JPH0472704A - Magnetic field correction device - Google Patents
Magnetic field correction deviceInfo
- Publication number
- JPH0472704A JPH0472704A JP2185854A JP18585490A JPH0472704A JP H0472704 A JPH0472704 A JP H0472704A JP 2185854 A JP2185854 A JP 2185854A JP 18585490 A JP18585490 A JP 18585490A JP H0472704 A JPH0472704 A JP H0472704A
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- Prior art keywords
- magnetic
- magnetic field
- component
- output
- uniform
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Links
- 239000000696 magnetic material Substances 0.000 abstract description 21
- 230000003247 decreasing effect Effects 0.000 abstract description 2
- 238000000034 method Methods 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 239000002253 acid Substances 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 238000005481 NMR spectroscopy Methods 0.000 description 1
- 230000002457 bidirectional effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
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- Magnetic Resonance Imaging Apparatus (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は、核磁気共鳴用マグネット装置における不均
一磁場成分を補正する磁場補正装置に関するものである
。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic field correction device for correcting non-uniform magnetic field components in a magnet device for nuclear magnetic resonance.
第６図および第７図は従来の磁場補正装置を示す正面断
面図および側面断面図であり、図において、１は非磁性
体よりなる非磁性管、２はこの非磁性管１内に選択的に
挿入および引き抜き自在、すなわち、取り付けおよび取
り外しができるように設けられた棒状の磁性体、３はこ
れらの非磁性管１および磁性体２を内部に配設し、かつ
円筒状をなす回転不可能な非磁性筒５に取り付けられて
、主磁場を発生するコイル、４は均一性が要求される磁
場領域であり、ここでは点線の丸で囲んだ領域となって
いる。6 and 7 are a front sectional view and a side sectional view showing a conventional magnetic field correction device. In the figures, 1 is a non-magnetic tube made of a non-magnetic material, and 2 is a selective magnetic field inside the non-magnetic tube 1. A rod-shaped magnetic body provided so as to be able to be inserted and pulled out, that is, attached and removed; 3 is a cylindrical non-rotatable body in which the non-magnetic tube 1 and the magnetic body 2 are disposed; A coil 4 that is attached to a non-magnetic tube 5 and generates a main magnetic field is a magnetic field region where uniformity is required, and here it is the region surrounded by a dotted circle.
次に動作について説明する。Next, the operation will be explained.
まず、第８図および第９図に示すように、マグネット装
置の主磁場方向Ｚに長い、断面積Ａを有する棒状の磁性
体２が、ＸＹ面の取付角度ψ、ＺＹ面の端面角度α１．
α２の位置に配置された場合を考えると、磁性体２が均
一性の必要な磁場領域４の点Ｐ （ｒ、 θ、φ）に作
る磁場の２方向酸分Ｂ２は１次式で表わされる。First, as shown in FIGS. 8 and 9, a rod-shaped magnetic body 2, which is long in the main magnetic field direction Z of the magnet device and has a cross-sectional area A, is attached at an installation angle ψ in the XY plane and an end face angle α1 in the ZY plane.
Considering the case where the magnetic body 2 is placed at the position α2, the two-way acid component B2 of the magnetic field created at the point P (r, θ, φ) of the magnetic field region 4 that requires uniformity is expressed by a linear equation. .
Ｘ（ｒ／ａ） Ｘ Ｐｎ （ｃｏｓθ）ｘｃｏｓｍ（
φ−ψ）（１）ここで、
Ｋ：磁性体の磁気特性によって決まる値で定数ａ：磁性
体の取付半径
ε、：ノイマン係数（ｍ≠０ならε。＝２．ｍ＝０なら
εヨ＝１）Ｐｎ ： ｎ次ｍ位のルジャンドル陪多項式
となっている。この（１）式は極座標系での次式である
が、通常使われる直交座標との対応は、ｎ＝２までを例
に取ると、第１１図に示す通りである。X(r/a) X Pn (cosθ)xcosm(
φ−ψ) (1) where, K: Constant value determined by the magnetic properties of the magnetic material a: Mounting radius of the magnetic material ε,: Neumann coefficient (if m≠0, ε.=2.If m=0, εY) =1) Pn: It is a Legendre polynomial of order n and m. This equation (1) is the following equation in a polar coordinate system, but its correspondence with orthogonal coordinates, which is usually used, is as shown in FIG. 11, taking up to n=2 as an example.
