JPS61231444A - Coil for nmr apparatus - Google Patents

Abstract

PURPOSE:To simplify manufacturing and to obtain a coil excellent in accuracy and sensitivity, by delivering the patterns corresponding to a linear conductor and a circular arc conductor from a thin conductive plate and folding back said pattern along a predetermined fold line to mold the same into a cylindrical shape. CONSTITUTION:The original form pattern of two-turn coil for a NMR apparatus is delivered from a thin conductive plate and the linear conductor of this pattern corresponds to conductors 1A, 2A while the circular arc shaped conductor thereof corresponds to conductors 1B, 2B. Said pattern folds double along a fold line L and an insulating film F is inserted in the contact parts of the conductors 1, 2. The folded patterns is fixed to a cylindrical bobbin 3 in a wound state to be molded into a coil. Whereupon, the winding start part S and winding finish part E of the coil come to a state protruded to the outside of the coil and it is convenient from the aspect of signal detection. Because the coil pattern is delivered from the thin conductive plate, manufacturing can be made easy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a coil used in a nuclear magnetic resonance apparatus (NMR apparatus), and particularly to a coil that is easy to manufacture and has excellent precision and sensitivity.

[Prior art] In an NMR apparatus, a probe containing a sample is placed in a uniform static magnetic field, and a high-frequency magnetic field for excitation is irradiated from a coil placed close to the sample in the probe. This coil receives the resonance signal from N
Obtaining MR spectra. At that time, the geometrical symmetry of the coil and the quality of the coupling between the coil and the resonator of the sample are
Since the sensitivity of the R device is greatly influenced, great attention is paid to the manufacturing precision of the coil and the shape and structure of the coil.

In the case of an NMR apparatus using a superconducting magnet, a cylindrical saddle-shaped coil as shown in FIG. 4, for example, has been commonly used.

The saddle-shaped coil shown in Fig. 4 has two spirally wound coil sections 1.2 arranged symmetrically around the cylindrical axis 2 around a cylindrical region of radius R in which the sample tube containing the sample is arranged. has been done. This spirally wound coil portion consists of straight conductor portions 1A, 2A parallel to the cylindrical axis 2 and arcuate portions IB, 2B lying in a plane perpendicular to the cylindrical axis 2.

Conventionally, such a coil has been manufactured by winding a conductor wire with a circular cross section around the surface of a cylindrical bobbin, but this poses a problem in terms of manufacturing accuracy because the wire tends to shift.

FIG. 5 shows the original pattern of the coil proposed in Japanese Patent Application Laid-Open No. 57-147041. In this conventional example, the coil pattern is manufactured as a printed circuit on a printed board or by punching out a wide flat conductor from a thin conductor plate, so it is excellent in manufacturing accuracy. Also, when a coil is made from a flat conductor like this, the surface area is larger than a coil made from a circular cross-section conductor wire with the same cross-sectional area, so the resistance to the high-frequency current flowing through the surface layer is reduced, and the Q of the coil is significantly increased. Since the high-frequency magnetic field created by the high-frequency current flowing through the flat conductor runs parallel to the conductor surface, it has the excellent effect of increasing the uniformity of the high-frequency magnetic field irradiated onto the sample.

′ [Problem that the invention seeks to solve] However,
When making a coil with such a flat conductor, tm-11
Because the first coil pattern must be punched out or cut out from the conductor plate, the winding start part S and winding end part E of the coil cannot be taken out of the coil as they are, and are connected to an external circuit. S the conductor for
, I had to solder the E part.

As described above, connecting to an external circuit within the coil winding is not only disadvantageous in terms of signal detection, but also requires careful consideration in manufacturing the coil.

The present invention has been made in view of this point, and it is an object of the present invention to provide a coil that is easy to manufacture and has excellent precision and sensitivity.

[Means for Solving the Problems] In order to achieve this object, the coil for NMR equipment according to the present invention is produced by folding a coil pattern cut out from a thin conductor plate along a predetermined fold line and then forming it into a cylindrical shape. It is characterized by being molded.

[Example] Hereinafter, one embodiment of the present invention will be described in detail using the drawings.

FIG. 1(a) shows the original pattern of a two-turn coil for an NMR apparatus according to the present invention, which is created by punching or cutting out a thin conductive plate. In this pattern, IA and 2A correspond to straight conductors, and IB and 2B correspond to arcuate conductors.

FIG. 1(b) shows the state when this coil pattern is folded into two along a folding line. An insulating film F is inserted between the portions where the upper and lower conductors come into contact with each other due to folding to provide insulation.

FIG. 1(C) shows the state when it is further wound around the cylindrical bobbin 3, fixed, and formed into a coil. It goes without saying that the dimensions M1 to Q3 of the pattern are determined in accordance with the diameter R and height of the bobbin so that the spiral winding portion 1.2 becomes symmetrical when formed into a coil.

In the coil of the present invention created in this way, the coil is formed of one continuous flat conductor, and since the coil winding start part S and the winding end part E are outside the coil, there are parts S and E inside the coil. There is no disadvantage in terms of signal detection compared to the conventional method, and manufacturing is simple.

FIG. 2(a) shows the original pattern of the three-turn coil according to the present invention, and if this is folded along the fold line L1, the pattern shown in FIG.
b), and then fold only the drawer portion 4 along the fold line L2.
If it is turned back at this point, the state shown in FIG. 2(C) will be obtained. Then, if it is further wound around a cylindrical bobbin and formed into a cylindrical shape, it becomes a three-turn coil. Incidentally, the arc-shaped conductor 1B is given a width commensurate with the width occupied by the arc-shaped conductor 2B, so that the distribution of the conductor is symmetrical, and the static i! This prevents the uniformity of the field from decreasing.

Figure 3(a) shows the original pattern of the same 4-turn coil, and if you fold this along fold line L1, you will get the state shown in Figure 3(b), and then fold only the drawer portion 4 along Pi L2. If it is returned, the state shown in FIG. 3(C) will be obtained. Then, if it is further wound around a cylindrical bobbin and formed into a cylindrical shape, it becomes a 4-turn coil.

In the embodiments shown in FIGS. 2 and 3 as well, an insulating film F is inserted in the portion where the upper and lower conductors come into contact.

Further, in the above-described embodiments, the coil is wound around a cylindrical bobbin and fixed, but as long as the flat conductor has sufficient strength, the coil itself can support itself, and a support such as a bobbin is not necessarily necessary.

[Effects of the Invention] As detailed above, according to the present invention, a coil that is easy to manufacture and has excellent precision and sensitivity is provided.

[Brief explanation of drawings]

Figures 1, 2, and 3 are NMR images in which the present invention was implemented, respectively.
A diagram showing an example of a coil for a device, FIG. 4 is a diagram showing a conventional cylindrical saddle-shaped coil, and FIG. 5 is a diagram showing a conventional cylindrical saddle-shaped coil.
FIG. 2 is a diagram showing the original pattern of the coil proposed in No. 1. 1.2: Spiral winding coil portion IA, 2A: Straight conductor portion 1B, 2B: Arc-shaped conductor portion 3: Bobbin 4: Drawer portion L+, L2: Fold line F: Insulating film

Claims (1)

[Claims] A coil for an NMR device is made by cutting a coil pattern from a thin conductor plate, folding it back along a predetermined fold line, and then forming it into a cylindrical shape.