対象物
２６ 板状の検査対象物の欠陥部
３１，３２ 励磁用ソレノイドコイル DESCRIPTION OF SYMBOLS 1 Differential type magnetic flux detection coil 2 SQUID ring 3 Upper lead thin film pattern 4 Center lead thin film pattern 5 Lower lead thin film pattern 6 Josephson junction 7 Grain boundary 8 Applied magnetic field (applied magnetic field)
DESCRIPTION OF SYMBOLS 10 Planar thin film type SQUID differential type magnetic flux sensor 11, 12, 21, 22; 23, 24 Electromagnet 13, 33 Detection object 14, 27, 34 Cryostat (low temperature refrigerant holding container)
15, 28, 35 Excitation magnetic field 16, 29, 36 Bias current I B
25 Plate-like inspection object 26 Plate-like inspection object defective part 31, 32 Solenoid coil for excitation

Claims (5)

磁界微分を計測する一次以上の微分型磁束検出コイルを有する平面薄膜型ＳＱＵＩＤ微分型磁束センサにおいて、励磁磁場の方向と、ＳＱＵＩＤリング中のジョセフソン接合部に流れるバイアス電流の方向が平行になるようにＳＱＵＩＤリング部と磁束検出コイルを直接結合させることを特徴とする平面薄膜型ＳＱＵＩＤ微分型磁束センサ。   In a flat thin film type SQUID differential type magnetic flux sensor having a primary or higher differential type magnetic flux detection coil for measuring magnetic field differentiation, the direction of the excitation magnetic field and the direction of the bias current flowing through the Josephson junction in the SQUID ring are made parallel. A flat thin film type SQUID differential type magnetic flux sensor characterized in that the SQUID ring part and the magnetic flux detection coil are directly coupled to each other. 請求項１記載の平面薄膜型ＳＱＵＩＤ微分型磁束センサにおいて、前記バイアス電流を供給するリード線薄膜パターンの、中央部リード線薄膜パターンの方向を励磁磁場の方向と一致させるように配線することを特徴とする平面薄膜型ＳＱＵＩＤ微分型磁束センサを用いた非破壊検査用装置。   2. The flat thin film type SQUID differential magnetic flux sensor according to claim 1, wherein the lead thin film pattern for supplying the bias current is wired so that the direction of the central lead thin film pattern coincides with the direction of the excitation magnetic field. A non-destructive inspection apparatus using a flat thin film type SQUID differential type magnetic flux sensor. 請求項１又は２記載の平面薄膜型ＳＱＵＩＤ微分型磁束センサを用いた非破壊検査用装置において、前記励磁磁場を印加する逆向きの極性を持つ２個の電磁石を具備することを特徴とする平面薄膜型ＳＱＵＩＤ微分型磁束センサを用いた非破壊検査用装置。   3. A nondestructive inspection apparatus using the flat thin film type SQUID differential type magnetic flux sensor according to claim 1 or 2, comprising two electromagnets having opposite polarities for applying the excitation magnetic field. Non-destructive inspection apparatus using a thin film type SQUID differential magnetic flux sensor. 請求項１又は２記載の平面薄膜型ＳＱＵＩＤ微分型磁束センサを用いた非破壊検査用装置において、前記検出対象物が板状の検出対象物であり、前記励磁磁場を印加する二対の逆向きの極性を持つ４個の電磁石を具備することを特徴とする平面薄膜型ＳＱＵＩＤ微分型磁束センサを用いた非破壊検査用装置。   3. The nondestructive inspection apparatus using the flat thin film type SQUID differential magnetic flux sensor according to claim 1 or 2, wherein the detection target is a plate-shaped detection target and two pairs of opposite directions to which the excitation magnetic field is applied. Non-destructive inspection apparatus using a flat thin film type SQUID differential type magnetic flux sensor, comprising four electromagnets having the following polarities. 請求項１又は２記載の平面薄膜型ＳＱＵＩＤ微分型磁束センサを用いた非破壊検査用装置において、前記励磁磁場を印加する逆向きの極性を持つ２個のソレノイドコイルを具備することを特徴とする平面薄膜型ＳＱＵＩＤ微分型磁束センサを用いた非破壊検査用装置。   3. A nondestructive inspection apparatus using the flat thin film type SQUID differential magnetic flux sensor according to claim 1 or 2, further comprising two solenoid coils having opposite polarities for applying the excitation magnetic field. Non-destructive inspection apparatus using a flat thin film type SQUID differential magnetic flux sensor.
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