一方、コイル３が均一度領域４に作る磁場の２方向酸分
ＢＣＺは極座標表示にて次式で表わされる。On the other hand, the bidirectional acid component BCZ of the magnetic field created by the coil 3 in the uniformity region 4 is expressed by the following equation in polar coordinates.
Ｂｃｚ”Ｂｏ＋Ａ１Ｂ１１＋ＡＪ２１＋Ａ３Ｂ”＋Ａ４
Ｂ５１＋Ａ５Ｂ”ｍ＝ （ｊ）ここで、Ｂｏは位置によ
らず一定の成分を示し、具体的には原点（０，Ｏ，Ｏ）
での磁場に等しい。Bcz”Bo+A1B11+AJ21+A3B”+A4
B51+A5B”m= (j) Here, Bo indicates a constant component regardless of the position, specifically the origin (0, O, O)
is equal to the magnetic field at
従って、例えば、ＡｌＢ１１は、Ｂ １１ に比例した
誤差成分を示している。Therefore, for example, AlB11 shows an error component proportional to B 11 .
即ち、均一度領域４の均一性を高めるには、（２）式の
Ａより １１等Ｂ。以外の成分を打ち消すよ′うな磁性
体２が必要であることが分かる。以下に、従来例として
の、ＸおよびＹ方向空間不均一に対応するＢ１１成分補
正用の磁性体２について述べる。（１）式から分かるよ
うに、磁性体２が作る磁場成分は無限側あるが、一般に
ａ ） ｒであるからｎの値の大きい成分は（１）式中
の（ｒ ／ ａ）が非常に小さくなるために無視できる
。そこで、実用上はｎ、ｍの値が小さい成分についての
み考えればよい。ここでは上記磁場のＺ方向成分Ｂ２の
径方向成分（即ちｍ≠○）のみに注目して、以下に示す
不均一磁場補償成分を考える。この不均一磁場補償成分
は、Ｂ”、Ｂ”、Ｂ”、Ｂ”、Ｂ２Ｚ Ｂ３３．Ｂ４１
．Ｂ＊Ｚ Ｂ４３．Ｂ４４．ＢＳＺ Ｂ５２ＢＳ３．
Ｂ”である。ここで、Ｂ１１成分だけを発生するような
磁性体２の形状、位置は次の手順で決まる。まず、ｍ＝
２．３．４の成分を発生しないように、磁性体２を挿入
する非磁性管１の取付角度ψを、
に選ぶ。すなわち、各々の取付角度ψは、また、磁性体
２の一方の端面角度をαとした時。That is, in order to improve the uniformity of the uniformity region 4, from A of equation (2), 11 magnitude B is used. It can be seen that a magnetic material 2 that cancels out other components is required. Below, a conventional magnetic body 2 for correcting the B11 component corresponding to spatial non-uniformity in the X and Y directions will be described. As can be seen from equation (1), the magnetic field component created by magnetic material 2 has an infinite side, but in general it is a ) r, so for the component with a large value of n, (r / a) in equation (1) is very large. It can be ignored because it is small. Therefore, in practice, it is only necessary to consider components with small values of n and m. Here, we will focus only on the radial component of the Z-direction component B2 of the magnetic field (that is, m≠○), and consider the nonuniform magnetic field compensation component shown below. This non-uniform magnetic field compensation component is B'', B'', B'', B'', B2Z B33. B41
．． B*Z B43. B44. BSZ B52BS3.
B". Here, the shape and position of the magnetic body 2 that generates only the B11 component are determined by the following procedure. First, m =
2. In order to avoid generating the component of 3.4, the installation angle ψ of the non-magnetic tube 1 into which the magnetic body 2 is inserted is selected as follows. That is, each mounting angle ψ is when α is the angle of one end face of the magnetic body 2.
