JPH0652298B2 - NMR coil - Google Patents
NMR coilInfo
- Publication number
- JPH0652298B2 JPH0652298B2 JP61190278A JP19027886A JPH0652298B2 JP H0652298 B2 JPH0652298 B2 JP H0652298B2 JP 61190278 A JP61190278 A JP 61190278A JP 19027886 A JP19027886 A JP 19027886A JP H0652298 B2 JPH0652298 B2 JP H0652298B2
- Authority
- JP
- Japan
- Prior art keywords
- coil
- nmr
- coils
- arc
- magnetic field
- 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 - Fee Related
Links
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- Magnetic Resonance Imaging Apparatus (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、サンプルが装填される円筒空間の外周に２組
のコイルを同心円筒上に配置してなるＮＭＲ（核磁気共
鳴）用コイルに関する。The present invention relates to an NMR (nuclear magnetic resonance) coil in which two sets of coils are concentrically arranged on the outer periphery of a cylindrical space in which a sample is loaded. .
〔従来の技術〕 第４図はＮＭＲ用コイルの構成例を示す図、第５図は従
来のＮＭＲ用コイルの形状例を示す図である。図中、１
１と１２はコイル、１３は観測用端子、１４は照射用端
子、１５はロック用端子、１６と１７はボビンを示す。[Prior Art] FIG. 4 is a diagram showing an example of the configuration of an NMR coil, and FIG. 5 is a diagram showing an example of the shape of a conventional NMR coil. 1 in the figure
1 and 12 are coils, 13 is an observation terminal, 14 is an irradiation terminal, 15 is a locking terminal, and 16 and 17 are bobbins.
核スピン系を外部静磁場Ｈ0の中におくと、核磁化Ｍ
0は、静磁場Ｈ0の周りに ω0＝γＨ0……（１） のラーモア周波数で歳差運動する。ここで、γは磁気角
運動量比と呼ばれ、それぞれの磁性核に固有な定数であ
る。ＮＭＲ（核磁気共鳴）では、このラーモア周波数と
同じ周波数で静磁場Ｈ0に垂直な面内で回転する高周波
磁場（ラジオ波）を加えると、共鳴が起こって高周波磁
場からエネルギーが吸収される。そこで、ＮＭＲ装置で
は、一定磁場内にサンプルをおき、ＲＦ発振器からＮＭ
Ｒ用コイルに共鳴周波数を与えて高周波磁場を発生さ
せ、共鳴によって吸収されるエネルギーを検出する。When the nuclear spin system is placed in an external static magnetic field H 0 , the nuclear magnetization M
0 precesses around the static magnetic field H 0 at the Larmor frequency of ω 0 = γH 0 (1). Here, γ is called a magnetic angular momentum ratio, and is a constant unique to each magnetic nucleus. In NMR (nuclear magnetic resonance), when a high-frequency magnetic field (radio wave) rotating in a plane perpendicular to the static magnetic field H 0 is applied at the same frequency as the Larmor frequency, resonance occurs and energy is absorbed from the high-frequency magnetic field. Therefore, in the NMR apparatus, the sample is placed in a constant magnetic field and the NM is fed from the RF oscillator.
A resonance frequency is applied to the R coil to generate a high frequency magnetic field, and the energy absorbed by the resonance is detected.
ＮＭＲ装置では、第４図に示すようにＮＭＲ用コイルと
して２つのコイル１１及びコイル１２を備えている。そ
して、それぞれコイル１１を観測用として観測用端子１
３に接続し、コイル１２を高周波磁場の照射用とＮＭＲ
ロック用として照射用端子１４及びロック用端子１５に
接続している。このＮＭＲ用コイルは、第５図に示すよ
うに相互に適度な距離を保つようにして同心円筒のボビ
ン１６、１７を配置し、これらにＲＦ磁界の方向が直交
する（円筒空間の軸方向をＺ軸、円筒空間の断面をＸＹ
平面とすると、コイル１１のＲＦ磁界をＸ方向、コイル
１２のＲＦ磁界をＹ方向とする）ようにそれぞれのコイ
ル１１及びコイル１２を配置している。The NMR apparatus is equipped with two coils 11 and 12 as NMR coils as shown in FIG. Then, the observation terminal 1 is used for observing the coil 11 respectively.
