JP2015078835A - X-ray diffraction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray diffraction device capable of allowing X-ray diffraction measurement by plural types of characteristic X-rays under common circumstances.SOLUTION: The X-ray diffraction device comprises: an X-ray source emitting plural types of characteristic X-rays; an optical system including a multilayer film mirror selectively reflecting the plural types of characteristic X-rays of X-rays emitted by the X-ray source, and making the X-rays reflected by the multilayer film mirror incident into a sample; and an X-ray detector detecting a diffraction X-ray generated by the sample. The multilayer film mirror includes plural types of multilayer films respectively corresponding to the plural types of characteristic X-rays. The plural types of multilayer films are sequentially laminated to form a curved reflection surface, and each of the multilayer films includes lattice spacing for selectively reflecting the corresponding characteristic X-rays. The lattice spacing is inclined along an intersection line with an incidence surface of the curved reflection surface.

Description

  The present invention relates to an X-ray diffractometer, and more particularly to an X-ray diffractometer capable of X-ray diffraction measurement using a plurality of types of characteristic X-rays.

  In an X-ray diffraction apparatus, it may be necessary to perform measurement using a plurality of types of characteristic X-rays having different wavelengths with respect to a certain sample. For example, in the MAD method (multi-wavelength anomalous dispersion method) used in the structural analysis of proteins, a plurality of types of X-rays having different wavelengths are used for X-ray diffraction measurement.

  An X-ray generator that generates a plurality of types of characteristic X-rays by using a plurality of types of metals as a target has already been disclosed. The counter cathode of the X-ray tube is a rotating body (rotor target) having a target metal formed on the side surface, and a plurality of types of X-rays are generated by arranging a plurality of types of metal on the side surface of the rotating body. There are X-ray generators that can do this.

JP-A-5-152091 Japanese Patent Laid-Open No. 2003-14894 JP 2002-39970 A JP 62-014043 A

  Even when an X-ray generator capable of generating a plurality of types of X-rays is used as an X-ray source, in the case of normal X-ray diffraction measurement, the generated X-rays are separated from a spectroscopic crystal, a multilayer mirror, etc. It is necessary to select desired characteristic X-rays by a spectroscope. When a spectroscopic crystal or a multilayer mirror is used as a spectroscope, it is necessary to change the spectroscope for each desired characteristic X-ray. In Patent Document 1, it is possible to generate X-rays from a desired metal by arranging a plurality of types of metals periodically on the side of the rotating body and rotating the shutter in synchronization with the rotation of the rotating body. An X-ray generation apparatus is disclosed. However, even in this case, a spectroscope is required for each desired characteristic X-ray.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique for splitting X-rays from each of a plurality of X-ray sources with a single multilayer mirror. In the case of a multilayer mirror having a predetermined curved reflecting surface, the focal position is different for X-rays having different wavelengths. Therefore, by providing a large-diameter portion and a small-diameter portion on the outer peripheral surface of the rotating body and disposing different metals on each, two X-ray sources can be placed at the focal positions of the respective wavelengths. It is possible to simultaneously split X-rays emitted from two kinds of metals with the multilayer mirror. In this case, it is necessary to adjust the shape of the outer peripheral surface of the rotating body and the curvature of the multilayer mirror so that the two focal positions that differ depending on the wavelength come to the large diameter portion and the small diameter portion of the outer peripheral surface of the rotating body, In addition to the increase in the scale and cost of the apparatus, it takes time to make adjustments, leading to an increase in measurement time. Patent Document 2 discloses a technique for adjusting the curvature of a multilayer mirror so that when two X-ray sources are at the same position, the position of the X-ray source becomes a focal point of a wavelength to be selected. Yes. This makes it possible to separately separate specific X-rays emitted by two types of metal with a single multilayer mirror, but it is necessary to adjust the curvature of the multilayer mirror each time a different wavelength is measured. After all, the measurement time is increased.

  Patent Document 3 discloses an X-ray apparatus that is provided separately for a plurality of X-ray generators and that makes X-rays incident on a sample at different angles. In this case, the X-rays incident on the sample are realized by separate optical paths, and the measurement environment of the X-ray diffraction measurement differs depending on the wavelength, which is not desirable from the viewpoint of measurement accuracy. Or, in order to increase the measurement accuracy, it is necessary to adjust the optical axes of a plurality of X-ray generators with higher accuracy, leading to an increase in measurement time. Furthermore, by providing a plurality of X-ray generators, the arrangement location and movement range of the detector that detects the diffracted X-rays from the sample are limited, which is not desirable.

  An X-ray diffractometer capable of performing X-ray diffraction measurement with characteristics X of different wavelengths in a common environment is desired for higher accuracy X-ray diffraction measurement and shortening measurement time. Patent Document 4 discloses a multiple wavelength X-ray dispersion apparatus using a multilayer film. In such multilayers, there are different multilayer spacings each having dispersion characteristics for different wavelengths. However, the reflection surface of the multi-wavelength X-ray dispersion apparatus disclosed in Patent Document 4 is a flat surface. When X-rays are incident on the sample using the multi-wavelength X-ray dispersion apparatus, As a result, sufficient luminance cannot be obtained, leading to a decrease in measurement accuracy and an increase in measurement time.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an X-ray diffractometer that enables X-ray diffraction measurement using a plurality of types of characteristic X-rays under a common environment.

  (1) In order to solve the above-described problem, an X-ray diffraction apparatus according to the present invention emits a plurality of types of characteristic X-rays from a predetermined region during a predetermined measurement period, and the X-ray source. Including a multilayer mirror that selectively reflects the plurality of types of characteristic X-rays from the X-rays radiated from the predetermined region, and the X-ray reflected by the multilayer mirror is incident on the sample; An X-ray diffractometer comprising an X-ray detector for detecting diffracted X-rays generated from a sample, wherein the multilayer mirror is a plurality of types of multilayer films respectively corresponding to the plurality of types of characteristic X-rays The plurality of types of multilayer films are sequentially laminated to form a curved reflection surface, each multilayer film has a lattice plane interval that selectively reflects the corresponding characteristic X-rays, and the curved reflection surface The lattice spacing is inclined along the line of intersection with the incident surface of That, characterized in that.

  (2) In the X-ray diffractometer described in (1) above, the line of intersection of the curved reflecting surface with the incident surface may be an elliptic curve.