もう一方の端面角度を（π−α）に選べば、即ち、Ｚ軸
について対称な磁性体２であれば、（１）式の８か所と
なり、ｍ＝２．３．４に対して（１）式でｃｏｓ’
ｍ’（φ−ψ）二〇となる。βの値の決め方については
後述するが、βの値が如何に取られた場合でも、ｃｏｓ
ｍ（φ−ψ）＝ ｏの関係は成立しているので、Ｂ ”
、 Ｂ”、 Ｂ”、 Ｂ４２． Ｂ４３、 Ｂ”、 Ｂ
ｓ２． Ｂ”、 Ｂ”の成分はなくなることとなり、残
りはＢ １１． Ｂ”、 Ｂ”、 Ｂ４１． Ｂ”であ
る。If the other end face angle is chosen to be (π-α), that is, if the magnetic body 2 is symmetrical about the Z axis, there will be 8 points in equation (1), and for m = 2.3.4, ( 1) In the formula cos'
m'(φ−ψ) becomes 20. How to determine the value of β will be explained later, but no matter how the value of β is taken, cos
Since the relationship m(φ−ψ)=o holds, B ”
, B”, B”, B42. B43, B", B
s2. The components of B" and B" will disappear, and the remainder will be B11. B”, B”, B41. B”.
π −α
となり、結局、Ｂ”、Ｂ”は発生しない。最後にＢ５１
＝Ｏ，Ｂ５１＝０を満たすように第１０図に示すように
、２つの部分で構成された磁性体２の端面角度と、それ
らの断面積比を決める。Ｂ”＝０となる端面角度は３３
．８８° １４６．１２゜１１７．９６°である。端
面角度が （３３，８８°、１４６．１２°）の磁性体
２の断面積をＡ□、（６２，０４’ 、１１７．９６°
）の磁性体２の断面積をＡ２とすると、
Ｂ５１ｃＡ、［Ｐ、（ｃｏｓ ３３．８８°）（ｓｉ
ｎ ３３．８８°）Ｓコ＋ＡＸ ［Ｐ４ （ＣＯ５６
２，０４°）（ｓｉｎ ６２．０４°）’］＝０より、
八〇／Ａ２＝’１．１６であればＢ５１＝Ｏとなる。π −α, and B'' and B'' do not occur after all. Finally B51
As shown in FIG. 10, the end face angle of the magnetic body 2 composed of two parts and the ratio of their cross-sectional areas are determined so that =O,B51=0 is satisfied. The end face angle at which B”=0 is 33
．． 88° 146.12° 117.96°. The cross-sectional area of the magnetic body 2 whose end face angles are (33,88°, 146.12°) is A□, (62,04', 117.96°)
), then B51cA, [P, (cos 33.88°) (si
n 33.88°)S co+AX [P4 (CO56
2,04°)(sin 62.04°)']=0,
If 80/A2='1.16, B51=O.
以上、取付角度、端面角度、断面積比の条件を決定する
ことにより所望の磁場補償成分Ｂ１”を選択的に出力す
ることができる。As described above, by determining the conditions of the mounting angle, end face angle, and cross-sectional area ratio, it is possible to selectively output a desired magnetic field compensation component B1''.
次に、磁場補償成分Ｂ １１の実際の不均一磁界成分を
補償する際に、従来方式では上記の取付角度。Next, when compensating for the actual non-uniform magnetic field component of the magnetic field compensation component B 11, the above mounting angle is used in the conventional method.
端面角度、断面積比の条件の下で、補償磁界成分Ｂ１１
を直交座標系で示した場合のＸ成分、Ｙ成分の各成分に
相当する出力を得る。Under the conditions of end face angle and cross-sectional area ratio, compensation magnetic field component B11
Outputs corresponding to the X component and Y component when expressed in a rectangular coordinate system are obtained.
