JP2009271042A - Probe for continuous wave hf band magnetic resonance apparatus detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a probe for an HF band magnetic resonance apparatus detector which is mechanically stable and securely obtains orthogonality of a magnetic field generation axis, in a continuous wave HF band magnetic resonance apparatus. <P>SOLUTION: Three grooves, which are semicircular in cross section, are formed on wall surfaces of a pair of right and left coil bobbins for modulated magnetic field. A first groove reaches both ends of an outer circumference, a second groove is orthogonal to the first groove and reaches the first groove from one end of the outer circumference, and a third groove is formed from one end of the outer circumference on an opposite side to a middle of the wall surface. Bobbins are integrated by a tenon and mortise formed on the pair of the coil bobbins for modulated magnetic field respectively, and the three types of the grooves form cylindrical holes. A high frequency coil bobbin is housed in a first hole, and both ends are fixed by metal fittings screwed from upper and lower parts of a probe body frame. A high frequency coil lead-out wire is laid on a second hole. A deflection prevention pin is screwed from a tip end part of the body frame into a third hole. An opening part for inserting a sample tube as like to fit to the high frequency coil bobbin is formed on the metal fitting screwed from an upper part of the body frame. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a probe for a continuous wave HF band magnetic resonance apparatus detector.

Nuclear magnetic resonance and NMR of the condensate were reported by the Purcell and Bloch groups immediately after the Second World War. Over the course of several years, basic problems were solved both theoretically and experimentally. The same applies to electron spin resonance ESR. Advances in technology were in line with chemical research requirements to determine molecular structure.
E. M.M. Purcell, H.M. C. Torrey and R.M. V. Pound, Phys. Rev. 53, 318, 1946. F. Bloch, W.M. W. Hansen and M.M. Packard, Phys. Rev. , 70, 474, 1946. D. J. et al. E. Ingram, Spectroscopy at Radio and Microwave Frequenties Butterworth Scientific Publications, 1955.

The detector used to find the above phenomenon is a high-frequency bridge method that detects a decrease due to resonance absorption of the tank circuit Q value by Purcell et al., And detects an induced electromotive force generated in a direction orthogonal to the static magnetic field direction at the time of resonance by Bloch et al. The probe was based on the continuous wave method using a cross coil system, and various probes were developed in the early stages. However, the above chemical research requires high resolution as a spectroscope, and it takes a long time to measure, so the pulse method was developed soon, and the continuous wave method was limited to applications such as magnetic field measuring instruments and magnetic field stabilizers. in use. As a detection method, a self-excited LC marginal oscillator has been developed in place of the above-mentioned Purcell et al. Bridge method and is widely used for simplicity. In the limited applications described above, the apparatus configuration, hardware, operating parameters, sample type, etc. are selected and fixed to best suit these purposes. The sample used is also sealed.
W. Kempf, NMR in Chemistry, McCillan Publishers, 1986. Japanese Patent Application No. 2007-327998 Japanese Patent Application No. 2008-64884

  However, the continuous wave method as a magnetic resonance phenomenon observation method has an inherent advantage. In particular, observation of an electron spin resonance phenomenon in the HF band does not require a special and expensive electromagnet, and hardware for observation of the phenomenon is also required. Since advanced technology is not required, even if the performance and function are limited, it is easy to construct an inexpensive and versatile device (Patent Documents 5 and 6). For this purpose, the entire apparatus must be constructed and designed for the purpose of examining the properties of the sample. A probe used for a self-excited LC marginal oscillator type detector for a continuous wave HF band magnetic resonance apparatus that meets this purpose must be designed to have a structure suitable for that purpose. The present invention provides a probe for a continuous wave HF band magnetic resonance apparatus detector that satisfies the above requirements.

  An object of the present invention is to obtain a mechanically stable probe that can reliably obtain orthogonality in the magnetic field generation axis direction, which constitutes a continuous wave HF band magnetic resonance apparatus in combination with the self-excited LC marginal oscillator type detector. .

