JPH07333311A - Nuclear magnetic resonance device - Google Patents

Abstract

PURPOSE:To miniaturize a nuclear magnetic resonance device, so that, replacement work of a measurement probe and to be measured sample is done at a position where operativity is good, and, by attaching a measurement probe supporting mechanism to a magnet, taking in/out of the measurement prove is easier, for reduced operator work load. CONSTITUTION:On the side of a superconduction magnet 1, an insertion opening for a measurement probe and to-be-measured sample are provided. The measurement probe is taken in/out of measurement space 4 in horizontal direction, a to-be-measured sample tube 7 is held orthogonally, with orthogonal direction as an axis, rotation function is provided. Further, a measurement probe supporting tool 16 and a guide rail 17, for assisting taking in/out of the measurement probe, are attached to a magnet 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the internal structure and outer shape of a superconducting magnet which constitutes a nuclear magnetic resonance apparatus, and a measuring probe necessary for nuclear magnetic resonance measurement.

[0002]

2. Description of the Related Art Nuclear magnetic resonance (Nuclear Magnetic Reson)
ance; hereinafter abbreviated as NMR) device is for measuring a phenomenon in which a nucleus having a magnetic moment in a sample placed in a magnetic field resonates and absorbs a radio wave of a specific frequency,
It is a useful measurement device for obtaining information such as the molecular structure and physical / chemical properties of a sample.

The basic structure required for an NMR apparatus is a sample,
It is a transmitter and receiver of a magnetic field and a radio wave, and the outline of NMR measurement is to measure a magnetization generated by an NMR phenomenon by placing a sample in a magnetic field created by a magnet and irradiating a radio wave in the magnetic field. At this time, a measurement probe equipped with a coil necessary for irradiation of radio waves and measurement of magnetization is inserted into a magnetic field, and a sample is placed in the measurement probe for measurement. The measurement probe may need to be replaced depending on the nature of the sample and the purpose of the measurement.

Since NMR measurement has better spectral resolution and measurement sensitivity when measured in a stronger magnetic field, the magnet of the present NMR apparatus is a superconducting magnet that can obtain a higher magnetic field than a permanent magnet or an electromagnet. The one used is widely used. Further, in the superconducting magnet, the longer the coil of the magnet, the higher the uniformity of the magnetic field, and the better the resolution of the spectrum.

In the conventional superconducting magnet, a cylindrical measuring space is vertically elongated and the coil of the superconducting magnet is installed in a form wound around the long axis of the cylindrical measuring space. ing. Place the measurement sample in this measurement space,
The NMR measurement is performed at the position where the magnetic field is strongest. Since the superconducting magnet works at the temperature of liquid helium, the coil of the magnet is submerged in liquid helium in a vertically installed state and cooled, and the outside of the liquid helium tank is insulated by a vacuum tank. In addition, it has a double structure that it is cooled in a liquid nitrogen tank. The liquid helium and liquid nitrogen containers have a cylindrical shape with a hollow in the center, and both containers are arranged so that their central axes are the same. Further, as described above, since the magnet coil is cooled in the state of being immersed in liquid helium, the liquid helium container needs to have a depth of at least the length of the coil, and the outer liquid nitrogen container also has a liquid helium container. It needs to be large enough to cover.
In addition, since liquid helium and liquid nitrogen gradually evaporate, a space for the evaporation is also required, so both containers have a vertically long structure. Further, in order to place the measurement sample near the center of the magnetic field and to measure the magnetization of the NMR phenomenon, the measurement probe is inserted into the cylindrical measurement space in the center of the magnet. This measurement probe has the function of rotating the measurement sample tube and NMR.
It has the functions of transmitting and receiving radio waves necessary for measuring phenomena, and it may need to be replaced depending on the properties of the measurement sample and the measurement mode. Since the superconducting magnet coil is located at the bottom of the liquid helium container as described above, the measurement probe holding the measurement sample is inserted from the lower surface of the magnet. Due to such a structure, the operator must be located directly under the magnet and in a poor operability when exchanging the measurement probe. In addition, there is a risk of hitting the head with a magnet because the posture is such that it digs into the space directly below the magnet. Further, regarding the insertion of the measurement sample, since the measurement probe is inserted from the lower part of the magnet, the only part left as the measurement sample insertion port is the upper surface of the magnet. However, as described above, in a magnet having a vertically long structure, the total height of the magnet is high, so that it is not easy to take a sample in and out of the magnet upper surface. In addition, an automatic device such as an automatic sample changer may be provided around the magnet in the case of continuously measuring different samples.

