JP5417616B2 - Electromagnetic horn type electron spin resonance device (3) - Google Patents

Description

The present invention relates to an electromagnetic horn type electron spin resonance apparatus (3) in which the sensitivity / accuracy of the electromagnetic horn type ESR apparatus is improved, and the operability and applied measurement are greatly expanded (multipurpose).

Conventionally, it is an example that is limited to the magnetic field sweep method instead of the frequency sweep method, but the development of the electromagnetic horn type electron spin resonance device was developed in 1983 by Hiroaki Ohya, the X-band electromagnetic horn type ESR development case, In 1991, only K-band electromagnetic horn type ESR was developed by Junichi Soma and Hidemoto Hara.
Patents based on this are introduced in the following Patent Documents 1 to 4. Recently, an electromagnetic horn type electron spin resonance apparatus developed by the inventors and introduced next by Non-Patent Document 1 has been introduced and attracted attention.
In Non-Patent Document 1, the resonator-type ESR needs to maintain a high Q value at the time of ESR measurement. Therefore, measurement was possible only with a small amount, a small sample, and a small dielectric loss. For this reason, ESR measurement of samples with large dielectric loss (hydrated samples / biological samples), conductive samples, metal-containing samples, and large samples is difficult or impossible and has many limitations.
In order to solve this problem, as the first stage, in the case of the microwave transmission type electromagnetic horn type ESR, the space between the two electromagnetic horns on the microwave output side and the input side is adopted as the sample cell, and the second stage In the case of the microwave reflection type electromagnetic horn type ESR, the space between the opening of the electromagnetic horn and the microwave reflector is used as a sample cell, and a microwave traveling wave is used instead of a microwave standing wave, and resonance is performed. The microwave transmission type and reflection type electromagnetic horn type ESR, which has improved the limitations and difficulties of the resonator type ESR, are operated, and the cavity resonator type ESR which has a high Q value of a spherical or cylindrical resonator is also sensitive. In order to get closer to that, we have improved the measurement sensitivity by about three digits over the past three years, and for the first time we have improved it to a practical level as an electromagnetic horn type ESR.

<Electromagnetic horn type electron spin resonance apparatus developed and announced by the present inventors>
FIG. 4 shows a block diagram of a microwave solid circuit of a reflection type electromagnetic horn type ESR device which is an electromagnetic horn type electron spin resonance device.
In FIG. 4, this reflection type electromagnetic horn type ESR device is an electromagnetic wave that radiates a set sample output microwave mw0 to a sample sample via an attenuator ATT1 and a circulator circulator. Horn horn, magnetic field generator 002 for sample sample, microwave reflector 003 for reflecting microwave mw1 through sample sample again to electromagnetic horn horn through sample sample, and microwave mw3 from reference arm The reflected microwave mw2 from the electromagnetic horn horn is introduced, and the microwave mw3 is a microwave having the same phase and opposite intensity as that of the reflected microwave mw2, and this microwave cancels and balances the microwave mw2 with an electron in a certain magnetic field. When the spin is reversed by the so-called magnetic resonance where the spin changes from the │-1 / 2> state to the │1 / 2> state, the sample absorbs the microwave energy accordingly. A micro-wave processing circuit 004 Metropolitan be recorded as ESR spectra amplifies the trace amount change of the microwave due to unbalance at the time.
WG-N, WG-SMA: Coaxial waveguide exchanger, ATT2: Attenuator Magic tee: Magic tee, Phase shifter: Phase shifter at the introduction to microwave processing circuit 004 and microwave frequency meter (Frequency Counter) AMP: Indicates a preamplifier and a lock-in amplifier, respectively. In the figure, ATT3 is an attenuator.