ところで、極座標表示された磁性体２の補償磁界成分Ｂ
１１を直交座標Ｘ、Ｙに分離した成分Ｂ工。By the way, the compensation magnetic field component B of the magnetic body 2 expressed in polar coordinates
Component B works by separating 11 into orthogonal coordinates X and Y.
ＢＹは、上記の取付角度におけるβの値に対応して、
Ｂｘ ＝Ｂ１１ｃｏｓ β、 Ｂｙ ＝Ｂ１１ｓｉｎ
βと表わせることから、Ｘ成分のプラス出力のみを得る
ためには、β＝Ｏ，Ｙ成分のプラス出力のみを得るため
にはβ＝π／２の各取付角度とすればよく、これは第１
２図（ａ）および（ｂ）に示した位置への磁性体２の取
り付けとなる。逆にＢｘのマイナス出力のみを得るため
にはβ＝π、ＢＹのマイナス出力のみを得るには（３／
２）πとすればよく、これは第１２図（ｃ）および（ｄ
）に示した位置への磁性体２の取り付けとなる。従って
、任意のＸ成分とＹ成分を出力するためには、磁性体２
を挿入する非磁性管１を第１２図（ｅ）に示すように、
同一に重なることを考慮しても最低１６個設けることと
なる。BY corresponds to the value of β at the above mounting angle,
Bx = B11 cos β, By = B11 sin
Since it can be expressed as β, in order to obtain only the positive output of the X component, the mounting angle should be β = O, and in order to obtain only the positive output of the Y component, the mounting angle should be β = π/2, which is 1st
The magnetic body 2 is attached to the position shown in FIGS. 2(a) and 2(b). Conversely, to obtain only the negative output of Bx, β = π, and to obtain only the negative output of BY, use (3/
2) π, which is shown in Figure 12 (c) and (d)
) The magnetic body 2 is attached to the position shown in (). Therefore, in order to output arbitrary X and Y components, the magnetic material 2
As shown in FIG. 12(e), the non-magnetic tube 1 into which the
Even if we consider that they overlap, at least 16 pieces will be provided.
一方、Ｘ、Ｙ各成分の出力の大きさは、（１）式で明ら
かなように、使用する磁性体２の断面積に比例するため
、必要に応じた断面積を有する磁性体２をＸ成分、Ｙ成
分発生位置の非磁性管１の中に挿入することとなる。On the other hand, as is clear from equation (1), the magnitude of the output of each of the X and Y components is proportional to the cross-sectional area of the magnetic body 2 used. component, and the Y component is inserted into the non-magnetic tube 1 at the position where the Y component is generated.
従来の磁場補償装置は以上のように構成されているので
、元来、極座標系で１成分であった不均一成分を直交座
標系の２成分に分解して補償するため、磁性体２を取り
付ける非磁性管１の数が多くなり、使用する磁性体２の
数も多くなって、構成の複雑化およびコストアップを招
くなどの課題があった。Since the conventional magnetic field compensator is configured as described above, the magnetic body 2 is attached to compensate by decomposing the non-uniform component, which was originally one component in the polar coordinate system, into two components in the orthogonal coordinate system. The number of non-magnetic tubes 1 increases, and the number of magnetic bodies 2 used also increases, resulting in problems such as a complicated structure and an increase in cost.
この発明は上記のような課題を解消するためになされた
もので、極座標系で１成分となる補償磁界を直交座標系
の２成分に分解することなく、簡単な構成で不均一成分
を補償することができる磁場補正装置を得ることを目的
とする。This invention was made to solve the above-mentioned problems, and compensates for non-uniform components with a simple configuration without decomposing the compensation magnetic field, which is one component in a polar coordinate system, into two components in an orthogonal coordinate system. The purpose is to obtain a magnetic field correction device that can perform the following steps.
この発明に係る磁場補正装置は、非磁性筒の筒内空間に
おける不均一磁場成分が最大となる周方向角度を中心と
して、該不均一磁場成分を補正する最適角度となるよう
に、上記非磁性筒を回転可能または固定的に設けたもの
である。The magnetic field correction device according to the present invention adjusts the non-magnetic cylinder so that the angle in the circumferential direction at which the non-uniform magnetic field component in the cylinder space of the non-magnetic cylinder becomes the maximum is the optimum angle for correcting the non-uniform magnetic field component. The tube is either rotatable or fixed.