As described above, the NMR apparatus has been variously devised in order to improve the performance of NMR measurement, but for this reason, a very large space is required to install the NMR apparatus, especially the superconducting magnet.

[0007]

As mentioned above, the NMR
The superconducting magnet of the device has a vertically elongated measuring space, a magnet coil is also vertically installed, and a liquid helium container and a liquid nitrogen container for cooling are also vertically elongated, so that the magnet itself is large. Furthermore, since the measurement space extends vertically, it is necessary to insert the measurement probe and measurement sample required for NMR measurement from the lower and upper surfaces of the magnet, and a working space is required above and below the magnet. Become.
In order to install the superconducting magnet in this way, considering the space around the magnet required for the work, a very large space is required.

An object of the present invention is to reduce the size of the device by eliminating unnecessary space around the magnet. Further, since the work of exchanging the measurement probe and the measurement sample in the space below and above the magnet places a heavy burden on the operator, there is a need to change the work position of the operator to a place that is easy to operate and reduce the work burden. .

[0009]

In order to solve the above problems, the present invention uses the following means.

In the internal structure of the superconducting magnet that constitutes the NMR apparatus, the cylindrical measurement space at the center of the magnet is made horizontally long, the measurement probe insertion port and the measurement sample insertion port are provided on the side surface of the magnet, and the magnet coil is the measurement space. It will be installed horizontally with a shape that is wound around the long axis of.

Further, in the measurement probe used for the NMR measurement, the measurement probe is taken in and out in a horizontal direction, and the structure of the measurement sample installation position at the tip of the measurement probe is made a structure in which the sample tube can be installed vertically.

Further, in the superconducting magnet constituting the NMR apparatus, a measurement probe support and a guide rail are attached so that the measurement probe can be smoothly taken in and out.

[0013]

[Function] Since the measurement space in the center of the magnet is horizontally long, and the measurement probe and the measurement sample insertion opening are provided on the side surface of the magnet, unnecessary space immediately below the magnet can be eliminated and the apparatus can be downsized. Become. Further, unlike the conventional case, the measurement probe and the measurement sample can be taken in and out in the horizontal direction, which simplifies the operation of the operator and reduces the work load.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 each show an outline of an NMR apparatus, which is composed of a superconducting magnet 1, a spectrometer 30, and a data system 40. FIG. 1 shows an example of a cross section of the internal structure of a superconducting magnet according to the present invention, and FIG. 2 shows an example of a cross section of the internal structure of a conventional superconducting magnet for comparison.

Since the superconducting magnet 1 works at the temperature of liquid helium, the internal structure of the magnet is basically the superconducting magnet coil 1a installed at the bottom of the liquid helium container 2 in both FIGS. The magnet coil 1a is submerged in the liquid helium 2a and cooled. The magnet coil 1a is preferably longer in order to generate a stable and uniform magnetic field. The liquid helium container 2 in which the magnet coil 1a is installed has a depth that allows the entire magnet coil 1a to be immersed in the liquid helium 2a, and the internal pressure rises rapidly when the liquid helium 2a gradually evaporates. It requires a space that does not exist. Further, in order to minimize the evaporation of the liquid helium 2a, the outside of the liquid helium container 2 is insulated by vacuum and further cooled by the liquid nitrogen 3a. It must be large enough to cover.

