JPH1064459A - X-ray generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the X-ray generator with a simple constitution, capable of emitting X-rays of a plurality of wavelengths out of a plurality of X-ray radiation windows. SOLUTION: The characteristic X ray for each target element is emitted out of a rotary target 3 formed by Cu, Cr, Fe and Co targets 3cu, 3cr, 3fe and 3co of an X-ray generator so as to be radiated out of X-ray radiation windows 6a and 6b, monochromaters 11a and 11b are set to each angle capable of extracting a desired characteristic X-ray, and the characteristic X-ray of each wavelength is injected into measurement specimens 15a and 15b mounted on goniometers 12a and 12b. The excitement of unwanted characteristic X-rays is blocked by an exciting voltage adjusting circuit, so as to allow a S/N ratio to be enhanced, the characteristic X-ray is selectively injected into the measurement specimens 15a and 15b so as to allow the diffracted X-rays to be detected, and the measurement results of the diffracted X-rays of various kinds of wavelengths are thereby integrated. By this constitution, characteristic measurement by X-ray diffraction with respect to the measurement specimens 15a and 15b, such as an evaluation of a radius vector distribution function and the like thereby can be performed with a simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an X-ray generator used for X-ray analysis of a sample, and more particularly to an X-ray generator for generating X-rays having different wavelengths.

[0002]

2. Description of the Related Art As an effective method for analyzing the characteristics of a sample, an X-ray analysis method using X-rays is widely used.
In this case, an X-ray diffraction method for irradiating a sample with X-rays of a predetermined wavelength, detecting diffracted X-rays from the sample, and measuring the composition and internal crystal structure of the sample will be described as an example. When performing the analysis of the above, the characteristic X-ray of the line focus that is emitted from the Cu target is used in many cases. Often used. Also, when performing analysis of a wide angle range and measuring the radial distribution function for analyzing liquid and amorphous,
An individual measurement is performed using X-rays from Cu, Mo, and Ag targets, and the obtained data is comprehensively determined to evaluate and determine the radial distribution function.

As described above, when analyzing a sample by X-ray diffraction, it is sometimes necessary to use X-rays of different wavelengths. Conventionally, X-rays that generate X-rays of each wavelength have been used. A plurality of tubes are prepared, and X-rays of a desired wavelength are obtained by replacing the X-ray tubes with the X-ray generator. The replacement of the X-ray tube is complicated and time-consuming, and the sample cannot be analyzed efficiently.

In order to solve this problem, Japanese Patent Laid-Open Publication No. Hei 6-2
No. 15710, a plurality of X-ray focal regions made of different metals are provided on a peripheral surface of a target which is driven to rotate around an axis, and a plurality of filaments are arranged opposite to the respective X-ray focal regions. An X-ray generation device provided with a plurality of X-ray extraction windows from which X-rays of each wavelength are emitted from a plurality of X-ray focal regions is disclosed.

[0005]

SUMMARY OF THE INVENTION The aforementioned Japanese Patent Laid-Open No. 6-21 / 1994
According to the X-ray generator disclosed in Japanese Patent No. 5710, X-rays of different wavelengths are emitted from the corresponding X-ray extraction windows,
By using these X-rays, it becomes possible to analyze a plurality of samples with X-rays having different wavelengths. However, if the X-ray generator disclosed in Japanese Patent Application Laid-Open No. 6-215710 attempts to irradiate X-rays of different wavelengths to the same position on the same sample, a plurality of complicated optical systems must be arranged or a plurality of X-rays must be arranged. It is necessary to provide a complicated sample transfer system that can transfer the sample to the line irradiation position with high precision.

SUMMARY OF THE INVENTION The present invention has been made in view of the present situation of this type of X-ray generator as described above.
An object of the present invention is to provide an X-ray generator capable of emitting X-rays of a plurality of wavelengths.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, a filament which emits thermoelectrons and a target which is driven to rotate about an axis are vacuum sealed in a housing. An X-ray generation device, wherein the thermoelectrons are applied to the target, and characteristic X-rays emitted from the target are emitted to the outside from a plurality of X-ray emission windows formed in the housing. The target is configured to emit characteristic X-rays from a plurality of elements.

[0008] Similarly, in order to achieve the above object, the invention according to claim 2 is different from the invention according to claim 1 in that the excitation voltage applied to the filament is changed to change the plurality of characteristic X-rays. It is characterized in that selection means for selecting is provided.

[0009] Similarly, in order to achieve the above object, according to a third aspect of the present invention, in the first or second aspect of the invention, the target comprises a plurality of members of different elements centered on the axis. It is characterized by being formed in individual arrangement.

