JP5481643B2 - Electromagnetic horn type electron spin resonance device (1) - Google Patents

Description

The present invention relates to an electromagnetic horn type electron spin resonance apparatus with good operability, which has improved sensitivity and accuracy, and greatly expanded (multipurpose) operability and applied measurement performance.

The pioneer of the development of the electromagnetic horn type electron spin resonance device is the first case by Hiroaki Ohya in 1983, the development case of the X-band electromagnetic horn type ESR, and the K- by Junichi Soma and Hidemoto Hara in 1991. There is a development example of band electromagnetic horn type ESR.
Improvement techniques based on this are introduced in the following Patent Documents 1 to 3. 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.
According to Oya and Soma and Hara's papers and patent documents, since the ESR device was invented in 1945 by Zavoi Key, in most cases as a sample cell, a resonator (cavity resonator, dielectric resonator, loop)・ Gap resonators have been adopted. For this reason, since it is necessary to maintain a high Q value of the resonator during measurement, measurement was possible only with a small sample size and a small dielectric loss. For this reason, ESR measurement is difficult for samples with large dielectric loss (aqueous solution samples, water-containing samples, biological samples), conductive samples, metal-containing samples, large samples, and large amounts of solutions (especially aqueous solutions with large dielectric loss). It was impossible and there were many restrictions. In particular, many / most commercially available ESR devices use an AFC (automatic frequency control) device for tuning the resonator, but in the case of an electromagnetic horn type ESR device, it is tuned to the natural frequency of the resonator. Otherwise, the AFC does not work well because of the widening of the Q dip in the sample with a large dielectric loss at that time. Therefore, there is no difficulty that ESR measurement is impossible. Further, it is not necessary to use a sample container made of synthetic quartz having a small capacity that is extremely thin or extremely thin as an aqueous solution sample in a resonator type sample cell. This is also a matter that leads to the idea and invention of the novel frequency sweep type electromagnetic horn type ESR of the electromagnetic horn type electron spin resonance apparatus (2). The inventor has also succeeded in measuring a frequency-swept ESR spectrum in which the microwave frequency is swept over a wide region with a static magnetic field fixed (the frequency sweep between 2 GHz from 8.5 GHz to 10.5 GHz and Mn ( II) We obtained 6 ESR spectra of ions (CaCO ₃ : Mn (II)) and frequency sweep ESR spectra of DPPH solid powder standard sample and 40cc capacity TEMPOL aqueous solution sample.Limits of the frequency sweep type YIG oscillator It is possible to secure a frequency swept ESR spectrum even at values from 8 GHz to 12.4 GHz.

In order to solve the above-mentioned various problems, the space between the electromagnetic horns (antennas) is adopted as a sample cell as one step, and the microwave traveling wave is used instead of the microwave standing wave like a resonator. 、 Transmission type electromagnetic horn type ESR or reflection type electromagnetic horn type ESR that greatly improved the limitations and difficulties of resonator type ESR (Note: Oya's paper on transmission type, reflection type, induction type etc. However, the sensitivity was inferior to that of a spherical or cylindrical high-Q cavity resonator type ESR, but in any case it was possible to measure ESR in 2006. Since then, in 2009, the sensitivity has improved by about three orders of magnitude. Thus, ESR measurement at a practical level has become possible.
The above-mentioned device, which was previously developed by the pioneer of electromagnetic horn type ESR invention, still has low sensitivity.