  (3) In the X-ray diffractometer according to (1), an intersection line with the incident surface of the curved reflecting surface is an elliptic curve, and the predetermined point of the X-ray is at one focal point of the curved reflecting surface. The sample may be arranged at the other focal point of the curved reflecting surface.

  (4) In the X-ray diffractometer described in (1) above, the line of intersection of the curved reflecting surface with the incident surface may be a parabola.

  (5) In the X-ray diffractometer according to (1), an intersection line with the incident surface of the curved reflecting surface is a parabola, and the predetermined region of the X-ray is at a focal point of the curved reflecting surface. It may be arranged.

  (6) In the X-ray diffractometer described in (1) above, the plurality of types of multilayer films may be stacked in order from the shorter wavelength of the characteristic X-ray that selectively reflects.

  (7) The X-ray diffraction apparatus according to any one of (1) to (6), wherein the X-ray source includes an anti-cathode rotating body that collides electrons with an outer peripheral surface, and the electrons scan. A plurality of types of metals having different atomic numbers may be arranged in order in a direction perpendicular to the direction in which they are performed, and may be continuously arranged on the outer peripheral surface along the direction in which electrons scan.

  (8) The X-ray diffraction apparatus according to any one of (1) to (6), wherein the X-ray source includes an anti-cathode rotating body that causes electrons to collide with an outer peripheral surface, and the outer peripheral surface In addition, a plurality of types of metals having different atomic numbers may be periodically arranged along the direction in which electrons scan.

  (9) The X-ray diffractometer according to any one of (1) to (6), wherein the X-ray source includes a counter-cathode rotating body in which electrons collide with an outer peripheral surface, and the outer peripheral surface In addition, a plurality of types of metal alloys having different atomic numbers may be formed.

  (10) The X-ray diffraction apparatus according to any one of (1) to (9), wherein the X-ray detector receives light corresponding to wavelengths of the plurality of types of characteristic X-rays. It may be a wavelength discrimination type detector that detects the intensity of the line.

  (11) The X-ray diffractometer according to (10), wherein X-ray information detected by the X-ray detector is classified into X-ray wavelengths, and X-ray intensity information corresponding to the wavelengths is obtained. An analysis unit that outputs data, a data processing unit that performs data analysis based on the X-ray intensity information output by the analysis unit, and an analysis data storage unit that stores analysis result data of the data processing unit And may be further provided.

  (12) The X-ray diffraction apparatus according to (8), wherein rotation information of the counter-cathode rotator is obtained, and the X-rays radiated from each of the plurality of types of metals are obtained based on the rotation information. And you may further provide the synchronous control means which controls the detection of the said X-ray detector so that the intensity | strength of an X-ray may be detected, respectively.

  (13) The X-ray diffraction apparatus according to (12), further including a filter that is disposed between the multilayer mirror and the sample and absorbs scattered X-rays caused by continuous X-rays. May be.

  (14) The X-ray diffraction apparatus according to (12), wherein the multilayer mirror absorbs scattered X-rays caused by continuous X-rays in at least one of the plurality of types of multilayer films. A filter layer may be included.

  The present invention provides an X-ray diffractometer capable of X-ray diffraction measurement using a plurality of types of characteristic X-rays under a common environment.

It is a schematic diagram which shows the structure of the X-ray-diffraction apparatus which concerns on the 1st Embodiment of this invention. It is a schematic diagram which shows the structure of the X-ray source which concerns on the 1st Embodiment of this invention. It is a schematic diagram which shows the structure of the multilayer mirror which concerns on the 1st Embodiment of this invention. It is a schematic diagram which shows the structure of the X-ray detector which concerns on the 1st Embodiment of this invention. It is a schematic diagram which shows the structure of the X-ray source which concerns on the 2nd Embodiment of this invention. It is a figure which shows the intensity | strength of the incident X-ray which concerns on the 2nd Embodiment of this invention. It is a schematic diagram explaining the synchronous control means which concerns on the 2nd Embodiment of this invention. It is a schematic diagram which shows the structure of the other example of the X-ray source which concerns on embodiment of this invention. It is a schematic diagram which shows the structure of the other example of the X-ray source which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the drawings shown below are merely examples of the embodiment, and the scales shown in the drawings do not necessarily coincide with the scales described in the examples.

[First Embodiment]
FIG. 1 is a schematic diagram showing the structure of an X-ray diffraction apparatus 1 according to the first embodiment of the present invention. The X-ray diffractometer 1 according to this embodiment is an X-ray diffractometer capable of performing X-ray diffraction measurement of a sample 100 using a plurality of types of specific X-rays. Here, although the sample 100 is a single crystal, it is needless to say that the sample 100 is not limited thereto. The X-ray diffractometer 1 includes an X-ray source 2 that emits X-rays including a plurality of types of characteristic X-rays, and a multilayer mirror 3 and an optical system that causes X-rays reflected by the multilayer mirror 3 to enter a sample 100. 4, a sample stage 5 that supports the sample 100, an X-ray detector 6 that detects diffracted X-rays generated from the sample 100, and a rotational drive system 7 that moves the X-ray detector 6 at an angle with respect to the sample 100. And a control analysis unit 9 for controlling the X-ray diffraction measurement and analyzing the measurement data. The control analysis unit 9 includes an analysis unit 8 that analyzes the energy of diffracted X-rays detected by the X-ray detector 6.

  The X-ray diffraction apparatus 1 according to this embodiment is characterized in that the multilayer mirror 3 selectively reflects a plurality of types of characteristic X-rays from the X-rays emitted from the X-ray source 2 and the multilayer mirror 3 reflects X. The reason is that the optical system 4 is incident on the sample 100. Accordingly, X-ray diffraction measurement can be performed using a plurality of types of characteristic X-rays under a common environment. In the present specification, “selectively reflecting” X-rays having a predetermined wavelength means that the reflectance of the X-rays having the predetermined wavelength among X-rays incident on the mirror from a predetermined angle is: It is said to be specifically higher than the reflectance of other X-rays. That is, when some or all of the plurality of types of characteristic X-rays are included in the incident X-rays, the X-rays reflected by the multilayer mirror 3 are the partial or all characteristic X-rays.

  Hereinafter, the configuration of the X-ray diffraction apparatus 1 according to the embodiment will be described.

