JPH11133190A - X-ray diffraction element and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new X-ray diffraction element capable of efficiently condensing X-rays coming out of a divergent X-ray source, and make X-ray intensity at a condensation point more intense. SOLUTION: In an X-ray diffraction element having an X-ray diffraction surface made up of a crystal face Bragg-reflecting X-rays and used in an X-ray condensing device for condensing X-rays coming out of a divergent X-ray source, the X-ray diffraction surface constitutes a part of a surface of a body of revolution obtained by revolving a part of a curve expressed by an expression, y=b(1-x<2> /a<2> )<1/2> +x<n> /k (where, a=(b<2> +L<2> /4)<1/2> , b=L.tan θ/2, L is a distance between two focal points, θ is a Bragg angle, n is a positive integer, and k is an arbitrary number larger than zero), modified from the expression of an ellipse having, as two focal points, the X-ray source and a point at which X-rays are to be condensed, with a straight line passing through the two focal points used as an axis of revolution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray condensing device used for a micro area X-ray analysis, an X-ray transmission inspection, an X-ray microscope, and an X-ray exposure apparatus, and in particular, to an X-ray radiated from an X-ray source. The present invention relates to an X-ray diffraction element used for an X-ray condensing device that increases the intensity of X-rays by collecting them substantially in a point shape.

[0002]

2. Description of the Related Art Conventionally, in order to collect X-rays divergent from an X-ray source, an X-ray condensing apparatus uses an X-ray using a curved crystal.
A line diffraction element is used. Such curved crystals include one-dimensionally curved singly-bent type crystals and two-dimensionally curved doubly-bent type crystals.

When X-rays are condensed using a singly-bent type crystal, the X-rays emitted from the point light source are collected in a linear shape, and thus are collected linearly using another singly-bent type crystal. It is necessary to collect the obtained X-rays in a point shape. On the other hand, doubly
When condensing X-rays using a -bent type crystal, it can be condensed in a point shape with one crystal.

In an optical system in which two singly-bent type crystals are combined, the solid angle of X-rays incident on the singly-bent type system is small, and most of the X-rays emitted from the X-ray source cannot be collected.
Further, since the Bragg reflection is performed twice using two crystals, the intensity of the collected X-rays is greatly reduced. In addition, this optical system has a lower intensity of collected X-rays because the distance from the X-ray source to the focal point is longer, thereby increasing the amount of X-rays absorbed by the intervening air. . Thus, in an optical system combining a singly-bent type crystal, X-rays can be collected, but the intensity of the collected X-rays is not so strong.

[0005] Doubly-bent in which a crystal is curved two-dimensionally
When using a type crystal, compared to a singly-bent type crystal,
Since the solid angle of the X-ray incident on the crystal can be made large and can be collected by one Bragg reflection, a higher X-ray intensity can be achieved than when a singly-bent type crystal is used. By forming a toroidal shape by combining a plurality of such doubly-bent type crystals, a substantial portion of the X-rays emitted from the X-ray source can be focused, so that the intensity of the focused X-rays can be further increased. . The “toroidal shape” is used to mean a shape obtained by rotating a curve having a finite length by 360 ° around an axis not including the finite length.

FIG. 3 shows a specific example of a curved crystal.
FIG. 3 shows a Johann shape 1 as shown in FIG.
The Johansson type shape 2 as shown in FIG.
It has been proposed for type crystals. In addition, by partially rotating the Johann or Johansson shape around a straight line connecting the X-ray source (S) and the focal point (F) as a rotation axis, the doub is obtained.
A ly-bent type shape is obtained, and by rotating through 360 °, a doubly-bent type X-ray diffraction element having a toroidal shape is obtained.

In order to obtain such a curved crystal, it is necessary to bend the crystal. For this purpose, elastic deformation or plastic deformation of the crystal is used. For example, in the case of quartz or silicon crystal, the crystal can be curved by sandwiching a thin crystal between two metal plates, bending them in the transverse direction while gradually applying pressure in the longitudinal direction, and elastically deforming them. In the case of lithium fluoride crystals, the crystals can be uniformly plastically deformed by bending the crystals in heated oil. As another method, Japanese Patent Application Laid-Open No. 4-120500 proposes a diffractive element for an X-ray condensing device in which a toroidal inner surface is formed by powder crystals.