3 and the coil 12 for irradiation of high frequency magnetic field and NMR
It is connected to the irradiation terminal 14 and the locking terminal 15 for locking. In this NMR coil, as shown in FIG. 5, concentric cylindrical bobbins 16 and 17 are arranged so as to maintain an appropriate distance from each other, and the direction of the RF magnetic field is orthogonal to these (the axial direction of the cylindrical space is Z axis, XY cross section of cylindrical space
If it is a plane, the coils 11 and 12 are arranged such that the RF magnetic field of the coil 11 is in the X direction and the RF magnetic field of the coil 12 is in the Y direction.
また、図示しないが、ＮＭＲ用コイルの形状として第５
図に示すボビン１６、１７を共通にしてその内側と外側
にそれぞれコイル１１及びコイル１２を配置するものも
ある。Although not shown, the shape of the NMR coil is the fifth.
There is also one in which the bobbins 16 and 17 shown in the figure are common and the coil 11 and the coil 12 are arranged inside and outside, respectively.
ＮＭＲ共鳴信号は、サンプルに近ければそれだけ強い信
号が検出できる。しかし、基本的な形状としてヘルムホ
ルツ（馬蹄）型を採用しているため、コイル１１とコイ
ル１２とをあまり近接して配置すると、第５図(b)から
明らかなように円筒断面に沿って配置される円弧形のア
ークコイル部では、相互の電磁結合がかなり強くなって
しまうため、最も重視される観測側の共鳴信号がコイル
１２に吸収され、感度低下をもたらすという問題が生じ
る。The closer the NMR resonance signal is to the sample, the stronger the signal can be detected. However, since the Helmholtz (horseshoe) type is adopted as the basic shape, when the coil 11 and the coil 12 are arranged too close to each other, the coil 11 and the coil 12 are arranged along the cylindrical cross section, as is apparent from FIG. 5 (b). In the arc-shaped arc coil section described above, mutual electromagnetic coupling is considerably strengthened, so that the resonance signal on the observation side, which is most important, is absorbed by the coil 12, resulting in a problem that sensitivity is lowered.
そこで従来は、第５図に示すようにボビン１６と１７と
の径の差を大きくすることによって前記の問題の改善を
図っている。しかし、この場合、相互に離す距離が無視
できなくなる。なぜなら、コイル１１とコイル１２との
間で相互に離す距離を大きくすればするほどコイル１２
により検出される共鳴信号の強度が弱まり、照射、ＮＭ
Ｒロックの効率低下を引き起こし前記とは別の問題が生
じる。従って、この距離は、極端に大きくとれない。Therefore, conventionally, as shown in FIG. 5, the above problem is improved by increasing the difference in diameter between the bobbins 16 and 17. However, in this case, the distance between them cannot be ignored. This is because the larger the distance between the coil 11 and the coil 12 is, the more the coil 12 is separated.
The intensity of the resonance signal detected by
This causes a decrease in the efficiency of the R lock and causes a problem different from the above. Therefore, this distance cannot be extremely large.
本発明は、上記の問題点を解決するものであって、コイ
ル１１及びコイル１２のアークコイル部における相互の
電磁結合をなくし、相互に近接配置できるＮＭＲ用コイ
ルを提供することを目的とするものである。The present invention solves the above-mentioned problems, and an object of the present invention is to provide an NMR coil that can be placed close to each other by eliminating mutual electromagnetic coupling in the arc coil portions of the coil 11 and the coil 12. Is.