  FIG. 2 is a schematic diagram showing the structure of the X-ray source 2 according to the embodiment. The X-ray source 2 emits a plurality of types of X-rays using a plurality of types of metals having different atomic numbers as targets. Here, two types of metals having different atomic numbers are formed as targets on the counter cathode. The rotating body 11 is an anti-cathode, and two kinds of metals T1 and T2 are formed on the outer peripheral side surface of the rotating body 11. Here, the two types of metals T1 and T2 are Cu (copper) and Cr (chrome), respectively, but it is needless to say that the two types of metals T1 and T2 are not limited to these two types, for example, Mo (molybdenum), Co ( Cobalt), W (tungsten), or the like is used. The filament 12 is a cathode, the filament 12 emits electrons, and the electrons collide with the outer peripheral surface of the rotating body 11 that is an anti-cathode. The rotating body 11 is rotated by a drive system (not shown) in the direction of the arrow in the figure, and the electron scanning direction is opposite to the direction of the arrow in the figure.

  An area where the electrons collide with the outer peripheral surface of the rotating body 11 is an X-ray emission area BS, and X-rays are emitted in all directions from the X-ray emission area BS (predetermined area) on the outer peripheral surface of the rotating body 11. From the shape of the filament 12, the X-ray emission region BS has a band shape extending perpendicular to the electron scanning direction. Provided in a partition wall (not shown) surrounding the rotator 11 in a plane perpendicular to the X-ray emission region BS on the outer peripheral surface and in a direction forming a predetermined angle with the belt-shaped center line. There is an X-ray window 13 from which the X-ray S1 is emitted to the outside. This X-ray S 1 enters the multilayer mirror 3 of the optical system 4.

  On the outer peripheral surface of the rotator 11, a plurality of types of metals are arranged in order in a direction perpendicular to the direction in which electrons are scanned (lateral direction in the figure), and are continuously arranged along the direction in which electrons are scanned. Here, two kinds of metals T1 and T2 are arranged in order perpendicularly to the direction in which the electrons scan (in the horizontal direction in the figure), and are continuous with the outer peripheral surface of the rotating body 11 along the direction in which the electrons scan. The regions where the two types of metals T1 and T2 are formed are both ring-shaped around the outer peripheral surface. In addition, although a ring shape is desirable from the viewpoint of X-ray generation efficiency, there may be a shape in which metal is formed only at a part of the peripheral edge of the outer peripheral surface for other reasons.

  Of the X-ray emission region BS, from the region where the metal T1 is formed (here, Cu), the X-ray including the characteristic X-ray of the metal T1 is changed into the region where the metal T2 is formed (here, Cr). ), X-rays including the characteristic X-rays of the metal T2 are respectively emitted, and the X-rays S1 emitted from the X-ray window 13 include a plurality of types of characteristic X-rays. Here, the plurality of types of characteristic X-rays are, for example, a CuKα ray (wavelength 1.542Å) and a CrKα ray (2.291Å). That is, here, the X-ray source 2 emits a plurality of types of characteristic X-rays at the same time, and accordingly, emits a plurality of types of characteristic X-rays from a predetermined region at a predetermined measurement time.

  FIG. 3 is a schematic diagram showing the structure of the multilayer mirror 3 according to this embodiment. FIG. 3A is a cross-sectional view of the incident surface of the multilayer mirror 3. The multilayer mirror 3 is obtained by laminating a multilayer multilayer film 22 on the surface of a substrate 21 made of Si (silicon). The multi-layer multilayer film 22 is a curved reflecting surface, and the intersection line of the curved reflecting surface with the incident surface is an elliptic curve (a part of an ellipse). The curved reflecting surface has two focal points P1 and P2. When an X-ray generation source is disposed at the focal point P1, the X-rays reflected by the multilayer mirror 3 are collected at the focal point P2. Therefore, it is desirable that the X-ray radiation region BS on the outer peripheral surface of the rotating body 11 is disposed at the focal point P1 (one focal point) of the multilayer mirror 3. The X-ray source 2 emits X-rays from the X-ray emission region BS. Furthermore, it is desirable that the sample stage 5 supports the sample 100 so that the sample 100 is disposed at the focal point P2 (the other focal point) of the multilayer mirror 3. In addition, you may arrange | position the filter 26 between the multilayer mirror 3 and the sample 100 as needed. The filter 26 includes a metal layer, and the filter 26 can absorb scattered X-rays caused by continuous X-rays among the X-rays emitted from the X-ray source 2.

  FIG. 3B is a schematic diagram showing a cross section of the multilayer multilayer film 22 of the multilayer mirror 3. Here, the cross section is a cross section with respect to the incident surface of the multi-layer multilayer film 22. The multi-layer multilayer film 22 includes a plurality of types of multilayer films that are sequentially stacked, and the plurality of types of multilayer films constitute a curved reflecting surface. Here, the plurality of types of multilayer films respectively correspond to the plurality of types of characteristic X-rays, and each multilayer film selectively reflects X-rays having the wavelength of the corresponding characteristic X-rays from the incident X-rays. Each multilayer film selectively reflects X-rays having the corresponding characteristic X-ray wavelength, so that the multilayer mirror 3 selectively reflects all of the plurality of types of characteristic X-rays from the incident X-rays. I can do it. Therefore, when the incident X-ray includes a part or all of a plurality of types of characteristic X-rays, the X-rays reflected by the multilayer mirror 3 are part or all of the characteristic X-rays. In the figure, two types of multilayer films L1 and L2 are shown.

  In each multilayer film, heavy element layers 23 and light element layers 24 are alternately stacked. In each multilayer film, the heavy element layer 23 and the light element layer 24 are repeatedly laminated as a pair of layers, but it is desirable that 200 pairs or more are laminated. Further, considering the transmission of X-rays to the multilayer film disposed below, it is desirable that 1000 pairs or less are stacked. The interval between two pairs of adjacent layers is defined as a multilayer interval d. The multilayer interval d is, for example, the distance between the upper surfaces of two adjacent heavy element layers 23. In each multilayer film, as the X-ray reflection surface advances from the incident side to the reflection side, that is, from the left side to the right side of the cross section shown in FIG. Is gradually changing. In other words, the multilayer interval d gradually changes along the intersection line of the curved reflecting surface with the incident surface. The multilayer interval d of the multilayer film L1 is d1 at the left end of the cross section shown in the drawing and d2 at the right end. The multilayer interval d increases from the left side to the right side of the drawing, and d2 is larger than d1 (d1 <d2). It is. The multilayer interval d of the multilayer film L2 is D1 at the left end of the cross section shown in the drawing and D2 at the right end, and similarly, D2 is larger than D1 (D1 <D2). Strictly speaking, the multilayer interval d gradually changes along the stacking direction.