<Electromagnetic horn type electron spin resonance apparatus developed and announced by the present inventors>
FIG. 2 shows a block diagram of a microwave solid circuit of a K-band / X-band reflection type electromagnetic horn type ESR device which is an electromagnetic horn type electron spin resonance device.
In FIG. 2, this X-band reflection type electromagnetic horn type ESR device is a microwave oscillator 001 that oscillates microwaves in a high frequency range, and a set output microwave mw0 to a sample sample via an attenuator ATT1 and a circulator circulator. Radiating electromagnetic horn, magnetic field modulation device 002 to sample sample, sweep magnetic field application device (electromagnet) with good magnetic field uniformity, microwave mw1 through sample sample again to electromagnetic horn horn through sample sample Reflecting microwave reflector 003, setting output microwave mw0 and reflected microwave mw2 from electromagnetic horn horn are introduced to create a reversed-phase microwave with opposite phase to reflected microwave mw2 and equal intensity Waves are counterbalanced by retroreflecting microwaves, and the electron spin changes from the │-1 / 2> state to the │1 / 2> state in a certain magnetic field. A micro-wave processing circuit 004 Metropolitan be recorded as ESR spectra amplifies the trace amount change of the microwave due to imbalance upon absorption of microwave energy by the amount of.
In the microwave processing circuit 004, WG-N, WG-SMA: coaxial waveguide exchanger, ATT2: attenuator Magic tee: Magic tee, Phase shifter: phase shifter, AMP: preamplifier and 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 Examined Patent Publication No. 3-78591 (basic unidirectional transmitting electromagnetic horn and receiving electromagnetic horn type) Japanese Examined Patent Publication No. 3-78944 (Basics of crossing arrangement of transmitting electromagnetic horn and receiving electromagnetic horn) Japanese Examined Patent Publication No. 3-78946 (Receiving electromagnetic horn and no reflection plate, detecting the reflected microwave from the sample “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 present invention improves the microwave radiation surface of the electromagnetic horn and the reflection surface of the microwave reflector so as to maintain good convergence / focusing of the microwave, drastically reduce noise, and achieve the desired ESR measurement sensitivity (2 The position of the sample mounting table and microwave reflector on the microwave radiation surface of the electromagnetic horn is optimized according to the size, mass, shape, component, etc. of the sample mounted on the sample mounting table. Provided is an electromagnetic horn type electron spin resonance apparatus which is adjusted to further increase ESR measurement sensitivity.

The features of the present invention are as follows (1) to (2).
(1), an electromagnetic horn (11) that radiates the microwave from the microwave transmission device to the sample (13a) on the sample mounting table (13) via the main arm (01) of the microwave waveguide,
Sweep magnetic field application device (171) (electromagnet) and modulation device (170) for modulation spectroscopy provided around the sample mounting table (13),
A microwave reflector (14) that reflects the microwave from the electromagnetic horn (11) through the sample (13a) to the electromagnetic horn (11) again through the sample (13a),
Transmitting microwave for reference from the reference arm (03) branched from the main arm (02) of the microwave waveguide, the sample (13a), the electromagnetic horn (11), and the main arm from the microwave reflector (14) Introducing the reflected microwave through (02) into the mixer (32), and the minute amount of 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 (40), a lock-in amplifier (41), and a recording device (42) for detecting and recording a change,
A microwave radiation convex lens (12) is provided on the surface (exit) of the electromagnetic horn (11) of the electromagnetic horn antenna device, and the microwave reflector (14) is, for example, a parabolic concave surface, a spherical concave surface, a planar combined concave surface, An electromagnetic horn type electron spin resonance apparatus characterized by a concave reflecting surface type reflector (14a) having a concave surface such as a bay surface combined concave surface or an elliptical concave surface.

(2), an electromagnetic horn (11) that radiates the microwave from the microwave transmission device to the sample (13a) on the sample mounting table (13) through the main arm (01) of the microwave waveguide,
Sweep magnetic field application device (171) (electromagnet) and modulation device (170) for modulation spectroscopy provided around the sample mounting table (13),
A microwave reflector (14) that reflects the microwave from the electromagnetic horn (11) through the sample (13a) to the electromagnetic horn (11) again through the sample (13a),
Transmitting microwave for reference from the reference arm (03) branched from the main arm (02) of the microwave waveguide, the sample (13a), the electromagnetic horn (11), and the main arm from the microwave reflector (14) Introducing the reflected microwave through (02) into the mixer (32), and the minute amount of 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 (40), a lock-in amplifier (41), and a recording device (42) for detecting and recording a change,
A microwave radiation convex lens (12) is provided on the surface (exit) of the electromagnetic horn (11) of the electromagnetic horn antenna device, and the microwave reflecting plate (14) is a concave reflecting surface type reflecting plate (14a). For the tuning / tuning to obtain the ESR spectrum, the microwave power monitor device, the sample mounting table (13) position adjusting device (15), and the reflector (14) position adjusting device (16) were provided. An electromagnetic horn type electron spin resonance apparatus.