If the electromagnetic horn of this reflection type electromagnetic horn type ESR device is a waveguide having a square cross section, for example, the shape of the truncated pyramid or the truncated cone with the bottom open so that the open area of the open end gradually increases. The horn of the shape is attached. In principle, it can be said that the electromagnetic wave transmitted through the inside of the waveguide is the simplest form for radiating into the space without being reflected at the open end. The longer the electromagnetic horn, the sharper the directivity. When a pyramid / cone is used as a reference for the shape of the horn, the apex angle is called the central angle. This has an optimum value for sharpening directivity.
On the other hand, the reflection surface of the microwave reflection plate is generally a flat surface, and although the three-dimensional shape is not certain, it is curved as viewed from the side.
As described above, the microwave radiation surface of the electromagnetic horn is a flat surface, and the reflection surface of the microwave reflector is flat or similar. The sensitivity was not satisfactory.
Japanese Patent Publication No. 3-78945 (basic of the type in which a reflector is placed opposite to a transmitting / receiving electromagnetic horn) Japanese Patent Publication No. 3-78591 (Transmission Electromagnetic Horn and Reception Electromagnetic Horn Type Basics) Japanese Examined Patent Publication No. 3-78944 (Basics of crossing arrangement of transmitting electromagnetic horn and receiving electromagnetic horn) Japanese Patent Publication No. 3-78946 (A type that detects the reflected microwave from the sample without receiving electromagnetic horn and microwave reflector) “Development of Electromagnetic Horn-type Electron Spin Resonance (ESR) Apparatus and Application of ESR Measurement” Masaru Kobayashi, Kenichi Kuwata ・ ・ ・ Journal of AEM Society of Japan Vol.17, No.1, pp138-143

The above-mentioned device developed by the inventor is still low in sensitivity, and is only in the range of trial production without coupling with a personal computer.
The present invention improves the ESR measurement sensitivity by two digits or more. Improved operability by PC automation. It is possible to measure samples with large dielectric loss and large / mass samples with multi-purpose specifications, blood / histological examinations from basic science to material engineering / environmental science / pharmaceutical fields, redox-related aging phenomenon・ To provide a microwave-reflecting electromagnetic horn type electron spin resonance (ESR / EPR) device that can be immediately applied to research on carcinogenic mechanisms.

The features of the present invention that satisfy the above-described problems are the following (1) to (2).
(1), an electromagnetic horn (12) that radiates the microwave from the microwave transmission device to the sample (14a) on the sample mounting table (14) via the main arm (01) of the microwave waveguide,
An open magnetic path magnetic field generator (200) provided around the sample (14a) of the sample mounting table (14),
A microwave reflector (15) that reflects the microwave from the electromagnetic horn (12) through the sample (14a) to the electromagnetic horn (12) again through the sample (14a),
The reference transmission microwave from the reference arm (02) branched from the main arm (01) of the microwave waveguide, and the sample from the microwave reflector through the sample, the electromagnetic horn (12), and the main arm (01) Introduced into the mixer (42) to detect and record the minute changes in microwave power when the sample absorbs microwave energy during magnetic resonance in which the spin of unpaired electrons in the sample is reversed In an electromagnetic horn type electron spin resonance apparatus comprising a differential amplifier (43), a lock-in amplifier (44), and a recording device (45),
As the open magnetic path magnetic field generator (200), an upper portion, a lower portion, a left portion, a right portion around the sample (14a) on the sample mounting table (14), the other portion other than these, etc. A yoke (210) is provided in parallel on each side of any one part, and a magnetic field modulation coil (240) and a magnetic field sweep coil are provided so as to face each of the yokes (210) at a predetermined angle (θ) with respect to the front sample side. (260) is installed, and a first permanent magnet (220) having the same direction component of magnetization is arranged in parallel with the back in parallel, and the magnetization direction is set between the first permanent magnets (220) in the first permanent direction. An electromagnetic horn type electron spin resonance apparatus comprising a second permanent magnet (230) oriented in the same direction as a magnet, and a magnetic metal (231) attached to the opposite side of the second permanent magnet (230) .
(2), a convex radiation lens (13) is provided on the surface (exit) of the electromagnetic horn, and a concave reflector (15a) is provided on the microwave reflector (15),
The sample mounting table (14) and the microwave reflector (15) are provided with a position adjusting device (RP1, RP2) in the direction of the electromagnetic horn,
The first power monitor (22) that displays and records the output of the microwave emitted to the sample (14a) and the second power that displays and records the microwave output just before the mixer (42) of the reference arm (02) A third power monitor (21) that displays and records the output of the reflected microwave after passing through the sample (14a), electromagnetic horn (12), and circulator (6) in sequence from the monitor (20) and concave reflector (15a) ) And introduce the microwave output measurement values from these power monitors, and adjust the position adjustment device so that the microwave output from the third power monitor (21) becomes a certain set value for balance. The electromagnetic horn type electron spin resonance apparatus according to (1), further comprising a control device (Co) for balancing the microwave output value from the second power monitor (20).

