Cavity resonator and ESR measurement device

Abstract

To enhance sensitivity and spatial resolution in ESR measurement using a cavity resonator which generates a leakage magnetic field.SOLUTION: In a cavity resonator 70, a cavity body 74 has an opening 82. A part of a resonance magnetic field 88 leaks to an external space 71B through the opening 82. The magnetic field having leaked out is a probe magnetic field 90 for causing ESR of an object to be measured and then detecting the ESR. In the opening 82, a thin and long stub 84 is provided which crosses the center of the opening 82. An induction current flows to the stub 84.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a cavity resonator and an ESR measuring device, and more particularly to a structure of a cavity resonator. [Background technology]

[0002] The ESR measurement device measures Electron Spin Resonance (ESR). More specifically, ESR measurement measures the ESR generated by radicals (chemical substances with unpaired electrons) contained in the measurement subject. ESR measurement allows for the quantification of radicals.

[0003] An ESR measurement device generally has a cavity. Microwaves are supplied into the cavity, which generates a resonant magnetic field as a high-frequency magnetic field inside the cavity. In a typical ESR measurement, the ESR generated in a sample placed in the resonant magnetic field is measured.

[0004] When measuring the two-dimensional distribution of radicals, a cavity having an emission window is used. The emission window is a through hole or opening formed in the cavity body as a housing or container. Through the emission window, a part of the resonant magnetic field in the cavity leaks out to the outside world. The leaked magnetic field is called a fringing magnetic field. The fringing magnetic field functions as a probe. From that point of view, the fringing magnetic field is a probe magnetic field.

[0005] By bringing the surface of the object close to the emission window and two-dimensionally scanning the object with respect to the emission window (or by two-dimensionally scanning the emission window with respect to the object), ESR is measured at each position on the surface of the object. Two-dimensional radical distribution information can be obtained by such surface ESR measurement. The radical distribution information is then analyzed and imaged.

[0006] Patent Documents 1 to 5 disclose cavities for ESR measurement. Each cavity has an emission window. All the emission windows are simply openings, and no members exist inside the emission windows. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 5-2060 [Patent Document 2] Japanese Patent Application Publication No. 11-64243 [Patent Document 3] Patent No. 2892005 [Patent Document 4] Patent No. 2967224 [Patent Document 5] Patent No. 5481651 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to improve one or both of the sensitivity and the spatial resolution in ESR measurement using a cavity resonator that generates a leakage magnetic field, or to provide a new aperture structure in the cavity resonator that generates the leakage magnetic field. [Means for solving the problem]

[0009] The cavity resonator according to the present invention has an internal space into which an electromagnetic wave for ESR measurement is input, and includes a cavity body that generates a resonant magnetic field in the internal space, and the cavity body includes an opening that is provided between the internal space and an external space and generates a probe magnetic field that leaks into the external space, and a stub that is provided within the opening and electromagnetically acts on the probe magnetic field.

[0010] The ESR measurement apparatus according to the present invention is characterized by including the above-mentioned cavity resonator, and an image generator which generates a two-dimensional ESR image based on a series of ESR signals obtained by two-dimensionally scanning the cavity resonator relatively to the object to be measured while maintaining the opening in close proximity to the object to be measured. Effect of the Invention

