JPS5915843A - Radiation analysis of structure - Google Patents

Abstract

PURPOSE:To detect a diffraction image in high sensitivity and a high resolving degree, by detecting the radiation diffracting rays of a specimen to be detected through light stimulation fluorescent sheet. CONSTITUTION:Laser beam 11 emitted from a laser beam source 10 linearly scans light stimulation fluorescent sheet 5 in a direction shown by an arrow X through a light deflector 12 while the fluorescent sheet 5 is transferred to a direction shown by an arrow Y to carry out auxiliary manipulation and the entire surface of the fluorescent sheet 5 is irradiated with laser beam. Because the fluorescent sheet 5 is preliminarily irradiated with radiation diffracting rays and brought to a light accumulated state, stimulation fluorescent light proportional to the accumulated and recorded energy of radiation is emitted by the irradiation of laser beam 11 and injected into a light detector 15 through a light pervious sheet 14. The output thereof is inputted to a light modulator through an amplifier 16 and laser beam 21 is modulated to be scanned to the direction X through a scanning mirror 23 and a diffraction image is recorded by a photosensitive material moving to the direction Y. By this method, the diffraction image is measured in high sensitivity and a high resolving degree.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radiation structure analysis method, and more particularly to a radiation structure analysis method using a stimulable phosphor sheet.

The test sample is irradiated with radiation such as X-rays or electron beams, and the resulting diffraction image of the test sample is detected using an X-ray photographic film or diffractometer. A radiation structure analysis method is widely used in which the structure of a test sample is analyzed and the structure of the test sample, such as the crystal structure or molecular structure, is determined.

However, X-ray photographic film has economical problems as it requires expensive silver, and X-ray photographic film has low sensitivity, for example when examining microcrystals or gases. In order to obtain a blackening density, long-term exposure for several days is required in some cases.

Such a long exposure not only increases the measurement time (but also changes the photographing conditions during that time, which may cause the problem that a desired diffraction image cannot be obtained).

On the other hand, when a diffractometer is used, the sensitivity is high, but there are problems in that the device is complicated and large, and it also requires a long time to obtain a high-resolution diffraction image.

Japanese Patent Application Laid-Open No. 101575/1986 was an attempt to eliminate the drawbacks of conventional radiation structure analysis methods.
In this issue, the diffraction images obtained by irradiating each sample with radiation are recorded on a thermal phosphor layer made of a thermal phosphor.
Thereafter, the thermal phosphor layer on which the diffraction image etc. has been recorded is heated by a method such as sweeping with infrared rays such as carbon dioxide laser light to emit the diffraction image as thermal fluorescence, and this thermal fluorescence is received by a photodetector. A method of detecting the diffraction image by doing this has been proposed. Since this radiation detection method utilizes a thermal phosphor, it is possible to detect diffraction images with high sensitivity without using silver.

However, in this method, heat is propagated to the thermal phosphor layer other than the heat ray irradiated part due to thermal conduction, so there is a problem that thermal fluorescence is also emitted from the thermal phosphor layer other than the heat ray irradiated part. results in a decrease in resolution. Furthermore, there is a problem in that applying heat to the thermal phosphor layer deteriorates the thermal phosphor layer or the support supporting the thermal phosphor layer.

As described above, the above-mentioned radiation detection device using a thermal phosphor has a very serious problem in practical use.

Therefore, an object of the present invention is to provide a radiation structure analysis method that can solve the problems in the conventional radiation structure analysis method using an X-ray photographic film or diffractometer, and the above-mentioned radiation detection device using a thermal phosphor. It is about providing.

The radiation structure analysis method of the present invention irradiates a test sample with radiation, detects a diffraction image of the test sample obtained by this, and uses the diffraction image of the test sample obtained by this detection. In a radiation structure analysis method for performing structural analysis, a photoluminescent phosphor sheet is irradiated with a diffraction line of the test sample obtained by irradiating the test sample with radiation, and the photoluminescent phosphor sheet is produced. The diffraction image of the test sample is accumulated and recorded, and then the excitation light is scanned over the photoluminescent phosphor sheet to convert the diffraction image into stimulated luminescence light, and this stimulated luminescence light is used for photoelectric conversion. This radiation structure analysis method is characterized in that a diffraction image of each specimen to be examined is detected by reading the diffraction image.