この発明における磁場補正装置は、不均一磁場の成分に
応じて磁性体を適切な位置に配置することにより、その
磁性体を取り付ける非磁性管の数を減らし、使用する磁
性体の量も低減し、構成の簡素化およびローコスト化を
可能にする。The magnetic field correction device of the present invention reduces the number of non-magnetic tubes to which the magnetic material is attached by arranging the magnetic material at appropriate positions according to the components of the non-uniform magnetic field, and also reduces the amount of magnetic material used. , making it possible to simplify the configuration and reduce costs.
以下、この発明の一実施例を図について説明する。 An embodiment of the present invention will be described below with reference to the drawings.
第１図および第２図において、１は非磁性体よりなる非
磁性管、２はこの非磁性管１内に選択的に挿入および引
き抜き自在、すなわち、取り付けおよび取り外しができ
るように設けられた棒状の磁性体、３はこれらの非磁性
管１および磁性体２を内部に配設し、かつ円筒状をなす
回転可能な非磁性筒６に取り付けられて、主磁場を発生
するコイル、４は均一性が要求される磁場領域であり、
ここでは点線の丸で囲んだ領域となっている。In FIGS. 1 and 2, 1 is a non-magnetic tube made of a non-magnetic material, and 2 is a rod-shaped tube that can be selectively inserted into and pulled out of the non-magnetic tube 1, that is, can be attached and removed. 3 is a coil in which the non-magnetic tube 1 and the magnetic material 2 are disposed, and is attached to a cylindrical rotatable non-magnetic tube 6 to generate a main magnetic field; 4 is a uniform coil; This is a magnetic field area that requires
Here, the area is surrounded by a dotted circle.
次に動作について説明する。Next, the operation will be explained.
まず、主磁場方向Ｚに長い断面積Ａを有する棒状の磁性
体２がＸ、Ｙ面取付角度ψ、Ｚ、Ｙ平面の端面角度α０
．α２の位置に配置された様子は、第８図および第９図
に示した通りであり、棒状の磁性体２が断面積Ａ１およ
びＡ２の２つの部分から構成されている様子は、第１０
図に示した通りである。そして、極座表系で示された磁
場補償成分Ｂ １１だけの補正磁場を磁性体２により発
生するためのＢ２２．Ｂ３Ｚ Ｂ３３．Ｂ１２ Ｂ１２
Ｂ４４．Ｂ５２Ｂｓｆｆ、 Ｂｓ４（７）各成分Ｂ”
、 Ｂ”（７）各成分オヨヒＢ１”の成分を発生させな
いようにする各条件は従来例と全く同一である。First, a rod-shaped magnetic body 2 having a long cross-sectional area A in the main magnetic field direction Z has a mounting angle ψ on the X and Y planes and an end face angle α0 on the Z and Y planes.
．． The state in which the rod-shaped magnetic body 2 is arranged at the position α2 is as shown in FIGS.
As shown in the figure. Then, B22.B22 is used to generate a correction magnetic field of only the magnetic field compensation component B11 shown in the polar coordinate system by the magnetic body 2. B3Z B33. B12 B12
B44. B52Bsff, Bs4(7) each component B”
, B'' (7) Each component The conditions for preventing the generation of the component Oyohi B1'' are exactly the same as in the conventional example.