The electromagnetic horn type electron spin resonance apparatus of the present invention maintains the convergence / focusing of the microwave of the electromagnetic horn with the above-described configuration, drastically reduces noise, and improves the ESR measurement sensitivity to a desired sensitivity (a few orders of magnitude improvement). At the same time, according to the size, mass, shape, composition, condition, etc. of the sample placed on the sample mounting table, the ESR is adjusted by optimally adjusting the position of the sample mounting table and the microwave reflector on the microwave radiation surface of the electromagnetic horn. The measurement sensitivity is further enhanced, and a temperature variable device is provided on the sample mounting table, allowing simultaneous measurement of the sample's dielectric constant, electrical conductivity, specific heat, thermal conductivity, thermal expansion coefficient, sound velocity, etc. along with the ESR spectrum. It exhibits excellent effects such as.
The technical operational effects of the electromagnetic horn type electron spin resonance apparatus of the present invention will be described in detail below.

1. A microwave radiation convex lens is provided at the opening (surface) of the electromagnetic horn of the electromagnetic horn antenna device, and the microwave is converged / focused well by making the microwave reflecting plate a concave reflecting surface type microwave reflecting plate, It exhibits excellent effects that reduce noise and improve sensitivity.

2. The sample mounting table between the microwave radiating convex lens and the microwave concave reflecting surface type reflecting plate and the concave reflecting plate can be moved, and the position of the sample with the power monitor device is precisely fine-tuned to adjust its position. By installing the device, the relative position of the sample, the microwave radiation convex lens and the microwave concave reflecting surface type reflector can be set to the optimum ESR measurement conditions, and ESR measurement with maximum sensitivity is possible Exhibits excellent operational effects.

3. Said 1.2. The overall function and effect of the entire system by adopting is the adjustment of the position of the sample, the position of the reflector (in the case of a sample in which microwaves easily pass through the sample), the adjustment of the attenuator of the reference arm, The maximum measurement sensitivity can be easily and surely tuned (tuned) by four factors such as adjustment of a phase shifter.

4). In order to greatly improve the sensitivity in this way, it is possible to change the AMP for the magnetic field modulation coil to one that has a higher output than before, and to create and install a multi-turn magnetic field modulation coil that matches this AMP. It became possible, and a significant improvement in sensitivity became possible.

5. 1. Installation of a microwave power monitor before and after passing through the sample and installation of a power monitor immediately before the mixer in the microwave main arm and reference arm. And 3. Tuning has become more precise.

6). In addition, by installing a temperature variable device on the sample mounting table, construction of a simultaneous measurement system of ESR spectrum and dielectric constant by installing a sample such as a ferroelectric with electrodes, ESR spectrum and heat capacity (specific heat), ESR spectrum Simultaneous measurement of electrical conductivity, thermal conductivity, coefficient of thermal expansion, sound velocity in sample, ESR spectrum and STM / STS (scanning tunneling microscope image / scanning tunneling current spectroscopy) or AFM (interatomic) Measurement of ESR spectrum when applying ultrahigh pressure hydrostatic pressure using diamond anvil or micro cylinder method, and installing uniaxial stress application device to spin sample strain when applying uniaxial stress Enables research through the Hamiltonian.

Sample temperature variable device specially developed for the electromagnetic horn type ESR (a Sample temperature variable device with resistance heating specification from room temperature to high temperature, b Leading antifreeze and silicone oil to temperature variable device made of aluminum block, cooling circulator Sample temperature variable device that can vary from -20 ° C to + 150 ° C, for a low temperature in which a stage with a non-inductive winding heater is placed in a synthetic quartz dewar (a thermos bottle) and liquid nitrogen or refrigerant is injected below the heater level Install a goniometer for single-crystal rotation, 2-axis rotation, and 3-axis rotation specifications for single crystal samples (with variable temperature specifications) to measure the temperature change of the ESR spectrum of solid / solution samples. ESR spectrum (resonance magnetic field and line width, intensity) angle dependence of single crystal sample considering static magnetic field or microwave magnetic field orientation of ESR spectrum. Simultaneous measurement of dielectric constant, electrical conductivity, heat capacity (specific heat), thermal conductivity, and coefficient of thermal expansion (the inventor has already installed an electrode perpendicular to the ferroelectric axis of triglycine sulfate single crystal) As a capacitor, we have succeeded in the simultaneous measurement of the ESR spectrum and dielectric constant for each step change in the temperature range of ± 30 ° C (20 ° C to 80 ° C) around the ferroelectric Curie temperature of 49 ° C. Or equipped with a vibration isolation mechanism, a scanning tunneling spectroscopy (STS) device is installed in the sample space, and simultaneous measurement of tunneling current and ESR spectroscopy, measurement of mutual enhancement effect of tunneling current and ESR spectrum intensity change, and strain gauge are used. This enables simultaneous measurement with other physical properties such as a simple thermal dilatometer while changing the sample temperature.