[0010] Similarly, in order to achieve the above object, the invention according to claim 4 is the invention according to claim 1 or 2, wherein the target is formed of an alloy containing a plurality of elements. It is assumed that.

[0011] Similarly, in order to achieve the above object, the invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the target is a disk centered on the axis. It is characterized by being formed in a shape.

[0012] Similarly, in order to achieve the above object, according to a sixth aspect of the present invention, in the first aspect of the present invention, the target is a cylindrical body centered on the axis. It is characterized by being formed in.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram showing a configuration of a main part of the present embodiment, FIG. 2 is an explanatory diagram showing a configuration of a target of the present embodiment, and FIG. 3 is a diagram showing a configuration of an X-ray diffraction apparatus using the present embodiment. FIG.

In this embodiment, as shown in FIG. 1, a disk-shaped target 3 rotatable about a shaft core 2 and a target 3 are irradiated with thermoelectrons in a vacuum-sealed housing 1. X-ray emission windows 6a and 6b from which characteristic X-rays from the target 3 are extracted are formed on side surfaces of the housing 1 facing each other, and the target 3 is rotated by the housing 1. A motor 7 is attached, and an excitation voltage adjusting circuit 8 that changes an excitation voltage supplied to the filament is connected to the filament 5.

As shown in FIG. 2, the target 3 of the present embodiment has a Cu target 3cu, a Cr target 3cr, a Fe target 3fe, and a Co target 3co formed by dividing a disk into four parts. Are adhered to each other to form a disc shape.

An X-ray diffractometer using the X-ray generator 10 according to the present embodiment, as shown in FIG. 3, has an X-ray radiated from an X-ray radiation window 6a of a housing 1 of the X-ray generator 10. A monochromator 11a using (111) plane of single-crystal Si that separates X-rays of four wavelengths emitted from the X-ray emission window 6a by diffraction angles is disposed in the passage. At the subsequent stage of the monochromator 11a, X-rays of a desired wavelength enter the mounted measurement sample 15a,
A goniometer 12a for reflecting diffracted X-rays is disposed at a reflection angle position corresponding to the lattice constant of a, and an X-ray detector 13a for detecting diffracted X-rays at the reflection angle position is attached to the goniometer 12a. I have. Housing 1
X-rays radiated from the X-ray emission window 6b of the monochromator 11b and the goniometer 12
b and the X-ray detector 13b.

Table 1 shows the Kα rays emitted from the Cu target 3cu, the Cr target 3cr, the Fe target 3fe, and the Co target 3co that constitute the target 3 of the present embodiment. Wavelength (Å)
The minimum excitation voltage (kV) required to excite k-shell electrons and generate kα rays is shown, and the excitation voltage can be adjusted and selected by an excitation voltage adjustment circuit 8 operated by an operator. Has become.

[0018]

[Table 1]

The operation of the present embodiment having such a configuration is described below.
An X-ray diffractometer using the present embodiment is used to measure X
The case of performing line diffraction will be described.

When the measurement samples 15a and 15b are mounted on the goniometers 12a and 12b, respectively, and the excitation voltage adjusting circuit 8 is operated to apply an excitation voltage of 10.0 KV to the filament 5, a Cu target constituting the target 3 is formed. 3cu, Cr target 3cr, Fe target 3fe, and Co target 3co emit characteristic X-rays having wavelengths of 1.54, 2.29, 1.94, and 1.79, respectively. X-rays are emitted from the X-ray emission windows 6a and 6b to the outside of the X-ray generator.

The monochromators 11a and 11b have Si
Since the (111) plane of a single crystal is used, its Brag
The g-angle is 21.46 ° for characteristic X-rays of Cr,
18.05 ° for characteristic X-ray, 16.61 ° for characteristic X-ray of Co, and 1 for characteristic X-ray of Cu.
4.28 °.

Here, when the set angle of the monochromator 11b is adjusted to 21.46 ° and the set angle of the monochromator 11a is adjusted to 14.28 °, the monochromator 11
b, a characteristic X-ray of Cr-Kα is extracted and incident on the measurement sample 15b, and a diffraction line of the characteristic X-ray of Cr-Kα is emitted from the measurement sample 15b. The diffraction line of the characteristic X-ray of Cr-Kα from 15b is detected.