一方、磁場補償成分Ｂ”の実際の不均一磁界成分を補償
する際には、磁場補償成分Ｂ１１を直交座標系で示した
場合のＸ成分、Ｘ成分の成分比に相当する出力を得るこ
と、および不均一磁界の大きさに相当する大きさの逆極
性の補償磁界出力を得ることが必要となる。まず、Ｘ成
分とＸ成分の出力比については、磁性体２の出力が上記
取付角度におけるβの値に対応して、Ｂ工＝ Ｂ １１
ｃｏｓ β、Ｂ、＝ｓｉｎ βと表わせることから、β
は：ｔａｎ−１（ＢＹ／Ｂ工）となる。すなわち、回転
可能な非磁性筒６に相対角度が、
の計８ケ所に取り付けられた非磁性管１に磁性体２を必
要な量挿入した後、非磁性筒６を第３図に示す様にβだ
け回転させる。これにより、所望のＸ成分とＸ成分の比
率を有する磁場補償成分７３１１の出力を得ることがで
きる。このとき、磁場補正用の磁性体２は周方向角度β
を中心に配置されることになるが、この角度βで磁場補
償成分Ｂｔｕの値が最大となっていることは明らかであ
る。On the other hand, when compensating for the actual non-uniform magnetic field component of the magnetic field compensation component B'', it is necessary to obtain an output corresponding to the X component and the component ratio of the X component when the magnetic field compensation component B11 is expressed in an orthogonal coordinate system. It is necessary to obtain a compensating magnetic field output of opposite polarity and a magnitude corresponding to the magnitude of the non-uniform magnetic field.First, regarding the output ratio of the X component and the X component, the output of the magnetic body 2 at the above mounting angle is Corresponding to the value of β, B engineering = B 11
Since it can be expressed as cos β, B, = sin β, β
: Tan-1 (BY/B engineering). That is, after inserting the required amount of magnetic material 2 into the non-magnetic tube 1 attached to the rotatable non-magnetic tube 6 at a total of eight locations with a relative angle of , the non-magnetic tube 6 is inserted as shown in FIG. Rotate by β. Thereby, it is possible to obtain an output of the magnetic field compensation component 7311 having a desired ratio of the X component to the X component. At this time, the magnetic body 2 for magnetic field correction has a circumferential angle β
It is clear that the value of the magnetic field compensation component Btu is maximum at this angle β.
次に、不均一磁界の大きさに相当する大きさの補償磁界
出力を得ることが必要であるが、これは（１）式で示し
た磁性体２の出力が断面積Ａに比例していることから、
使用する磁性体２の２つの部分の断面積Ａ工、ＡＸを従
来例の条件と同じく断面積比率Ａ工／Ａ２＝７．１６を
条件として増減させることで、所望の大きさの補償磁界
を得ることができる。Next, it is necessary to obtain a compensation magnetic field output of a magnitude corresponding to the magnitude of the nonuniform magnetic field, which is because the output of the magnetic body 2 shown in equation (1) is proportional to the cross-sectional area A. Therefore,
By increasing or decreasing the cross-sectional areas A and AX of the two parts of the magnetic body 2 to be used under the condition of the cross-sectional area ratio A / A2 = 7.16 as in the conventional example, a compensation magnetic field of the desired magnitude can be obtained. Obtainable.
ここで、従来例との比較を行うと、磁性体２を挿入する
非磁性管ｌは従来１６個必要であったものが８個に減少
し、従来、磁性体２の必要断面積Ｘ成分用Ａ、、Ｙ成分
用Ａ７であったものが、この実施例の必要面積では、
＼ρＥ丁ゝ＋ Ａ Ｔ”−となり１、ん（７ゝ４−ス］
７≦ Ａ工＋Ｂ。Here, when compared with the conventional example, the number of non-magnetic tubes l into which the magnetic body 2 is inserted is reduced from 16 to 8, and the required cross-sectional area of the magnetic body 2 is reduced to 8. What was A7 for A, Y component becomes \ρE dingゝ+ A T”- for the required area of this example, which becomes 1, N (7ゝ4-s)
7≦ A work + B.
（等号はＡ工＝０もしくはＡＶ＝Ｏ）が明らかに成り立
つことから、必要磁性体量は従来必要量に対して
ｍンー／Ａ工＋Ａアの比率で少なくすることができる。(The equal sign is A = 0 or AV = O), so the amount of magnetic material required can be reduced by the ratio of m-/A = 0 or AV = O compared to the conventionally required amount.
