JP3160135B2 - X-ray analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray analyzer for analyzing a sample based on X-ray fluorescence and X-ray diffraction from the sample.

[0002]

2. Description of the Related Art X-ray fluorescence analyzers and X-ray diffraction analyzers are both types of X-ray analyzers. An X-ray fluorescence spectrometer irradiates a sample with excitation X-rays and excites the atoms of the sample, thereby detecting X-rays specific to the elements contained in the sample and analyzing the composition and thickness of the sample. It is a device that performs. On the other hand, an X-ray diffraction analyzer is an apparatus that irradiates a sample with X-rays and detects a diffracted X-ray diffracted by a crystal structure (lattice) of the sample, thereby analyzing a crystal structure of the sample.

[0003]

Generally, when analyzing a sample, only one of the composition and the crystal structure of the sample is often analyzed, and both the composition and the crystal structure are rarely analyzed. However, it is necessary to know both the composition and the crystal structure of a clinker or the like as a raw material for cement in terms of quality control. Therefore, it is significant that one X-ray analyzer can perform X-ray fluorescence analysis and X-ray diffraction analysis.

However, conventionally, two types of analysis have not been performed by one apparatus for the reasons described below. The X-ray diffraction condition is given by the following Bragg equation. 2d sin θ = nλ d: plane spacing of crystal θ: diffraction angle λ: wavelength of diffracted X-ray n: order of reflection (1, 2, 3,...) Where the plane spacing d of CaO crystal in the clinker is , 2.40
56 °, and the wavelength λ of the X-ray B1 to be used is 1.5418 ° (Cu
Kα ray), the diffraction angle θ is 18.69 °. Therefore, as shown in FIG. 3A, when performing reflection X-ray diffraction, the incident angle α (α = θ) to the sample 1 is set to a relatively small angle.

On the other hand, as shown in FIG. 3 (b), in the X-ray fluorescence analyzer, the intensity of the excitation X-ray B1 applied to the sample 1 is increased to increase the intensity of the X-ray fluorescence B2.
The incident angle α of the excitation X-ray B1 is set to a large angle of about 90 °.

As described above, in X-ray diffraction and X-ray fluorescence analysis, since the incident angle α of the X-ray B1 incident on the sample 1 is greatly different, two types of analysis are performed by one apparatus. Absent.

As shown in FIG. 3C, it is conceivable to increase the incident angle α in X-ray diffraction. However, this results in transmission type X-ray diffraction in which the diffracted X-ray B3 is extracted to the surface of the sample 1. On the other hand, the thickness of the sample 1 is generally about 2 mm to 3 mm.
3 cannot be taken out, so that the incident angle α cannot be increased.

The present invention has been made in view of the above problems, and has as its object to provide an X-ray analyzer capable of performing both X-ray fluorescence analysis and X-ray diffraction analysis with a single device.

[0009]

In order to achieve the above object, the present invention provides a method for producing an X-ray in a vacuum atmosphere or a rare gas atmosphere.
An X-ray analyzer that passes through the atmosphere,
Instead of an irradiation device consisting of an X-ray tube and a filter device.
Have. The above X-ray tube uses rhodium as the target material.
X-rays including a plurality of types of characteristic X-rays having different wavelengths from each other
Is emitted. The filter device includes a transmission window, a collimator
And have multiple filters, any of them above
It faces the emission window of the X-ray tube. Here, the plurality of files
Ruta contains different elements, and X
Characteristic X-rays that are excited by X-rays and have a longer wavelength than RhLα rays
generate. And this device is X
Of X-rays emitted from the sample
The first spectral element and the first spectral element
A fluorescent X-ray detector for detecting the fluorescent X-rays.
Further, among the characteristic X-rays emitted from the X-ray tube, RhL
α ray or RhLα ray generated from the above filter
A second spectral element for dispersing characteristic X-rays having a long wavelength and diffracted and reflected by the sample, and a diffracting X-ray for detecting characteristic X-rays disperse by the second spectral element; A line detector.

[0010]

According to the present invention, characteristic X-rays emitted from an X-ray tube
RhL rays generated from the filter or RhL
Since X-ray diffraction analysis is performed using characteristic X-rays having a longer wavelength than α-rays , the diffraction angle increases. Therefore, even if X-rays are incident on the sample at a large incident angle, diffracted X-rays can be extracted from the surface of the sample.

[0011]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, a sample 1 is a clinker of a cement raw material and contains polycrystals of CaO. X-ray analyzer, X-rays tube (configuration irradiation device with the following filter device
And formed to) 3, a filter unit 2, the first and second spectral element 4A, and 4B, the first and second measuring device 5A, 5
B is provided.