[0008]

However, FIG.
As shown in (a), when the Johan type is used as the curved crystal shape (1), the X-rays emitted from the point light source (S) do not substantially converge to one point (F), and astigmatism Occurs. Therefore, the aberration increases as the reflection point or the diffraction point shifts from the central portion (3) of the curved crystal, and the incident angle of the X-ray incident on the crystal shifts from the Bragg angle (θ), so that Bragg reflection does not occur. Therefore, only X-rays incident near the center of the curved crystal can be focused, so that
The X-ray intensity at the focal point (F) cannot be increased beyond a certain value.

On the other hand, as shown in FIG. 3B, the Johansson type crystal has substantially no aberration, and the X-rays emitted from the point light source (S) can be substantially condensed at one point (F). . However, in order to form a Johansson type crystal, after the crystal surface is cut into a curved surface having a circumference of radius 2R, the crystal is further reduced to radius R.
Must be bent to have a curved surface having a circumference of. Therefore, in forming the X-ray diffraction element of the Johansson type crystal, it is necessary to perform processing with high accuracy. However, such processing is very difficult, and the X-ray diffraction of the Johansson type crystal having a small radius of curvature is required. Elements have not yet been formed. In addition, it is very difficult to form a crystal having a large area such as a toroidal shape. Furthermore,
Some crystals cannot be precisely sharpened or bent. For example, ordinary graphite crystals cannot be subjected to such processing.

Further, in the X-ray concentrator disclosed in Japanese Patent Application No. 4-120500, in which the inner surface of the toroidal surface is formed of powder crystals, the crystal orientation of the powder crystals is random, so that the X-ray reflectivity is low. Although it is low, it can focus X-rays, but the X-ray intensity at the focus is not so strong.
When forming an X-ray diffraction surface by combining crystal pieces obtained by dividing an X-ray diffraction element having an X-ray diffraction surface of a predetermined shape, for example, an X-ray diffraction element having a toroidal shape surface as an X-ray diffraction surface into a plurality of parts. It is necessary to precisely adjust each part so that the crystal planes are aligned so as to have a predetermined toroidal surface, but this precise adjustment is very difficult.

The present invention solves the above-mentioned problems, and provides a new X-ray diffraction element capable of efficiently collecting X-rays emitted from a divergent X-ray source. It is another object of the present invention to provide an X-ray condensing device capable of increasing the X-ray intensity at the converging point. Also, the present invention
Provided are a method for easily forming an X-ray diffraction element having a predetermined shape using a plurality of crystal pieces, and an X-ray diffraction element formed by the method.

[0012]

As a result of investigations to solve the above problems, the present inventors have found that an X-ray diffraction surface having a curved surface obtained by rotating a curve obtained by correcting an elliptical equation rather than a Johann type shape. By concentrating the X-rays using X-rays, more improved light-collecting efficiency is achieved.
An X-ray diffraction element having a X-ray diffraction surface is easily formed by forming a hollow member having a curved surface obtained by rotating a curve obtained by correcting an elliptic equation with a resin, and attaching a crystal fragment to an outer surface of the member. The present invention has been completed by finding what can be obtained.

That is, in one aspect, the present invention provides an X-ray focusing apparatus for collecting X-rays from a divergent X-ray source, the X-rays being constituted by a crystal plane configured to Bragg-reflect X-rays.
An X-ray diffraction element having a X-ray diffraction surface, wherein the X-ray diffraction surface is an elliptic expression having an X-ray source and a point where X-rays are to be collected at both focal points: y = b (1-x ² / a ^{2) 1/2} equation (1) ^{(wherein, a = (b 2 + L} 2/4) 1/2, b = L · tanθ
/ 2, L is the distance between the focal points, and θ is the Bragg angle. ) Plus x ⁿ / k as a correction term (hereinafter referred to as a curve).
Y = b (1−x ² / a ² ) ^1/2 + x ⁿ / k Equation (2) (where n is a positive integer, and k is an arbitrary number greater than 0) Is obtained by rotating at least a part of a straight line passing through both focal points (that is, the x axis) as a rotation axis (hereinafter, also referred to as a “rotation correction ellipsoid”).
An X-ray diffraction element is provided, wherein the X-ray diffraction element substantially constitutes at least a part of the surface of the X-ray diffraction element.

