JP2971270B2 - Mossbauer sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Mossbauer sensor which simultaneously detects reflected electron X-rays and .gamma.-rays. The invention relates to a non-destructive method such as heating embrittlement detection of a two-phase (ferrite phase and austenite phase) stainless steel structure. The present invention relates to a Mossbauer sensor applicable to inspection.

[0002]

2. Description of the Related Art The Mossbauer effect, also called non-recoil γ-ray resonance absorption or nuclear γ-ray resonance, has been widely applied in various fields of science. And
Inspection of metal structures is one of the fields of application.

[0003] In the measurement of fluorescence γ-ray resonance, a γ-ray is modulated by the Doppler phenomenon by moving a radiation source that emits γ-rays.
When the modulated γ-ray is made incident on the sample (absorber), a part of the γ-ray is absorbed by the sample and then re-emitted in all directions. This is performed by collecting the γ-ray with an anode line.

[0004] Not only γ-rays but also electrons are re-emitted by γ-ray irradiation. However, these electrons are obtained only at a position very close to the sample. The information on the depth of the subject (sample) differs depending on whether the object to be collected is a γ-ray, an X-ray, or an electron. Therefore, by measuring both, the influence of the surface (such as an oxide film) can be removed and the internal structure can be analyzed.

[0005] A conventional backscattered electron detection sensor used for detecting heating embrittlement of a two-phase (ferrite phase and austenite phase) stainless steel structure and nondestructive inspection of a metal structure containing iron utilizing the Mossbauer effect. The backscattered electron γ-ray X-ray detection sensor will be described with reference to FIGS.
FIG. 4 is a block diagram of the backscattered electron detection sensor, and FIG. 5 is a block diagram of the backscattered X-ray γ-ray detection sensor.

As shown in FIG. 4, a radiation transmitting window 41 is formed at the center of one side of a box-shaped detecting sensor 40 made of a radiation shielding material. The sample 20 is arranged at the facing portion of 41. The anode wire 8 extends in the detection sensor 40.

In such a configuration, γ from the radiation source
When the ray 1 is incident on the detection sensor 40 through the radiation transmission window 41 and is incident on the sample 20 disposed in the detection sensor 40, the γ-ray 1 Generates electrons 6. The generated electrons 6 are collected by the anode wire 8 to obtain a detection signal, and the sensor performs deterioration detection based on the detection signal.

As shown in FIG. 5, the reflection X-ray γ-ray detection sensor has a relatively large opening concave portion 50a formed in the center of one surface of a block-shaped sensor main body 50 formed of a radiation shielding material. And a γ-ray introduction path 51 communicating with the concave portion at the center of the other surface of the sensor body 50.
A space having a circular cross section is formed beside the γ-ray introduction path 51 so that a part of the space opens into the concave portion 50a.
Has an anode wire 8 stretched over it.

In such a configuration, the sensor body 50
After setting the opening of the concave portion 50 a to the surface of the sample 20, the γ-ray 1 from the radiation source is incident on the sample 20 through the γ-ray introduction path 51. As a result, X-rays or γ-rays are re-emitted from the sample 20. The emitted X-rays or γ-rays enter the detection chamber 52 via the concave portion 50a of the sensor main body 50. In the detection chamber 52, the incident X-rays or γ-rays 7 are collected by the anode rays 8 and are obtained as signals. Then, deterioration detection is performed based on this detection signal.

As described above, the reflected X-ray γ-ray detection sensor and the backscattered electron detection sensor collect the radiation or the electron beam emitted from the sample by the anode electrode by irradiating the sample with the γ-ray, and detect the deterioration. Conventionally, the sensor for radiation and the sensor for electron beam are different from each other. Therefore, it is necessary to measure separately, respectively.In addition, in the case of the backscattered electron detection sensor, the sample must be arranged in the sensor body. Therefore, it was not configured for non-destructive inspection.

[0011]

As described above, the conventional sensors used for detecting the heating embrittlement of a duplex stainless steel structure utilizing the Mossbauer effect are the ones for electronic use and those for γ-ray and X-ray.
For inspection, it is necessary to measure each of them for inspection.
Detection was performed separately using two types of sensors for lines.

[0012] Since these sensors have different information on the depth of the subject, it is difficult to know how much influence is exerted on the surface (such as an oxide film) by an inspection using only one of them. Therefore, detection by two types of sensors is performed, but after measurement by one of the sensors is completed,
Since the measurement is performed by the other sensor, the inspection takes time and the handling is inconvenient. Moreover, the conventional backscattered electron detection sensor has a structure in which a sample is used in the sensor, and thus cannot be applied to nondestructive inspection.