  Magnetic resonance detection probes in limited applications such as magnetic field measuring instruments and magnetic field stabilizers generate a high-frequency magnetic field and a low-frequency modulated magnetic field at right angles and apply them to the sample. The object to be stabilized is applied from the outside in a direction parallel to the modulation magnetic field. The three types of magnetic fields form one magnetic field system. Samples in such applications are sealed and fixed in the magnetic field system and do not require access to the magnetic field system from the outside. On the other hand, in the probe for a magnetic resonance apparatus detector to which the present invention is applied, access to the center of the magnetic field system from the outside of various samples to be tested is essential. In addition, it is necessary to appropriately set various operating parameters of the detector according to the properties of the sample. The basic form of the probe is common to both, but the specific form of both differs greatly depending on the necessity of the access. In the present invention, a probe for a detector of a continuous wave HF band magnetic resonance apparatus can be manufactured by solving the above-described problems, and the probe can be accessed using the probe so as to realize the continuous wave HF band magnetic resonance apparatus. All elements are structured in an integrated and organic manner.

  A basic diagram of a probe according to the present invention is shown in FIG. In the following description, the side where the cable is located with the coaxial cable 9 facing up and the two-core cable 10 facing down is referred to as the back surface, the opposite side as the front end surface, and the right and left as viewed from the back. FIG. 1 is a schematic diagram of the inside of a completed probe when the right side plate is placed on the paper surface and the left side plate is removed. Reference numeral 1 denotes a frame that forms the main body of the probe. A circular punch hole for storing the modulation magnetic field coil bobbins 6a and 6b, a high frequency coil 5, and a lead wire for the modulation magnetic field coil are connected to the coaxial cable and the two-core cable. Square hole for creating a void, the above-mentioned coaxial cable on the back side, a groove with a semicircular cross section for introducing a 2-core cable, the screw hole for the anti-fretting pin on the tip side, and the side plate for attaching the side plate on both sides Has screw holes.

  In FIG. 1, reference numeral 2a denotes left and right side plates, and 2b denotes a back plate that is screwed to the main body frame 1 and mechanically protects and electrically shields components housed therein. Reference numeral 3a denotes an upper fixing bracket which is screwed into the upper end of the high-frequency coil bobbin 4a by screwing the front end portion thereof from the upper surface of the main body frame 1 to constrain the upper portion of the high-frequency coil bobbin 4a. Reference numeral 3b denotes a lower fixing metal fitting whose front end is screwed into the lower surface of the main body frame 1 and is fitted into the lower portion of the high-frequency coil bobbin 4a so as to abut against the lower portion of the high-frequency coil bobbin 4a. The high frequency coil 5 is wound around the central portion of the high frequency coil bobbin 4a. Reference numeral 4b denotes a second groove provided in the right modulation magnetic field coil bobbin 6a, which forms a space for passing through the high-frequency coil lead wire. Reference numeral 4c denotes a third groove provided in the right modulation magnetic field coil bobbin 6a, into which the tip of the modulation magnetic field coil bobbin anti-spin pin 8 enters. Reference numerals 7a and 7b denote a side wall and a side hole provided on the right modulation magnetic field coil bobbin 6a.

  A modulation magnetic field coil bobbin 6b is a left modulation magnetic field coil bobbin which is positioned on the right modulation magnetic field coil bobbin 6a from the upper part of the paper by a pair of ridges and horn holes positioned in a mirror image relationship, and is formed into a cylindrical shape by three grooves which are also in a mirror image relationship position. Holes are created. The cylindrical hole formed by the first groove becomes a hole for the high-frequency coil bobbin 4a. The cylindrical hole formed by the second groove is a hole for passing the high-frequency coil lead wire. The cylindrical hole by the third groove is a hole into which the tip of the anti-spin pin 8 of the modulation magnetic field coil bobbin in which the left and right modulation magnetic field coil bobbins are integrated. The two pairs of lead wires of the left and right modulated magnetic field coils are connected in series so that the generated magnetic field is a polar. Reference numeral 9 denotes a high-frequency coaxial cable connected to the high-frequency coil lead wire. Reference numeral 10 denotes a low-frequency two-core cable connected to the modulation coil lead wire terminal connected in series. Reference numeral 11 denotes a sample tube that is inserted into the upper opening of the probe upper fixing bracket 3a completed by screwing the side plate 2a to the main body frame 1. The sample tube is coaxially fitted to the inner periphery of the high-frequency coil bobbin. Reference numeral 12 denotes a sample position adjusting ring that is slidably fixed so that the center of the sample at the bottom of the sample tube is aligned with the center of the magnetic field system.