7). For various types of specimens and measuring containers, devices such as devices, and ESR measurement for simultaneous measurement with other physical properties, working holes and gaps and attachment mechanisms for various materials and equipment can be provided at various locations. It was.
Thereby, in order to use the apparatus for multiple purposes, it is in a specification that a working hole and a fixing device for attaching materials can be installed in various places. (1) Installation mechanism of ultraviolet irradiation light, visible light, or infrared irradiation device for variable temperature, (2) Installation mechanism of single- and double-axis rotation device for single crystal sample, (3) Vertical vertical movement of chromatography column, etc. Installation of movement / measuring mechanism, (4) Installation of two types or various reagents in the sample cell, installation of reaction mechanism, (5) Simultaneous measurement of various physical properties such as ESR spectrum and dielectric constant / specific heat / thermal expansion coefficient Securing installation space for measurement (a considerably large space is provided behind the detachable microwave reflector) and installation of mounting mechanisms such as screw holes for installing various multipurpose measurement instruments, fixtures for jig installation, etc. It is possible freely.

<Examples of use>
An application example of the electromagnetic horn type electron spin resonance apparatus of the present invention is as follows.
(1) Future a Electromagnetic horn type 3D ESR imaging device equipped with a double power supply Zupancic type MRI coil and an anti-helmholtz MRI coil developed by the inventors, a ESR measurement under ultra-high hydrostatic pressure with a diamond anvil, c Using electromagnetic horn-type cwESR system with pulse ESR and combined measurement and cross measurement with d-scanning tunneling spectroscopy (STS)
(2) The time dependence of the ESR spectrum of carbon radicals in the electrolyte and manganese divalent ions generated from the middle while connecting resistance to single to AA type manganese batteries and discharging / consuming them.
(Already measured and analyzed) Applicable to the development of new secondary batteries, solar cells and fuel cells.
(3) Measurement of Cr (III) and Mn (II) ions in domestic wastewater and industrial wastewater. (Partially implemented: Application to environmental science: water treatment, water monitor, exhaust gas / dust monitor, etc.)
(4) In situ experiment of radical scavenging of TEMPOL radical by L-ascorbic acid (vitamin C). (Already measured and analyzed)
(5) ESR measurement of dissolution process of DPPH solution, TEMPOL aqueous solution and manganese sulfate aqueous solution. Concentration dependence of ESR spectra of these samples. (Already measured and analyzed)
(6) Simultaneous measurement of ESR spectrum and dielectric constant at Curie point with large dielectric loss such as ferroelectric barium titanate: Mn (II), glycine sulfate: Cu (II) ion, and temperature around it. (Already measured and analyzed)
(7), O using spin trapping agent such as DMPO ₂ ^- (superoxide) radicals, the measurement of the OH radicals, the verification of the erase process of these radicals by vitamin C and vitamin E, or coenzyme agents, development means of new drugs Take advantage of.
(8) Radiation dose measurement system using ESR sample and ESR imaging plate made with alanine or sucrose. ESR imaging when the line width of the ESR spectrum is large.

The best mode for implementing the microwave reflection type electromagnetic horn type ESR device is as follows.
The microwave reflection type electromagnetic horn type ESR device includes a microwave oscillator, an electromagnetic horn antenna device that radiates microwaves from the microwave radiating convex lens 12 of the electromagnetic horn 11, and a sweep magnetic field applying device 171 (electromagnet) to the sample. ), A magnetic field modulator 170 for modulation spectroscopy, a microwave reflecting plate 14a of a concave reflecting surface type that reflects the microwave through the sample again to the electromagnetic horn 11 through the sample, and a main arm of the microwave waveguide The microwave is split from 02 to the reference 03, and this is mixed through the circulator 5, electromagnetic horn 11, sample 13a, reflector 14a, sample 13a, electromagnetic horn 11, and circulator 5 in the main arm 02 through the mixer 32 (magic tee) Have a phase opposite to that of the microwave to be introduced into the sample, the microwave via the main arm 02 and the microphone via the reference arm 03 By detecting put a wave to the mixer 32, after differentially (pre) amplifier, leading to the lock-in amplifier.
As a result, when the magnetic field sweep or frequency sweep is performed, the microwave is absorbed by magnetic resonance, and the change due to the unbalance of the microwave power on the main arm side and the reference arm side when the sample absorbs the microwave energy only at the time of electron spin inversion. A microwave amplification circuit that records the minute as a magnetic field swept ESR spectrum or frequency swept ESR spectrum detected with high sensitivity by magnetic field modulation or frequency modulation spectroscopy, and to obtain the optimum ESR spectrum by optimizing the sample position and reflector position It comprises a sample position adjusting device having a power monitoring device for each microwave for tuning / tuning.