  From the viewpoint of X-ray diffraction, the multilayer interval d corresponds to the lattice spacing of the crystal, and as described above, the multilayer film in which the multilayer spacing d varies depending on the location is referred to as a “tilted lattice spacing” multilayer film. It is. The multilayer interval d at each position is determined by the shape of the curved reflecting surface and the wavelength of light to be selected. That is, each multilayer film has a lattice plane interval that selectively reflects X-rays having the wavelength of the corresponding characteristic X-ray, and each multilayer film has a lattice plane interval that changes in the lateral direction with an inclination. Yes. Ideally, the intersecting line with the incident surface on the upper surface of each heavy element layer 23 is preferably an elliptic curve having two focal points P1 and P2 as focal points.

  In addition, since the wavelengths of characteristic X-rays corresponding to the plurality of types of multilayer films are different, the lattice plane spacings of the plurality of types of multilayer films are also different. In the multilayer multilayer film 22, a plurality of types of multilayer films are sequentially stacked along the stacking direction. When the lattice plane spacing of the multi-layer multilayer film 22 is observed along the stacking direction, the lattice plane spacing gradually changes in a certain multilayer film, and takes a substantially constant value. The interplanar spacing varies greatly discontinuously. That is, for each multilayer film, the lattice spacing changes greatly in a discontinuous manner. Such a state may be called that the lattice spacing is inclined in the stacking direction.

Here, if the multilayer mirror 3 selectively reflects X-rays having two different wavelengths from the X-rays, two multilayer films that selectively reflect X-rays having the respective wavelengths are required. FIG. 2 shows two multilayer films L1 and L2. For example, the multilayer film L1 selectively selects X-rays having the wavelength of CrKα rays, and the multilayer film L2 selectively selects X-rays having the wavelength of CuKα rays. If it can be reflected, the multilayer mirror 3 can selectively reflect two types of characteristic X-rays, CuKα ray and CrKα ray, from the X-rays emitted from the X-ray source 2. The optical system 4 including can collect two types of characteristic X-rays, CuKα ray and CrKα ray, so as to be incident on the sample 100. In general, the longer the X-ray wavelength, the lower the degree of X-ray transmission. Therefore, when a plurality of types of multilayer films are disposed, it is desirable that the multilayer film having a long wavelength to be reflected is disposed above the substrate 21 so as to be closer to the reflective surface of the multilayer film mirror 3. That is, it is desirable that a plurality of types of multilayer films are stacked in order from the shorter wavelength to the longer wavelength to selectively reflect. It is desirable to dispose downward from the reflective surface (curved reflective surface). Here, the wavelength of the CrKα line is longer than the wavelength of the CuKα line, and the multilayer film L2 that reflects the CuKα line is disposed below the multilayer film L1 that reflects the CrKα line. Since the wavelength of the CrKα ray is longer than the wavelength of the CuKα ray, the multilayer interval d of the multilayer film L1 is longer at the same place than the multilayer interval d of the multilayer film L2. That is, d1> D1 at the left end and d2> D2 at the right end. Here, the heavy element layer 23 of the multilayer film L1 that reflects CrKα rays is formed of V (vanadium), and the light element layer 24 is formed of C (carbon). The heavy element layer 23 of the multilayer film L2 that reflects CuKα rays is formed of Ni (nickel), and the light element layer 24 is formed of C (carbon). However, it is not limited to these combinations, and an appropriate material may be selected according to the wavelength of the X-ray to be selected. The substances formed in the heavy element layer 23 and the light element layer 24 are, for example, W (tungsten) and B ₄ C (boron carbide), or Mo (molybdenum) and Si (silicon) may be used.

  Instead of disposing the filter 26 shown in FIG. 3A, a filter layer 27 made of a predetermined metal may be disposed between adjacent multilayer films as necessary. Here, for example, a filter layer 27 made of Ni is laminated between the multilayer films L1 and L2. Further, it is more preferable that a filter layer (not shown) made of V, for example, is laminated on the upper surface of the multi-layer multilayer film 22. Such a filter layer can absorb scattered X-rays caused by continuous X-rays among X-rays emitted from the X-ray source 2.

Since the optical system 4 includes the multilayer mirror 3, the multilayer mirror 3 selectively reflects a desired plurality of types of characteristic X-rays from the X-rays radiated from the X-ray source 2. The reflected X-rays can be collected and incident on the sample 100 supported by the sample stage 5. Thereby, for example, the X-ray dose per unit area can be increased to high-intensity X-rays of 10 kW / mm ² and incident on the sample, and X-ray diffraction measurement with higher accuracy can be performed. Note that the curved reflecting surface of the multilayer mirror 3 is not limited to that shown in FIG. 3, and the intersecting line with the incident surface of the curved reflecting surface may be a parabola.

  FIG. 4 is a schematic view showing the structure of another example of the multilayer mirror 3 according to this embodiment, and shows a cross section on the incident surface of the multilayer mirror 3. The curved reflecting surface of the multilayer mirror 3 shown in FIG. 4 is a part of a parabolic curve having P1 as a focal point. By disposing the X-ray emission region BS on the outer peripheral surface of the rotator 11 at the focal position of the parabola, a desired plurality of types of characteristic X-rays can be selectively reflected and converted into parallel X-rays. The parallel X-rays obtained here may be collected by another optical member provided in the optical system 4 and incident on the sample. Further, by making parallel X-rays incident on the sample, it can also be used for measuring X-ray reflectivity.

  A sample stage 5 shown in FIG. 1 includes a needle-shaped sample holder and one or a plurality of rotational drive systems, and a sample 100 that is a single crystal is attached to the tip of the needle-shaped sample holder. 100 is supported by the sample holder. The sample holder is arranged so that the sample 100 is irradiated with a plurality of types of characteristic X-rays incident from the optical system 4. Furthermore, the other end of the sample holder is fixed to the rotation drive system, and the sample 100 can be three-dimensionally changed by the rotation drive system. The shape of the sample holder of the sample stage 5 is selected according to the type of the sample 100.