A conventional superconducting magnet 1 as shown in FIG.
Then, there is a vertically long cylindrical measurement space 4 in the center of the magnet, and a measurement sample is placed in this space for NMR measurement. The magnet coil 1a is installed vertically so as to be wound around the measurement space 4. For this reason, the liquid helium container 2 and the liquid nitrogen container 3 for cooling the magnet coil 1a are also vertically long cylindrical containers having a cylindrical space in the central portion around the major axis of the measurement space 4. As described above, how to install the magnet coil 1a and the shapes of the liquid helium container 2 and the liquid nitrogen container 3 have been factors that determine that the superconducting magnet has a vertically long shape.

On the other hand, in the case of the present invention shown in FIG. 1, the most important feature is that the internal structure of the superconducting magnet is made to be a laterally inverted form of the conventional one, and the measuring probe and the insertion port of the measuring sample are superconductive. It is provided on the side surface of the magnet 1. That is,
The cylindrical measurement space 4 is horizontally long, and the magnet coil 1a wound around the major axis of the measurement space 4 is horizontally long. Since the magnet coil 1a is horizontally long, the depth of the liquid helium container 2 need not be deeper than the conventional one. That is, unlike the prior art, since the magnet coil 1a is installed horizontally long, the depth of the liquid helium container 2 required to sink the magnet coil 1a into the liquid helium 2a is determined by the thickness of the magnet coil 1a. After that, as usual,
The size of the container may be determined in consideration of the evaporation amount of the liquid helium 2a. Further, the liquid nitrogen container 3 is installed outside the liquid helium container 2 so as to cover the liquid helium container 2, and the space between the two containers is insulated by vacuum. Here, the liquid helium container 2 and the liquid nitrogen container 3 have a shape in which the bottom of the container is fitted to the cylindrical shape of the magnet coil 1a as shown in FIG. Although it is possible to have more space as an evaporation space for liquid helium and liquid nitrogen if the upper part has a rectangular parallelepiped shape, the performance of the superconducting magnet is not required even if the outer shape of the container is cylindrical at the bottom and the upper part is not rectangular parallelepiped. There is no effect. That is, the overall outer shape of both containers may be cylindrical or rectangular. Further, the location of the magnet coil 1a in the container, that is, the cavities of the measurement space 4 should be well-balanced so that the thickness of the container is uniform as shown in FIG. Is good. However, when the measurement space 4 is moved to the bottom of the container to some extent, the position of the magnet coil 1a is lowered. This makes it possible to extend the time until the magnet coil 1a is exposed due to evaporation of liquid helium without changing the size of the container itself, so that the period until replenishment of liquid helium necessary for cooling can be extended.

Since the measurement space 4 is horizontally long,
Unlike the conventional case, the measurement probe does not have to be taken in and out in the space directly below the magnet, and the space directly below the magnet becomes unnecessary. On the other hand, replacement of the measurement sample, which was performed from above the magnet, can now be performed at a low position. In this way, both measurement probe and measurement sample exchange can be done at the same height,
Moreover, since the height can be set to a position where the operator has a sufficient visibility in the standing posture and is easy to work, the work burden on the operator is greatly reduced. In addition, the space surrounding the superconducting magnet can be reduced more than before, and the nuclear magnetic resonance apparatus can be downsized.

Next, the method of installing the measurement sample in the measurement probe applied to the superconducting magnet of the present invention and the structure of the measurement probe will be described. The basic principle of the measuring probe applied to the superconducting magnet of the present invention is not significantly different from the conventional measuring probe. However, in the superconducting magnet of the present invention, the insertion direction of the measurement probe and the direction of the external magnetic field generated by the magnet are different from the conventional ones, and therefore, the method for holding the measurement sample tube and the resolution of the measurement spectrum are improved. It is necessary to devise the axis of rotation of the measurement sample tube.