The microwave reflection type electromagnetic horn type ESR device improves the ESR measurement sensitivity by 3 digits or more by the above configuration. Improvement of S / N ratio (sensitivity) and operability by ESR spectrum integration function by personal computer automation. Using a microwave wavelength meter (microwave frequency counter) and a magnetic field measuring device using proton NMR (nuclear magnetic resonance), the precise microwave frequency and resonance magnetic field (magnetic flux density) are measured, and hν = From the equation of gβH, accurate g value (g tensor in the case of crystal), zero field splitting interaction constant (D tensor in the case of crystal, D, E constant) and hyperfine structure constant (hfs constant, in the case of crystal) hfs interaction tensor) can be measured.
In this way, with precision and multi-purpose specifications, from basic science in physics and chemistry to material science, environmental science, clinical practice in the field of medicine, development of new biomedical tests and redox-related aging phenomena, X-band and K-band that can be applied immediately to research on carcinogenic mechanisms (and Q that can increase sensitivity if the magnetic field (magnetic flux density) of a uniform magnetic field generator such as an electromagnet can be increased) -It is an electromagnetic horn type ESR device that can realize an electromagnetic horn type electron spin resonance (ESR / EPR) device with a microwave reflection system.
Furthermore, an electromagnetic horn type (or different antenna type) ESR device in a high frequency long band provided with a microwave of several tens to several hundreds GHz band as a light pipe, a small electromagnetic horn, and a planar waveguide circuit is also possible.

As an embodiment of the electromagnetic horn type electron spin resonance apparatus of the present invention, an X-band and K-band reflection type electromagnetic horn type ESR apparatus is shown in FIG. 1, and its configuration and technical significance will be described in detail below.
The basic circuit configuration of the electromagnetic horn type electron spin resonance apparatus of the first embodiment shown in FIG. 1 includes a microwave oscillation device, an electromagnetic horn antenna device that radiates microwaves to a sample, a magnetic field modulation device for the sample, and a sample. Introducing the microwave reflector 14 that reflects the reflected microwave to the electromagnetic horn again through the sample, and the reflected microwave from the electromagnetic horn 11, and having the opposite phase to that of the reference arm 03 and having the same strength A phase microwave is created and the reflected microwave is counterbalanced by an antiphase microwave and balanced, and the change in the reflected microwave due to unbalance when the sample absorbs the microwave energy during spin reversal by magnetic resonance at a certain magnetic field intensity ( Magic Tee) Microwave stereo circuit that detects at 32 parts, and differential amplification that records with high sensitivity and records as ESR spectrum 4 0 and a lock-in amplifier 41.

1. Microwave Oscillator Configuration and Operational Effects Microwave Oscillator converts from Gunn Oscillator Power Supply 33, Gunn Oscillator 34, Unidirectional Tube 35, Semi-fixed Attenuator 36, Microwave Waveguide to Microwave Coaxial Cable A microwave generator comprising a coaxial waveguide converter 39a, an amplifier power supply 37, and a broadband amplifier 38 capable of high output, a coaxial waveguide converter 37a for introducing the microwave from the amplifier 38, and a main arm waveguide Tube 01, isolator 1, microwave frequency counter 2, directional coupler 3, attenuator (for main arm) 4, circulator 5, main arm waveguide 02, microwave power monitor measurement terminal section 6 before sample incidence And a microwave waveguide main arm portion comprising a power monitor measurement terminal portion 6 'for reflected microwaves from the sample.
The microwave generation unit generates a predetermined microwave by the gun oscillator 34 by supplying a constant voltage from the gun oscillator power supply 33, and generates a microwave mixed with a traveling wave and a backward wave from the gun oscillator 34. The traveling microwave from the unidirectional tube 35 is sent to the microwave coaxial cable by the semi-fixed attenuator 36 and the coaxial waveguide converter 39a, and the amplifier for microwave amplification is selected. Then, the microwave is again introduced from the amplifier 38 to the waveguide through the coaxial waveguide converter 37a.
As a result, the microwave introduced into the microwave waveguide 01 by the coaxial waveguide converter 37a is selected only as the traveling microwave by the unidirectional tube (isolator) 1, and only a part of the microwave is selected by the coaxial waveguide converter 1a. Is introduced into the microwave frequency counter 2 to measure the exact frequency of the Gunn oscillator with 6 to 7 digits accuracy. The main arm waveguide 01 is branched by the directional coupler 3 into a main arm waveguide 02 and a reference arm waveguide 03, and an attenuator for adjusting microwave power is provided on the main arm waveguide 02 side. Go through 4 and enter circulator 5 with adjusted power.
This microwave is a characteristic of the circulator 5, and all the microwaves are guided to the electromagnetic horn 11 side where the sample is located. This microwave is detected by the power monitor measuring terminal 6 in the middle and measured by the power monitor 22. On the other hand, the microwave returning to the electromagnetic horn via the sample is detected by the power monitoring measurement terminal 6 ′ and measured by the power monitor 23.