  The X-ray detector 6 is, for example, a wavelength classification type two-dimensional pixel detector, and can classify received X-rays by wavelength (energy) and detect the intensity of X-rays according to the wavelength. The optical system 4 irradiates the sample 100 with a desired plurality of types of characteristic X-rays, and the sample 100 generates diffraction X-rays for each of the plurality of types of characteristic X-rays. The X-ray detector 6 can classify a plurality of types of characteristic X-rays and detect diffraction images of the plurality of types of characteristic X-rays.

  FIG. 5 is a schematic diagram showing the structure of the X-ray detector 6 according to this embodiment. The X-ray detector 6 has a planar X-ray detector 30 and a signal processing unit (not shown) provided on the back surface of the planar X-ray detector 30. A plurality of regularly arranged pixels 31 are provided. When X-rays reach a semiconductor (for example, Si) provided in each pixel 31, electric charges are generated. The signal processing unit includes a plurality of pulse height classification circuits corresponding to the respective pixels 31, and each wave height classification circuit classifies the detected charges, thereby increasing the intensity of the X-rays according to the wavelength (energy) of the X-rays. Can be detected.

  As shown in FIG. 1, the X-ray detector 6 is disposed on a rotational drive system 7 that can be moved angularly about the sample 100. The X-ray detector 6 can detect the entire diffraction image of the sample 100 by the rotation drive system of the sample stage 5 and the rotation drive system 7.

  The control analysis unit 9 controls the X-ray source 2 and X-ray diffraction measurement, and analyzes the obtained measurement data. The control analysis unit 9 drives the rotating body 11 of the X-ray source 2 and generates X-rays from the X-ray source 2 by applying a predetermined voltage between the cathode and the counter cathode. In addition, the control analysis unit 9 performs drive control of the rotation drive system of the sample stage 5 and the rotation drive system 7 in which the X-ray detector 6 is disposed, and further performs detection control of the X-ray detector 6 to perform X-ray detection. A plurality of pieces of information related to the diffraction images detected by the detector 6 are collected, thereby obtaining measurement data of the entire diffraction images of the plurality of types of characteristic X-rays. At that time, the analysis unit 8 provided in the control analysis unit 9 is a multi-channel pulse height analyzer (Multi-Channel pulse height Analyzer, MCA), which measures a peak height value and generates a peak height spectrum. I can do it. The analysis unit 8 classifies the X-ray information detected by the X-ray detector 6 into the X-ray wavelength (energy), and outputs the X-ray intensity information according to the wavelength. Furthermore, the control analysis unit 9 stores a data processing unit (not shown) that performs data analysis of the single crystal structure of the sample 100 based on the analysis data of the analysis unit 8 and data of the analysis result of the data processing unit. And an analysis data storage unit (not shown).

  In the X-ray diffraction apparatus 1 according to the embodiment, the X-ray source 2 can emit X-rays including a plurality of types of characteristic X-rays simultaneously from a predetermined region at a predetermined measurement time. The optical system 4 including the multilayer mirror 3 selectively reflects and collects a desired plurality of types of characteristic X-rays from the X-rays radiated from the X-ray source 2, and collects the desired plurality of types of samples on the sample 100. A characteristic X-ray is incident. The optical system 4 makes it possible to simultaneously irradiate the sample 100 with high-intensity X-rays composed of a desired plurality of types of characteristic X-rays. Since one multilayer mirror 3 can select and reflect a desired plurality of types of characteristic X-rays, the curved reflection is performed so that the spectrometer is changed according to the wavelength or the wavelength at which the spectrometer is dispersed is changed. There is no need to change the face. Therefore, the time required for X-ray diffraction measurement using a plurality of wavelengths can be shortened without increasing the scale of the apparatus. Although X-rays are irradiated and diffracted X-rays are generated from the sample 100, since the sample 100 is irradiated with high-brightness X-rays by the optical system 4, a diffraction image having a high S / N ratio is obtained, and the measurement time Can be shortened.

  Since the sample 100 is irradiated with a plurality of types of characteristic X-rays at the same time, the diffracted X-rays include diffracted X-rays of a plurality of types of wavelengths. However, the X-ray detector 6 is a wavelength separation type detector, and the analysis unit 8 of the control analysis unit 9 can separate the information of the measured diffraction X-rays into each of a plurality of types of wavelengths. At the same time, it is possible to obtain information on diffraction images of a plurality of types of wavelengths. Further, the data processing unit of the control analysis unit 9 can perform data analysis of the sample from information of diffraction images of a plurality of types of wavelengths. As a result, X-ray diffraction measurements using a plurality of types of wavelengths can be performed simultaneously without having to be performed separately, and furthermore, data analysis can be performed at the same time, so that the measurement time and data analysis time can be further greatly reduced. I can do it.

  Since a plurality of types of characteristic X-rays are emitted from the X-ray emission region BS of the X-ray source 2 and are incident on the sample 100 from the optical system 4, the paths to the sample 100 are the same. As a result, since X-ray diffraction measurement can be performed simultaneously in a common environment using a plurality of types of characteristic X-rays, not only the measurement time is shortened but also high quality measurement data is obtained. In particular, a remarkable effect can be obtained for short-time measurement of a sample that easily changes in quality or measurement performed while changing the environment (for example, when measuring while changing temperature).

  Conventionally, X-ray diffraction measurements at different wavelengths are performed separately. In this case, in an unstable substance that is rapidly deteriorated with time, the sample is subdivided and the subdivided sample is used to measure the X of each wavelength. There was a need to perform line diffraction measurements. In that case, after performing a certain X-ray diffraction measurement, in order to perform X-ray diffraction measurement of other wavelengths, it is necessary to set the sample in addition to replacing the spectroscope, etc. Time has increased. Further, the measurement environment of the optical system such as a spectroscope is different, and the samples to be measured are not the same, and the reliability of the measured data has to be reduced. This problem is solved by enabling X-ray diffraction measurement simultaneously under a common environment using a plurality of types of characteristic X-rays under a common environment. In particular, the present invention is effective for measuring samples such as proteins that are easily altered, samples that are sensitive to changes in temperature and humidity, such as pharmaceuticals, and samples that are produced in limited amounts or are expensive. Become prominent.

  Furthermore, by performing X-ray diffraction measurement simultaneously in a common environment using a plurality of types of characteristic X-rays, the advantages of using a plurality of types of characteristic X-rays can be used together. For example, as for the information of the diffracted X-ray for the region where the lattice distance (d value) of the crystal of the sample is large, information with better angular resolution than the measurement data of the characteristic X-ray having a long wavelength is obtained. Diffraction X-ray information for a region where the lattice spacing (d value) of the sample crystal is small is obtained from characteristic X-ray measurement data having a short wavelength.

  In addition, the X-rays emitted from the X-ray source 2 include characteristic X-rays other than the desired characteristic X-rays and continuous X-rays. Diffracted X-rays are also generated from the line. If these X-rays include an X-ray having a wavelength in the vicinity of the wavelength of the desired characteristic X-ray, when the X-ray detector 6 classifies the wavelength, the diffracted X-ray from the desired characteristic X-ray Not only that, but also the diffracted X-rays from this X-ray may be detected together. In order to prevent this, it is necessary to improve the wavelength resolution (energy resolution) of the X-ray detector 6. However, in the X-ray diffraction apparatus 1 according to this embodiment, the optical system 4 selects a desired characteristic X-ray and makes it enter the sample 100 by the multilayer mirror 3. That is, X-rays other than the desired characteristic X-rays are excluded by the multilayer mirror 3, and X-rays other than the desired characteristic X-rays are greatly suppressed from reaching the sample 100, and the X-ray detector 6 does not require a high wavelength resolution, thereby reducing the increase in cost and obtaining high-quality measurement data.

  The X-ray diffraction apparatus 1 according to the embodiment is suitable for protein structural analysis, for example. In the X-ray structural analysis of proteins, the MAD method is used to determine the phase information of the crystal structure factor. The MAD method performs phase determination using an anomalous dispersion effect near the absorption edge of a specific atom contained in a protein, and uses measurement data of X-ray diffraction images of a plurality of wavelengths.

  A plurality of characteristic X-rays are emitted from one type of metal. Therefore, for example, one type of characteristic X-ray may be selected from a certain metal, two types of characteristic X-rays may be selected from another metal, and the three types of characteristic X-rays may be set as desired characteristic X-rays. In this case, the number of types of multilayer films formed on the multilayer mirror 3 is larger than the number of types of metals formed as targets on the rotating body 11 of the X-ray source 2. Furthermore, in some cases, a desired plurality of types of characteristic X-rays can be obtained from one type of metal. In this case, as shown in FIG. 2, it is not necessary to cause electrons to collide with a plurality of metals to generate X-rays, and one type of metal may be formed on the outer peripheral surface of the rotating body 11. It may be an X-ray source in which the metal formed on the counter cathode is fixed (fixed target).

[Second Embodiment]
The X-ray diffraction apparatus 1 according to the second embodiment of the present invention is different from the X-ray diffraction apparatus 1 according to the first embodiment in the following points, but the other configurations are the same. As a first point, the shapes of a plurality of types of metals formed as targets on the rotating body 11 of the X-ray source 2 are different. As a second point, the X-ray detector 6 is a two-dimensional detector that does not have a wavelength separation function. Thirdly, the analysis unit 8 of the control analysis unit 9 does not necessarily need to be a multi-wave height analyzer that can be classified into X-ray wavelengths, and the control analysis unit 9 has a synchronization control means 10. doing.

  FIG. 6 is a schematic diagram showing the structure of the X-ray source 2 according to the embodiment. As described above, the shapes of the plurality of types of metals formed on the outer peripheral surface of the rotating body 11 are different. A plurality of types of metals are periodically arranged on the outer peripheral surface of the rotator 11 along the direction in which electrons scan. Here, along the direction in which the electrons scan, the outer peripheral surface of the rotator 11 is periodically arranged with two types of metals T1 and T2, and in each region where the two types of metals T1 and T2 are formed, The length in the direction in which electrons are scanned is equal. The horizontal width of the region where the metal T2 is formed is longer than the width of the X-ray emission region BS. Therefore, the metal formed in the X-ray emission region BS (predetermined region) where the electrons collide with the rotation of the rotating body 11 periodically repeats two kinds of metals T1 and T2. As a result, the X-ray S1 emitted from the X-ray window 13 alternately repeats the X-ray emitted from the metal T1 and the X-ray emitted from the metal T2. When the metal T1 is Cu, the metal T2 is Cr, and two desired characteristic X-rays are CuKα ray and CrKα ray, the X-ray source 2 includes an X-ray including a CuKα ray and an X-ray including a CrKα ray. Are periodically emitted. That is, the X-ray source 2 emits CuKα rays and CrKα rays alternately from a predetermined region during a predetermined measurement period. Here, the predetermined measurement period is, for example, a period in which the X-ray detector 6 is arranged at a certain position and the X-ray detector 6 detects X-rays at the position. In addition, the X-ray source 2 emits a plurality of types of characteristic X-rays. In this embodiment, during such a period, the X-ray source 2 alternately emits CuKα rays and CrKα rays each time, but considering the time scale of such a period, the X-ray source 2 is substantially At the same time, it can be considered that CuKα rays and CrKα rays are emitted.

  The multilayer mirror 3 selectively reflects desired types of characteristic X-rays. Here, X-rays including CuKα rays and X-rays including CrKα rays are periodically and repeatedly incident on the multilayer mirror 3. Therefore, the multilayer mirror 3 periodically and selectively reflects the CuKα ray from the X-ray including the CuKα ray and the CrKα ray from the X-ray including the CrKα ray to the sample 100 by the optical system 4. Incident.

FIG. 7 is a diagram showing the intensity of incident X-rays according to the embodiment. FIG. 7A shows the characteristic X-ray of the metal T1 (CuKα ray) and FIG. 7B shows the characteristic X-ray of the metal T2 (CuKα ray). CrKα line). As shown in FIG. 7, a characteristic X-ray intensity I ₁ of the metal T1, the characteristic X-ray intensity I ₂ of the metal T2, are cyclically repeated. Here, if the period in which the characteristic X-ray of the metal T ₁ has the intensity I ₁ is the odd period T _odd , and the period in which the characteristic X-ray of the metal T ₂ has the intensity I ₂ is the _even period T _even , the odd period T _odd is obtained. The diffracted X-rays generated from the sample 100 are due to the characteristic X-rays of the metal T1, and the diffracted X-rays generated from the sample 100 during the _even period Teven are due to the characteristic X-rays of the metal T2, and the odd period T _odd and the even period The wavelength of the generated diffracted X-rays can be separated in the period T _even .

In the first embodiment, since the sample 100 is irradiated with a plurality of types of characteristic X-rays simultaneously, the diffracted X-rays include diffracted X-rays of a plurality of types of wavelengths, and the X-ray detector 6 is Therefore, it was necessary to use a wavelength separation type detector. However, in this embodiment, the synchronization control means 10 is provided so that the X-rays received by the X-ray detector 6 can be detected separately in synchronization with the odd period T _odd and the _even period T _even . Even a detector that does not have a wavelength separation function can separate and detect the diffracted X-ray from the characteristic X-ray of the metal T1 and the diffracted X-ray from the characteristic X-ray of the metal T2. That is, the synchronization control means 10 obtains the rotation information of the rotating body 11 of the X-ray source 2, and based on the rotation information, the X-ray intensity corresponding to the X-rays radiated from each of the plurality of types of metals. The detection of the X-ray detector 6 is controlled to detect each.

FIG. 8 is a schematic diagram for explaining the synchronization control means 10 according to the embodiment. The synchronization control means 10 is provided in the control analysis unit 9. The synchronization control means 10 is connected to the X-ray source 2 and obtains rotation information of the rotating body 11 from the X-ray source 2. For example, if the rotating body rotates 100 times per second and five metal T1s and five metal T2s are alternately formed on the outer peripheral surface of the rotating body 11, one odd period _Todd and even number Each period T _even is 1 ms. The rotation information is information indicating where a predetermined point on the rotating body 11 is, for example. Considering such information and the shape of the outer peripheral surface of the rotating body 11, the synchronization control means 10 generates a synchronization signal.

The synchronization control means 10 is connected to the X-ray detector 6. Here, the X-ray detector 6 is a two-dimensional detector such as a CCD, a CMOS sensor, or a TFT sensor. These two-dimensional detectors have a plurality of regularly arranged pixels, and detect the intensity of X-rays received by each of the plurality of pixels. As described above, in the present embodiment, the X-ray detector 6 does not need to have a wavelength classification function, and can detect information to be detected at a predetermined time (odd period T _odd , _even period T _even, etc.). Good. Similarly, the analysis unit 8 of the control analysis unit 9 does not need to have a wavelength classification function, and it is only necessary to output information on the intensity of received X-rays regardless of the wavelength. The synchronization control means 10 outputs the generated synchronization signal to the X-ray detector 6. By setting the integration time in the X-ray detector 6 to be shorter than one odd period T _odd and _even period T _even , the intensity of diffracted X-rays can be detected in each period, so that the desired characteristic X Corresponding to the line, the X-ray intensity is detected. The X-ray detector 6 outputs an X-ray intensity detection result to the synchronization control means 10. The control analysis unit 9 including the synchronization control means 10 adds the obtained detection results, thereby measuring the diffraction image from the characteristic X-ray of the metal T1 and the measurement data of the diffraction image from the characteristic X-ray of the metal T2. And get.

Note that X-rays emitted by metal include specific X-rays and continuous X-rays. For example, when X-rays from the metal T1 (Cu) are selectively reflected by the multilayer mirror 3, the characteristic X-rays of the metal T1 from the continuous X-rays of the metal T1 together with the characteristic X-rays of the metal T1 (CuKα rays). The X-ray having the wavelength of the line (CrKα line) is reflected by the multilayer mirror 3 and is incident on the sample 100 by the optical system 4. In FIG. 7, the intensity ΔI ₂ is shown in the characteristic X-ray of the metal T2 in the odd period T _odd , and the intensity ΔI ₁ is shown in the characteristic X-ray of the metal T1 in the _even period T _even . In general, the strength of the continuous X-rays is sufficiently small compared to the intensity of the characteristic X-rays, as shown in FIG. 7, the X-ray of the same wavelength as the characteristic X-ray of the metal T2 in odd period T _odd is偶期between T _{the even} Even if X-rays having the same wavelength as the characteristic X-rays of the metal T1 are included in a minute amount, the influence on the measurement of diffracted X-rays is not great. The measurement data of the diffraction image of the characteristic X-ray of the metal T1 (T2) includes a minute diffraction image of the characteristic X-ray of the metal T2 (T1), but if necessary, both diffraction images. By comparing and correcting the measured data, it is possible to reduce the influence of minute X-ray intensity.

Further, as shown in FIGS. 3 and 4, the filter 26 may be disposed between the multilayer mirror 3 and the sample 100, or the filter layer 27 may be laminated on the multilayer mirror 3. When these filters (filter layers) absorb scattered X-rays caused by continuous X-rays, for example, the intensity ΔI ₂ of the characteristic X-rays of the metal T2 in the odd period T _odd becomes the metal T1 in the _even period T _even . The intensity ΔI ₁ of the characteristic X-rays is reduced, and these effects can be suppressed, and further effects can be obtained.

  In the X-ray diffraction apparatus 1 according to this embodiment, the X-ray source 2 can emit a plurality of types of characteristic X-rays, as in the first embodiment. However, in the first embodiment, desired multiple types of characteristic X-rays are simultaneously included in the X-ray S1 emitted from the X-ray window 13, whereas in the present embodiment, the desired multiple types of characteristic X-rays are included. These characteristic X-rays are periodically and repeatedly emitted separately from the X-ray window 13, and a desired plurality of types of characteristic X-rays can be separated. This makes it possible to irradiate the sample 100 periodically and separately with a plurality of desired types of characteristic X-rays as high-intensity X-rays. Unlike the first embodiment, the X-ray diffractometer 1 according to this embodiment includes the synchronization control means 10 and diffracts a desired plurality of types of characteristic X-rays without using a wavelength discrimination detector. Image measurement data can be obtained respectively. In addition, with respect to the same points as the configuration of the first embodiment, the same effect is obtained also in the embodiment, and the X-ray diffraction measurement can be performed simultaneously in a common environment, so that the measurement time is shortened. Not only that, high-quality measurement data is obtained.

[Other Embodiments]
Although the present invention has been described with reference to the preferred embodiments, it is needless to say that the present invention is not limited thereto.

  FIG. 9 is a schematic diagram showing the structure of another example of the X-ray source according to the embodiment of the present invention. In FIG. 9A, a plurality of types of metal alloys T3 having different atomic numbers are formed on the outer peripheral surface of the rotating body 11. As a result, the X-ray S1 emitted from the X-ray window 13 includes a plurality of types of characteristic X-rays, and simultaneously emits a plurality of types of characteristic X-rays, similar to the X-ray source 2 shown in FIG. Yes. The counter-cathode of the X-ray source shown in FIG. 9B is not a rotating body but a fixed counter-cathode 15, and a plurality of types of metal alloys T3 having different atomic numbers are formed on the surface of the fixed counter-cathode 15. Yes. Thus, the X-rays emitted from the X-ray source include a plurality of types of characteristic X-rays, and a plurality of types of characteristic X-rays are simultaneously emitted in the same manner as the X-ray source 2 shown in FIG.

  The X-ray source shown in FIG. 9 emits a desired plurality of types of characteristic X-rays simultaneously. Therefore, even if the X-ray source 2 of the X-ray diffraction apparatus 1 according to the first embodiment is changed to these X-ray sources and the other configurations are the same, the effects of the present invention are obtained. That is, by making the X-ray detector 6 a wavelength classification type detector, X-ray diffraction measurement using a plurality of types of characteristic X-rays is possible in a common environment.

  The X-ray detector 6 according to the embodiment of the present invention is a two-dimensional detector having a plurality of regularly arranged pixels, but may be a one-dimensional detector having pixels arranged in one column. Although a two-dimensional detector is desirable from the viewpoint of reducing measurement time, it may be selected according to the purpose of measurement.

DESCRIPTION OF SYMBOLS 1 X-ray diffraction apparatus, 2 X-ray source, 3 Multilayer mirror, 4 Optical system, 5 Sample stand, 6 X-ray detector, 7 Rotation drive system, 8 Analysis part, 9 Control analysis part, 10 Synchronous control means, 11 Rotating body, 12 Filament, 13 X-ray window, 15 Fixed anti-cathode, 21 Substrate, 22 Multi-layered multilayer film, 23 Heavy element layer, 24 Light element layer, 30 Planar X-ray detector, 31 pixels, 100 sample, BS X-ray emission region, L1, L2 multilayer film, P1, P2 focal point, S1 X-ray, T1, T2, metal, T3 alloy, T _{even even} period, T _odd odd period.

Claims (14)

An X-ray source that emits a plurality of types of characteristic X-rays in a predetermined measurement period from a predetermined region;
An optical system that includes a multilayer mirror that selectively reflects the plurality of types of characteristic X-rays from the X-rays emitted from the predetermined region by the X-ray source, and that causes the X-rays reflected by the multilayer mirror to enter the sample; The system,
An X-ray detector for detecting diffracted X-rays generated from the sample;
An X-ray diffraction apparatus comprising:
The multilayer mirror includes a plurality of types of multilayer films respectively corresponding to the plurality of types of characteristic X-rays,
The plurality of types of multilayer films are sequentially laminated to form a curved reflection surface, each multilayer film has a lattice plane interval that selectively reflects a corresponding characteristic X-ray, and the incident surface of the curved reflection surface The lattice spacing is inclined along the line of intersection with
An X-ray diffractometer characterized by that. The line of intersection of the curved reflecting surface with the incident surface is an elliptic curve,
The X-ray diffraction apparatus according to claim 1, wherein: The line of intersection of the curved reflecting surface with the incident surface is an elliptic curve, the predetermined region of the X-ray is disposed at one focal point of the curved reflecting surface, and the sample is disposed at the other focal point of the curved reflecting surface. Arranged,
The X-ray diffraction apparatus according to claim 1, wherein: The line of intersection with the incident surface of the curved reflecting surface is a parabola,
The X-ray diffraction apparatus according to claim 1, wherein: The line of intersection of the curved reflecting surface with the incident surface is a parabola, and the predetermined region of the X-ray is disposed at the focal point of the curved reflecting surface.
The X-ray diffraction apparatus according to claim 1, wherein: The plurality of types of multilayer films are stacked in order from the shorter wavelength of the characteristic X-ray that selectively reflects,
The X-ray diffraction apparatus according to claim 1, wherein: The X-ray source has an anti-cathode rotating body with which electrons collide with the outer peripheral surface,
A plurality of types of metals having different atomic numbers are arranged in order perpendicular to the direction in which the electrons are scanned, and are continuously arranged on the outer peripheral surface along the direction in which the electrons are scanned.
The X-ray diffraction apparatus according to claim 1, wherein The X-ray source has an anti-cathode rotating body with which electrons collide with the outer peripheral surface,
A plurality of types of metals having different atomic numbers are periodically arranged on the outer peripheral surface along the direction in which electrons scan.
The X-ray diffraction apparatus according to claim 1, wherein The X-ray source has an anti-cathode rotating body with which electrons collide with the outer peripheral surface,
A plurality of types of metal alloys having different atomic numbers are formed on the outer peripheral surface,
The X-ray diffraction apparatus according to claim 1, wherein The X-ray detector is a wavelength classification type detector that detects the intensity of received X-rays corresponding to the wavelengths of the plurality of types of characteristic X-rays.
The X-ray diffraction apparatus according to claim 1, wherein the X-ray diffraction apparatus is characterized in that Analyzing the X-ray information detected by the X-ray detector into an X-ray wavelength, and outputting X-ray intensity information corresponding to the wavelength;
A data processing unit that performs data analysis based on the X-ray intensity information output by the analysis unit;
An analysis data storage unit for storing data of analysis results of the data processing unit;
The X-ray diffraction apparatus according to claim 10, further comprising: The X-ray detector is configured to obtain rotation information of the counter-cathode rotating body and detect X-ray intensities corresponding to X-rays radiated from the plurality of types of metals based on the rotation information. Synchronization control means for controlling the detection of
The X-ray diffraction apparatus according to claim 8, wherein: A filter that is disposed between the multilayer mirror and the sample and absorbs scattered X-rays caused by continuous X-rays;
The X-ray diffraction apparatus according to claim 12, further comprising: The multilayer mirror is
A filter layer that absorbs scattered X-rays caused by continuous X-rays is included in at least one of the plurality of types of multilayer films;
The X-ray diffraction apparatus according to claim 12, wherein:

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