The microwave reflection type electromagnetic horn type electron spin resonance (ESR / EPR) apparatus of the present invention improves the ESR measurement sensitivity by two digits or more. Improved operability by PC automation. It is possible to measure samples with large dielectric loss and large / mass samples with multi-purpose specifications, blood / histological examinations from basic science to material engineering / environmental science / pharmaceutical fields, redox-related aging phenomenon -It can be applied immediately to research on carcinogenic mechanisms.
1. The open magnetic circuit magnetic field generator (200) having the above-mentioned configuration is an open magnetic circuit type that can obtain a uniform magnetic field necessary for magnetic resonance without sandwiching the test subject (person) between magnets. In this way, measurement of large / large samples can be advantageously performed.
2. The convex radiating lens 13 on the surface of the electromagnetic horn 12 and the concave reflecting plate (15a) advantageously enable microwave convergence and convergence reflection.
3. The position adjusting device (RP1, RP2) can adjust and control the optimum relative relationship between the concave reflector (15a) and the sample mounting table (14) with respect to the electromagnetic horn 12 in cooperation with the control device (Co). I made it.

Further, the best mode of the electromagnetic horn type electron spin resonance apparatus of the present invention will be described in detail with reference to examples (specific examples) shown in FIGS.

Example 1 of a microwave solid circuit of a reflection type electromagnetic horn type ESR device which is an example of an electromagnetic horn type electron spin resonance device of the present invention will be described in detail below.
The basic configuration of the three-dimensional microwave circuit of the reflection type electromagnetic horn type ESR device shown in FIG. 1 and FIG.
○ Microwave transmitter,
An electromagnetic horn device that radiates microwaves from a microwave transmission device to the sample 14a on the sample mounting table 14 through the main arm (01) of the microwave waveguide,
A microwave reflector 15 having a concave reflector 15a that reflects the microwave from the electromagnetic horn 12 of the electromagnetic horn device through the sample 14a to the electromagnetic horn 12 again through the sample 14a,
○ On the orthogonal plane YF passing through the center 14ac of the sample 14a with respect to the straight line X connecting the center 14ac of the convex radiation lens 13, the concave reflector 15a and the sample 14a, the straight upper and lower portions D, U of the center 14ac A yoke 210 is provided in parallel on each of the left and right parts R, L, or an intermediate part of each of the left and right parts, and a unidirectional part set arbitrarily, and each yoke 210 is inclined (θ) toward the sample side. A magnetic field modulation coil 240 and a magnetic field sweep coil 260 are placed opposite to each other, and a first permanent magnet 220 having the same magnetization direction component is arranged behind and parallel to the rear thereof. A second permanent magnet 230 for adjusting the magnetic field of the second permanent magnet 230, and an open magnetic path magnetic field generator 200 formed by mounting a magnetic metal 231 on the opposite side of the second permanent magnet 230,
A reference transmission microwave from the reference arm 02 branched from the main arm 01 of the microwave waveguide, a sample from the concave reflector 15a of the microwave reflector 15, the electromagnetic horn 12, and the main arm 01 The reflected microwave is introduced into the mixer 42, and the differential amplification device 43 uses the differential amplification device 43 to detect a very small change in microwave power when the sample absorbs microwave energy during magnetic resonance in which the spin of unpaired electrons in the sample is reversed. A microwave processing device for detecting and amplifying with a lock-in amplifying device 44 and recording with a recording device 45;
It consists of.
This microwave processing device comprises a mixer 42, a differential amplification device 43, a lock-in amplification device 44, and a recording device 45, and creates microwaves having the opposite phase from the microwave from the reference arm 02 and having the same intensity. Due to the unbalance when the sample absorbs the microwave energy by the amount of energy required to cancel the reflected microwave from the electromagnetic horn 12 by the microwave and balance the electron spin during the magnetic resonance of the electron spin. A change in the reflected microwave is amplified and recorded as an ESR spectrum.