そのために本発明は、サンプルが装填される円筒空間の
外周に、円弧形のアークコイル部と軸に平行な軸方向コ
イル部とにより構成されＲＦ磁場を発生させる２組のコ
イルを同心円筒上に配置してなるＮＭＲ用コイルにおい
て、前記ＲＦ磁場を発生させる２組のコイルの軸方向コ
イル部より上方と下方にシールド環を分割し、それぞれ
のシールド環をアークコイル部間に挟み込むように配置
したことを特徴とするものである。Therefore, in the present invention, two sets of coils for generating an RF magnetic field, which are composed of an arc-shaped arc coil section and an axial coil section parallel to the axis, are provided on the outer circumference of a cylindrical space in which a sample is loaded on a concentric cylinder. In the NMR coil arranged as described above, the shield rings are divided above and below the axial coil portions of the two sets of coils that generate the RF magnetic field, and the shield rings are sandwiched between the arc coil portions. It is characterized by having done.
本発明のＮＭＲ用コイルでは、シールド環が２組のコイ
ルのアークコイル部間に挟み込まれるので、両コイルを
近接して配置しても電磁結合がなくなり、観測側の共鳴
信号が照射／ロック用のコイルに吸収されて感度低下を
もたらすことがなくなる。また、照射／ロック用のコイ
ルをサンプルの近くに配置しても観測用のコイルとの電
磁結合が遮断でき、共鳴信号の強度が弱まることもなく
なるので、照射、ＮＭＲロックの効率低下を防止するこ
とができる。In the NMR coil of the present invention, since the shield ring is sandwiched between the arc coil portions of the two sets of coils, electromagnetic coupling is lost even if both coils are arranged close to each other, and the resonance signal on the observation side is for irradiation / locking. It will not be absorbed by the coil and cause a decrease in sensitivity. Further, even if the irradiation / locking coil is arranged near the sample, the electromagnetic coupling with the observation coil can be blocked and the intensity of the resonance signal is not weakened. be able to.
以下、図面を参照しつつ実施例を説明する。 Hereinafter, embodiments will be described with reference to the drawings.
第１図は本発明に係るＮＭＲ用コイルの１実施例を示す
図、第２図は本発明に係るＮＭＲ用コイルの回路図、第
３図はシールド環の他の実施例を示す図である。図中、
１と３はボビン、２はシールド環、４と５はコイルを示
す。FIG. 1 is a diagram showing one embodiment of an NMR coil according to the present invention, FIG. 2 is a circuit diagram of an NMR coil according to the present invention, and FIG. 3 is a diagram showing another embodiment of a shield ring. . In the figure,
1 and 3 are bobbins, 2 is a shield ring, and 4 and 5 are coils.
本発明に係るＮＭＲ用コイルは、第１図に示すように同
心円筒のボビン１、３を配置し、これらにＲＦ磁界の方
向が直交する（円筒空間の軸方向をＺ軸、円筒空間の断
面をＸＹ平面とすると、コイル４のＲＦ磁界をＸ方向、
コイル５のＲＦ磁界をＹ方向とする）ようにそれぞれの
コイル４及びコイル５を配置する。そして、コイル４及
びコイル５のアークコイル部が相対する部分のボビン
１、３間にシールド環２を挟み込むようにしたものであ
る。その横断面図（平面図）が第１図(a)、斜視図が第
１図(b)、縦断面図が第１図(c)であり、内側のコイル４
が観測用、外側のコイル５が照射／ロック用である。The NMR coil according to the present invention has concentric cylindrical bobbins 1 and 3 arranged as shown in FIG. 1, and the directions of the RF magnetic fields are orthogonal to these (the axial direction of the cylindrical space is the Z axis, and the cross section of the cylindrical space is cross section). Is the XY plane, the RF magnetic field of the coil 4 is in the X direction,
The respective coils 4 and 5 are arranged so that the RF magnetic field of the coil 5 is in the Y direction). Further, the shield ring 2 is sandwiched between the bobbins 1 and 3 at the portions where the arc coil portions of the coils 4 and 5 face each other. The cross-sectional view (plan view) is shown in FIG. 1 (a), the perspective view is shown in FIG. 1 (b), and the vertical cross-sectional view is shown in FIG. 1 (c).
Is for observation, and the outer coil 5 is for irradiation / locking.