Further, from the monochromator 11a, Cu
The characteristic X-ray of -Kα is extracted and incident on the measurement sample 15a, and a diffraction line of the characteristic X-ray of Cu-Kα is emitted from the measurement sample 15a, and the measurement sample 1 is detected by the X-ray detector 13a.
The characteristic X-ray diffraction line of Cu-Kα from 5a is detected.

In this case, when the set angle of the monochromator 11b is adjusted to 18.05 ° and the set angle of the monochromator 11a is adjusted to 16.61 °, the monochromator 1
1b, the characteristic X-ray of Fe-Kα is extracted and incident on the measurement sample 15b.
The X-ray detector 13b detects the characteristic X-ray diffraction line of Fe-Kα from the measurement sample 15b. Further, characteristic X-rays of Co-Kα are extracted from the monochromator 11a and the measurement sample 15a
From the measurement sample 15a.
The X-ray detector 13a detects the diffraction line of the characteristic X-ray of Co-Kα from the measurement sample 15a.

Further, in the present embodiment, the measurement sample 15
For example, if it is not necessary to detect the characteristic X-ray diffraction line of Cu-Kα for a and 15b, the excitation voltage adjustment circuit 8 is adjusted to increase the excitation voltage applied to the filament 5 to 8.5 KV. When K is set, K-shell electrons of Cu are not excited and Cu-Kα rays are not generated, and X-ray diffraction can be performed with an improved S / N ratio.

As described above, according to the present embodiment, the target 3 cu made of Cu, the target 3 cr made of Cr, the target 3 fe made of Fe,
1.54Å, 2.
Characteristic X-rays having wavelengths of 29 °, 1.94 ° and 1.79 ° are emitted and radiated from the X-ray emission windows 6a and 6b, and the set angles of the monochromators 11a and 11b are extracted to extract the characteristic X-rays having desired wavelengths. By setting the angle to
A characteristic X-ray of a desired wavelength is transmitted to the goniometers 12a and 12b.
Can be made incident on the measurement samples 15a and 15b respectively mounted on the
Excitation of unnecessary characteristic X-rays can be prevented to improve the S / N ratio. For this reason, in the present embodiment, characteristic X-rays of a desired wavelength are selectively incident on the measurement samples 15a and 15b under a measurement condition with a simple configuration and an improved S / N ratio. 15a, 15b to detect the diffracted X-rays of the characteristic X-rays of the desired wavelength, comprehensively determine the measurement results of individual diffracted X-rays for the X-rays of various wavelengths, and evaluate the radial distribution function. Various characteristics can be measured on the measurement sample by X-ray diffraction.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIG. FIG. 4 is an explanatory diagram showing the configuration of the target of the present embodiment.

In this embodiment, as shown in FIG. 4, the target 20 is a Cu target 20cu, a Cr target 20cr, an Fe target 20fe, and a Co target 20co each having a shape obtained by dividing a cylindrical body into four parts. The target 20 is driven to rotate about an axis, and a filament 21 is provided to face the peripheral surface of the target 20. The configuration of the other parts of the present embodiment is the same as that of the first embodiment already described, and therefore, will not be described repeatedly.

In this embodiment, the peripheral surface of the target 20 rotating about the axis is irradiated with thermoelectrons from the filament 21 to produce a Cu target 3cu, a Cr target 3cr, and a Fe target 3fe. , Co target 3co, 1.54Å, 2.29 respectively
Characteristic X-rays with wavelengths of {1.94} and 1.79} are emitted and emitted through X-ray emission windows 6a and 6b, and the same operation as in the first embodiment described above is performed.

In particular, according to the present embodiment, in addition to the effects obtained in the first embodiment, the surface area of the target 20 is set large to improve the intensity of the emitted X-rays. Becomes possible.

Third Embodiment A third embodiment of the present invention will be described with reference to FIG. FIG. 5 is an explanatory diagram illustrating the configuration of the target according to the present embodiment.

In this embodiment, as shown in FIG. 5, in the configuration based on the first embodiment or the second embodiment already described, the target is formed of an alloy. It is a feature. That is, FIG.
Shows a configuration of a target 3A of the present embodiment based on the first embodiment already described. In the present embodiment, a disk-shaped target 3A is made of Cu-Al.
Alloy target 3Aa, Fe-Co alloy target 3A
b, composed of an Au-Pt alloy target 2Ac.

The structure of the other parts of the present embodiment shown in FIG. 5A is the same as that of the first embodiment already described, and will not be described again. Also, FIG.
This shows a configuration of a target 20A of the present embodiment based on the second embodiment already described. In this embodiment, the target 20A of a cylindrical body is made of Cu-Al.
Alloy target 20Aa, Fe-Co alloy target 2
It is composed of 0Ab and an Au-Pt alloy target 20Ac. The configuration of the other parts of the present embodiment shown in FIG. 5B is the same as that of the second embodiment already described, and will not be described again.