In the present invention, the photoluminescent fluorophore refers to radiation (X-rays, α
rays, β rays, γ rays, electron beams, neutron beams, ultraviolet rays, etc.), it can absorb some of this radiation energy, and then excite it with light energy such as visible light (to raise the temperature). A phosphor that has the property of emitting stimulated luminescence light in an amount corresponding to the amount of stored energy (even if it is not used).

According to the present invention, by using a photoluminescent phosphor sheet, the sheet is hardly heated by irradiation with excitation light such as visible light (the diffraction image is emitted as stimulated luminescence light). Therefore, unlike when a thermal phosphor is used, there is no phenomenon in which stimulated luminescence light is emitted from the phosphor other than the part irradiated with the excitation light due to heat conduction, so a diffraction image with extremely high resolution can be obtained. Furthermore, there is no risk of deterioration of the phosphor sheet when reading a diffraction image.Furthermore, the photoluminescent phosphor sheet does not require expensive materials such as silver salt; , at the time of measurement
Since it can be handled in the same manner as radiographic film, it also has the advantage that conventional structural analysis equipment using radiographic film can be used as is. Many of them have higher sensitivity than thermal phosphors, so they can provide a wide dynamic range with short-time X-ray irradiation, making them advantageous for determining diffraction intensity ratios.

Furthermore, since the diffraction image can be obtained as an electrical signal,
Converting this electrical signal into a digital signal has the advantage that structural analysis calculations can be performed directly using this digital signal.

In addition, the detection of the diffraction image of the test sample in the present invention is specifically performed using the conventionally known Debye-Scherrer method, rotating crystal method,
It is carried out using the vibrating crystal method, the Kossel method, the Weisenberg photography method, the preset method, the Laue photography method, the diffraction microscopy method, etc.

In the present invention, it is preferable that the wavelength region of the excitation light and the wavelength region of the stimulated luminescent light do not overlap in order to improve the S/N, and the excitation light source and the stimulable fluorescent light are selected so as to satisfy such a relationship. It is preferable to choose the body. Specifically, the excitation light wavelength is 450 to 800 nm (especially 500 to 70 nm).
0 nm), and the wavelength of stimulated luminescence light is 300 to 5 Q
It is desirable to set the value to Q nm.

Photostimulable phosphors that satisfy these conditions and have higher sensitivity than thermal phosphors include, for example, rare earth element-activated alkaline earth metal fluorohalide phosphors [specifically, JP-A-Sho et al. It is described in Publication No. 55-12143 (
Ba1-x-y rMg, Cap()FX:
aEu'' (where X is at least one of C1 and Br, X and y are O<x+y≦0.6 and xy\0, and a is 10-6≦a≦5X10''), (Bat-x, Mx) FX: yA- (where M is Mg, Ca, Sr) described in JP-A-55-12145.

at least one of Zn and Cd, X is C1, B
At least one of r and ■, AhaEu, Tb
5Ce,, Tm, Dy, Pr, Ho1Nd,
Minor of Yb and Er (both 1, x Hao≦X
≦0.6, y is 0≦y≦0.2), etc.];
ZnS:Cu described in Publication No. 5-12142
, Pb, Ba0-xA7203:Eu (however, 0
．． 8≦X≦10) Oyohi MO-XS102: A (However, M
r1 is Mg, Ca, 5r1Zn1Cd or Ba, A is Ce, Tb, Eu, Tm1Pb, 'r, 6. B
i or pigeon, and X is 0.5≦X≦2.5);
LnOX described in JP-A-55-12144:
xA- (where Ln is La 1Y, (at least one of 3d and Lu, X is at least one of CI and Br, A is at least one of Ce and Tb, X is O(x ( Among these, rare earth element-activated alkaline earth metal fluorohalide phosphors are preferred, but among them, barium fluorohalides shown as specific examples are particularly bright. It is preferable because it has excellent exhaustive luminescence.

Furthermore, barium fluorohalide phosphor was developed in Japanese Unexamined Patent Publication No. 56
Metal fluoride added as disclosed in Publication No. 2385 and No. 56-2386, or Japanese Patent Application No. 54
- As disclosed in No. 150873 (metal chloride,
Addition of at least one of metal bromide and metal iodide is preferable because stimulated luminescence is further improved.

Furthermore, as disclosed in JP-A-55-163500, the phosphor layer of a photostimulable phosphor sheet prepared using the above-mentioned photostimulable phosphor is colored with a pigment or dye. This improves the sharpness of the finally obtained image, which is preferable.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a schematic diagram showing how a diffraction image of a test sample is photographed using the Laue method.