また、Ｂ ２１の成分、Ｂ２２の成分についても、磁性
体２を回転可能な非磁性筒６に取り付けた非磁性管１内
に挿入し、非磁性筒６を回転させることにより、ＺＸ成
分とＺＹＸ成分よびＸＸ成分とＸ−Ｙ２構成を同時にか
つ少ない磁性体量で補正することが可能である。このと
きの取付角度、端面角度、断面積比は以上説明と同様な
方法で決定することができ、その結果は第４図に示すよ
うになる。Furthermore, regarding the component B21 and the component B22, the ZX component and the ZYX component can be determined by inserting the magnetic body 2 into the nonmagnetic tube 1 attached to the rotatable nonmagnetic tube 6 and rotating the nonmagnetic tube 6. It is possible to correct the component, the XX component, and the X-Y2 configuration simultaneously and with a small amount of magnetic material. At this time, the mounting angle, end face angle, and cross-sectional area ratio can be determined in the same manner as described above, and the results are shown in FIG. 4.
なお、上記実施例では磁場補正用の磁性体２が主磁場発
生用のコイル３の内側に設けたものについて示したが、
第５図に示すように主磁場発生用のコイル３の外側に設
けてもよい、また、Ｂ”用。In addition, in the above embodiment, the magnetic body 2 for magnetic field correction is provided inside the coil 3 for generating the main magnetic field, but
As shown in FIG. 5, it may be provided outside the coil 3 for generating the main magnetic field.
Ｂ”用ｔ Ｂ”用のコイルを同時に１つの電磁石に用い
てもよい、さらに、上記実施例では磁場補正用の磁性体
２が回転可能な非磁性筒６に取り付けられ、この非磁性
筒６を回転させることによって位置を決め、磁場補正を
行うものを示したが、回転させた位置へ当初より固定取
付するようにしてもよい。The coils for B" and tB" may be used in one electromagnet at the same time.Furthermore, in the above embodiment, the magnetic body 2 for magnetic field correction is attached to a rotatable non-magnetic cylinder 6, and this non-magnetic cylinder 6 Although the magnetic field correction is performed by determining the position by rotating the magnetic field, it is also possible to fix the magnetic field to the rotated position from the beginning.
以上のようにこの発明によれば、不均一磁場成分が最大
となる周方向角度を中心として、該不均一磁場成分を補
正する最適角度となるように、上記非磁性筒を回転可能
または固定的に設けるように構成したので、極座標系で
示される１つの磁界成分を一度に且つ少ない磁性体で補
正することが可能となり、磁場補正に要する作業時間が
短縮され、使用材料も少なく、ローコストに構成できる
ものが得られる効果がある。As described above, according to the present invention, the non-magnetic cylinder is rotatable or fixed so that the angle in the circumferential direction at which the non-uniform magnetic field component is maximum is the optimum angle for correcting the non-uniform magnetic field component. Since the structure is configured such that one magnetic field component shown in the polar coordinate system can be corrected at once with a small number of magnetic materials, the working time required for magnetic field correction is shortened, less materials are used, and the structure is low cost. There is an effect that you can get what you can.
