JP5116014B2 - Small-angle wide-angle X-ray measurement system - Google Patents

Description

  The present invention relates to an X-ray measuring apparatus for measuring scattered rays, diffraction rays, and the like generated from a sample, and in particular, both scattered rays generated in a small angle region and scattered rays generated in a wide angle region are simultaneously detected. The present invention relates to an X-ray measuring apparatus for measurement.

  It is already known that when a sample is irradiated with X-rays, scattered X-rays and diffraction lines, which are secondary X-rays, are generated from the sample under predetermined conditions. The diffracted rays are X-rays in a state where the intensity is increased due to the concentration of scattered rays at a specific angle. Whether secondary X-rays generated from a sample are called scattered rays or diffracted rays is appropriately selected depending on the case, but in this specification, scattered rays generated in a small-angle region are This is called scattered radiation, and scattered radiation or diffraction radiation generated in a wide angle region is called wide angle scattered radiation.

  Conventionally, for example, Patent Document 1 discloses a small-angle X-ray scattering measurement apparatus. In the small-angle X-ray scattering measurement device disclosed herein, point-focused X-rays are taken out from an X-ray source, and the X-rays are condensed by a multilayer mirror that is an X-ray condensing unit, and the condensed light is collected. The sample is irradiated with X-rays through three slits. Then, the scattered radiation, which is the secondary X-ray generated from the sample within a small angle region (for example, 0 ° <2θ ≦ 5 °) of the diffraction angle 2θ, is detected by the two-dimensional X-ray detector.

  Further, for example, Patent Document 2 discloses a wide-angle X-ray scattering measurement apparatus. In the wide-angle X-ray scattering measurement apparatus disclosed herein, X-rays radiated from an X-ray source are collimated by a collimator including a first pinhole and a second pinhole and irradiated onto a sample. Then, the scattered light or diffraction lines generated on the reflection side (back side) of the sample and within the wide angle region (5 ° ≦ 2θ) of the diffraction angle 2θ are converted into a visible light image by the fluorescent screen, and the visible light image is converted into the visible light image. Reflected by a mirror surface and detected by a TV camera.

  Further, for example, Non-Patent Document 1 discloses an apparatus for simultaneously measuring small-angle scattering and wide-angle scattering. In this apparatus, two flat panel X-ray sensors are juxtaposed on the X-ray optical path of the small-angle X-ray scattering measurement apparatus at a position on the near side of the sample with an interval corresponding to the X-ray optical path. When a small-angle scattered ray is generated from the sample, the small-angle scattered ray is detected by an X-ray detector disposed behind the two panel sensors. When wide-angle scattered rays are generated from the sample, the wide-angle scattered rays are detected by two panel sensors.

JP 2001-356197 (pages 3 to 4, FIG. 1) Japanese Examined Patent Publication No. 52-41073 (pages 1 and 2, Fig. 1) N.Yagi, “Simultaneous recording of SAXS / WAXS patterns using modified Shad-o-Box”, [online], [Search April 17, 2007], Internet <URL: http: // www .ads-img.co.jp / products / rad-icon / pdf / saxswaxs.pdf>

In general, according to the small-angle X-ray scattering measurement, a nanometer (10 ⁻⁹ m) order structure in a substance can be analyzed. On the other hand, according to the wide-angle scattering measurement, a sub-nanometer (10 ⁻¹⁰ m) order structure in the substance can be analyzed. According to the small-angle X-ray scattering measurement device disclosed in Patent Document 1, it is possible to perform a nanometer-order structural analysis in a substance by performing small-angle X-ray scattering measurement. The measurement in this case is performed by setting the distance (so-called camera length) from the sample to the two-dimensional X-ray detector to be long (for example, about 1 m). In this small-angle X-ray scattering measurement apparatus, if the camera length is shortened, wide-angle X-ray scattering measurement can be performed, and sub-nano-order structural analysis in a substance can also be performed.

  In recent years, there has been a desire to simultaneously perform small-angle X-ray scattering measurement and wide-angle X-ray scattering measurement for substances. The reason is, for example, when measuring while applying a load to a substance, when measuring while changing the temperature of the substance, or when measuring while changing the humidity of the substance, etc. And wide-angle X-ray scattering measurement are not performed at the same time, the load conditions, temperature conditions, and humidity conditions for the substance will be different between the small-angle X-ray scattering measurement and the wide-angle X-ray scattering measurement. This is because the small-angle X-ray scattering measurement and the wide-angle X-ray scattering measurement are not performed.

  In the small-angle X-ray scattering apparatus disclosed in Patent Document 1, since either the small-angle X-ray scattering measurement or the wide-angle X-ray scattering measurement is selected by changing the camera length, these measurements cannot be performed simultaneously. . In addition, since the wide-angle X-ray scattering measurement device disclosed in Patent Document 2 cannot perform small-angle scattering measurement in the first place, naturally, small-angle X-ray scattering measurement and wide-angle X-ray scattering measurement can be performed simultaneously. Can not.

  In the apparatus disclosed in Non-Patent Document 1, both small-angle scattered rays and wide-angle scattered rays can be detected simultaneously by using two panel sensors and a rear-arranged X-ray detector. However, in the apparatus disclosed in Non-Patent Document 1, since a long slit-shaped opening is formed between the two panel sensors, as shown in FIG. There was a slit-like region where data could not be acquired corresponding to the aperture. This data unacquisable area often contains valuable data. Therefore, in this device, the reliability of the wide angle scatter measurement data is low when the small angle scatter measurement data and the wide angle scatter measurement data are obtained simultaneously. There is a problem that it is low.