Therefore, the object of the present invention is to:
Reflected electrons, X-rays and γ-rays can be measured at the same time, making it possible to reduce the size and measurement time.
It is to provide a Mossbauer sensor applicable to nondestructive inspection.

[0014]

In order to achieve the above object, the present invention is configured as follows. That is, the inside is hollow, two opposing surfaces are open, and an anode wire for electron collection is disposed inside, and one of the open surfaces is a reflection surface serving as a contact surface with the subject. An electron detection sensor portion, and a γ-ray introduction path provided on the other open surface side of the reflected electron detection sensor portion and toward the one open surface side of the reflected electron detection sensor portion at the center. And a sensor unit for detecting a backscattered electron X-ray and γ-ray which is provided with a detection means for detecting radiation incident through the backscattered electron detection sensor unit.

[0015]

The present device having the above-described configuration has a laminated structure in which a reflected X-ray γ-ray detection sensor is disposed on the back of the reflected electron detection sensor, and one open surface of the reflected electron detection sensor is brought into contact with the subject. And irradiating the subject with γ-rays from the back of the reflected X-ray γ-ray detection sensor section through its introduction path,
The electrons emitted from the subject and the X-ray γ-rays are detected by the reflected electron detection sensor unit close to the subject, and the X-ray γ-rays are detected by the reflected X-ray γ-ray detection sensor unit. In a single measurement, electrons, γ-rays and X-rays can be obtained simultaneously, so that information from different depths (surface layer and inside) of the subject can be obtained at once. As a result, information on the surface layer can be obtained from the reflected electrons, and more internal information can be obtained from the reflected γ-rays and X-rays. In addition, if arithmetic processing is performed on the reflected γ-ray and X-ray signals and the corrected reflected electron signal, it is possible to obtain internal information that is not affected by an impurity layer (such as an oxide film) on the surface, and perform the surface treatment. Without this, information inside the material can be obtained.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A Mossbauer sensor for simultaneous detection of reflected electron X-rays and gamma rays according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the present invention. In FIG. 1, reference numeral 2 denotes a block-shaped subject, and reference numeral 100 denotes a Mossbauer sensor of the present invention mounted on the surface of the subject 2. The Mossbauer sensor 100 includes a reflected electron detection sensor unit 4A and a reflected γ-ray X-ray detection sensor unit 5A.
Consists of

The backscattered electron detection sensor section 4A has an anode wire 8 extending in a cylindrical or frame-shaped sensor main body 4 formed of a radiation shielding material, and a groove 4 is formed on one opening surface side.
a is formed and an O-ring 3 for sealing is attached, and the arrangement portion of the O-ring 3 is brought into close contact with the surface of the subject 2 by bringing it into contact with the surface of the subject 2 to form an airtight structure with respect to the outside. .

A reflected γ-ray X-ray detection sensor 5A is provided in the other opening of the reflected electron detection sensor 4A. The reflected X-ray γ-ray detection sensor portion 5A is a relatively large recessed portion in the center of one surface (the surface on the backscattered electron detection sensor portion 4A side) of the block-shaped sensor main body 5 formed of a radiation shielding material. 5a, and the sensor body 5
A γ-ray introduction path 5b penetrating the concave portion 5a is formed at the center of the other side surface of the γ-ray introduction path 5b, and a part thereof surrounds the γ-ray introduction path 5b or partially surrounds the γ-ray introduction path 5b. A space having a circular cross section is formed so as to open in the concave portion 5a, and this space is used as a detection chamber 5c.
Is stretched out.

Reference numeral 10 denotes a signal compensating circuit, and the signals 9a and 9b detected by the backscattered electron detection sensor unit 4A and the reflected γ-ray X-ray detection sensor unit 5A are directly affected by the surface condition (oxide film or the like). Therefore, the influence is compensated for these signals 9a and 9b.

The Mossbauer sensor 100 having such a configuration
Has a configuration in which a backscattered electron detection sensor unit 4A and a reflected γ-ray X-ray detection sensor unit 5A are stacked.
The arrangement is devised so that the A side is close to the subject 2.

Then, from the back side of the reflected γ-ray X-ray detection sensor section 5A, γ-rays 1 generated from the source are introduced through the γ-ray introduction path 5b. The γ-ray introduction path 5b faces the subject 2 via the backscattered electron detection sensor unit 4A in a hollow state, and the subject 2 is irradiated with the γ-ray 1 incident from the radiation source, thereby 2, reflected electrons 6 and reflected γ-rays and X-rays 7 are generated from the subject 2 by the Mossbauer effect. The O-ring 3 is used in the backscattered electron detection sensor unit 4A in order to improve the contact with the subject 2 and increase the degree of sealing.