[0011] According to the present invention, in ESR measurement using a cavity resonator that generates a leakage magnetic field, one or both of the sensitivity and the spatial resolution can be improved. Alternatively, according to the present invention, a new opening structure in the cavity resonator that generates the leakage magnetic field can be provided. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of an ESR measurement apparatus according to an embodiment. [Diagram 2] FIG. 4 is a diagram showing a cavity resonator according to a comparative example. [Diagram 3] FIG. 13 is a diagram showing an opening according to a comparative example. [Figure 4] FIG. 2 is a diagram showing a cavity resonator according to an embodiment. [Diagram 5] FIG. 13 illustrates an aperture with stubs according to an embodiment. [Figure 6] FIG. 13 is a diagram showing a simulation result according to a comparative example. [Figure 7] FIG. 11 is a diagram showing a simulation result according to the first configuration example. [Figure 8] FIG. 13 is a diagram showing a simulation result according to the second configuration example. [Figure 9] FIG. 13 is a diagram showing an ESR signal according to a comparative example. [Figure 10] FIG. 4 is a diagram showing an ESR signal according to the embodiment. [Figure 11] FIG. 1 is a diagram showing an ESR measuring apparatus according to a first embodiment. [Figure 12] FIG. 13 is a diagram showing an ESR measuring apparatus according to a second embodiment. [Figure 13] FIG. 13 is a diagram showing a first modified example of the stub. [Figure 14] FIG. 13 is a diagram showing a second modified example of the stub. [Figure 15] FIG. 13 is a diagram showing a third modified example of the stub. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment will be described with reference to the drawings.

[0014] (1) Overview of the embodiment The cavity resonator according to the embodiment has an internal space into which an electromagnetic wave for ESR measurement is input, and includes a cavity body that generates a resonant magnetic field in the internal space. The cavity body has an opening and a stub. The opening is provided between the internal space and an external space, and generates a probe magnetic field that leaks into the external space. The stub is provided within the opening and acts electromagnetically on the probe magnetic field.

[0015] According to the above configuration, a part of the resonant magnetic field leaks out through the opening into the external space. The leaked magnetic field is the probe magnetic field for ESR measurement. The stub installed inside the opening acts electromagnetically on the probe magnetic field. This increases the strength of the probe magnetic field or sharpens the magnetic field distribution of the probe magnetic field.

[0016] In the embodiment, the stub is a passive element that interacts with the probe magnetic field (and the resonant magnetic field). A loop-shaped magnetic flux (magnetic flux of the probe magnetic field) is generated around the stub. The interaction between the stub and the probe magnetic field (and the resonant magnetic field) causes an induced current to flow in the stub, which increases the magnetic flux density near the central axis of the probe magnetic field.

[0017] The cavity body is basically made of a non-magnetic metal material. The stub may be integrated with the cavity body, or may be made of a separate member from the cavity body. In either case, the stub is made of a conductive material. The shape of the opening may be, for example, circular, rectangular, or other. When the plane surrounded by the edge of the opening is defined as the opening surface, the stub is provided on the opening surface, or provided inside or outside the opening surface. In either case, the stub is provided at a position where it interacts with the probe magnetic field leaking from the opening (i.e., within the opening).

[0018] In an embodiment, a base end of the stub is connected to the periphery of the opening, and a tip end of the stub is spaced from the periphery of the opening. This configuration can reliably create a state in which an induced current can flow in the stub, or can facilitate the flow of an induced current in the stub.

[0019] In the embodiment, the stub has an intermediate portion that crosses the center of the opening. The center of the opening corresponds to the center of the probe magnetic field. In other words, the central axis of the opening corresponds to the central axis of the probe magnetic field. By having the stub cross the center of the opening, the magnetic flux density near the central axis of the probe magnetic field can be increased. This sharpens the intensity distribution of the probe magnetic field, and allows the probe magnetic field to reach a location farther away from the opening.

[0020] In the embodiment, the direction of magnetic flux in the resonant magnetic field near the opening is a first direction. The intermediate portion of the stub extends in a second direction perpendicular to the first direction. With this configuration, the strength of the probe magnetic field can be increased by increasing the induced current.

[0021] In the embodiment, when a third direction perpendicular to the first direction and the second direction is defined, the thickness of the middle part in the third direction is 2 mm or less. If the thickness of the stub in the third direction is increased, leakage of the magnetic field is less likely to occur. If the thickness of the stub in the third direction is decreased, leakage of the probe magnetic field is more likely to occur. In the embodiment, the thickness of the entire stub in the third direction is set to 2 mm or less.