The filter device 2 is provided near the exit window of the X-ray tube 3, and includes a plurality of filters 2a and 2b, a transmission window 21, and a collimator 20, as shown in FIG. Each of the filters 2a and 2b, the transmission window 21, and the collimator 20 are rotated around the zero point and inserted into the optical path of the excitation X-ray B1 in FIG. Each of the above filters 2a, 2
b (FIG. 2) contains elements different from each other,
It is used at the time of X-ray analysis and absorbs a component of a predetermined wavelength serving as a background in the X-ray B1. On the other hand, the collimator 20 (FIG. 2) converts the X-ray B1 into parallel light to reduce the spread of the angle of the X-ray B1 incident on the sample 1. First and second measuring instruments 5A, 5
B includes a fluorescent X-ray detector 8A and a diffracted X-ray detector 8B, and first and second counting circuit units 9A and 9B, respectively.

The X-ray tube 3 is provided so as to face the surface of the sample 1. The X-ray tube 3 uses, for example, rhodium Rh as a target material, and emits X-rays B1 including a plurality of types of characteristic X-rays having different wavelengths such as RhKα rays, RhKβ rays, and RhLα rays. In the sample 1 which has received the X-ray B1, the atoms are excited to generate the fluorescent X-ray B2 unique to the element contained in the sample 1, and the Ca 1
A part of the X-ray B1 is diffracted as a diffracted X-ray B3 by the polycrystal of O.

The two spectroscopic elements 4A and 4B and the X-ray detectors 8A and 8B are housed in a spectroscopic chamber maintained in a vacuum atmosphere or an atmosphere of a rare gas such as helium. B2, B21, and B3 pass through such an atmosphere. Although not shown, a plurality of first spectral elements 4A are provided, and the fluorescent X-rays B
2 and the X-ray diffraction B3, the fluorescent X-ray B21 of the element to be measured is separated. On the other hand, the second spectral element 4B
Is a characteristic X-ray having a longer wavelength, RhLα ray (diffraction X-ray B
3) Disperse the light. These first and second spectral elements 4
X-ray fluorescence B21 and X-ray diffraction B separated by A and 4B
3 are first and second X-ray detectors 8A and 8A, respectively.
B is incident. The extraction angle β of the diffracted X-ray B3 (RhLα ray) is 2θ (145) calculated from the lattice spacing d of the polycrystal of CaO to be measured and the wavelength of the diffracted X-ray B3 to be detected according to the Bragg equation. .69 °). For example, if the incident angle α of the X-ray B1 is 90
°, the extraction angle β becomes 55.69 °.

The first and second X-ray detectors 8A, 8A
B represents the incident fluorescent X-ray B21 and the diffracted X-ray, respectively.
Line B3 (RhLα line) is detected, and detection outputs e1, e2
To the first and second counting circuits 9A and 9B. The first and second counting circuit sections 9A and 9B count the detection outputs e1 and e2, respectively, and measure the intensities of the fluorescent X-ray B21 and the diffracted X-ray B3 (RhLα ray) as measurement signals x1 and x.
2 and is output to the first and second computing units 6A and 6B. The first and second computing units 6A and 6B are respectively
Upon receiving the measurement signals x1 and x2, based on the measurement intensities of the fluorescent X-ray B21 and the diffracted X-ray B3 (RhLα ray),
The concentration of the element in the sample and the crystal state of CaO are determined.

Next, an analysis method will be described. First, when performing X-ray fluorescence analysis, the filters 2a and 2a of FIG.
2b or the transmission window 21 is selected to face the emission window of the X-ray tube 3 in FIG. Subsequently, the sample 1 is irradiated with X-rays B1 having spread from the X-ray tube 3 as excitation X-rays. X-ray B
In the sample 1 receiving the sample 1, the atoms are excited by the RhKα ray, the RhKβ ray, or the like, and the fluorescent X-ray B2 unique to the element is generated. The fluorescent X-ray B2 is diffracted by the first spectral element 4A into the fluorescent X-ray B21 having the wavelength to be measured, detected by the fluorescent X-ray detector 8A, and subjected to a well-known fluorescent X-ray analysis.
Thus, the composition of the sample 1 is analyzed.

Next, when performing X-ray diffraction analysis, FIG.
Of the X-ray tube 3 of FIG. 1 is selected. Subsequently, the collimator 20 is moved from the X-ray tube 3 to the collimator 20.
Irradiates the sample 1 with parallel X-rays B1. X-ray B1
The sample 1 which has received X-ray fluorescence B2,
The X-ray B1 is diffracted in various directions by the crystal lattice included in the sample 1. Since 2θ is set to a predetermined angle, the characteristic X-ray of a predetermined wavelength (for example, RhLα ray) in relation to the lattice of the crystal contained in the sample 1 is set as the diffraction X-ray B3.
Only goes to the second spectral element 4B. The second spectroscopic element 4 </ b> B, among the incident fluorescent X-rays B <b> 2 and diffracted X-rays B <b> 3, diffracted X-rays (RhLα rays) B according to Bragg's equation.
Disperse only 3 The separated RhLα ray B3 is detected by the diffraction X-ray detector 8B, and a known X-ray diffraction analysis is performed. Thereby, the crystal structure of Sample 1 can be known.