Radiation 2 such as X-rays and electron beams emitted from a radiation source 1 irradiates a test sample 3 . When the test sample 3 is irradiated with the radiation 2, the test sample 3 emits a diffraction line 4 corresponding to the qualified element.
occurs. This diffraction ray 4 is irradiated onto a photostimulable phosphor sheet 5 comprising a support 5a and a phosphor layer 5b made of a photostimulable phosphor. The phosphor layer 5b of the photostimulable phosphor sheet 5 absorbs the radiation energy of the diffraction line 4, and the diffraction image of the test sample 3 is accumulated and recorded on the photostimulable phosphor sheet. The diffraction image accumulated and recorded on the photostimulable phosphor sheet in this way is read and reproduced in the following manner.

FIG. 2 is a schematic diagram showing an example of a reading and reproducing system for reading and reproducing a diffraction image accumulated and recorded on a photoluminescent phosphor sheet.

Laser light 11 (e.g. 644 nm He-N laser) emitted from a laser light source 10 (e.g. He-Nev laser)
The ev-boo light) is incident on the photostimulable phosphor sheet 5 after being one-dimensionally deflected in the direction of arrow X by a light deflector 12 such as a galvanometer. On the other hand, the phosphor sheet 5 is conveyed in the direction of arrow Y to perform sub-scanning, and as a result, the entire surface of the phosphor sheet 5 is irradiated with laser light. Here, the laser light source 10 is selected so that the wavelength range of the excitation light does not overlap with the wavelength range of the stimulated emission light from the photostimulable phosphor. When the laser beam 11 is irradiated in this way, the phosphor sheet 5 emits stimulated luminescence light whose amount is proportional to the radiation energy stored and recorded.
This emitted light is incident on the condensing means 14. This light collecting means 1
4 may be a light-guiding sheet made of a transparent sheet having, for example, a linear incident surface for stimulated luminescent light and an annular exit surface; They are arranged adjacent to each other so as to face the line, and their exit surfaces are brought into close contact with the light-receiving surface of the photodetector 15, such as the first circle.

The above-mentioned light-condensing sheet is made by processing a transparent thermoplastic resin sheet such as acrylic resin, so that the light incident from the incident surface is transmitted to the exit surface while being totally reflected inside. The stimulated luminescence light from the phosphor sheet 5 is guided through the light guide sheet 14, exits from the exit surface, and is received by the photodetector 15.The preferred shape of the light guide sheet is Materials etc. are according to JP-A-55-87970 and JP-A-56.
It is disclosed in Japanese Patent Application No.-11397. Photodetector 15
Only light in the wavelength range of stimulated luminescence is transmitted through the light-receiving surface of the
A filter is attached that cuts light in the wavelength range of the excitation light, making it possible to detect only stimulated luminescence light. The output 11 − of the photodetector 15 is amplified by the amplifier 16 and then input to the optical modulator 22 . The laser beam 21 is modulated by a light modulator 22 and scanned by a scanning mirror 23 over a photosensitive material 20 such as photographic film in the direction of arrow X. At this time, since the photosensitive material 20 is transported in a direction perpendicular to this scanning direction (arrow Y direction) in synchronization with the scanning, the photosensitive material 20
The diffraction image of the test sample is output and recorded on the top. In this way, by analyzing the obtained diffraction image, the structure of the test sample can be analyzed.

Note that instead of outputting the diffraction image as a visible image as described above, the electrical signal output from the amplifier 16 is converted into a digital value and then input into a computer etc. to directly perform structural analysis calculations. You can also do that.

As explained above in detail, the present invention uses a photoluminescent phosphor sheet to detect diffraction images with high sensitivity and high resolution, and also facilitates structural analysis. It has various advantages such as:

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing how a diffraction image of a test sample is photographed, and Figure 2 is an example of a reading and reproducing system that reads and reproduces diffraction images accumulated and recorded on a photoluminescent phosphor sheet. FIG.

Claims (1)

[Claims] In the radiation structure analysis method, the method of radiation structure analysis involves irradiating the test sample with radiation, detecting the resulting diffraction image of the test sample, and analyzing the structure of the test sample from the diffraction image obtained by this detection. irradiating a photoluminescent phosphor sheet with a diffraction line of the test sample obtained by irradiating the test sample with radiation to accumulate and record a diffraction image of the test sample;
After that, excitation light is scanned over this photoluminescent phosphor sheet,
A radiation structure analysis method characterized in that the diffraction image of the test sample is detected by converting the diffraction image into stimulated luminescence light and photoelectrically reading the stimulated luminescence light.