[0022] In one embodiment, the width of the stub in the first direction is substantially the same across the width in the second direction. This configuration makes it easier to manufacture the stub. If the tip of the stub is arc-shaped, the object and the stub can be protected when the stub comes into contact with the object.

[0023] In another embodiment, the stub has a base portion, a tip portion, and an intermediate portion. The base portion is connected to the intermediate portion and includes a base end connected to the periphery of the opening. The tip portion is connected to the intermediate portion and includes a tip end separated from the periphery of the opening. The intermediate portion is between the base portion and the tip portion. The width of the intermediate portion in the first direction increases with increasing distance from the center of the opening to both sides in the second direction. With this configuration, the magnetic field strength of the central portion of the probe magnetic field becomes greater, and the magnetic field distribution of the central portion becomes sharper. In the stub, the intermediate portion extends in the stub central axis direction, crosses the center of the opening, and corresponds to 1 / 3 or more of the total length of the stub.

[0024] The ESR measuring device according to the embodiment includes a cavity resonator and an image generator. The cavity resonator includes a cavity body. The cavity body has an internal space into which an electromagnetic wave for ESR measurement is input, and generates a resonant magnetic field in the internal space. The cavity body includes an opening and a stub. The opening is provided between the internal space and the external space, and generates a probe magnetic field that leaks into the external space. The stub is provided within the opening, and acts electromagnetically on the probe magnetic field.

[0025] The image generator generates a two-dimensional ESR image based on a series of ESR signals obtained by two-dimensionally scanning the cavity resonator relative to the object to be measured while keeping the aperture close to the object to be measured.

[0026] When the above-mentioned configuration is adopted, either the measurement target or the cavity resonator may be moved. When the measurement target is an electric component, the ESR generated in the electric component may be measured while applying power or a signal to the electric component.

[0027] (2) Details of the embodiment An ESR measurement device according to an embodiment is shown in Figure 1. The ESR measurement device is a device that analyzes a measurement object by measuring the ESR generated in the measurement object.

[0028] In Fig. 1, reference numeral 10 denotes a microwave circuit. A microwave is generated by an oscillator 12. The frequency of the microwave is determined so as to satisfy a predetermined resonance condition. The generated microwave is sent to a cavity resonator 17 via an attenuator 14 and a circulator 16.

[0029] The cavity resonator 17 has a cavity body 18 as a container. An opening 20 is formed in the cavity body 18. When microwaves are supplied to the internal space of the cavity body 18, a resonant magnetic field is generated in the internal space as a high-frequency magnetic field. A part of the resonant magnetic field leaks out through the opening 20. The leaked magnetic field is the probe magnetic field. The probe magnetic field is irradiated onto the surface of a measurement target placed in the external space.

[0030] Reference numeral 24 denotes an electromagnet that generates a static magnetic field. The cavity resonator 17 is placed in the static magnetic field. Reference numeral 26 denotes a magnetic field modulation coil. The static magnetic field is modulated by the magnetic field generated by the magnetic field modulation coil 26. A modulation signal generated by a modulation signal generator 28 is supplied to the magnetic field modulation coil 26.

[0031] When ESR occurs on the surface of the measurement target due to irradiation of the probe magnetic field, the electrical state in the cavity resonator 17 changes, generating a reflected wave 30. The reflected wave 30 is processed as an ESR detection signal. Specifically, the ESR detection signal is sent to a phase detector 34 via a circulator 16. The microwave generated by the oscillator 12 is sent to the phase detector 34 via a phase shifter 32. The phase detector 34 performs phase detection on the input ESR detection signal using the input microwave. The ESR detection signal output from the phase detector 34 is sent to a lock-in amplifier 38 via a preamplifier 36.

[0032] The lock-in amplifier 38 is supplied with the modulated signal generated by the modulated signal generator 28. In the lock-in amplifier 38, the phase detector 40 performs phase detection on the ESR detection signal output from the preamplifier 36, using the input modulated signal. The ESR detection signal output from the phase detector 40 is sent to the PC 46 via the preamplifier 42 and the AD converter 44. The PC 46 analyzes the ESR detection signal processed as described above. The PC 46 functions as a spectrometer or a signal analyzer.