第１図(b)、(c)に示すようにコイル４及びコイル５のア
ークコイル部と円筒空間の軸に平行な軸方向コイル部と
により形成される窓部をあけ、アークコイル部の間にシ
ールド環２を挟み込むことによって、アークコイル部の
間に電磁障壁を設けている。このため、両コイル４、５
を近接して配置しても相互で問題となる電磁結合をなく
すことができ、コイル５もコイル４との電磁結合を意識
することがないので、コイル４と同様にサンプルの近く
に配置することができる。As shown in FIGS. 1 (b) and (c), the window formed by the arc coil portions of the coils 4 and 5 and the axial coil portion parallel to the axis of the cylindrical space is opened, and the space between the arc coil portions is opened. An electromagnetic barrier is provided between the arc coil portions by sandwiching the shield ring 2 in the. Therefore, both coils 4, 5
Even if they are arranged close to each other, it is possible to eliminate the mutual electromagnetic coupling, and the coil 5 is not aware of the electromagnetic coupling with the coil 4. You can
コイル４、５のそれぞれのアークコイル部及び軸方向コ
イル部の関係を表すと第２図のようになる。この第２図
に示すようにアークコイル部の断面方向（Ｚ）は、コイ
ル４、５のいずれもが同じ方向であるのに対して、軸方
向コイル部の断面方向（Ｘ，Ｙ）は、それぞれが直交す
る方向である。本発明のＮＭＲ用コイルでは、この同じ
方向で電磁結合するアークコイル部の間に点線で示すシ
ールドを施したものである。なお、このシールドは、ア
ースしてもよいし、アースから浮かしてもよい。The relationship between the respective arc coil portions and axial coil portions of the coils 4 and 5 is shown in FIG. As shown in FIG. 2, the arc coil section has the same cross-sectional direction (Z) as the coils 4 and 5 have the same direction, whereas the axial coil section has the cross-sectional direction (X, Y) as follows. Each is a direction orthogonal to each other. In the NMR coil of the present invention, a shield shown by a dotted line is provided between the arc coil portions that are electromagnetically coupled in the same direction. The shield may be grounded or may be floated from the ground.
また、シールド環２は、第２図に示すように円筒状のパ
イプでもよいが、相互のコイルのアークコイル部間で電
磁障壁の作用をするものであれば、第３図(a)に示すよ
うなパイプを半分に割った形状のものを用意してこれを
向き合わせるようにして使ってもよいし、第３図(b)に
示すような円盤型のものを使ってもよい。The shield ring 2 may be a cylindrical pipe as shown in FIG. 2, but as long as it acts as an electromagnetic barrier between the arc coil portions of the mutual coils, it is shown in FIG. 3 (a). It is possible to prepare such a pipe by dividing it into halves and use them by facing each other, or to use a disc type as shown in FIG. 3 (b).
シールド環としては、導電材料や金属、高分子材料等を
用いることができ、これらの材料を使ったフィルム状の
プリント板や、ガラス、セラミックに蒸着したもの、箔
状板をガラス、セラミック基材に張り付けたものでもよ
い。As the shield ring, conductive materials, metals, polymer materials, etc. can be used. Film-shaped printed boards using these materials, glass or ceramic vapor-deposited, foil-shaped boards made of glass, ceramic base materials. It may be pasted on.