First, the principle of the sample setting method in the case of a liquid sample is shown in FIG. In the conventional case, as shown in FIG. 3A, the external magnetic field 6 in the measurement space is a vertical magnetic field, and the measurement sample tube 7 is held vertically with the vertical direction parallel to the vertical magnetic field as an axis. . Further, the rotation of the measurement sample tube 7 for increasing the measurement resolution is centered on the direction of the external magnetic field 6, that is, the vertical direction. However, the external magnetic field 6 in the measurement space in the superconducting magnet of the present invention is a horizontal magnetic field. Therefore, if the measurement sample tube 7 is rotated around the direction of the external magnetic field 6, the measurement sample tube 7 must be held horizontally as shown in FIG. 3B. That is, the measurement probe applied to the present invention needs a structure having a function of rotating the measurement sample tube 7 in the horizontal magnetic field direction without tilting even if the measurement sample tube 7 is held horizontally. However, it is difficult to hold the measurement sample tube 7 horizontally and rotate it around the horizontal direction as shown in FIG. 3B. On the other hand, as shown in FIG. 3 (c), a measurement probe having a function of holding the measurement sample tube 7 in a vertically long position and rotating it about a vertical direction perpendicular to the external magnetic field 6 is an axis. The same level of NMR measurement as in the past can be performed. However, in this case, the length of the measurement sample tube 7 needs to be short enough to fit within the diameter of the measurement space.

FIG. 4 shows an example of a measuring probe applicable to the superconducting magnet of the present invention. The measurement probe has a cylindrical portion inserted into the magnet and a portion with screws 9 for fixing the measurement probe to the magnet outside the magnet and a connection terminal 10 of a signal line for connecting to the spectrometer. is there. A measurement sample tube 7 is held at the tip of a cylindrical portion inserted inside the magnet, and a radio wave transmitting and receiving coil for NMR measurement is provided at that position to rotate the measurement sample tube 7. There are a plurality of compressed air outlets 11 and their respective wirings and pipes pass through the inside of the cylindrical portion of the measurement probe and are exposed to the outside of the magnet.
It extends to zero. In addition, a notch serving as a measurement sample introduction path 12 having a width that allows the measurement sample tube 7 to pass therethrough is formed at the tip of the measurement probe from the insertion direction of the sample tube to the compressed air outlet 11.
Is provided up to the center hole. This central hole becomes the measurement sample tube installation hole 13. After the measurement probe is inserted and installed in the magnet, the measurement sample tube 7 is attached to the sample tube support 14 through the measurement sample insertion port on the surface opposite to the measurement probe insertion port.
It is inserted while being held by. A rotor (or rotor) 15 is attached to the measurement sample tube 7 so as to rotate with compressed air. The length of the measurement sample tube 7 is set to be within the diameter of the cylindrical measurement space inside the magnet, and is set to be perpendicular to the external magnetic field direction. The measurement sample tube 7 inserted from the measurement sample insertion port is installed through the clearance of the measurement sample introduction path 12. At this time, the sample tube support tool 14 functions as a wall in conformity with the tip portion of the measurement probe, and closes the gap of the measurement sample introduction path 12. After that, the rotation and measurement of the measurement sample tube 7 are started. In the case of the measurement probe shown here, it is possible to perform measurement by exchanging only the measurement sample while fixing the measurement probe unless the measurement mode is changed.