1. Microwave Oscillator Microwave Oscillator has functions of both a magnetic field sweep specification and a frequency sweep specification. Regarding the magnetic field sweep specification, a Gunn oscillator power supply 31, a Gunn oscillator 32, a unidirectional tube 33, Semi-fixed attenuator 34, coaxial waveguide switch 35, microwave broadband amplifier 36 with amplifier power supply 36a, YIG sweep oscillator 37 with spectrum analyzer 37a for frequency sweep specification (8 GHz to 12.5 GHz microwave frequency sweep possible) HP, or Agilent products: E8257D, etc.), a large output consisting of a coaxial waveguide exchanger 38 for exchanging microwaves from the coaxial cable 020 to the main arm waveguide 01 is also possible. A microwave generator capable of frequency sweeping by the sweep oscillator 37 with fixed frequency and magnetic field at the time,
Isolator 1 interposed in main arm waveguide 01 connected to coaxial waveguide exchanger 38, coaxial waveguide exchanger 3 with frequency counter 2, directional coupler 4, attenuator attenuator 5, circulator 6. A microwave waveguide main arm portion including a microwave power monitor measurement terminal portion 7a before sample incidence and a reflected microwave power monitor measurement terminal portion 7b reflected from the sample.
The microwave generation unit selects a microwave mixed with a traveling wave and a backward wave as a traveling microwave only in the unidirectional tube 33, and the traveling microwave from the unidirectional tube 33 is coaxially guided with the semi-fixed attenuator 34. It comes to the coaxial cable 010 for microwaves by the wave tube exchanger 35 and is introduced into the microwave broadband amplifier 36. Similarly, the microwave broadband amplifier 36 is capable of sweeping the YIG sweep oscillator (8 GHz to 12.4 GHz microwave frequency HP) (Agilent product: E8257D, etc.) A microwave of several mW from 37 is broadband-amplified up to 1 W, and the microwave is introduced into the main arm waveguide 01 through the coaxial waveguide exchanger 38. The frequency value of the microwave from the HP YIG sweep oscillator 37 is monitored and confirmed by the spectrum analyzer 37a, and is also used as an integration monitor during the frequency sweep of the ESR spectrum.
Next, the microwave introduced into the microwave waveguide 01 is selected as a traveling microwave only by a unidirectional tube (isolator) 1, and a small part of the microwave is passed through a coaxial waveguide exchanger 3 and a frequency counter 2. Introduced to monitor the frequency.
The main arm waveguide 01 branches the reference arm waveguide 02 separately by the directional coupler 4, and enters the circulator 6 with the power adjusted through the attenuator 5 for adjusting the microwave power. This microwave is a feature of the circulator 6, and all microwaves are guided to the electromagnetic horn 12 side where the sample 14a is located. The output value of the microwave is detected by the power monitoring measuring terminal 7 a in the middle and measured by the first power monitor 22. On the other hand, the microwave returned to the electromagnetic horn 12 through the sample 14a is detected by the output value power monitor measurement terminal 7b and measured by the power monitor 23.