[0033] As described below, an ESR signal is observed at each position on the surface of the object 22 by two-dimensionally scanning the cavity resonator 17 with respect to the object 22. A two-dimensional image is generated based on a series of ESR signals obtained by the two-dimensional scanning. The two-dimensional image represents a two-dimensional distribution of radicals. The amount and type of radicals at each position may be analyzed in the PC 46.

[0034] 2 and 3 show a cavity resonator 50 according to a comparative example. In FIG. 2, the cavity resonator 50 has a cavity body 54. The cavity body 54 has an opening 58 and an opening 62. A waveguide 52 that transmits microwaves is connected to the cavity body 54. Microwaves are supplied from the waveguide 52 to the internal space 51A of the cavity body 54 through the opening 58. This generates a resonant magnetic field 66 in the internal space 51A (note that each broken line represents a magnetic flux). Note that reference numeral 64 indicates a magnetic field generated in the waveguide 52.

[0035] An opening 62 formed in the cavity body 54 functions as an emission window. A part of the resonant magnetic field 66 leaks out to the external space 51B through the opening 62. The leaked magnetic field is a probe magnetic field 68. A part of the probe magnetic field 68 enters the external space 51B, and a part of it is irradiated onto the surface of the measurement target.

[0036] 3 shows an opening 62 formed in the cavity body 54 of the cavity resonator 50 according to the comparative example. The opening 62 shown in the figure is a simple circular opening. No member is provided inside the opening 62.

[0037] 4 and 5 show a cavity resonator 70 according to an embodiment. In FIG. 4, the cavity resonator 70 has a rectangular or box-shaped cavity body 74. A cavity body having another shape (e.g., a cylindrical shape) may be adopted. The cavity body 74 is made of a non-magnetic metal material, for example, copper. The cavity body 74 has an opening 78 and an opening 82. In the illustrated example, the opening 78 is formed in a side plate 76 of the cavity body 74, and the opening 82 is formed in a side plate 80 of the cavity body 74.

[0038] A waveguide 72 is connected to the cavity body 74. Microwaves are supplied from the waveguide 72 to the internal space 71A of the cavity body 74 through an opening 78. This generates a resonant magnetic field 88 in the internal space 71A. In FIG. 4, the magnetic flux of the resonant magnetic field 88 has a loop shape along the XY plane. Reference numeral 86 denotes a magnetic field generated in the waveguide 72.

[0039] 5 shows an opening 82 formed in the cavity body 74 in the cavity resonator 70 according to the embodiment. The opening 82 is a circular opening that extends parallel to the YZ plane. A stub 84 is provided in the opening 82 as a passive element. The stub 84 extends along the Z direction and has a thin plate-like shape. A base end 92 of the stub 84 is connected to the circular opening edge 82A. A tip end 94 of the stub 84 is close to the opening edge 82A without contacting it. A minute gap exists between the opening edge 82A and the tip end 94.

[0040] F indicates the magnetic flux passing near the opening 82 in the resonant magnetic field. The magnetic flux F flows along the Y direction. A stub 84 is provided so as to be perpendicular to the magnetic flux F. L indicates the central axis of the stub 84. The central axis L crosses the center C of the opening 82. In practical terms, the stub 84 covers the entire Z direction of the opening 82. A semicircular half opening is formed on one side of the stub 84 in the Y direction, and a semicircular half opening is formed on the other side of the stub 84 in the Y direction. These two half openings act as paths for passing the magnetic flux of the probe magnetic field.