The reflected electron 6 generated by the subject 2 has a short range and has information on the surface layer. Then, the reflected electrons 6
Is captured by the anode wire 8 of the backscattered electron detection sensor unit 4A,
It is detected and becomes signal 9b.

On the other hand, reflected gamma rays generated by the subject 2
The X-ray 7 has a long range and has internal information. The reflected γ-rays and X-rays 7 are caught and detected by the anode lines 8 of the reflected γ-ray X-ray detection sensor unit 5, and become signals 9a.

Since the detected signals 9a and 9b are affected by the surface condition (oxide film or the like) as they are, these signals 9a and 9b are input to the signal compensating circuit 10 and
By subtracting the corrected signal 9b from a, an adverse effect on the surface is removed.

As described above, when the Mossbauer sensor has a stacked structure in which the reflected electron detection sensor section is provided on the subject contact side and the X-ray γ-ray detection sensor section is provided on the back surface thereof, electrons generated by the sensor are reduced. X-rays and γ-rays can be detected at the same time, making it possible to make the apparatus compact and reduce the measurement time. In addition, by compensating with the signal compensation circuit, it is not affected by surface contamination (oxide film, etc.)
Information inside the subject can be obtained.

As a second embodiment, a configuration as shown in FIG. 2 can be adopted. This is a configuration in which the signal compensating circuit 10 in the first embodiment shown in FIG. 1 is removed. In this case, the surface of the test sample (test object) is previously finished with sandpaper or the like so as not to be affected by oxidation. With such a specimen, it is possible to detect non-destructively the characteristics of the specimen at different points at once without using a signal compensation circuit.

Next, the configuration of a Mossbauer inspection device using the above-described Mossbauer sensor will be described. FIG. 3 is a block diagram showing a configuration of the Mossbauer inspection device. In FIG. 3, reference numeral 2 denotes a block-shaped subject, and the Mossbauer sensor 100 of the present invention is attached to the surface of the subject 2 with its backscattered electron detection sensor unit 4A side. The transducer 12 moves the radiation source 11 that emits the γ-ray 1 in the direction of the subject 2 to cause a Doppler phenomenon.

When the γ-ray 1 modulated by the transducer 12 is incident on the subject 2, the reflected γ-ray or X-ray 7 and the reflected electrons 6 are re-emitted from the subject 2. Among them, the reflected γ-ray X-ray 7 is detected by the reflected γ-ray X-ray detection sensor 5A of the Mossbauer sensor 100.
It is.

The signals 9a and 9b detected by the respective sensor units 4A and 5A are amplified by the preamplifier 14 and stored by the multi-channel analyzer 15. The multi-channel analyzer 15 is synchronized with the function generator 16, and determines the storage location based on the correlation with the function generator 16.

The function generator 16 is a device for determining the moving distance (amplitude) and moving speed of the radiation source 11 attached to the transducer 12. The signal output from the function generator 16 is amplified by the power amplifier 17, It is transmitted to the transducer 12 to be driven.

In the present apparatus having such a configuration, a desired moving distance (amplitude) is transmitted from the function generator 16.
When an output signal giving the speed and the moving speed is generated, the output signal is amplified by the power amplifier 17 and transmitted to the transducer 12. Then, the transducer 12
Moves the radiation source 11 by the moving speed and the moving distance corresponding to the moving speed (amplitude) and the moving distance described above, and modulates the γ-ray 1.

The reflected γ-rays or X-rays 7 from the subject 2 due to the modulated γ-rays 1 are reflected by the reflected γ-ray X-ray detection sensor unit 5A of the Mossbauer sensor 100, and the reflected electrons 6
Is detected by the backscattered electron detection sensor unit 4A, and the respective detection signals 9a and 9b are amplified by the preamplifier 14 and stored by the multi-channel analyzer 15, so that the subject 2 re-emitted by γ-ray irradiation Γ from
It becomes possible to measure a line (or X-ray) and an electron. The detection signals 9a and 9b stored in the multi-channel analyzer 15 are subjected to arithmetic processing by the personal computer 18 so as to remove the adverse effect on the surface.

As a result, the Mossbauer sensor 1 of this embodiment
The use of 00 makes it possible to measure not only γ-rays (or X-rays) but also electrons that can be detected only at a position very close to the sample re-emitted by γ-ray irradiation. The information on the depth of the subject (sample) differs depending on whether the object to be measured is γ-rays, X-rays, or electrons, so that both can be measured, and the influence of the surface (oxide film, etc.) Removal and internal structure analysis.