2. Configuration and Effect of Electromagnetic Horn Antenna Device The electromagnetic horn antenna device includes a slew tab tuner 7, a twist waveguide 8, a rectangular circular waveguide 9, a circular waveguide 10, an electromagnetic horn 11, and Teflon (registered trademark). It consists of a microwave radiation convex lens 12.
In the electromagnetic horn antenna device, the microwave passing through the circulator 5 and the power monitoring measurement terminal 6 is a sliving stub tuner 7 which has a function of placing the sample position in a virtual position. In order to rotate the microphone vibration surface by 90 °, it is introduced into the twisted waveguide 8 to be further turned into the circular microwave mode in the rectangular circular waveguide 9, It is introduced into the electromagnetic horn 11 on the extension of the circular waveguide 10 and radiates from the microwave radiation convex lens 12 toward the concave reflecting surface type microwave reflecting plate 14a through the sample 13a.
As a result, the microwave power measured by the microwave power measuring terminal 6 enters the stub tuner 7, and the microwave vibration surface in the standing wave mode is rotated by 90 ° with the twisted waveguide, and then the rectangular to circular microwave. The mode is converted by the rectangular and circular waveguide 9, and the electromagnetic horn antenna 11 changes from a standing wave to a spherical traveling wave and is emitted to the sample space. This is converged as much as possible by the microwave radiation convex lens 12 made of Teflon (registered trademark) in order to increase the measurement sensitivity. A sample with a large dielectric loss and poor transmission is immediately reflected by the sample 13, and a sample with good microwave transmission reaches the rear microwave reflecting plate 14a of the concave reflecting surface type. Here, the concave reflecting surface type Due to the effect of the reflecting plate 14a, the light is converged and reflected and enters the sample 13a again, passes through the sample 13a, returns to the electromagnetic horn 11, and enters the circulator 5 after power measurement at the microwave power measuring terminal 6 '. Then, the light travels through the coaxial waveguide exchanger 51, the attenuator 52, and the coaxial waveguide exchanger 53, is guided to the mixer (magic tee) 32, and power is measured by the power monitor 21.

3. The configuration of the sweep magnetic field application device (electromagnet) and the magnetic field modulation device and the effect magnetic field modulation device to the sample are known, and surround the electromagnetic horn 11, the sample 13a, and the concave reflecting surface type reflecting mirror 14a in FIG. A magnetic field modulation coil is installed in the circular part of the dotted line drawn as follows, a 100 kHz sine wave is amplified with a high output amplifier, and introduced into a pair of multi-winding coils impedance matched to the amplifier, A 100 kHz AC magnetic field is superimposed on a static magnetic field with good magnetic field uniformity generated by a device that applies a sweep magnetic field to the sample, and the measurement sensitivity is improved by about three orders of magnitude using modulation spectroscopy with the lock-in amplifier 41. Is going. In FIG. 1, portions other than the magnetic field modulation coil installation portion of the dotted circular portion are omitted.