FIG. 5 shows another example of the measuring probe applicable to the present invention. In the structure shown in FIG. 5, a hole for accommodating the measurement sample tube 7 is vertically provided at the tip of the measurement probe. This hole becomes the measurement sample tube installation hole 13. Around the hole, similarly to the above, a compressed air outlet 11 for rotating the measurement sample tube 7 to which the rotary blade 15 is attached is provided. In the case of the measurement probe as shown in FIG. 5, since the measurement sample tube 7 is installed in the measurement sample tube installation hole 13 and then the measurement probe is inserted into the magnet, the measurement probe is placed outside the magnet every time the sample is replaced. The need arises. Therefore, if the measurement probe support 16 and the guide rail 17 as shown in FIG. 6 are attached to the measurement probe and the guide rail 17 is fixed around the measurement probe insertion opening on the side surface of the magnet, the measurement probe can be easily pulled out. . However, in this case, the guide rail 17 remains outside the magnet even after the measurement probe is inserted. Therefore, the measurement probe support 16 and the guide rail 17 are attached to the magnet in advance so that they can match the measurement probe when the measurement probe is inserted, and the guide rail 17 is housed after the measurement probe is inserted so that it does not remain outside the magnet. Is preferable. FIG. 7 shows an example of a superconducting magnet with a guide rail. On the outer wall of the superconducting magnet 1, the measurement space 4
Attach the slide type guide rail 17 of two or more stages in parallel. When inserting the measurement probe into the measurement space 4 in the superconducting magnet 1, first, the slide guide rail 17 is inserted.
Is pulled out, and the measurement probe is placed on the measurement probe support tools 16a and 16b connected to the guide rail 17 and supported horizontally. Further, in order to carry out the insertion / removal of the measurement probe and the sliding movement of the guide rail 17, it is preferable to fix the measurement probe to the guide rail 17 or the measurement probe support 16a or 16b. In practice, fixing the part handled by the operator when the measurement probe is taken in and out is the easiest to operate, so the part that remains outside the magnet even after the measurement probe is inserted is stopped by the stopper 1.
It is better to fix at 9. That is, it is a position supported by the measurement probe support 16a. In addition, the support 16
The shapes of a and 16b may be a ring shape through which the cylindrical shape of the measurement probe passes or a semicircular shape in which the cylindrical shape is simply placed. In this way, the measurement probe held horizontally is inserted into the measurement space 4 inside the superconducting magnet 1, and at the same time, the slide-type guide rail 17 is pushed in. Finally, when the insertion of the measurement probe is completed, the guide rail is completed. Storage of 17 is also completed. In this way, only a part of the measurement probe having the connection terminal 10 and the thickness of the probe supporting members 16a and 16b are left outside the superconducting magnet 1, so that an extra space is not required. However, the measurement probe supports 16a and 16b are supported by the guide rails 17 on both sides of the magnet in a bridging state. Particularly, when the measurement probe is pulled out, the measurement probe floats in the air, and the support 16a supports the weight of the measurement probe in the air at two points of the stopper 19. That is, the guide rail 17 and the measurement probe supporters 16a and 16b need to have sufficient strength to bear the weight of the measurement probe. Therefore, the auxiliary casters 20 that reach the floor are attached to the support 16a in advance. This way
Since the measurement probe is supported at three points at the position of the support 16a, the strength with respect to the weight of the measurement probe is improved. Moreover, even when the measurement probe is pulled out, the movement of the auxiliary caster 20 facilitates the pulling out in the horizontal direction. The superconducting magnet having the measurement probe holding mechanism such as the guide rail can be applied to both the measurement probes shown in FIGS. 4 and 5.

On the other hand, the principle of sample installation in the case of a solid sample is shown in FIG. In the case of a solid sample, the measurement sample tube 7 is held with the axis of 54.7 ° (magic angle) with respect to the external magnetic field 6 in the measurement space as the rotation axis 8, so that the conventional type is as shown in FIG. ing. On the other hand, in the case of the present invention, since the external magnetic field 6 is in the horizontal direction, the axis of 54.7 ° with respect to the horizontal direction is the rotation axis 8 as shown in FIG. 6B.
If the measurement sample tube 7 is installed so that, the same NMR measurement as the conventional one can be performed. In other words, the solid sample measurement probe needs to adjust the angle at which the measurement sample tube 7 is held. Specifically, the angle at which the measurement sample tube 7 is installed is 54.7 ° with respect to the vertical direction and 35.3 ° with respect to the vertical direction.
Can be applied to the superconducting magnet of the present invention in which the measurement space extends in the lateral direction. Further, in the case of a measurement probe for a solid sample, since the measurement sample tube 7 is installed in a certain angle, the measurement probe must be pulled out to the outside of the magnet each time the measurement sample is replaced. Therefore, even for the measurement probe for solid samples, it is easier to operate if the measurement probe support 16 and the guide rail 17 are attached.
When used in a superconducting magnet as shown in FIG. 7, the work becomes simple.