The present invention has been described in various ways. In short, the apparatus according to the present invention has a laminated structure in which a reflected X-ray γ-ray detecting sensor is disposed on the back of a reflected electron detecting sensor. The inside of the reflection X-ray γ-ray detection sensor unit is communicated, and one open surface of the reflection electron detection sensor unit is arranged in contact with the subject. Irradiates the subject with γ-rays through the
By detecting the γ-rays of the electrons by the reflected electron detection sensor unit close to the subject, and detecting the X-ray γ-rays by the reflected X-ray γ-ray detection sensor unit, the electron and γ-ray can be measured in one measurement. And X-rays can be obtained at the same time, so that information from different depths (surface layer and inside) of the subject can be obtained at once.

As a result, information on the surface layer can be obtained from the reflected electrons, and more internal information can be obtained from the reflected γ-rays and X-rays. In addition, if arithmetic processing is performed on the reflected γ-ray and X-ray signals and the corrected reflected electron signal, it is possible to obtain internal information that is not affected by an impurity layer (such as an oxide film) on the surface, and perform the surface treatment. Without this, information inside the material can be obtained. It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately modified and implemented without departing from the scope of the invention.

[0037]

As described above, according to the present invention, simultaneous measurement of backscattered electrons, X-rays and γ-rays becomes possible, which makes it possible to reduce the size of the apparatus and the measurement time. Thus, information inside the subject can be obtained regardless of the surface state. Further, since it is only necessary to dispose the sensor in contact with the subject, it is possible to provide a Mossbauer sensor having such a feature that it can be used for nondestructive inspection of a duplex stainless steel structure or the like.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of a Mossbauer sensor for simultaneous detection of reflected electron X-rays and γ-rays according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an overall configuration of a Mossbauer sensor for simultaneous detection of reflected electron X-rays and γ-rays according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a Mossbauer inspection device using the Mossbauer sensor of the present invention.

FIG. 4 is a block diagram showing a configuration of a conventional reflected X-ray detection Mossbauer sensor.

FIG. 5 is a block diagram showing a configuration of a conventional reflected X-ray γ-ray detection Mossbauer sensor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... γ-ray incident from a radiation source 2 ... Subject 3 ... O-ring for sealing 4 ... Sensor body 4A ... Reflection electron detection sensor part 4a ... Groove 5 ... Sensor body 5A ... Reflection gamma
X-ray detection sensor section 5a ... concave section 5b ... gamma ray introduction path 5c ... detection chamber 6 ... reflected electrons 7 ... reflected gamma rays or X-rays 8 ... anode rays 9a ... signals detected from reflected gamma-X rays 9b ... reflected electrons Signal detected from 10: Signal compensation circuit 100: Mossbauer sensor

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seichi Kawaguchi 2-1-1, Shinhama, Arai-machi, Takasago-shi, Hyogo Mitsubishi Heavy Industries, Ltd. Inside Takasago Research Laboratory (72) Inventor Takashi Yamaoka Wakazaki-cho, Hyogo-ku, Kobe-shi, Hyogo 1-1-1 1-1 Inside Kobe Shipyard, Mitsubishi Heavy Industries, Ltd. (56) References JP-A-4-160351 (JP, A) JP-A-64-43747 (JP, A) JP-A-2-131143 (JP, A) JP-A-1-102348 (JP, A) JP-A-59-150333 (JP, A) JP-A-3-24235 (JP, A) JP-B-50-35832 (JP, B1) JP-B-47 5836 (JP, Y1) (58) Field surveyed (Int. Cl. ⁶ , DB name) G01T 1/02 G01N 23/22

Claims (2)

(57) [Claims] 1. An interior having a hollow shape, two opposing surfaces are opened, and an anode wire for electron collection is disposed inside, and one of the opened surfaces is a contact surface with a subject. A backscattered-electron detection sensor section, which is provided on the other open surface side of the backscattered-electron detection sensor section, and has a center toward the one open surface side of the backscattered-electron detection sensor section. A ray introduction path is formed, and a reflected electron X-ray γ-ray detection sensor unit configured to include a detection unit for detecting radiation incident through the reflected electron detection sensor unit inside. Messbauer sensor. 2. The Mossbauer sensor according to claim 1, further comprising a signal compensation circuit for correcting a reflected electron detection signal and a reflected γ-ray X-ray detection signal.