4). Positioning device configuration and effects (signal processing content)
The sample mounting table 13 provided between the microwave radiating convex lens 12 and the microwave concave reflecting surface type reflecting plate 14 and the concave reflecting surface type microwave reflecting plate 14 are each provided with a rack and pinion type of position adjusting device. Position adjusting mechanisms 15 and 16 are provided.
The position adjusting device may be manually operated, but in this example, the rack and pinion type position adjusting mechanisms 15 and 16 are respectively connected to the pinion stepping motors M1 and M2 via the GP-IB controllers Co1 and Co2. The following operations are performed by the device Co.
a, The power monitor 22 sets a predetermined microwave output value. (Eg 300mW)
b, Move the concave reflecting surface type reflector 14 to the rearmost position by the stepping motor M2 (or insert a microwave absorbing plate between the sample 13a and the concave reflecting surface type reflector 14)
c. Next, the motor M2 is rotated so that the reading of the power monitor 21 is maximized, and the concave reflecting surface type reflecting plate 14 is brought close to the sample 13a.
d, The output of the power monitor 22 is set by the attenuator 4 of the main arm waveguide 02. The power monitor 32a is adjusted by the reference-side attenuator 39, and the microwave output value of the measurement is adjusted to be balanced by the power monitor 21 and the power monitor 32a.
e. In this state, the phase adjuster 31 of the reference arm waveguide 03 is adjusted to adjust the phase so that the monitor current of the microwave unit made by JEOL (manufactured by JEOL Ltd.) is minimized.
f, The magnetic field sweep ESR spectrum is obtained on the personal computer screen by the magnetic field sweep.
The above processing from a to f is performed manually or by PC control automation (GP-IB or lab view).

5. Configuration and operation effect of temperature variable device, single crystal goniometer, dielectric constant measuring device and their simultaneous measuring means.

(1) The temperature variable device provided on the sample mounting table 13 performs the following three types of temperature variations.
a, Make a hole in the aluminum block, insert a heater, a thermocouple for control, and a thermocouple for sample temperature measurement, and change the temperature by PID control. The temperature was variable from room temperature to 200 ° C.
b, Prepare a dewar bottle with synthetic quartz, install a copper vertical sample holder in the dewar bottle, place the sample at the highest part of the sample holder, and place a non-inductively wound manganin wire directly under the sample. Install a heater and fill the refrigerant (liquid nitrogen or a mixture of alcohol and dry ice, etc.) below the heater,
Variable temperature from -196 ° C to + 70 ° C with PID control.
In this apparatus, a sample rotating device is provided in the sample mounting table portion to make a temperature variable device of a single-axis sample rotating specification.
c, An L-shaped aluminum block is provided with a single-stroke solution path in the vertical and horizontal height direction, a thermocouple hole for temperature measurement is also provided, and the antifreeze from the cooling circulator is poured so far at the sample installation section at -15. The temperature can be varied from ℃ to + 60 ℃, and the temperature can be varied from room temperature to + 130 ℃ by switching to silicone oil.

(2) About the goniometer for single crystals provided on the sample stage 13
a, Two cylindrical plastic containers are stacked, the outside is fixed to the sample mounting table 13, and a single crystal sample etc. is fixed to the internal cylindrical plastic container with an angle scale with lightweight paper clay. A sample rotation device with a single-axis rotation mechanism for rotation. The sample rotation axis is parallel to the vertical line.
b, the sample mounting part is fixed to a sample mounting table made in a container made of Macor or soft Teflon (registered trademark) or Delrin (registered trademark) with lightweight paper clay, and an aluminum stand plate is mounted on the sample mounting table 13 A sample rotation device with a single-axis rotation mechanism that is installed in the center and rotates while reading the angle with a large dial with a rear scale. The sample rotation axis is parallel to the microwave irradiation direction.
c, 5 types of 2-axis goniometers developed by the inventor for resonator-type ESR devices in the past, specifications were changed and the goniometers were enlarged, and some gears and rotating devices were changed from Teflon to metal (aluminum or brass). 2 axis goniometer changed to). (Two-axis goniometer for automatic measurement using room temperature measurement, variable temperature measurement, stepping motor)
The direct search method of the main axis of the spin Hamiltonian tensor using the Wolfnet and the biaxial goniometer developed by the inventor in 1985 can be applied to this.
d, the inventor has previously developed a three-axis goniometer for the resonator type ESR device, changed the specification and increased the size of the goniometer, and changed some gears and rotating devices from Teflon to metal (aluminum or brass) 3 axis goniometer. It can be used for quantitative state analysis of only sites with a certain unpaired electron center in a single crystal.

(3) Simultaneous measurement device for dielectric constant measurement and ESR spectrum
Install a sample with a strip-shaped electrode on a part of the sample and a capacitor part of the sample on the temperature variable device in (1) a, and change the temperature by PID control by step scan at each measurement temperature. The ESR measurement and dielectric constant measurement are performed in a fixed state. For simultaneous measurement of ESR and other physical properties, the Curie point of a ferroelectric triglycine sulfate single crystal sample to which Cu (II) ions are added and before and after that. The ESR spectrum and dielectric constant (ε ', ε ") have been measured simultaneously in the ferroelectric and paraelectric phases.