The X-ray diffraction surface of the X-ray diffraction element of the present invention may be a complete rotation-corrected ellipsoid obtained by rotating the entire correction elliptic curve. Even if the surface of the solid is cut off, the surface of the rotator obtained by rotating only a part of such a solid, for example, only a portion near x = 0 of the corrected elliptic curve around the X axis ( Therefore, the surface of the rotating body may be band-shaped). Further, the rotation angle does not necessarily have to be 360 ° (that is, a so-called toroidal shape), and may be a smaller angle, for example, 20 °.

When such an X-ray diffraction element of the present invention is used and an X-ray divergence source is arranged at one focal point, it is possible to efficiently collect X-rays at the other focal point,
X-ray monochromation can also be improved. By first determining the distance between the focal points, varying the values of the various n and k sets, and repeating the theoretical calculations, the appropriate n and k sets can be selected. That is, when n and k are selected, the correction elliptic curve is uniquely determined. Therefore, the incident angle of the X-rays from the focal point toward the diffraction point, and the X-ray diffraction point at the diffraction point, It is possible to calculate whether the line is illuminated, and if this is calculated for various combinations of n and k, an appropriate set of n and k can be obtained.

In a preferred embodiment of the X-ray diffraction element according to the present invention, in the above correction term, n is preferably an odd number, and in particular, is an odd number of 1 or more. For example, n is 1,
3 or 5 can be used. For example, k is n = 1
When k = 1.8 × 10 ² , When n = 3, k = 5.0 ×
10 ⁵ , and when n = 5, it is preferable that k = 10 ⁹ . The crystal used for Bragg reflection may be any suitable crystal that can be used for X-ray diffraction, for example, diamond, graphite, pentaerythritol, lithium fluoride, and the like. Most preferred in terms of efficiency. The graphite used in the element of the present invention may be obtained by any method.
It is particularly preferable to use graphite having a curved surface shape obtained from the beginning, which is obtained by the method described in JP-A-9. That is, it is preferable to previously form the graphite plane using a mold corresponding to at least a part of the surface of the rotation correction ellipsoid.

In another preferred embodiment of the X-ray diffraction element of the present invention, the X-ray diffraction surface has x = 0 on both sides of x = 0 of the corrected elliptic curve.
Extending around 0, more preferably -L / 2 <x <
A partial curve extending in the range of L / 2, most preferably in the range of -L / 4 <x <L / 4, particularly preferably in the range of -L / 8 <x <L / 8, is rotated by 360 [deg.] Around the rotation axis. It has a band-shaped rotation-corrected ellipsoidal surface obtained by the above. In another aspect, the present invention is an X-ray collector comprising an X-ray divergence source and the X-ray diffraction element described above, wherein the X-ray divergence source is located at one focal point, and the X-ray diffraction element is The X-ray diffraction plane is arranged so as to coincide with at least a part of the surface of the spheroid from which it is derived, and the divergent X-rays are collected at or near the other focal point. provide.

In still another aspect, the present invention is a method of forming an X-ray diffraction element, comprising forming a planar support made of resin having a surface corresponding to at least a portion of a surface of a rotation correction ellipsoid, At least one crystal fragment for Bragg-reflecting X-rays is mounted on any major surface of the support, the crystal fragment substantially corresponding to at least a portion of the surface of the rotation correction ellipsoid of the support. The present invention provides a method of forming an X-ray diffraction element for forming a surface portion of the X-ray diffraction element, and an X-ray diffraction element formed by the method. In this method, “substantially corresponds” means that the surface of the support and the surface formed by the crystal fragments are substantially the same,
It can be said that “substantially corresponds” if the surface portion of the rotation correction ellipsoid formed by the support and the crystal piece can achieve X-ray focusing more improved than when a Johan-type doubly-bent type crystal plane is used. Like the X-ray diffraction surface of the above-described X-ray diffraction element of the present invention, the planar support may be the entire surface of the rotation correction ellipsoid or a toroidal portion, for example, a band shape. Also, a portion of the toroidal shape (ie,
(Which can be achieved by a rotation smaller than 360 °).