As described above, the X-ray analyzer separates the RhLα ray, which is a characteristic X-ray having a long wavelength, from the X-ray B1 emitted from the X-ray tube 3 by the second spectral element 4B. As can be seen from the Bragg equation, 2θ increases. Therefore, even if the incident angle α of the X-ray B1 from the X-ray tube 3 is large, the diffracted X-ray B3 (RhLα ray) can be taken out on the surface side of the sample 1. Therefore, the X-ray tube 3
X-ray diffraction analysis can be performed by using a fluorescent X-ray analyzer that faces the sample 1.

Incidentally, X-rays having a long wavelength such as RhLα-rays are absorbed by air or the like. Therefore,
In the case of an X-ray diffraction apparatus that performs analysis in the atmosphere, it is not possible to perform X-ray diffraction analysis using long-wavelength X-rays such as RhLα rays. On the other hand, since this X-ray analyzer uses a general fluorescent X-ray analyzer, the X-ray B
Since 1, B2 and B3 pass in a vacuum atmosphere or a rare gas atmosphere, there is no possibility that even long-wavelength RhLα rays will be absorbed. Therefore, X-ray diffraction analysis can be performed using characteristic X-rays having a long wavelength included in the X-ray B1.

In the above-described embodiment, the collimator 20 is provided in the filter device 2 shown in FIG. 2, and the X-ray fluorescence analysis and the X-ray diffraction analysis are performed separately.
There is no need to use . For example, when the accuracy with respect to X-ray diffraction may be low, the X-ray B
It is not necessary for 1 to be a parallel light, in this case the filter 2
The X-ray fluorescence analysis and the X-ray diffraction analysis can be performed simultaneously by using the transmission window 21a or 2b.

In the above embodiment, the characteristic X having a long wavelength is used.
Although the RhLa ray generated from the X-ray tube 3 in FIG. 1 is used as the line, it is not always necessary to use the characteristic X-ray generated from the X-ray tube 3. For example, the fluorescent X-rays generated by exciting the atoms of the filters 2a and 2b in FIG. 2 with the X-rays B1 from the X-ray tube 3, and the L-rays from the X-ray tube 3, ie, Rh
The X-ray diffraction analysis may be performed using a characteristic X-ray having a longer wavelength than the Lα ray , for example, an L-line of zirconium .

[0022]

As described above, according to the present invention, among the characteristic X-rays emitted from the X-ray tube, RhLα ray or
Is a characteristic having a longer wavelength than the RhLα ray generated from the filter.
Since the X-ray diffraction analysis is performed using the neutral X-ray, the diffraction angle is increased. Therefore, even if X-rays are incident on the sample at a large incident angle, diffracted X-rays can be extracted from the surface of the sample. Therefore, X-ray diffraction analysis can be performed using a fluorescent X-ray analyzer that makes excited X-rays incident on a sample at a large incident angle.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an X-ray analyzer showing one embodiment of the present invention.

FIG. 2 is a perspective view of a filter device.

FIG. 3 is a front view showing a relationship between an incident angle and an extraction angle of X-rays.

[Explanation of symbols]

1 ... Sample, 3 ... X-ray tube, 4A ... First spectroscopic element, 4B ...
Second spectral element, 8A: X-ray fluorescence detector, 8B: X-ray diffraction
X-ray detector B1, X2, B2, B21 X-ray fluorescence, B3
... X-ray diffraction.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-213836 (JP, A) JP-A-3-206951 (JP, A) JP-A-61-88128 (JP, A) JP-A-58-58 77645 (JP, A) Japanese Patent Publication No. 54-6910 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 23/223 G01N 23/20-23/207 JICST file (JOIS)

Claims (1)

(57) [Claims] An X-ray is irradiated in a vacuum atmosphere or a rare gas atmosphere.
An X-ray analyzer for passing in the air, comprising rhodium as a target material and a plurality of wavelengths different from each other.
An X-ray tube that emits X-rays containing various types of characteristic X-rays, and an X-ray tube containing different elements and excited by X-rays from the X-ray tube
To generate characteristic X-rays having a longer wavelength than RhLα rays.
Multiple filters, transmission windows and collimators
One of them is opposed to the emission window of the X-ray tube.
An irradiation device consisting of a filter device and the above X-ray tube and filter device
A first spectroscopic element for dispersing fluorescent X-rays generated from the sample by being irradiated with X-rays, a fluorescent X-ray detector for detecting fluorescent X-rays disperse by the first spectral element, and the X-ray Of the characteristic X-rays emitted from the tube,
Is longer than the wavelength of RhLα ray generated from the filter.
A second spectroscopic element for dispersing characteristic X-rays diffracted and reflected by the sample, and a diffracted X-ray detection for detecting characteristic X-rays disperse by the second spectral element X-ray analysis apparatus provided with an analyzer.