2. Electromagnetic horn device and microwave reflector Electromagnetic horn device includes a sleeving tuner 8 connected to the main arm waveguide 01, a twisted waveguide 9, a rectangular circular waveguide 10, a circular waveguide 11, an electromagnetic horn 12, It comprises a microwave radiation convex radiation lens 13 made of Teflon (registered trademark).
The electromagnetic horn device has the function of placing the sample position in a virtual position with the remaining microwave, which is partly branched from the measurement terminal 7a for power monitoring. In addition, it is introduced into the twisted waveguide 9 in order to rotate the oscillation surface of the microphone wave by 90 °, and is then set to the circular microwave mode by the rectangular circular waveguide 10, and the circular waveguide 11 The microwave is radiated from the convex radiation lens 13 toward the concave reflector 15a of the microwave reflector 15 through the sample 14a.
As a result, the microwave power measured at the microwave power measuring terminal 7a enters the sliving tab tuner 8, and the microwave vibration surface in the standing wave mode is rotated 90 ° by the twisted waveguide 9 and then the rectangular to circular microwave is rotated. The wave mode is exchanged in the rectangular circular waveguide 10, and the electromagnetic horn 12 changes from a standing wave to a spherical traveling wave and is emitted to the sample space. In order to increase the measurement sensitivity, a convex radiation lens 13 such as a transparent lens made of glass or plastic or a translucent lens made of Teflon (registered trademark) is provided on the microwave radiation surface of the electromagnetic horn 12 as much as possible. Converge. Among these, a convex-type radiation lens made of Teflon (registered trademark) is preferable because it is easy to process, has a high microwave transmittance, a high refractive index, and good convergence.
In the sample 14a having a large dielectric loss and poor transmittance, the sample 14a is immediately reflected by the sample 14a, and in the sample having good microwave transmittance, further reaches the rear concave reflector 15a, where the reflection effect of the concave reflector 15a is obtained. Then, after being converged and reflected, it enters the sample 14a again, passes through the sample 14a, returns to the electromagnetic horn 12 through the convex radiating lens 13, and enters the circulator 6 after power measurement at the microwave power measurement terminal 7b. 6 proceeds in the direction of a downward arrow and is guided to the mixer (magic tee) 42 through the coaxial waveguide exchanger 16, the attenuator 17, and the coaxial waveguide exchanger 18.