[0025]

The cylindrical measurement space at the center of the magnet is horizontally elongated, and the magnet coil wound around the long axis of the measurement space is installed horizontally, and the measurement probe and the measurement sample insertion port are provided on the side surface of the magnet. Therefore, the measurement probe and the measurement sample tube can be inserted from the side surface of the magnet. That is, it is possible to eliminate the space directly below the magnet, which was conventionally required for inserting the measurement probe, and it is possible to reduce the total height of the magnet and downsize the magnet. In addition, when the measurement sample needs to be replaced, or the measurement probe needs to be replaced depending on the properties of the sample and the purpose of measurement, the working position of the operator can be lowered, and a superconducting guide rail is attached. When a magnet is used, the work of pulling out the measurement probe can be performed smoothly, so the work burden on the operator can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a comparative example.

FIG. 3 is an explanatory diagram of a method of installing a sample tube when a measurement sample is a liquid.

FIG. 4 is an explanatory diagram showing an example of a measurement probe of the present invention.

FIG. 5 is an explanatory view showing another example of the measurement probe of the present invention.

FIG. 6 is an explanatory view showing an example of a guide rail for inserting a measurement probe.

FIG. 7 is an explanatory diagram showing an example of a superconducting magnet having a measurement probe holding mechanism.

FIG. 8 is an explanatory diagram showing the principle of a method of installing a sample tube when a measurement sample is a solid.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Superconducting magnet, 1a ... Magnet coil, 2 ... Liquid helium container, 2a ... Liquid helium, 3 ... Liquid nitrogen container, 3a ...
Liquid nitrogen, 4 ... Measuring space, 30 ... Spectrometer, 40 ... Data system.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location 9307-2G G01R 33/22

Claims (4)

[Claims] 1. A superconducting magnet constituting a nuclear magnetic resonance apparatus, wherein a measurement probe for measuring nuclear magnetic resonance and an insertion port of a measurement sample tube are provided on a side surface of the superconducting magnet, and the measurement probe and the measurement sample are provided. A nuclear magnetic resonance apparatus, characterized in that the tube is moved in and out horizontally from the side surface of the superconducting magnet. 2. In a superconducting magnet constituting a nuclear magnetic resonance apparatus, a cylindrical measurement space for inserting a measurement probe and a measurement sample tube for nuclear magnetic resonance measurement is horizontally long, and the length of the measurement space is long. A nuclear magnetic resonance apparatus in which a coil of the superconducting magnet wound around an axis is installed in a horizontally long shape. 3. A measurement probe used for nuclear magnetic resonance measurement, comprising a function of holding a measurement sample tube, a function of rotating the measurement sample tube, and a function of measuring magnetization generated by a nuclear magnetic resonance phenomenon, A nucleus characterized in that the conductive sample is horizontally taken in and out from a laterally vacant cylindrical measurement space, the measurement sample tube is held vertically, and the measurement sample tube is rotated about the vertical axis. Magnetic resonance measurement probe. 4. A superconducting magnet constituting a nuclear magnetic resonance apparatus, wherein a guide rail for putting the measuring probe in and out of a horizontally elongated cylindrical measuring space is provided on a magnet wall surface, and the measuring probe is pulled out when the measuring probe is pulled out. A superconducting magnet having a support that holds the magnet horizontally.