以上の説明から明らかなように、本発明によれば、観測
用コイルと照射／ロック用コイルとの間でアークコイル
部に起因する電磁結合を遮断するため、両コイル共にサ
ンプルに近接して配置できる。その結果、それぞれのコ
イルでのＮＭＲ共鳴信号の感度を高め、測定効率の向上
を図ることができる。特に、従来のＮＭＲ用コイルで
は、コイル相互間の電磁結合により共振波が数多く発生
するため、目的とする共振波の発生エネルギーを吸収す
る場合が多く、また、検出空間外の空間にある物質の信
号をピックアップし、スペクトラムの裾の広がりが大き
くしていた。しかし本発明によれば、シールド環を設
け、不要な共振波の減少を図ると共に、検出空間外から
の信号のピックアップを遮断するので、上記のような従
来のＮＭＲ用コイルによる問題が解消し、測定感度や測
定効率の向上を図ることができる。As apparent from the above description, according to the present invention, the electromagnetic coupling caused by the arc coil portion is cut off between the observation coil and the irradiation / lock coil, so that both coils are arranged close to the sample. it can. As a result, the sensitivity of the NMR resonance signal in each coil can be increased and the measurement efficiency can be improved. In particular, in a conventional NMR coil, a large number of resonance waves are generated due to electromagnetic coupling between the coils, so that the generated energy of the target resonance wave is often absorbed, and the presence of substances in the space outside the detection space The signal was picked up and the spread of the hem of the spectrum was wide. However, according to the present invention, a shield ring is provided to reduce unnecessary resonance waves, and the pickup of a signal from outside the detection space is blocked, so that the problem with the conventional NMR coil as described above is solved, It is possible to improve the measurement sensitivity and the measurement efficiency.
第１図は本発明に係るＮＭＲ用コイルの１実施例を示す
図、第２図は本発明に係るＮＭＲ用コイルの回路図、第
３図はシールド環の他の実施例を示す図、第４図はＮＭ
Ｒ用コイルの構成例を示す図、第５図は従来のＮＭＲ用
コイルの形状例を示す図である。 １と３…ボビン、２…シールド環、４と５…コイル。FIG. 1 is a diagram showing one embodiment of an NMR coil according to the present invention, FIG. 2 is a circuit diagram of the NMR coil according to the present invention, and FIG. 3 is a diagram showing another embodiment of a shield ring, Figure 4 is NM
FIG. 5 is a diagram showing a configuration example of an R coil, and FIG. 5 is a diagram showing an example of the shape of a conventional NMR coil. 1 and 3 ... Bobbin, 2 ... Shield ring, 4 and 5 ... Coil.
Claims (1)
円弧形のアークコイル部と軸に平行な軸方向コイル部と
により構成されＲＦ磁場を発生させる２組のコイルを同
心円筒上に配置してなるＮＭＲ用コイルにおいて、前記
ＲＦ磁場を発生させる２組のコイルの軸方向コイル部よ
り上方と下方にシールド環を分割し、それぞれのシール
ド環をアークコイル部間に挟み込むように配置したこと
を特徴とするＮＭＲ用コイル。1. An outer periphery of a cylindrical space in which a sample is loaded,
In an NMR coil in which two sets of coils for generating an RF magnetic field, which are composed of an arc-shaped arc coil portion and an axial coil portion parallel to the axis, are arranged on a concentric cylinder, generate the RF magnetic field. An NMR coil characterized in that a shield ring is divided above and below an axial coil portion of a pair of coils, and each shield ring is arranged so as to be sandwiched between arc coil portions.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61190278A JPH0652298B2 (en) | 1986-08-13 | 1986-08-13 | NMR coil |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61190278A JPH0652298B2 (en) | 1986-08-13 | 1986-08-13 | NMR coil |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6345549A JPS6345549A (en) | 1988-02-26 |
| JPH0652298B2 true JPH0652298B2 (en) | 1994-07-06 |
Family
ID=16255501
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61190278A Expired - Fee Related JPH0652298B2 (en) | 1986-08-13 | 1986-08-13 | NMR coil |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0652298B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0722576B2 (en) * | 1988-04-11 | 1995-03-15 | 三菱電機株式会社 | Magnetic resonance device |
| JP2002085373A (en) * | 2000-09-14 | 2002-03-26 | Ge Medical Systems Global Technology Co Llc | Method for inhibiting electromagnetic coupling between coils, orthogonal coil, mri device and method of making orthogonal coil |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4642569A (en) * | 1983-12-16 | 1987-02-10 | General Electric Company | Shield for decoupling RF and gradient coils in an NMR apparatus |
-
1986
- 1986-08-13 JP JP61190278A patent/JPH0652298B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6345549A (en) | 1988-02-26 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |