JPH0738871Y2 - Compensation device for magnetic field gradient sensor coil - Google Patents
Compensation device for magnetic field gradient sensor coilInfo
- Publication number
- JPH0738871Y2 JPH0738871Y2 JP1987011738U JP1173887U JPH0738871Y2 JP H0738871 Y2 JPH0738871 Y2 JP H0738871Y2 JP 1987011738 U JP1987011738 U JP 1987011738U JP 1173887 U JP1173887 U JP 1173887U JP H0738871 Y2 JPH0738871 Y2 JP H0738871Y2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic field
- sensor coil
- field gradient
- gradient sensor
- magnetic
- 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.)
- Expired - Lifetime
Links
Description
【考案の詳細な説明】 （産業上の利用分野） 本考案は、磁界勾配センサーコイルの補償装置につい
て、脳磁計、心磁計などの生体磁気用の高感度磁束計、
磁気遮蔽効果や磁化率の測定、あるいは地磁気の測定な
ど、絶体零度に近い極低温においてみられる超伝導効果
を利用した磁界勾配センサーコイルの補償装置に関す
る。[Detailed Description of the Invention] (Industrial field of application) The present invention relates to a compensating device for a magnetic field gradient sensor coil, a highly sensitive magnetic flux meter for biomagnetism such as a magnetoencephalograph and a magnetocardiograph,
The present invention relates to a compensator for a magnetic field gradient sensor coil, which utilizes the superconducting effect observed at extremely low temperatures near zero, such as the measurement of magnetic shielding effect and magnetic susceptibility, or the measurement of geomagnetism.
（従来の技術） センサーコイルの代表的な利用例としてのSQUID（超伝
導量子干渉素子）磁束計に用いるものを例にとって説明
する。(Prior Art) A description will be given of an example of using a SQUID (superconducting quantum interference device) magnetometer as a typical application example of a sensor coil.
第4A図に示すように、逆向きにセットした一対のコイル
L1、L2を用い軸方向に対する一次微分回路を構成し、局
所的な磁界計測精度の向上を図っている。すなわち、セ
ンサーコイルにおいて、２個のコイルを逆向きに接続す
ることにより、距離に対する磁界の勾配（微分）に応答
することになり、周囲の一様な磁界による信号は打ち消
され、不要な信号（磁気ノイズ）を著しく少なくするこ
とができる。このセンサーコイルは、一次微分型磁界勾
配センサーコイルと呼ばれる。A pair of coils set in opposite directions, as shown in Figure 4A.
By using L 1 and L 2 to form a primary differentiating circuit in the axial direction, the local magnetic field measurement accuracy is improved. That is, in the sensor coil, by connecting two coils in opposite directions, a response to the gradient (differentiation) of the magnetic field with respect to the distance is responded, the signal due to the uniform magnetic field in the surrounding is canceled, and an unnecessary signal ( Magnetic noise) can be significantly reduced. This sensor coil is called a first derivative magnetic field gradient sensor coil.
更に、第4B図に示すように、一次微分型磁界勾配センサ
ーコイルの２組を逆向きに接続することにより、一様な
磁界ばかりでなく、一様な磁界の勾配をも打ち消すこと
ができ、一層、周囲の磁気ノイズの影響を受け難く、安
定した磁界計測を行うことができる。Furthermore, as shown in FIG. 4B, by connecting two sets of first-order differential type magnetic field gradient sensor coils in opposite directions, not only a uniform magnetic field but also a uniform magnetic field gradient can be canceled. Furthermore, it is possible to perform stable magnetic field measurement, which is less affected by the surrounding magnetic noise.
これら微分コイルの特性は、それを構成する一対のコイ
ルのバランス（特性の一致度）及び機械的・電気的な安
定性により決定される。製作に際して、完全な特性の一
致、具体的には、コイル対の各コイルの磁界と発生誘導
電流との関係の一致を実現することは困難なため、何ら
かの補償手段が必要となる。The characteristics of these differential coils are determined by the balance (coincidence of characteristics) and mechanical / electrical stability of a pair of coils forming the differential coils. At the time of manufacture, it is difficult to achieve complete matching of characteristics, specifically, matching of the relationship between the magnetic field of each coil of the coil pair and the generated induced current, and therefore some compensation means is required.
従来、これら磁界勾配センサーコイルにおいては、第５
図に示すように、液体ヘリウム容器Ｄ内で、非磁性材質
のボビンＢの回りに巻き線した磁界勾配センサーコイル
Ｃの近傍に、導体あるいは磁性体などの薄片円筒Ｒを配
置し、この薄片円筒の位置を容器の外部から操作し、移
動させることにより、磁界勾配センサーコイルを構成す
る一対のコイルL1、L2のバランス調整（補償）すること
が行われている。Conventionally, in these magnetic field gradient sensor coils,
As shown in the figure, in a liquid helium container D, a thin piece cylinder R such as a conductor or a magnetic body is arranged in the vicinity of a magnetic field gradient sensor coil C wound around a bobbin B made of a non-magnetic material. By operating and moving the position from the outside of the container, the balance adjustment (compensation) of the pair of coils L 1 and L 2 forming the magnetic field gradient sensor coil is performed.
（考案が解決しようとする問題点） しかし、このように従来の磁界勾配センサーコイルの補
償方式は、液体ヘリウム容器内で薄片円筒を移動させる
ため、容器外からの遠隔操作機構が必要であり、その操
作も煩雑であり、更に、それらの機構や構造体により熱
抵抗が低下するなど種々の問題点があった。(Problems to be solved by the invention) However, in the conventional magnetic field gradient sensor coil compensation system as described above, since the thin cylinder is moved in the liquid helium container, a remote operation mechanism from the outside of the container is required, The operation is also complicated, and there are various problems such as a decrease in thermal resistance due to the mechanism and the structure.
（問題点を解決するための手段） 上記の問題点は、同じ軸上の異なる位置に設置され、同
一方向磁界により誘導された電流の差を出力するよう結
合されたループ状コイル対を少なくとも１つ有する磁界
勾配センサーコイルと、この磁界勾配センサーコイルを
収納する非磁性の液体ヘリウム容器と、磁性材料から構
成されており、前記容器の外周に軸方向に移動できるよ
うに螺合し、前記ループ状コイル対の各インダクタンス
の実効的な値に影響して、前記コイル対の各コイルの磁
界と発生誘導電流との関係を同一にする補償リングとか
ら成る本考案の補償装置によって解決される。(Means for Solving the Problems) The above-mentioned problems are caused by at least one pair of loop-shaped coils which are installed at different positions on the same axis and are coupled so as to output a difference in current induced by a magnetic field in the same direction. A magnetic field gradient sensor coil, a non-magnetic liquid helium container for housing the magnetic field gradient sensor coil, and a magnetic material, which are screwed onto the outer periphery of the container so as to be axially movable, and the loop This is solved by the compensating device of the present invention, which comprises a compensating ring which influences the effective value of each inductance of the coil pair and makes the relationship between the magnetic field and the induced current of each coil of the coil pair the same.
（作用） 本考案では、液体ヘリウム容器の外周に配置した１個ま
たは数個の補償リング（一次微分型磁界勾配センサーコ
イルの場合には１個、二次微分型磁界勾配センサーコイ
ルの場合には少なくとも３個）を個々に独立して、ある
いは全体を同時に回転して軸方向に移動させてバランス
調整を行う。すなわち、一次微分型磁界勾配センサーコ
イルのバランス調整は１個の補償リングを軸方向に移動
させ、二次微分型磁界勾配センサーコイルの場合には、
連結した一次微分型磁界勾配センサーコイル部分の２組
について、各々バランス調整を行い、続いてどちらか１
組を軸方向に移動させ、バランス調整を行うことができ
る。(Operation) In the present invention, one or several compensating rings arranged on the outer periphery of the liquid helium container (one in the case of the first derivative type magnetic field gradient sensor coil, one in the case of the second derivative type magnetic field gradient sensor coil) At least three) are individually or individually and simultaneously rotated to move in the axial direction for balance adjustment. That is, the balance adjustment of the primary differential type magnetic field gradient sensor coil moves one compensation ring in the axial direction, and in the case of the secondary differential type magnetic field gradient sensor coil,
Balance adjustment is performed for each of the two sets of the coupled first-order differential type magnetic field gradient sensor coils, and then either 1
The set can be moved in the axial direction for balance adjustment.
（考案の効果） 液体ヘリウム容器外に配置した補償リングで調整を行う
ので、調整が容易で、構造が簡単かつ制作が容易であ
る。非磁性材質のリングの外周面に厚さ1,000Å程度の
パーマロイなどの磁性薄膜を被覆した補償リングを用い
る場合、カットオフ周波数は1MHz程度となり高い周波数
成分までのバランスがとれる（すなわち、DC成分のみな
らず、変化する信号成分に対しても良い結果を得ること
ができる）。(Effect of the Invention) Since the adjustment is performed with the compensation ring arranged outside the liquid helium container, the adjustment is easy, the structure is simple, and the production is easy. When using a compensating ring in which a magnetic thin film such as permalloy with a thickness of about 1,000Å is coated on the outer surface of a ring made of non-magnetic material, the cutoff frequency is about 1 MHz, which balances high frequency components (that is, only the DC component In addition, good results can be obtained even for changing signal components).
（実施例） 第１図は、本考案の二次微分型磁界勾配センサーコイル
についての一実施例を一部破断して示す斜視図である。
同図では、二次微分型のセンサーコイル１をガラスやベ
ークライトなどの非磁性（非金属）の液体ヘリウム容器
２の中に配置してあるが、通常、ボビンなどにコイルを
巻き線してあるのを便宜上省略してある。(Embodiment) FIG. 1 is a partially cutaway perspective view showing an embodiment of a second derivative magnetic field gradient sensor coil of the present invention.
In the figure, the sensor coil 1 of the second derivative type is arranged in a non-magnetic (non-metal) liquid helium container 2 such as glass or bakelite, but the coil is usually wound around a bobbin or the like. Are omitted for convenience.
液体ヘリウム容器２の外周に、軸方向に移動できる非磁
性のネジ付き円筒３を装備してあり、この円筒とネジ結
合する４個の補償リング4a、4b、4c、4dを回転して軸方
向に移動させることによりセンサーコイルのバランス調
整を行う。第１図は、一次微分型磁界勾配センサーコイ
ルが２個逆向きに連結されたものであり、下段の一次微
分型磁界勾配センサーコイル部分L1、L2に相対する補償
リング4a、4b、または上段の補償リング4c、4dを逆向き
に（リング間隔が変化するように）移動させることによ
り、一次微分型磁界勾配センサーコイル部分の各々につ
いてバランス調整を行うことができる。更に、一次微分
型磁界勾配センサーコイル部分の２組のうちの１組L1、
L2またはL3、L4の補償リング4a、4bまたは4c、4dを同じ
方向に（リング間隔を保ったまま）平行移動させること
により二次微分型磁界勾配センサーコイルとしてのバラ
ンス調整を行うことができる。補償リング4a〜4bは、外
径20mm、高さ10mm程度のベークライトまたはガラスなど
の非磁性の円筒の外周面にパーマロイなどの磁性薄膜を
1,000Å程度の厚さに被覆したものを用いる。このよう
な磁性薄膜を被覆した補償リングを使用する場合には、
カットオフ周波数は1MHz程度となり高い周波数成分まで
センサーコイルの補償を行うことができた。On the outer circumference of the liquid helium container 2, there is provided a non-magnetic threaded cylinder 3 that can move in the axial direction, and four compensating rings 4a, 4b, 4c, 4d that are screw-connected to this cylinder are rotated to rotate the axial direction. Adjust the balance of the sensor coil by moving to. FIG. 1 shows two first-order differential magnetic field gradient sensor coils connected in reverse directions, and compensating rings 4a, 4b, which are opposed to the first-order first-order differential magnetic field gradient sensor coil portions L 1 and L 2 in the lower stage, or By moving the upper compensating rings 4c and 4d in opposite directions (so that the ring spacing changes), balance adjustment can be performed for each of the first-order differential magnetic field gradient sensor coil portions. Furthermore, one set L 1 of the two sets of the first-order differential type magnetic field gradient sensor coil portion,
Performing parallel adjustment as a second-order differential type magnetic field gradient sensor coil by translating the compensating rings 4a, 4b or 4c, 4d of L 2 or L 3 , L 4 in the same direction (while maintaining the ring spacing). You can Compensation rings 4a-4b have a magnetic thin film such as permalloy on the outer surface of a non-magnetic cylinder such as bakelite or glass with an outer diameter of 20 mm and a height of about 10 mm.
Use a coating with a thickness of about 1,000Å. When using a compensation ring coated with such a magnetic thin film,
The cutoff frequency was around 1MHz, and the sensor coil could be compensated for even high frequency components.
第２図は本考案の二次微分型磁界勾配センサーコイルに
ついての別の実施例の一部破断斜視図である。本実施例
においては各コイルL1、L2、L3、L4の間隙に対応して３
個の補償リング4e、4f、4gが設けられており、補償リン
グ4e、4gによってコイルL1、L2およびL3、L4間のバラン
ス調整され、コイル対L1、L2とL3、L4との間のバランス
はリング4fによって調整されるように構成されている。FIG. 2 is a partially cutaway perspective view of another embodiment of the second derivative magnetic field gradient sensor coil of the present invention. In this embodiment, the number of coils corresponding to the gaps between the coils L 1 , L 2 , L 3 and L 4 is 3
A number of compensating rings 4e, 4f, 4g are provided, which are balanced by the compensating rings 4e, 4g between the coils L 1 , L 2 and L 3 , L 4 , and the coil pair L 1 , L 2 and L 3 , The balance with L 4 is configured to be adjusted by the ring 4f.
第３図は本考案の一次微分型磁界勾配センサーコイルに
ついての一実施例の一部破断斜視図であり、コイルL1と
L2との間の感度バランスの調整は、補償リング4hを容器
の軸方向に移動することによって達成さる。Figure 3 is a partially broken perspective view of an embodiment for one-order differential magnetic field gradient sensor coil of the present invention, a coil L 1
Adjustment of the sensitivity balance with L 2 is achieved by moving the compensation ring 4h in the axial direction of the container.