In a preferred embodiment, the crystal pieces are mosaic crystals, the mosaic spread of which is preferably 0.1 m.
1 ° to 8 °, more preferably 0.3 ° to 2 °. The crystal fragments may be attached to either the inside or the outside of the support, but when the support has a toroidal shape, it is preferable to attach the crystal fragments to the outer surface of the support.

In the present specification, the term “mosaic crystal” is a crystal which contains a lot of lattice defects such as grain boundaries and dislocations, and is relatively easily available and has a disordered three-dimensional periodicity. A large number of micro regions (mosaic pieces) having no disorder are gathered together with a slight crystal plane (or lattice plane) orientation deviation distribution and used as one crystal piece. The “mosaic spread” represents the distribution of the inclination angles of the lattice planes of the mosaic pieces.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings. The X-ray diffraction surface of the X-ray diffraction element according to the present invention forms at least a part of the surface of the rotation correction ellipsoid as described above. As schematically shown in FIG. 1, when the distance between the X-ray source S and the focal point F is L and the Bragg reflection angle of the crystal is θ, a corrected elliptic curve 10 (only a part of which is shown) is obtained. When the curve 10 in FIG. 1 is rotated about the x-axis, a rotation correction ellipsoid is obtained, and the X-ray diffraction element 12 of the present invention uses at least a part of the surface of the rotation correction ellipsoid as an X-ray diffraction surface 14. Have.

In a preferred embodiment, the X-ray diffraction surface 14 is at least a portion of the surface of the spheroid as shown, and in particular, has substantially the same x on both sides of the y-axis, centered on x = 0. Range (eg -w <x <w as shown)
(I.e., a portion of -w <x <w of the correction elliptic curve (2)) extending around the X-axis, a portion of a surface of a belt-shaped rotation correction ellipsoid obtained by rotating the portion, preferably Constitutes a toroidal portion. Normally, L> 2w. However, on any side close to the focal point, the incident angle is greatly different from the Bragg angle on any side.
The X-ray diffraction surface in that part is not adopted so effectively. In particular, it is most common that L / 6 <2w <L / 3.

The rotation angle of the corrected elliptic curve around the x-axis is
Generally, the closer to 360 ° (that is, toroidal shape) is advantageous because more X-rays can be collected,
If the X-rays are not uniformly diverged around the X-ray source, the X-ray diffraction surface in the direction in which the X-rays are not diverged may be partially omitted in consideration of the fact. Thus, if the X-rays are divergent to one side only, the rotation angle may be, for example, 180 ° or less.

By simulating the case of using such an X-ray diffraction surface, the diffraction position of the diverged X-ray (x coordinate value), the incident angle of the X-ray at that position (θ ₁ ), and the position The distance between the point at which the X-ray intersects the x-axis and F when Bragg reflection occurs (ie, the deviation (d) from the focal point F)
For example, the X-ray wavelength is changed to copper Kα ray (λ = 1.5418).
Å), when the X-ray diffraction crystal plane is a graphite (002) plane (Bragg reflection angle θ = 13.3 °) and the distance L between the X-ray source and the focal point is 240 mm, the results shown in Table 1 are obtained. Was done. However, at the time of calculation, n in equation (2)
= 5 and k = 10 ⁹ . For comparison, the incident angle and the shift were also calculated for the case of using a Johann type crystal. This calculation was performed geometrically to satisfy the Bragg reflection condition at the diffraction position.

[0025]

[Table 1]

As is clear from Table 1, when the corrected elliptic curve of the present invention is used as compared with the Johann shape, the incident angle (θ ₁ ) of the X-ray is close to the Bragg reflection angle, and the deviation from the condensing point is obtained. (D) is also small. Therefore, by shaping the X-ray diffraction surface having the same shape as the surface shape of the rotating body obtained by rotating the corrected elliptic curve around the x-axis as a rotation axis by a crystal capable of diffracting X-rays, the X-ray intensity at the focal point is reduced. Can be strong.

The inventors of the present invention have already found that the correction term in the equation (2) of the correction elliptic curve of the present invention is preferably negative in a region where x is negative and positive in a region where x is positive. I know. That is, when n is an even number, in the region where x is negative, the correction term shifts the original elliptic curve to the side where y increases, that is, in the region where x is negative, the incident angle of the incident X-ray increases. After that, the deviation from the Bragg angle increases.
Therefore, n is preferably an odd number. Of course, in the region where x is positive, the effect of the correction term is the same whether n is an even number or an odd number, and the angle of incidence of the incident X-ray becomes too large by shifting the original elliptic curve to the side where y increases. hand,
This is preferable because the deviation from the Bragg angle is prevented from increasing. In this sense, the correction elliptic curve is effective even when n is an even number, and using a curved surface obtained by rotating the correction elliptic curve in the range of x = 0 and x> 0 is not a collection of X-rays. Effective for light.

As described above, although it is affected by the value of k, it is generally preferable that n is large. However, even if the effect of the correction term is 6 or more, it does not differ so much.
In practice, 5 is sufficient. Of course, n may be smaller than 5. The value of k is not particularly limited, but an appropriate pair of n and k can be selected as described above. This suitability may be determined to be appropriate if it is superior to a Johann type X-ray diffraction surface.

If the incident angle of X-rays is slightly deviated from the Bragg reflection angle, Bragg reflection is stopped. Therefore, when the crystal used for the X-ray diffraction surface is a perfect crystal, only a part of the crystal has a shape other than the Johansson type. Bragg incident angle is not secured. On the other hand, when a mosaic crystal is used, even if the incident angle slightly deviates from the Bragg angle, there is an advantage that the Bragg incident angle is secured for at least a part of the crystal because of the mosaic spread. Therefore, it is preferable that the X-ray diffraction surface of the X-ray focusing element of the present invention is formed by a mosaic crystal.

When a mosaic crystal is used, the angle adjustment of the crystal plane does not need to be as strict as when a perfect crystal is used.
It is not always easy to process the line diffraction surface so as to form at least a part of the surface of the above-mentioned correction ellipsoidal rotator.

Therefore, in the present invention, as schematically shown in FIG. 2, a hollow or planar support 22 is formed in advance on a toroidal surface or a part 20 thereof by using a resin, and the surface of the support, hollow In particular, in the case of mosaic crystal fragments 2
By attaching 4, the mosaic crystal can be accurately arranged in a toroidal shape. This eliminates the necessity of precisely adjusting the arrangement of the mosaic crystal pieces to form a toroidal shape directly from the crystal pieces, and the mosaic crystal so as to follow (or substantially correspond to) the shape of the support. Conveniently, the piece only has to be arranged on the surface of the support, especially on the outside. Of course, it is also possible to arrange the mosaic crystal pieces inside the support, but when the support is hollow, when arranging the crystal pieces outside the support, the crystal arrangement work is very simple and easy. Is preferred. In addition, when the crystal piece is attached to the outside of the support, the thickness of the crystal piece is advantageous because it does not affect the diffraction surface.

According to the present invention in which such a support is formed in advance, even if the X-ray diffraction surface has the shape of a part of the above-mentioned rotation-corrected ellipsoid, the toroids having other shapes proposed so far have been proposed. Even in the case of faces, the same applies.
That is, the present invention can be applied to a case where crystal pieces are arranged to form a toroidal X-ray diffraction surface having a desired shape. Not only the shape obtained by rotating the corrected elliptic curve of the present invention, for example, as a toroidal shape, a Johan type, a support is also formed in advance in the case of a shape obtained by rotating a curve such as an ellipse,
By disposing a crystal piece on the surface, a toroidal surface that is precisely adjusted can be easily formed.

Accordingly, the present invention provides a method for forming an X-ray diffraction element, comprising forming a planar support made of resin having a surface corresponding to at least a part of a toroidal surface, and forming any one of the supports. Mounting at least one crystal fragment for Bragg reflection of X-rays on the main surface of the substrate such that the crystal fragment forms a toroidal surface portion substantially corresponding to at least a portion of the toroidal surface of the support. A method for forming a line diffraction element is provided.

The resin material used to form the support has a small X-ray absorption coefficient, and
What is necessary is just what is relatively easy to process. For example, polyethylene, polypropylene, and polystyrene are suitable.
As a method of forming the resin material into a toroidal shape, any suitable processing method such as blow molding, grinding, and polishing may be used.

As the crystal, for example, graphite, lithium fluoride, pentaerythritol and the like can be obtained, and these can be preferably used. However, in order to further increase the intensity at the X-ray converging point, a high X-ray reflectance is required. Graphite is suitable.

For example, as the mosaic spread of the (002) plane of graphite, a maximum mosaic spread of 0.1 mm that can be produced as graphite and a minimum line of 8 mm that can obtain high X-ray reflectivity are convenient. Can be used. X when mosaic spread exceeds 8 ゜
This is not so preferable because the reflection intensity at the light condensing point of the line decreases.

Graphite is also particularly suitable as a piece of crystal glued to the outside of the toroidal support. Graphite has a high X-ray reflectivity, and has a layered crystal structure, so that it has a property of easily delamination. Therefore, the flat graphite can be thinly exfoliated and attached to the outside of the toroidal support. Alternatively, graphite may be formed into a toroidal shape by the method described in Japanese Patent Application Laid-Open No. 8-244119, and it may be attached to the outside of the toroidal-shaped support. The size of the crystal pieces can be appropriately selected according to the curvature of the support, and for example, in the case of graphite obtained by the method described in JP-A-8-244119, for example, 5
One having a size of about 0 × 80 × 3 mm can be used.

[0038]

Next, examples of the shell of the present invention will be described. (Example 1) X-rays are copper Kα rays (wavelength λ = 1.541).
8) The crystal is a graphite (002) plane (Bragg reflection angle θ = 13.3 °), and the distance L between the X-ray source S and the focal point F =
As the X-ray diffraction element used in the case of 240 mm, the correction elliptic curve of the present invention shown in FIG. 1 (correction terms are n = 5, k = 1
A part of ⁰⁹ ) was made of a toroidal graphite having a rotation correction ellipsoid (w = 40 mm) rotated around SF as a rotation axis.

The method for producing graphite is disclosed in
No. 44119, two pieces were obtained by dividing the rotation-corrected ellipsoid into halves on a plane including the x-axis, and these pieces were precisely adjusted and arranged so as to form a toroidal shape. . An X-ray tube (target: copper, focal point size: 0.7 mm point focal point) was placed at the focal point of this X-ray diffractometer, and an experiment was conducted to collect the X-rays emitted therefrom.

First, a φ2.0 mm pinhole was placed at a position F of L = 240 mm from the X-ray focal point S without an X-ray focusing device, and the X-rays passing through the pinhole were counted by a scintillation counter. Thereafter, the X-ray was condensed by the above-mentioned X-ray condensing device, a pinhole having a diameter of 2.0 mm was set at the condensing point, and the X-ray passing through the pinhole was forced down. When the light collection magnification was defined as the ratio of the X-ray intensity when the X-ray light collector was attached to the X-ray intensity without the X-ray light collector, a light collection magnification of 10 times was obtained.

(Example 2) As shown in FIG. 2, a support 22 having a toroidal surface 20 was formed of a resin, and an X-ray diffraction element 26 having a graphite piece 24 attached to the outer surface thereof was prepared. The support was made of polypropylene, and the toroidal shape of the rotating body having the corrected elliptic curve used in Example 1 was blow-molded with a mold (thickness: 0.3 mm). 0.2 m thick
Plate-like graphite of mosaic crystals (dimensions: 5 mm x 5 mm, mosaic spread 0.5 mm) peeled to m to 0.4 mm was attached to the outer surface of the support. Using this X-ray diffraction element, the light-gathering power was measured in the same manner as in Example 1, and as a result, three times the light-gathering power was obtained.

[0042]

According to the present invention, when the shape of the X-ray condensing device is formed by rotating the correction elliptic curve of the present invention, compared to the Johan type, Bragg reflection of X-rays from the X-ray tube at a large solid angle can be obtained. In addition, the X-ray intensity at the focal point increases because the aberration at the focal point is small.

Further, an X-ray diffraction element having a high X-ray intensity at the converging point can be manufactured accurately and easily by forming a toroidal-shaped support from a resin and attaching an X-ray diffractible crystal to the outer surface thereof. It is possible to do.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing the principle of an X-ray diffraction element obtained based on a corrected elliptic curve shape according to the present invention.

FIG. 2 is a schematic cross-sectional view of an X-ray diffraction element of the present invention in which a toroidal-shaped support is formed of a resin and a crystal is attached to an outer surface thereof.

3A and 3B are schematic cross-sectional views of a curved crystal shape according to a conventional technique, wherein FIG. 3A is a principle diagram of a Johann-type shape, and FIG. 3B is a principle diagram of a Johansson-type shape.

[Explanation of symbols]

S: X-ray source, F: Focus point, 1 ... Johansian shape, 2 ... Johansson-shaped shape, 3 ... Center, 10 ... Corrected elliptic curve, 12 ...
X-ray diffraction element, 14: part of X-ray diffraction surface or corrected elliptic curve), 20: toroidal surface, 22: support, 24 ...
Mosaic crystal fragments, 26 X-ray diffraction elements.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Eiichiro Matsubara 1st Kume Mansion 4-16, Takano Nishikaicho, Sakyo-ku, Kyoto, Kyoto (72) Inventor Tsutomu Kawashima 1006 Kazuma Kazuma, Kadoma, Osaka Matsushita Electric Within Sangyo Co., Ltd. (72) Inventor Naomi Nishiki 1006, Kazuma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Yukio Maeda 1006, Oaza Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Invention Person Yasushi Okada 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd.

Claims (8)

[Claims] 1. An X-ray diffraction device having an X-ray diffraction surface constituted by a crystal surface for Bragg reflection of X-rays, which is used in an X-ray concentrator for concentrating X-rays from a divergent X-ray source. Element, the X-ray diffraction surface is represented by an elliptic expression having the X-ray source and the point at which the X-rays should be collected at both focal points: y = b (1−x ² / a ² ) ^1/2 (where a is a ^{= (b 2 + L 2/} 4) 1/2, b = L · tanθ
/ 2, L is the distance between the focal points, and θ is the Bragg angle. ) Plus x ⁿ / k as a correction term: y = b (1−x ² / a ² ) ^1/2 + x ⁿ / k (where n is a positive integer and k is greater than 0) At least a portion of the surface of the rotating body obtained by rotating at least a portion of the curve represented by the formula (1) by using a straight line passing through both focal points (ie, the x-axis) as a rotation axis. An X-ray diffraction element. 2. The element of claim 1, wherein n is one or more odd numbers. 3. The element according to claim 1, wherein the crystal plane is a mosaic crystal plane of graphite. 4. The element according to claim 3, wherein the mosaic spread of the mosaic crystal plane is in the range of 0.1 to 8 °. 5. An X-ray collector comprising an X-ray divergence source and the X-ray diffraction element according to claim 1, wherein the X-ray divergence source is arranged at one focal point. , The X-ray diffraction element is arranged such that its X-ray diffraction surface coincides with at least a portion of the surface of the spheroid from which it was derived,
An apparatus wherein the divergent X-rays are collected at or near the other focal point. 6. A method for forming an X-ray diffraction element, comprising: forming a planar support made of resin having a surface corresponding to at least a part of a toroidal surface; An X-ray diffraction element comprising: at least one crystal fragment that Bragg-reflects X-rays, wherein the crystal fragment forms a toroidal surface portion that substantially corresponds to at least a portion of the toroidal surface of the support. Forming method. 7. The method according to claim 6, wherein the toroidal shape is a shape obtained by rotating a part of the correction elliptic curve according to claim 1 around the x-axis. 8. An X-ray diffraction element formed by the method according to claim 6.