(4) Same as (3)
a, Simultaneous measurement of heat capacity (specific heat) and ESR spectrum,
b, Simultaneous measurement of simple thermal dilatometer with strain gauge attached to phosphor bronze spring and ESR measurement
c, Apparatus for simultaneous measurement of thermal conductivity and ESR spectrum
d, device for simultaneous measurement of electrical conductivity and ESR spectrum
e, STS (scanning tunneling current spectroscopy) device installed in the vibration isolation mechanism, and studying the electronic state at the Fermi level through simultaneous measurement and cross measurement of tunneling current and ESR spectrum.
f, The uniaxial stress applying device developed by the inventor in the past for the resonator ESR device is modified and installed in the electromagnetic horn type ESR.
g. Install diamond anvil device and apply ultra-high hydrostatic pressure to observe ESR spectrum under high pressure.
h, Installed a three-dimensional MRI coil using a multi-winding Zupancic type MRI coil and an anti-helmholtz MRI coil developed by the inventor in the past for two current power sources,
Use ESR imaging (ESR-CT) specifications.

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 fields of physics and basic science of chemistry 2. Rapid examination of blood and living tissue in medical clinical laboratories. Elucidation of redox-related aging phenomena and intractable diseases (cancer, diabetes, ischemia, hypertension, Alzheimer, etc.) in the pharmaceutical field.
4). Water treatment in the field of environmental science, water quality inspection, and dust inspection of diesel exhaust.
5. ESR imaging using MRI coil, ESR-STM (scanning tunneling microscope) device development and acquisition of high-resolution ESR imaging images selected for frequencies with Larmor precession caused by magnetic field application.
6). Construction of radiation dosimetry 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 the microwave solid circuit of the X-band and K-band reflection system electromagnetic horn type | mold ESR apparatus which is an example of an electromagnetic horn type | mold electron spin resonance apparatus. It is a block diagram which shows an example of the conventional electromagnetic horn type | mold electron spin resonance apparatus.

In FIG. 1, 1: isolator 2: frequency counter 3: directional coupler 4: attenuator (main arm)
5: Circulator 7: Three-stub tuner 8: Twisted waveguide 9: Rectangular circular waveguide
10: Circular waveguide
11: Electromagnetic horn
12: Microwave radiation convex lens
13a: Sample
13: Sample mounting table
14a: concave reflector type microwave reflector
15: Sample position adjustment mechanism (rack and pinion type)
16: Position adjustment mechanism of concave reflecting surface type reflector (rack and pinion type)
17: Magnetic field modulation coil
21: Power monitor
22: Power monitor
23: Power monitor
32a: Power monitor
31: Phaser (reference arm)
32: Mixer (Magic T)
33: Gun power supply
34: Gun oscillator
35: Unidirectional pipe
36: Semi-fixed attenuator
37: Amplifier power supply
38: Amplifier

Claims (1)

An electromagnetic horn (11) that radiates microwaves from the microwave transmission device to the sample (13a) on the sample mounting table (13) via the main arm (01) of the microwave waveguide, of the sample mounting table (13) Sweep magnetic field applying device (171) (electromagnet) and modulation device (170) for modulation spectroscopy provided around, microwave from the electromagnetic horn (11) through the sample (13a) again through the sample (13a) A microwave reflector (14) that reflects to the electromagnetic horn (11), a reference transmission microwave from the reference arm (03) branched from the main arm (02) of the microwave waveguide, and a microwave reflector ( 14) from the sample (13a), the electromagnetic horn (11), and the reflected microwave through the main arm (02) are introduced into the mixer (32), and the microscopic resonance occurs when the unpaired electron spin in the sample is reversed. A differential amplifier that detects and records very small changes in microwave power when a sample absorbs wave energy In an electromagnetic horn type electron spin resonance device comprising a device (40), a lock-in amplifier (41), and a recording device (42), a microwave is applied to the surface (exit port) of the electromagnetic horn (11) of the electromagnetic horn antenna device. A power monitor device for each microwave is provided for tuning / tuning to obtain an optimum ESR spectrum by providing a radiation convex lens (12) and making the microwave reflector (14) a concave reflector type reflector (14a). And a position adjusting device (15) for the sample mounting table 13) and a position adjusting device (16) for the reflecting plate (14).

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