[0041] In the illustrated example, the stub 84 is integrated with the cavity body 74. The stub 84 is made of copper, which is a conductive material. The stub 84 may be made of other non-magnetic conductive materials. The stub 84 may be made of a member separate from the cavity body 74. When a plane within the opening 82 is defined as the opening plane, the stub 84 is located on the opening plane in the embodiment. A modified example in which the stub 84 is provided inside or outside the opening plane is also possible. In the embodiment, the stub 84 extends on the opening plane and crosses the center C of the opening 82. The central axis of the probe magnetic field is perpendicular to the opening plane and passes through the center C of the opening 82.

[0042] Returning to FIG. 4, the magnetic field leaking out from the opening 82 is the probe magnetic field 90. As described above, the stub 84 is provided inside the opening 82. The stub 84 and the probe magnetic field 90 (and the resonant magnetic field 88) electromagnetically interact with each other. This interaction causes an induced current (high-frequency induced current) to flow in the stub. As a result, the strength of the probe magnetic field 90 increases, and the strength distribution of the probe magnetic field 90 becomes sharper. In other words, the probe magnetic field 90 reaches farther.

[0043] From an electrical perspective, the stub 84 corresponds to reactance and capacitance. It may be interpreted that the action of these electrical elements changes the electrical characteristics in the vicinity of the opening 82, causing the strength of the probe magnetic field 90 to increase.

[0044] Regarding the internal space 71A of the cavity main body 74, its size in the X direction is, for example, 20 mm, its size in the Y direction is, for example, 20 mm, and its size in the Z direction is, for example, 10 mm. The diameter of the opening 82 is, for example, 5 mm. Regarding the stub 84, its length in the Z direction is, for example, 4.5 mm, its width in the Y direction is, for example, 0.5 mm, and its thickness in the X direction is, for example, 0.3 mm. All numerical values ​​described in this specification are merely examples.

[0045] In the embodiment, the stub 84 constitutes a part of the side plate 80, and the thickness of the stub 84 in the X direction is the same as the thickness of the side plate 80 in the X direction. When considering ensuring the rigidity of the cavity body 74, the thickness of the side plate 80 may be 2 mm, 1 mm, or 0.5 mm. In general, if the thickness is set to 2 mm or less, the magnetic field is likely to leak. The stub 84 may be made of a different material from the side plate 80.

[0046] 4, a loop-shaped magnetic flux (magnetic flux of probe magnetic field 90) is generated around stub 84, which is elongated in the Z direction. The magnetic flux density in the vicinity of the central axis of probe magnetic field 90 is increased, and probe magnetic field 90 extends significantly along the central axis. This means that the sensitivity and resolution in ESR measurement are improved.

[0047] The simulation results will be described with reference to Figures 6, 7, and 8. Figure 6 shows the simulation results according to a comparative example, Figure 7 shows the simulation results according to a first configuration example, and Figure 8 shows the simulation results according to a second configuration example. The first and second configuration examples correspond to the embodiment.

[0048] In FIG. 6, reference numeral 100 indicates the simulation conditions. The diameter D1 of the aperture generating the probe magnetic field is 5 mm. Reference numeral 102 indicates the two-dimensional intensity distribution of the probe magnetic field generated under the simulation conditions 100. The horizontal axis indicates the Z direction, and the vertical axis indicates the Y direction. The gray scale 104 indicates the relationship between brightness and magnetic field intensity, and the line 106 indicates a line of interest that crosses the center of the aperture and is parallel to the Y direction (this is the same in other figures described later). The intensity distribution 108 is a one-dimensional intensity distribution on the line of interest 106. The horizontal axis indicates the Y direction, and the vertical axis indicates the magnetic field intensity.

[0049] In FIG. 7, reference numeral 100 indicates a simulation condition for the first configuration example. The diameter D1 of the aperture is 5 mm, and the length L1 of the stub is 4.5 mm. The width W1 of the stub is 0.5 mm. In the illustrated simulation condition 110, the right end of the stub is the base end, and the left end of the stub is the tip end. In the two-dimensional intensity distribution 112 of the probe magnetic field generated under the simulation condition 110, a large positive magnetic field intensity occurs in the center in the Y direction (see the white part). Two large negative magnetic field intensities occur near the edge of the aperture in the Y direction (see the two black parts). The intensity distribution 114 is a one-dimensional intensity distribution on the line of interest 106. One large positive peak 116 occurs in the center in the Y direction. Two large negative peaks 118, 120 occur to the right and left of the positive peak 116. By using a probe magnetic field having such a profile, both sensitivity and resolution can be improved.