第１図はこの発明の一実施例による磁場補正装置を示す
正面断面図、第２図は第１図の磁場補正装置の詳細を示
す側面断面図、第３図は磁性体と非磁性筒との関係を示
す説明図、第４図はこの発明による磁性体の取付角度、
端面角度、断面積比の決定値を示す表口、第５図は磁場
補正装置の他の実施例を示す正面断面図、第６図は従来
の磁場補正装置を示す正面断面図、第７図は第６図の磁
場補正装置を示す側面断面図、第８図は２方向から見た
棒状の磁性体の配置関係を示す説明図、第９図は第８図
の磁性体をＸ方向から見た配置関係を示す説明図、第１
０図は磁性体を示す斜視図、第１１図は磁性体による磁
場の直交座標系での成分表示を示す表口、第１２図は磁
性体の磁場の成分に応じた取付角度を示す説明図である
。
２は磁性体、３はコイル、６は非磁性筒。
なお、図中、同一符号は同一、または相当部分を示す。
〜ｒＱ（Ｃ
第
図
第
図
第１０
図
第
図
（Ｏ
Ｘへ分プラス土り
工Ｔデ！ぺ４９）しラスｊ二Ｄ
Ｘ爪の、工への七ＤFIG. 1 is a front sectional view showing a magnetic field correction device according to an embodiment of the present invention, FIG. 2 is a side sectional view showing details of the magnetic field correction device shown in FIG. 1, and FIG. FIG. 4 is an explanatory diagram showing the relationship between the mounting angle of the magnetic body according to the present invention,
5 is a front sectional view showing another embodiment of the magnetic field correction device; FIG. 6 is a front sectional view showing a conventional magnetic field correction device; FIG. 7 is a side cross-sectional view showing the magnetic field correction device in Fig. 6, Fig. 8 is an explanatory diagram showing the arrangement relationship of the rod-shaped magnetic bodies viewed from two directions, and Fig. 9 is a side sectional view showing the magnetic body in Fig. 8 viewed from the X direction. Explanatory diagram showing the arrangement relationship, 1st
Figure 0 is a perspective view showing the magnetic body, Figure 11 is the front page showing the components of the magnetic field due to the magnetic body in an orthogonal coordinate system, and Figure 12 is an explanatory diagram showing the mounting angle according to the component of the magnetic field of the magnetic body. It is. 2 is a magnetic material, 3 is a coil, and 6 is a non-magnetic tube. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. ~rQ (C Figure Figure Figure 10 Figure Figure Figure (O
Claims (1)
た非磁性筒と、該非磁性筒の内部または外部に略筒形状
に沿って配置した複数の磁性体とを備えた磁場補正装置
において、上記空間の不均一磁場成分が最大となる周方
向角度を中心として、該不均一磁場成分を補正する最適
角度となるように、上記非磁性筒を回転可能または固定
的に設けたことを特徴とする磁場補正装置。A magnetic field correction device comprising: a non-magnetic tube in which a coil for forming a magnetic field region of a uniform magnetic field is disposed; and a plurality of magnetic bodies disposed inside or outside the non-magnetic tube along a substantially cylindrical shape; The non-magnetic cylinder is rotatably or fixedly provided so that the angle in the circumferential direction at which the spatial non-uniform magnetic field component is maximum is the optimum angle for correcting the non-uniform magnetic field component. Magnetic field correction device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2185854A JP2698209B2 (en) | 1990-07-13 | 1990-07-13 | Magnetic field correction device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2185854A JP2698209B2 (en) | 1990-07-13 | 1990-07-13 | Magnetic field correction device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0472704A true JPH0472704A (en) | 1992-03-06 |
| JP2698209B2 JP2698209B2 (en) | 1998-01-19 |
Family
ID=16178044
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2185854A Expired - Lifetime JP2698209B2 (en) | 1990-07-13 | 1990-07-13 | Magnetic field correction device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2698209B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103794333A (en) * | 2014-02-18 | 2014-05-14 | 哈尔滨理工大学 | Dry magnetic-strip type electric reactor |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01280447A (en) * | 1988-05-02 | 1989-11-10 | Hitachi Ltd | Nuclear spin resonance fault photographing device |
| JPH01305508A (en) * | 1988-06-03 | 1989-12-08 | Mitsubishi Electric Corp | Magnetic shim for correcting magnetic field |
-
1990
- 1990-07-13 JP JP2185854A patent/JP2698209B2/en not_active Expired - Lifetime
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01280447A (en) * | 1988-05-02 | 1989-11-10 | Hitachi Ltd | Nuclear spin resonance fault photographing device |
| JPH01305508A (en) * | 1988-06-03 | 1989-12-08 | Mitsubishi Electric Corp | Magnetic shim for correcting magnetic field |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103794333A (en) * | 2014-02-18 | 2014-05-14 | 哈尔滨理工大学 | Dry magnetic-strip type electric reactor |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2698209B2 (en) | 1998-01-19 |
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