JP2002168810A - X-ray diffraction apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable detection for diffraction X rays as well appearing in a higher angle region as in the measurement of the stress of a sample in the X-ray diffraction apparatus using a curved PSPC(Position Sensitive Proportional Counter). SOLUTION: The curved PSPC 20 is arranged to be so positioned that a virtual plane containing a circular arc-like core line 22 built therein 20 shifts parallel from the optical axis O of X rays R made to irradiate a sample S through a collimator 10. This enables the arranging of one end 22a of the core line 22 built in the curved PSPC 20 at a position that allows the detection of diffraction X rays generated from the sample to a higher angle region extending to 180 deg. in the angle of diffraction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray having a structure in which a minute portion of a sample or a minute sample is irradiated with X-rays, and a diffracted X-ray generated from the sample is detected by a so-called curved position-sensitive X-ray detector. The present invention relates to a line diffraction device.

[0002]

2. Description of the Related Art An X-ray diffractometer constructed for the purpose of X-ray diffraction measurement of a minute part of a sample or a minute sample is known. (MDG) (see, for example, JP-A-2000-146871).

FIG. 6 is a perspective view schematically showing a configuration example of a conventional minute part X-ray diffraction apparatus. X-ray collimator 1
The sample S is formed into a thin wire bundle passing through a thin metal tube designated as No. 0.
Is irradiated to the microscopic part of. In addition, the micro X-ray diffraction device
A mechanism for swinging the sample S around an ω axis orthogonal to the optical axis O of the incident X-ray R and around a χ axis that is coaxial with the optical axis O of the incident X-ray R, and a mechanism around the φ axis perpendicular to the sample surface. And a mechanism for in-plane rotation of the sample S.
By swinging and in-plane rotation of, the direction distribution of the crystal lattice plane of the crystal grain with respect to the incident X-ray is disordered, and the number of crystal grains contributing to diffraction is increased as much as possible. In addition,
The three axes of the ω axis, χ axis, and φ axis intersect at the X-ray irradiation point of the sample S.

[0004] Around the sample S, a position-sensitive X-ray detector (PSPC: Position Sensitive Proportional Coun- ter) which is curved in an arc centering on the X-ray irradiation point of the sample S is provided.
ter) 20 are arranged.

FIG. 7 shows a position-sensitive X-ray detector (hereinafter, referred to as a position-sensitive X-ray detector).
FIG. 3 is a diagram illustrating a schematic structure of a “curved PSPC”. As shown in the figure, the curved PSPC 20 has a core wire 22 bent and stretched inside a main body 21 curved in an arc shape. The core wire 22 is insulated from the main body 21 via a spacer (not shown), and a constant voltage (for example, 2000 to 3000 V) is applied between the core wire 22 and the main body 21.
Is applied. Further, an excitation gas is sealed in the internal space of the main body 21. In addition, X
An X-ray transmission window 23 made of a material such as beryllium (Be) that transmits light is provided.

When X-rays enter the main body 21 through the X-ray transmission window 23, the excited gas in the X-ray incident portion in the internal space of the main body 21 is ionized, and an electron avalanche is generated therearound. As a result, an electric pulse is generated on the core wire 22, and the electric pulse is transmitted to both ends 22 a and 22 b of the core wire 22. At this time, the incident position of the X-ray can be known from the time difference between the electric pulses detected at both ends 22a and 22b of the core wire 22.

[0007]

In the conventional X-ray diffractometer (micro X-ray diffractometer) described above, a curved PSP is used.
A virtual plane including the core line 22 of C20 and a virtual plane including the optical axis O of the X-ray R irradiated on the sample S are set on the same plane. And in such an arrangement structure,
The collimator 10 for irradiating the sample S with the X-rays R generated from the X-ray source into a thin flux is a core wire 2 of the curved PSPC 20.
2 will be arranged in a virtual plane including 2.