第１図は本考案の磁界勾配センサーコイル補償装置の一
実施例を一部破断して示す斜視図、 第２図は本考案の二次微分型磁界勾配センサーコイルに
ついての別の実施例の一部破断斜視図、 第３図は本考案の一次微分型磁界勾配センサーコイルに
ついての一実施例の一部破断斜視図、 第4A図及び第4B図はSQUIDに用いられるそれぞれ一次及
び二次微分型磁界勾配センサーコイルの原理図、 第５図は、従来の磁界勾配センサーコイルの補償装置の
説明図。 第１図の符号の説明 １……二次微分型磁界勾配センサーコイル、２……液体
ヘリウム容器、３……ネジ付き円筒、4a〜4d……補償リ
ング。 第３図の符号の説明 Ｃ……一次微分型磁界勾配センサーコイル、Ｄ……液体
ヘリウム容器、Ｒ……導体、Ｂ……ボビン。FIG. 1 is a partially cutaway perspective view showing an embodiment of a magnetic field gradient sensor coil compensator of the present invention, and FIG. 2 is another embodiment of a second-order differential type magnetic field gradient sensor coil of the present invention. Partly broken perspective view, FIG. 3 is a partially broken perspective view of one embodiment of the first-order differential type magnetic field gradient sensor coil of the present invention, and FIGS. 4A and 4B are first-order and second-order differential types used for SQUID, respectively. Principle diagram of magnetic field gradient sensor coil, FIG. 5 is an explanatory diagram of a conventional magnetic field gradient sensor coil compensator. Explanation of reference numerals in Fig. 1 1st-second derivative magnetic field gradient sensor coil, 2 liquid helium container, 3 cylinder with screw, 4a-4d compensating ring. Explanation of symbols in FIG. 3 C ... First-order differential magnetic field gradient sensor coil, D ... Liquid helium container, R ... Conductor, B ... Bobbin.
Claims (2)
向磁界により誘導された電流の差を出力するよう結合さ
れたループ状コイル対を少なくとも１つ有する磁界勾配
センサーコイルと、 この磁界勾配センサーコイルを収納する非磁性の液体ヘ
リウム容器と、 磁性材料から構成されており、前記容器の外周に軸方向
に移動できるように螺合し、前記ループ状コイル対の各
インダクタンスの実効的な値に影響して、前記コイル対
の各々の磁界と発生誘導電流との関係を同一にする補償
リングとから成る磁界勾配センサーコイルの補償装置。1. A magnetic field gradient sensor coil having at least one pair of looped coils arranged at different positions on the same axis and coupled to output a difference in current induced by a magnetic field in the same direction, and the magnetic field gradient sensor coil. A non-magnetic liquid helium container that houses the sensor coil, and a magnetic material that are screwed onto the outer circumference of the container so that they can move in the axial direction, and the effective value of each inductance of the loop coil pair. And a compensating ring for making the relationship between the magnetic field of each of the coil pairs and the induced current identical to each other, thereby compensating the magnetic field gradient sensor coil.
表面に被覆した磁性体薄膜であることを特徴とする請求
項１記載の磁界勾配センサーコイルの補償装置。2. The compensating device for a magnetic field gradient sensor coil according to claim 1, wherein the magnetic material is a magnetic thin film coated on the surface of a non-magnetic ring member.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1987011738U JPH0738871Y2 (en) | 1987-01-29 | 1987-01-29 | Compensation device for magnetic field gradient sensor coil |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1987011738U JPH0738871Y2 (en) | 1987-01-29 | 1987-01-29 | Compensation device for magnetic field gradient sensor coil |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63174077U JPS63174077U (en) | 1988-11-11 |
| JPH0738871Y2 true JPH0738871Y2 (en) | 1995-09-06 |
Family
ID=30799225
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1987011738U Expired - Lifetime JPH0738871Y2 (en) | 1987-01-29 | 1987-01-29 | Compensation device for magnetic field gradient sensor coil |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0738871Y2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007170880A (en) * | 2005-12-20 | 2007-07-05 | Yokogawa Electric Corp | Magnetic field detecting apparatus |
| UA102163C2 (en) | 2012-02-02 | 2013-06-10 | Владимир Николаевич Сосницкий | Device for compensation of electromagnetic interferences at measurement of bio-magnetic signals |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB8326581D0 (en) * | 1983-10-05 | 1983-11-09 | Picker Int Ltd | Detecting variations in magnetic fields |
| JPS61163994U (en) * | 1985-03-29 | 1986-10-11 |
-
1987
- 1987-01-29 JP JP1987011738U patent/JPH0738871Y2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63174077U (en) | 1988-11-11 |
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