  As described above, if the functions of the constituent elements of the probe according to the present invention are organically combined as described above, their specific shapes and dimensions are technical according to the required specifications. It may be changed as appropriate according to economic reasons.

  By using the probe according to claim 6 according to the present invention, the detector using the self-excited LC marginal oscillator as a detector for a continuous wave HF band magnetic resonance apparatus, such as frequency, oscillation level variability, stability, noise level, etc. It has been confirmed that it has a function and performance that can be put to practical use (Patent Documents 5 and 6).

An embodiment using the probe according to claim 6 of the present invention and the probe usage according to claim 7 of the present invention is shown in FIG. The upper sine wave in the figure is the voltage at the end of the modulation magnetic field coil, and has a frequency of 350 Hz, an average value of 524 mV, and a peak value of 358 mV. Below the figure is an example of observation of an electron spin resonance signal at 17 MHz. Average value corresponds to the static magnetic field H _o, peak values correspond to the modulated magnetic field peak value H _m. H _o signal appears at the resonance magnetic field H _r equal intervals every half cycle as shown is set to. This signal is obtained by the spurious removal averaging method (Patent Document 5). The static magnetic field H _o corresponding to 17 MHz is about 0.6 mT, and if calculated as a scale, H _m is about 0.4 mT.

1 is a basic view of a probe according to the present invention. It is an example of observation of magnetic resonance using the probe according to the present invention and the method of using the probe.

Explanation of symbols

In FIG. 1, 1 probe body frame 2a side plate 2b back plate 3a upper fixing bracket 3b lower fixing bracket 4a first groove and high frequency coil bobbin 4b second groove and high frequency coil lead wire 4c third groove and coil bobbin for modulation magnetic field Pin 5 High-frequency coil 6a Left modulation magnetic field coil bobbin 6b Right modulation magnetic field coil bobbin 7a Hozo 7b Eaves hole 8 Screw for fretting pin 9 Coaxial cable 10 2-core cable 11 Sample tube 12 Sample position adjustment ring x Horizontal axis y Vertical axis (High-frequency magnetic field axis )
z Horizontal axis (static magnetic field and modulation magnetic field axis)
T Probe thickness

Claims (8)