Therefore, as shown in FIG.
A certain gap had to be provided between the one end 21a of the main body 21 of the PC 20 and the collimator 10. Further, as shown in FIG. 7A, one end 22a of the core wire 22 in the curved PSPC 20 is arranged inside the one end 21a of the main body 21 in order to maintain an insulated state with the main body 21. As a result, one end 22a of the core wire 22 is arranged at a position separated by a certain distance e from the optical axis O of the incident X-ray R (see FIG. 8), and this distance e becomes a blind spot. In other words, the measurement range of the diffraction X-rays by the curved PSPC 20 is around 2θmax = 160 ° as the limit on the high angle side.

In ordinary X-ray diffraction measurement, since high-intensity diffracted X-rays appear in a low angle region, there is no problem in the measurement even with the above configuration. But,
In the stress measurement of a sample, the strain sensitivity increases as the diffraction X-ray appears at a higher angle. For example, in a steel material, stress measurement is generally performed using diffraction X-rays that appear at a diffraction angle of about 2θ = 156 ° with respect to the incidence of CrKα rays. The larger the amount, the higher the angle. Moreover, the half width of the peak profile of the diffracted X-ray is as wide as 4 ° to 6 °, and it is not unusual that the diffraction angle 2θ at the base greatly exceeds 160 °. Therefore, the conventional X-ray diffractometer having the above configuration cannot measure the profile of the diffracted X-ray appearing in such a high-angle region in a perfect form.

The present invention has been made in view of the above circumstances, and has as its object to detect a diffracted X-ray appearing in a high-angle region as in the measurement of stress on a sample.

[0011]

In order to achieve the above object, the invention according to claim 1 comprises a collimator for irradiating a minute part of a sample or a minute sample with X-rays and a core wire stretched in an arc shape. An X-ray detector comprising a position-sensitive X-ray detector, wherein the position-sensitive X-ray detector is arranged in an arc around the sample.
In the X-ray diffraction apparatus, a virtual plane including an arc-shaped core built in the position-sensitive X-ray detector is shifted parallel to an optical axis of the X-ray irradiated to the sample through the collimator. A position-sensitive X-ray detector is arranged.

By arranging the position-sensitive X-ray detector in this manner, one end of the X-ray detector can diffract a diffracted X-ray generated from the sample at a diffraction angle of 18 without interfering with the collimator.
It is possible to arrange one end of the core wire built in the position-sensitive X-ray detector at a position where detection is possible up to a high-angle region reaching 0 ° (claim 2). As a result, the present invention can be applied to, for example, stress measurement of a sample in which a peak profile of a diffracted X-ray appears in a high-angle region, and the use is expanded.

According to a third aspect of the present invention, there is provided a collimator for irradiating a minute portion of a sample or a minute sample with X-rays, and a position-sensitive X-ray detector incorporating a core wire stretched in an arc shape. In an X-ray diffraction apparatus in which the position-sensitive X-ray detector is arranged in an arc around a sample, the position-sensitive X-ray detector is positioned on the position-sensitive X-ray detector with respect to the optical axis of the X-ray irradiated on the sample through a collimator. A position-sensitive X-ray detector is arranged so that virtual planes including a built-in arc-shaped core line intersect.

According to the arrangement of the position-sensitive X-ray detector, diffracted X-rays generated from the sample can be obtained without causing one end of the position-sensitive X-ray detector to interfere with the collimator. Of the core wire built into the position-sensitive X-ray detector can be arranged at a position where the angle can be detected up to a high-angle region up to a diffraction angle of 180 ° (claim 4).

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view showing a first embodiment of the X-ray diffraction apparatus according to the present invention. The X-ray diffractometer shown in FIG.
G), which coincides with the optical axis O of the X-ray R.
An axis is taken, and a χ rotating device 31 is arranged on the χ axis. The χ rotating device 31 drives the χ arm 32 to rotate about the χ axis. χ Arm 32 is ω rotation device 33
And the ω rotation device 33 has ω about the ω axis.
The arm 34 is driven to rotate. The ω axis is the χ axis, that is, the axis orthogonal to the optical axis O of the incident X-ray R.

The .omega. Arm 34 supports a .phi. Rotating device 35, and the .phi. Rotating device 35 rotationally drives the sample S about the .phi. Axis, that is, in-plane rotation. φ axis is incident X
The axis includes the optical axis O of the line R, is included in a plane orthogonal to the ω axis, and further passes through the intersection of the ω axis and the χ axis.
The sample S is arranged at the X-ray R irradiation position by being arranged at the intersection of each of the χ axis, the ω axis, and the φ axis.

A curved PSPC 20 as an X-ray detector is arranged around the sample S. This curved PSPC2
0 is a main body 21 curved in an arc shape as shown in FIG.
A core wire 22 is also stretched inside the main body 21 along the arcuate curved line. When X-rays enter the main body 21, the core wire 22 is caused by an electron avalanche accompanying the ionization of the excitation gas sealed in the main body 21. Is detected at both ends 22a and 22b of the core wire 22, and the X-ray incident position can be measured based on the detection time difference.

In the present embodiment, as shown in FIG. 2B, X irradiating the sample S through the collimator 10 is used.
The curved PSPC 20 is arranged so that the virtual plane Ha including the arc-shaped core wire 22 built in the curved PSPC 20 is shifted parallel to the optical axis O of the line R. Specifically, the main body 21 of the curved PSPC 20 is
It is arranged so as to be shifted in parallel so as to be separated from. With such an arrangement, the main body 2 of the curved PSPC 20 is formed.
One end 22a of the core wire 22 incorporated in the collimator 10
2 and can be arranged on or below the virtual plane Hb including the sample surface (see FIG. 2C).

As a result, as shown in FIG. 2A, the curved PSPC 20 can detect the diffracted X-rays generated from the sample S even in the high angle region (around 180 °) of the diffraction angle 2θ. As a result, the diffraction angle 2
A profile of a diffracted X-ray appearing in a high-angle region exceeding θ = 160 ° can also be detected in a perfect form.

Here, as shown in FIG.
Numeral 20 detects the diffracted X-ray at a position shifted from the Debye ring D of the diffracted X-ray generated from the sample S in parallel with the virtual plane Ho cutting the center axis. The shift amount d is equal to the distance away from the optical axis O of the X-ray R irradiated on the sample S. If the diffracted X-ray is detected at such a shifted position with respect to the Debye ring D of the diffracted X-ray generated from the sample S, an error is strictly included. But,
The error caused by the change in the arrangement of the extent to avoid the interference with the collimator 10 (specifically, about the radius of the collimator) is very small and has a very small practical effect. Moreover, the sample S
Is a method of calculating the relative rate of change of the lattice spacing between crystal orientations obtained from the peak profile of the diffracted X-rays. Therefore, the error due to the deviation from the Debye ring as described above is ignored. can do.

Next, a second embodiment of the X-ray diffraction apparatus according to the present invention will be described with reference to FIGS. The X-ray diffractometer of the present embodiment is also a minute portion X-ray diffractometer similar to the device according to the first embodiment described above.
And a collimator 10 for irradiating a thin beam of X-rays to the sample, and a curved PSPC 20 for detecting diffracted X-rays generated in the sample S.

In this embodiment, the collimator 10
With respect to the optical axis O of the X-ray R radiated to the sample S through
The curved PSPC 20 is arranged so that the virtual planes Ha including the arc-shaped core wires 22 built in the curved PSPC 20 intersect, and one end 22a of the core wire 22 built in the curved PSPC 20 is placed on or below the virtual plane Hb including the sample surface. (See FIG. 5).

Even with such a configuration, the curved PSPC 20 can detect the diffracted X-rays generated from the sample S in the high angle region (around 180 °) of the diffraction angle 2θ. As a result, for example, in the stress measurement of the sample S, the diffraction angle 2θ =
A diffraction X-ray profile appearing in a high-angle region exceeding 160 ° can also be detected in a perfect form.

In the present embodiment, the curved PSPC
Numeral 20 detects a diffracted X-ray at a position inclined with respect to a virtual plane that cuts the central axis of the Debye ring of the diffracted X-ray generated from the sample S. Even when the diffracted X-rays are detected at such an inclined position with respect to the Debye ring of the diffracted X-rays generated from the sample S, the error is strictly included as in the first embodiment. . However, an error resulting from a change in the arrangement of such a degree as to avoid interference with the collimator 10 (specifically, about the radius of the collimator) is very small.
The effect on practical use is extremely small. In addition, the stress measurement of the sample S is a method of obtaining the relative rate of change of the lattice spacing between the crystal orientations obtained from the peak profile of the diffracted X-rays. The error can be ignored.

It should be noted that the present invention is not limited to the above-described embodiment, but can be applied to, for example, various minute portion X-ray diffractometers other than the entire structure as shown in FIGS.
It is possible to widen the measurement region (particularly, the measurement region on the high angle side) of the diffracted X-ray while avoiding the interference between the collimator and the curved PSPC.

[0026]

As described above, according to the present invention,
Without interfering one end of the curved PSPC with the collimator,
One end of the core wire built into the position-sensitive X-ray detector can be arranged at a position where a diffracted X-ray generated from the sample can be detected up to a high angle region having a diffraction angle of 180 °. As a result, the present invention can be applied to, for example, stress measurement of a sample in which a peak profile of a diffracted X-ray appears in a high-angle region, and the use is expanded.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of an X-ray diffraction apparatus according to the present invention.

2A is a simplified front view of the X-ray diffraction apparatus shown in FIG. 1, FIG. 2B is a side view thereof, and FIG. 2C is an enlarged view of one end of a curved PSPC incorporated in the apparatus. FIG.

FIG. 3 is a side view for explaining a positional relationship between the curved PSPC shown in FIG. 1 and a Debye ring of diffracted X-rays generated from a sample.

FIG. 4 is a perspective view showing a second embodiment of the X-ray diffraction apparatus according to the present invention.

5 is a simplified side view showing the X-ray diffraction device shown in FIG.

FIG. 6 is a simplified perspective view showing a configuration example of a conventional minute part diffracted X-ray.

7A is a front sectional view showing a structure of a curved PSPC, and FIG. 7B is a bottom view of the same.

FIG. 8 is a front view of the conventional minute part diffraction X-ray shown in FIG.

[Explanation of symbols]

 10: Collimator 20: Curved PSPC 21: Main body 21a: One end of main body 22: Core wire 22a: One end of core wire 23: X-ray transmission window 31: χ rotating device 32: χ arm 33: ω rotating device 34: ω arm 35: φ rotation device

Claims (4)

[Claims] 1. A position-sensitive X-ray detector comprising: a collimator for irradiating a minute part of a sample or a small sample with X-rays; and a position-sensitive X-ray detector having a core wire stretched in an arc shape. An X-ray diffractometer having a detector arranged in an arc around a sample, wherein an arc-shaped core wire incorporated in the position-sensitive X-ray detector with respect to an optical axis of X-ray irradiated to the sample through the collimator. Wherein the position-sensitive X-ray detector is arranged such that a virtual plane including
Line diffractometer. 2. The X-ray diffractometer according to claim 1, wherein the position-sensitive X-ray detector is built in a position where a diffracted X-ray generated from the sample can be detected up to a high angle region up to a diffraction angle of 180 °. An X-ray diffractometer, wherein one end of a core wire is arranged. 3. A position-sensitive X-ray detector comprising: a collimator for irradiating a minute part of a sample or a minute sample with X-rays; and a position-sensitive X-ray detector having a core wire stretched in an arc shape. An X-ray diffractometer having a detector arranged in an arc around a sample, wherein an arc-shaped core wire incorporated in the position-sensitive X-ray detector with respect to an optical axis of X-ray irradiated to the sample through the collimator. So that the virtual planes including
An X-ray diffractometer comprising a line detector. 4. The X-ray diffractometer according to claim 3, wherein the position-sensitive X-ray detector is provided at a position where a diffracted X-ray generated from the sample can be detected up to a high-angle region having a diffraction angle of 180 °. An X-ray diffractometer, wherein one end of a core wire is arranged.