3. Open magnetic circuit magnetic field generator 200
In order to cause magnetic resonance, a strong magnetic field with a uniform size and magnetization direction is required. Conventional MRI realizes a uniform magnetic field by sandwiching a subject between magnets. For this reason, there is a drawback that inspection is not possible if the gap is larger than the gap between magnets. Also, because of its cold form, some people hate that it is like a holy phobia or a crematorium that scares small children.
In order to solve these problems, the open magnetic path magnetic field generator 200 is an open magnetic path magnetic field generator that can obtain a uniform magnetic field necessary for nuclear magnetic resonance without sandwiching a test object (person) between magnets.
As shown in FIGS. 1 and 2, the open magnetic path magnetic field generator 200 is an orthogonal plane passing through the center 14ac of the sample 14a with respect to a straight line X connecting the convex radiation lens 13, the concave reflector 15a and the center 14ac of the sample 14a. The YF is arranged only in the lower part D along the center 14ac, and the other horizontal left and right parts R and L and the upper part U along the straight line are released, on both sides of the lower part D (in other words, In the orthogonal plane YF, preferably, a pair of yokes 210 are formed symmetrically on both sides of an arbitrary direction radial line of the orthogonal circular surface YFC centering on the center 14ac of the sample 14a (in this example, the downward rectilinear radial line Dr). A first permanent magnet that is arranged in parallel and has a 100 kHz magnetic field modulation coil 240 and a magnetic field sweep coil 260 that are installed opposite to each other at the tip of the open magnetic circuit special yoke 210 and in parallel with the rear thereof to have the same magnetization direction. 220 of the first permanent magnet 220 is arranged and the magnetization direction is the same as that of the first permanent magnet 220. Formed by mounting the iron plate 231 such as a magnetic metal in the counter sample side of the second permanent magnet 230 is disposed a permanent magnet 230. The central portions of the second permanent magnet 230 and the iron plate 231 are located on the straight radial line Dr.
The relative relationship between the magnetic field modulation coil 240, the magnetic field sweep coil 260, the first permanent magnet 220, and the second permanent magnet 230 is appropriately set to a relationship according to the sample condition from the analysis model, analysis conditions, and results introduced below. To do.
In the case of the frequency sweep type electromagnetic horn ESR, the open magnetic path magnetic field generator 200 uses only the magnetic field modulation coil 240 and does not use the magnetic field sweep coil 260 and sets the current to zero. On the other hand, in the case of the magnetic field sweep type electromagnetic horn ESR, the magnetic field modulation coil 240 and the magnetic field sweep coil 260 are used as a magnetic field sweep electromagnet.
The amplifier 250 shown in FIG. 1 amplifies a sine wave of 100 kHz, is introduced into a multi-turn magnetic field modulation coil 240 impedance-matched, performs a magnetic field sweep by the magnetic field sweep coil 260, and is generated by the magnetic field modulation coil 240. A 100kHz AC magnetic field is superimposed on a static magnetic field with good magnetic field uniformity, and the measurement sensitivity is improved by about 3 digits by modulation spectroscopy.
Further, when performing frequency sweep type electromagnetic horn type ESR measurement, the magnetic field sweep coil 260 is not used.

<Analysis model and analysis conditions of open magnetic circuit magnetic field generator 200>
The magnetic field distribution of the open magnetic path magnetic field generator 200 is analyzed by the two-dimensional finite element method, and the results of examining the uniform region of the magnetic field are as follows.
The analysis model is shown in (1) and (2) of FIG. In this model, an open magnetic path can be formed using three permanent magnets Mg1 to Mg3 to create a uniform magnetic field region. Analysis was performed according to the following conditions.
(A) An iron yoke Fe (231) is arranged on the opposite side of the permanent magnet Mg2 (230), and the width of the permanent magnet Mg2 and the iron yoke and the distance from the sample 14a are changed to obtain a uniform magnetic field region. We investigated the relationship between the size of the field and the strength of the magnetic field.
(B) In order to strengthen the magnetic field, a pair of open magnetic path special yokes 210 arranged parallel to each other at a predetermined interval are arranged, and the shape is analyzed by changing the thickness t and the inclination angle θ of the tip to be uniform. We investigated the area of the magnetic field and its influence on the strength of the magnetic field.
(C), changing the value of the magnetization M ₁ of the permanent magnet Mg2, we examined the effect of size of the region of uniform magnetic field to the strength of the magnetic field.

<From analysis results>
1) The width of the uniform region could be adjusted to be uniform by changing the distance between the permanent magnet Mg2 and the sample 14a and the widths of the permanent magnet Mg2 and the iron yoke. When the thickness of the permanent magnet Mg2 was zero, a uniform region could not be obtained.
2) By installing the open magnetic circuit special yoke 210, the magnetic flux density in the uniform region could be increased.
3) The higher the protruding height of the open magnetic circuit special yoke 210, the larger the magnetic flux density in the uniform region. If the height is the same, the smaller the thickness t is, the smaller the thickness t is without saturation. Become. The maximum magnetic flux density was 0.15 [T], which did not reach the target of 0.4 [T]. However, an L-band electromagnetic horn type ESR device can be used at about 0.035 [T]. Moreover, the width of the uniform area did not change much compared to the case without 210.
4), also by changing the value of the magnetization M ₁ of the permanent magnet Mg2, it could be adjusted in the same tendency as the distance between the permanent magnet Mg2 and the sample 14a, slightly the size of the region of uniform magnetic field.