  HF band magnetic resonance apparatus detector probe having a structure in which a high frequency coil bobbin and an outer peripheral portion of a sample tube inserted in an inner peripheral portion thereof are fitted within a tolerance range.   2. The probe for an HF band magnetic resonance apparatus detector having the structure according to claim 1, wherein the high frequency coil bobbin has a cylindrical shape whose bottom is sealed in a hemispherical shape, and a high frequency coil is wound around the outer periphery of the high frequency coil bobbin. And an opening for inserting the sample tube of the upper fixing bracket into the outer periphery of the sample tube. Probe for HF band magnetic resonance apparatus detector having structure to be fitted in range   The probe for an HF band magnetic resonance apparatus detector having the structure according to claim 2, wherein the high-frequency coil bobbin and an upper portion fitted to the high-frequency coil bobbin are arranged at the intersection of the center plane of the probe main body frame for housing the high-frequency coil bobbin and a plane perpendicular thereto. The upper and lower fixing brackets are screwed in from the upper and lower portions of the probe main body frame so as to be integrated with the high frequency coil bobbin and the probe main body frame, and the probe main body frame is integrated on the central axis. HF band magnetic resonance apparatus detector probe having a structure in which a high-frequency coil is wound symmetrically with respect to the center point of the high-frequency coil bobbin so as to coincide with the center point   The probe for an HF band magnetic resonance apparatus detector having the structure according to claim 3, wherein the probe main body includes the probe main body frame, a pair of left and right side plates and a back plate, and the upper and lower fixing bracket screw portions centered on the central point. A probe for an HF band magnetic resonance apparatus detector having a hole in the probe body frame for accommodating a pair of left and right modulation magnetic field coil bobbins having an outer diameter bounded by the distal end surface   5. An HF band magnetic resonance apparatus detector probe having the structure of claim 4, wherein an inner diameter of the pair of left and right modulation magnetic field coil bobbins is larger than an outer diameter of a high-frequency coil wound around the high-frequency coil bobbin, Is greater than the outer radius of the high frequency coil bobbin. The modulation magnetic field coil bobbin is formed by a central side wall plate having a thickness larger than the outer radius of the high frequency coil bobbin, a side plate side wall plate having a small thickness opposite to the central side wall plate, and an inner peripheral cylinder connecting the both wall plates. The outer surface of the central side wall plate has a first groove having a semicircular cross section having a radius larger than the outer radius of the high frequency coil bobbin along a diameter line passing through the center. A second groove is provided between the outer circumference and the inner circumference along a diameter line perpendicular to the center axis of the first groove and passing through the center. A third groove is formed from the outer periphery on the opposite side along the same diameter line as the second groove to near the center of the central side wall plate. A pair of ridges and ridge holes are provided near the center of the central side wall plate by distributing the center along a diameter line that is inclined at a right angle to the first groove and the second groove through the center. Each of the left and right modulation magnetic field coil bobbins has three grooves on the central side wall plate and a pair of ridges and holes, which are mirror-symmetrical. When the left and right bobbins are overlapped and the bobbin is integrated by two pairs of hozos and hozo holes, the modulated magnetic field coil bobbin having the structure in which the three kinds of grooves form a cylindrical hole has the same thickness as the probe body frame. HF band magnetic resonance apparatus detector probe   6. A probe for an HF band magnetic resonance apparatus detector having the structure according to claim 5, wherein a modulation magnetic field coil is wound in a space between a central side wall plate and a side plate side wall plate of the left and right modulation magnetic field coil bobbin, and the integrated main body is wound. The high-frequency coil bobbin is housed in a through hole that is housed in the frame punch hole and formed by the first groove, and is fixed to the body frame by the upper and lower fixing brackets, and is formed in the bottomed hole formed by the third groove. Screw the anti-spin pin from the front end of the main body frame to constrain the rotation of the modulation magnetic field coil bobbin, and screw the pair of left and right side plates to both sides of the main body frame to constrain the movement of the modulation magnetic field coil bobbin in the axial direction and From the face plate, the high frequency coaxial cable and the low frequency two-core cable are introduced into the main body frame to the inner periphery of the bobbin formed by the second groove. The terminal wire of the high frequency coil is pulled out from the through hole, connected to the coaxial cable for high frequency, and the lead wires of the pair of modulation magnetic field coils wound around the two empty spaces are connected so that both are polarized, HF band magnetic resonance apparatus detector probe having a structure in which both terminals are connected to the low-frequency two-core cable.   In the probe for an HF band magnetic resonance apparatus detector having the structure according to claim 6, a direct current and a low frequency sine wave current are superposed and applied to the modulation magnetic field coil through the low frequency two-core cable. HF band magnetic resonance apparatus detector probe used to superimpose a static magnetic field and a modulated magnetic field with the same magnetic field current conversion coefficient in the axial direction   The probe for an HF band magnetic resonance apparatus detector having the structure according to claim 6, wherein the upper and lower fixing brackets have the same shape, both ends of the high-frequency coil bobbin are opened, and a flow sample is formed using a test tube having both ends opened. HF band magnetic resonance detector detector probe

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