[0050] In FIG. 8, reference numeral 122 indicates the simulation conditions for the second configuration example. The diameter D1 of the aperture is 5 mm, and the length L1 of the stub is 4.5 mm. The width W2 of the stub is 1.75 mm. In the two-dimensional intensity distribution 124 of the probe magnetic field generated under the simulation conditions 122, a large positive magnetic field intensity occurs in the center in the Y direction (see the white part). Two large negative magnetic field intensities occur near the edge of the aperture in the Y direction (see the two black parts). The intensity distribution 126 is a one-dimensional intensity distribution on the line of interest 106. Two large positive peaks 128, 130 occur in the center in the Y direction. Two large negative peaks 132, 134 occur to the right and left of them. If the width of the stub is increased, the positive peaks split, but the split interval is not very large. By using a probe magnetic field having such a profile, both sensitivity and resolution can be improved. If the above splitting becomes a problem, the width of the stub can be reduced.

[0051] According to the first and second configuration examples shown in Fig. 7 and Fig. 8, it is possible to obtain a probe magnetic field intensity that is four or five times that of the comparative example shown in Fig. 6. Therefore, the distance that the probe magnetic field reaches can be significantly increased compared to the comparative example.

[0052] Fig. 9 shows an ESR detection signal 136 obtained using a cavity resonator according to a comparative example (see Figs. 2 and 3). The horizontal axis indicates the magnetic field strength axis, and the vertical axis indicates the magnitude of ESR. Fig. 10 shows an ESR detection signal 138 obtained using a cavity resonator according to an embodiment (see Figs. 4 and 5). As shown in the figure, according to the embodiment, the amplitude of the ESR detection signal can be increased compared to the comparative example.

[0053] FIG. 11 shows a first example of the ESR measuring device according to the embodiment. The ESR measuring device is composed of a device body 140 and a measuring unit 142. The measuring unit 142 has a cavity resonator 146 and a magnetic field generator. The cavity resonator 146 has an opening (radiation window) having a stub. The device body 140 has a microwave circuit, a lock-in amplifier, a spectrometer, and the like. A coaxial cable or a flexible waveguide is provided between the device body 140 and the measuring unit 142. In the illustrated first configuration example, the measuring unit 142 is manually two-dimensionally scanned along the surface of the measurement object 148. The two scanning directions are the x direction and the y direction. The measurement object 148 is, for example, a plate-like member.

[0054] FIG. 12 shows a second example of the scanning ESR measurement device according to the embodiment. The ESR measurement device is composed of a device body and a measurement unit. The measurement unit has a cavity resonator. FIG. 12 shows a cavity body 152 of the cavity resonator. The cavity body 152 has a cylindrical internal space 154, and microwaves are introduced into the internal space 154 from the side (the right side of the drawing). This generates a resonant magnetic field 160 in the internal space 154. An opening 156 having a stub 158 is provided at the top of the cavity body 152. A part of the resonant magnetic field 160 leaks out through the opening 156, and the leaked magnetic field is a probe magnetic field 162.

[0055] An object to be measured is provided on the upper side of the cavity body 152, specifically, in a position close to the opening 156. The object to be measured is, for example, a semiconductor device. The electric circuit 166 supplies power and signals to the object to be measured. With the power and signals supplied, a probe magnetic field is irradiated onto the object to be measured. As a result, the ESR generated in the object to be measured is observed.

[0056] 12, for example, a transport facility is provided for transporting the measurement target 164 in the x and y directions. The cavity resonator may be transported in the x and y directions.