4). Position adjustment device and its control device (including signal processing contents)
The sample mounting table 14 provided between the microwave radiation convex surface type radiation lens 13 and the concave reflection plate 15a and the concave reflection plate 15a are respectively provided with rack and pinion type position adjustment mechanisms RP1 and RP2. A separate lifting mechanism is provided in the sample mounting table 14, and a straight line X connecting the center 14ac of the sample 14a placed on the sample mounting table 14 by moving up and down in the direction of the arrow connects the center of the convex radiation lens 13 and the center of the concave reflector 15a It is possible to contribute to the improvement of measurement sensitivity accuracy by matching the above.
The position adjusting device may be manually operated, but in this example, an automatic control mechanism is adopted, and the configuration thereof is the rack and pinion type position adjusting mechanisms RP1 and RP2 and the pinion driving stepping motors M1 and M2, respectively. The GP-IB controllers Co1 and Co2 consist of the GP-IB controllers Co1 and Co2, and the first power monitor 22 and the second power monitor 20 connected to the overall controller Co. And the third power monitor 21. These four power monitors automatically measure the microwave output value with GPIB specifications (or USB specifications in the lab view).

5. The automatic control overall control device Co of the position adjusting device by the overall control device Co sequentially performs the following (1) to (6).
(1) The GP-IB controller Co3 turns a stepping motor (not shown) installed in the attenuator 5 linked to the first power monitor 22 to output the microwave to the main arm waveguide 01. Set the value to a predetermined value. (Eg 300mW)
(2) The stepping motor M2 is driven by the GP-IB controller Co2 to move the concave reflector 15a to the rearmost position, and at the same time, a microwave absorbing plate is inserted between the sample 14a and the concave reflector 15a. To do.
(3) Next, the concave reflector 15a is brought closer to the sample 14a by rotating the motor M2 by the GP-IB controller Co2 so that the reading of the third power monitor 21 is maximized.
(4) The M1 motor is turned by the GP-IB controller Co1 so that the microwave output value from the third power monitor 21 becomes a certain balance setting value.
(5) GP-IB so that the value of the third power monitor 21 introduced with the reflected microwave reflected from the sample 14a and guided to the circulator 6 is balanced with the microwave output value from the second power monitor 20. Adjustment is performed by turning a stepping motor (not shown) of the coaxial attenuator 40 immediately before the second microwave monitor 20 by the controller Co4.
(6) Stepping of the phase shifter 41 installed in the reference arm waveguide 02 by the GP-IB controller Co5 so that a part of the detected current value after passing through the differential amplifier 43 is minimized in this state. Turn the motor (not shown) to adjust the phase.
(7) In the XY recorder 45 (XY recording device or digital oscilloscope), the sweep magnetic field or sweep frequency is input on the horizontal axis, and the ESR intensity signal 100 obtained by magnetic field modulation is input on the vertical axis. An ESR spectrum and a frequency sweep type ESR spectrum are obtained.

The device of the present invention exhibits the excellent effects described above. For this reason, it can be applied to various fields introduced below and makes a great contribution to this kind of industry.
1. 1. Basic research on various solid-phase, liquid-phase, and gas-phase substances in the basic science fields of physics and chemistry 2. Rapid examination of blood and biological tissues in medical clinical laboratories. Elucidation of redox-related aging phenomena and intractable diseases (cancer, diabetes, ischemia, hypertension, Alzheimer, etc.) in the pharmaceutical field and development of new drugs.
4). Air treatment in the field of environmental science, water treatment / water quality inspection, dust inspection of diesel engines, etc.
5. ESR imaging using MRI coil, and further development of ESR-STM (scanning tunneling microscope) equipment and acquisition of selected high resolution ESR imaging images.
6). Construction of radiation dose 3D measurement system using alanine and alanine imaging plate. Application to non-destructive ESR dating of samples.
7). Simultaneous / continuous examination diagnosis with other diagnostic devices (X-ray computer tomography, ultrasonic imaging diagnosis, PET, etc.) becomes possible.