In this embodiment having such a configuration, FIG.
The target having the target 3A having the configuration shown in FIG.
By emitting characteristic X-rays of u, Al, Fe, Co, Au, and Pt, the same operation as in the first embodiment is performed, and FIG.
Those having the target 20A having the configuration shown in FIG.
Emit characteristic X-rays of Al, Fe, Co, Au and Pt,
An operation similar to that of the second embodiment is performed.

Further, in the present embodiment, the target having the target 3A having the configuration shown in FIG. 5A has the effect obtained in the first embodiment, and the target 20A having the configuration shown in FIG. Has the effects obtained in the second embodiment. In addition to these effects, according to the present embodiment, it is possible to radiate various types of characteristic X-rays in a miniaturized configuration. Becomes possible.

[0036]

According to the first aspect of the present invention, the filament for emitting thermoelectrons is driven to rotate about the axis,
A target configured to emit characteristic X-rays from a plurality of elements is held in a vacuum sealed state in a housing, and the target is irradiated with thermoelectrons, and characteristic X-rays emitted from the target are formed in the housing. Since the plurality of X-ray emission windows are radiated to the outside, X-ray analysis of a plurality of samples is efficiently performed simultaneously using a plurality of characteristic X-rays having different wavelengths in a state where the whole is miniaturized. It becomes possible.

According to the second aspect of the present invention, in addition to the effect obtained by the first aspect of the present invention, the selection means
By changing the excitation voltage applied to the filament, a plurality of characteristic X-rays can be selected and emitted, and X-ray analysis of the sample can be performed with an improved S / N ratio.

According to the third aspect of the present invention, the target is constituted by arranging a plurality of members of different elements around the axis, thereby realizing the effect obtained by the first or second aspect of the present invention. It becomes possible.

According to the fourth aspect of the present invention, the target is formed of an alloy containing a plurality of elements, thereby realizing the effects obtained by the first or second aspect of the present invention. It becomes possible to emit various types of characteristic X-rays.

According to the fifth aspect of the present invention, in addition to the effects obtained by the first aspect of the present invention, the target is formed in a disk shape about the axis. Therefore, it is possible to further reduce the overall size.

According to the sixth aspect of the present invention, in addition to the effects obtained by the first aspect of the present invention, the target is formed in a cylindrical body centered on the axis. Therefore, it is possible to increase the surface area of the target and increase the intensity of X-rays.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a main part of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a configuration of a target according to the embodiment.

FIG. 3 is an explanatory diagram showing a configuration of an X-ray diffraction device using the embodiment.

FIG. 4 is an explanatory diagram showing a configuration of a target according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a configuration of a target according to a third embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 housing 3 target 3cu Cu target 3cr Cr target 3fe Fe target 3co Co target 3Aa Cu-Al alloy target 3Ab Fe-Co alloy target 3Ac AU-At alloy target 5 Filament 6a, 6b X-ray emission window 8 Excitation voltage adjustment circuit 10 X Line generator 11a, 11b Monochromator 12a, 12b Goniometer 13a, 13b X-ray detector 15a, 15b Measurement sample 20 Target 20cu Cu target 20cr Cr target 20fe Fe target 20co Co target 20Aa Cu-Al alloy target 20Ab Fe-Co alloy target 20Ac AU-At alloy target

Claims (6)

[Claims] 1. A filament that emits thermoelectrons and a target that is driven to rotate about an axis are held in a vacuum sealed state in a housing, and the thermoelectrons are irradiated to the target and emitted from the target. Characteristic X-rays are emitted to the outside from a plurality of X-ray emission windows formed in the housing.
An X-ray generator, wherein the target is configured to emit characteristic X-rays from a plurality of elements. 2. The X-ray generator according to claim 1,
An X-ray generation apparatus comprising: a selection unit that changes an excitation voltage applied to the filament to select the plurality of characteristic X-rays. 3. The X-ray generator according to claim 1, wherein the target is formed by arranging a plurality of members of different elements in a row around the axis. X-ray generator. 4. The X-ray generator according to claim 1, wherein said target is formed of an alloy containing a plurality of elements. 5. The X-ray generator according to claim 1, wherein said target is formed in a disk shape centered on said axis. Generator. 6. The X-ray generator according to claim 1, wherein said target is formed in a cylindrical body centered on said axis. apparatus.