[0057] Several modified examples of the stub are shown in Figures 13 to 15. In Figure 13, a tip 172 of a stub 170 according to a first modified example has a semicircular shape. The entire stub 170 extends in the Z direction and crosses the center of the opening.

[0058] 14, a stub 174 according to the second modification has a portion (base end portion and intermediate portion) 176 extending along the Z direction, and a tip portion 178 spreading out in an arc or bow shape. The extended portion 176 crosses the center of the opening. An end face 178A of the tip portion 178 is close to but not in contact with an inner surface 180A of the opening edge. According to the second modification, the capacitance component can be increased.

[0059] In FIG. 15, a stub 182 according to the third modification comprises a base end portion 186, an intermediate portion 184, and a tip portion 188. The base end portion 186 is an enlarged portion including a base end that is connected to the opening edge. The tip portion 188 is an enlarged portion including a tip that is separated from the opening edge. The intermediate portion 184 is a portion between the base end portion 186 and the tip portion 188. The intermediate portion 184 extends in the Z direction, and specifically, the width of the intermediate portion 184 in the Y direction is smallest at the center C of the opening and gradually increases as it moves away from the center to both sides in the Z direction. By adopting such a configuration, the intensity distribution of the probe magnetic field can be made sharper.

[0060] In the above embodiment, it is easy to provide a stub for the opening that functions as an emission window. Therefore, an increase in manufacturing cost is hardly an issue. As described above, by providing a stub as a passive element in the opening, it is possible to increase the sensitivity and improve the resolution. The above stub technology can be applied to various ESR measurement devices. [Explanation of symbols]

[0061] 17,70 Cavity resonator, 18,74 Cavity body, 20,82 Aperture, 84 Stub, 88 Resonant magnetic field, 90 Probe magnetic field.

Claims

1. The present invention includes a cavity body having an internal space into which an electromagnetic wave for ESR measurement is input, the cavity body generating a resonant magnetic field in the internal space, The cavity body includes: An opening is provided between the internal space and the external space, and causes a probe magnetic field to leak into the external space; a stub provided within the opening and electromagnetically interacting with the probe magnetic field; A cavity resonator comprising:

2. 2. The cavity resonator according to claim 1, The stub and the probe magnetic field interact with each other, An induced current flows through the stub.

1. A cavity resonator comprising:

3. 2. The cavity resonator according to claim 1, a proximal end of the stub is connected to a periphery of the opening; a tip of the stub is spaced from a periphery of the opening; 1. A cavity resonator comprising:

4. 2. The cavity resonator according to claim 1, the stub having an intermediate portion across the center of the opening; 1. A cavity resonator comprising:

5. 5. The cavity resonator according to claim 4, a magnetic flux direction in the vicinity of the opening in the resonant magnetic field is a first direction; The intermediate portion extends in a second direction perpendicular to the first direction.

1. A cavity resonator comprising:

6. 6. The cavity resonator according to claim 5, When a third direction perpendicular to the first direction and the second direction is defined, the thickness of the intermediate portion in the third direction is 2 mm or less.

1. A cavity resonator comprising:

7. 6. The cavity resonator according to claim 5, a width of the stub in the first direction is substantially the same across the second direction; 1. A cavity resonator comprising:

8. 6. The cavity resonator according to claim 5, The stub is a proximal end portion connected to the intermediate portion and including a proximal end connected to a periphery of the opening; a tip portion connected to the intermediate portion and including a tip spaced from a periphery of the opening; having the width in the first direction of the intermediate portion increases with increasing distance from the center of the opening to both sides thereof in the second direction; 1. A cavity resonator comprising:

9. A cavity resonator according to claim 1; an image generator that generates a two-dimensional ESR image based on a series of ESR signals obtained by two-dimensionally scanning the cavity resonator relative to the measurement object while maintaining the opening in close proximity to the measurement object; An ESR measuring device comprising:

Images