It is a block diagram of a microwave solid circuit of an X-band reflection type electromagnetic horn type ESR device that serves both as a frequency sweep method and a magnetic field sweep method as an example of an electromagnetic horn type electron spin resonance device. It is a block diagram which shows the specific example of a magnetic path magnetic field generator. (1) and (2) are explanatory diagrams showing an analysis model of the magnetic path magnetic field generator. It is a block diagram of the microwave solid circuit of the conventional K-band reflection system electromagnetic horn type | mold ESR apparatus.

In FIG.
01: Main arm
02: Reference arm 1: Isolator 4: Directional coupler 6: Circulator
12: Electromagnetic horn
13: Radiation convex lens
14a: Sample
14: Sample mounting table
15a: Concave reflector
20, 21, 22, 23: Power monitor
RP1: Sample mounting table position adjustment mechanism (rack and pinion type)
RP2: Position adjustment mechanism for concave reflector (rack and pinion type)
Co: General control device
200: Open magnetic path magnetic field generator
210: Open magnetic circuit special yoke
220: First permanent magnet
230: Second permanent magnet
240: Magnetic field modulation coil
260: Magnetic field sweep coil

Claims (2)

An electromagnetic horn (12) that radiates the microwave from the microwave transmission device to the sample (14a) on the sample mounting table (14) through the main arm (01) of the microwave waveguide,
An open magnetic path magnetic field generator (200) provided around the sample (14a) of the sample mounting table (14),
A microwave reflector (15) that reflects the microwave from the electromagnetic horn (12) through the sample (14a) to the electromagnetic horn (12) through the sample (14a) again,
The reference transmission microwave from the reference arm (02) branched from the main arm (01) of the microwave waveguide, the sample from the microwave reflector 15, the electromagnetic horn (12), and the main arm (01) All the reflected microwaves are introduced into the mixer (42) to detect and record minute changes in the microwave power when the sample absorbs microwave energy during magnetic resonance in which the spin of unpaired electrons in the sample is reversed. In an electromagnetic horn type electron spin resonance apparatus comprising a differential amplifying device (43), a lock-in amplifying device (44), and a recording device (45),
As the open magnetic path magnetic field generator (200), any one of an upper part, a lower part, a left part, a right part around the sample (14a) on the sample mounting table (14), or the other part therebetween. A yoke (210) is provided in parallel on each side of either part, and a magnetic field modulation coil (240) and a magnetic field sweep coil (260) are installed on each yoke (210) so as to be inclined and opposed to the front sample side. In addition, a first permanent magnet (220) having the same direction component of magnetization is arranged in parallel behind it, and the magnetization direction is the same as that of the first permanent magnet between the first permanent magnets (220). An electromagnetic horn type electron spin resonance apparatus comprising a second permanent magnet (230) and a magnetic metal (231) mounted on the opposite side of the second permanent magnet (230). A convex radiation lens (13) is provided on the surface (exit) of the electromagnetic horn, and a concave reflector (15a) is provided on the microwave reflector (15).
The sample mounting table (14) and the microwave reflector (15) are provided with a position adjusting device (RP1, RP2) in the direction of the electromagnetic horn,
The first power monitor (22) that displays and records the output of the microwave emitted to the sample (14a) and the second power that displays and records the microwave output just before the mixer (42) of the reference arm (02) A third power monitor (21) that displays and records the output of the reflected microwave after passing through the sample (14a), electromagnetic horn (12), and circulator (6) in sequence from the monitor (20) and concave reflector (15a) ) And introduce the microwave output measurement value from these power monitors, and adjust the position adjustment device so that the microwave output value from the third power monitor (21) becomes a certain set value for balance The electromagnetic horn type electron spin resonance apparatus according to claim 1, further comprising a control device (Co) for balancing the microwave output value from the second power monitor (20).

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