  The present invention has been made in view of the above problems, and can perform small-angle X-ray scattering measurement and wide-angle X-ray scattering measurement at the same time, and can improve the measurement accuracy of wide-angle X-ray scattering measurement. An object is to provide a small-angle wide-angle X-ray measurement apparatus.

A small-angle wide-angle X-ray measurement apparatus according to the present invention irradiates a sample with X-rays emitted from an X-ray source and detects scattered rays generated from the sample by an X-ray detection means within a small-angle region. And a wide-angle X-ray optical system that is provided between the sample and the X-ray detection means and detects scattered rays generated from the sample in a wide-angle region. The wide-angle X-ray optical system includes a phosphor that converts the X-ray image with provided on the X-ray beam path between the sample and the X-ray detecting unit into a visible light image, formed on the phosphor A light reflector that reflects the visible light image; and a light detection unit that detects the visible light image reflected by the light reflector. An X-ray opening is provided in each of the phosphor and the light reflector at a portion that intersects the X-ray optical path, and the X-ray opening has an opening diameter that allows the maximum angle value of the small angle region.

  In the above configuration, the small angle region is an angle region where it is necessary to acquire a small angle scattered ray. If defined by the diffraction angle 2θ, generally an angle defined by 0 ° <2θ ≦ 5 °. It is an area. The wide angle region is an angle region where it is necessary to acquire a wide angle scattered ray, and is generally an angle region defined by 5 ° ≦ 2θ ≦ 50 °.

  According to the small-angle wide-angle X-ray measurement apparatus according to the present invention having the above-described configuration, the phosphor and the light reflector constituting the wide-angle X-ray optical system are provided at positions intersecting the X-ray optical axis of the small-angle X-ray optical system, Since the X-ray passage is provided in each of the fluorescent material and the light reflector that intersect the X-ray optical axis, the same sample is detected simultaneously with the detection of the small-angle scattered radiation generated from the sample using the small-angle optical system. Can simultaneously detect wide-angle scattered radiation generated from a wide-angle optical system.

  In a conventional small-angle wide-angle X-ray measuring apparatus using two panel sensors, a large slit-shaped opening is formed between the panels, and thus wide-angle scattered radiation corresponding to the opening cannot be detected. On the other hand, according to the small-angle wide-angle X-ray measurement apparatus according to the present invention, the diameter of the X-ray opening provided in the phosphor and the light reflector is the maximum angle value (for example, 2θ = 5 °) in the small-angle region. Since the expected diameter is not larger than necessary, all of the wide-angle scattered radiation can be detected without omission and the measurement accuracy of the wide-angle X-ray scattering measurement can be improved.

  Next, the small-angle wide-angle X-ray measurement apparatus according to the present invention preferably further includes a dark box that surrounds the phosphor and the light reflector, and further, an X-ray is applied to the dark box at a portion that intersects the X-ray optical path. It is preferable that an opening for use is provided, and the X-ray opening has an opening diameter that allows for the maximum angle value of the small angle region. According to this configuration, extra light is prevented from being taken into the light detection means, and accurate wide-angle scattering measurement can be performed.

  Next, in the small-angle wide-angle X-ray measurement apparatus according to the present invention, it is desirable that the light detection means is a two-dimensional CCD optical sensor. The two-dimensional CCD optical sensor is an optical sensor configured by arranging a plurality of CCD (Charge coupled device) elements in a matrix, for example, in an array of 512 × 512 pixels. When each CCD element receives light, charges are accumulated in the portion, and the position and light quantity received by the light can be detected as digital data by reading and scanning these charges by a predetermined method. If a CCD optical sensor is used as the detecting means, a phosphor and a light reflector need only be arranged on the X-ray optical path. Therefore, compared with the case where an X-ray panel sensor is provided on the X-ray optical path, Configuration is simplified.

  Next, in the small-angle wide-angle X-ray measuring apparatus according to the present invention, the phosphor is disposed at a right angle to the X-ray optical axis, and the light reflector is disposed to be inclined with respect to the X-ray optical axis. It is desirable. With this configuration, an accurate wide-angle scattered radiation image can be acquired by the phosphor. Moreover, it is desirable that the phosphor is disposed at a position closer to the sample than the light reflector. With this configuration, the distance between the sample and the phosphor can be reduced, and a clear wide-angle scattered radiation image can be formed on the phosphor.

Next, in the small-angle and wide-angle X-ray measurement apparatus according to the present invention, the small-angle X-ray optical system includes the X-ray source and generates X-rays that extract point-focused X-rays from the X-rays generated by the X-ray source. It is desirable to have an apparatus and X-ray condensing means that is arranged between the X-ray source and the sample and condenses X-rays extracted from the X-ray source. As the small-angle X-ray optical system, it is possible to use X-rays extracted by line focus. In this case, since scattered rays overlap in the line direction (vertical direction), an arithmetic process for correcting the overlap is performed. Need to do it. On the other hand, if point-focused X-rays are used, accurate scattered radiation data can be obtained without performing such correction. The intensity of point-focused X-rays is lower than that of line-focused X-rays. However, in the aspect of the present invention, the point-focused X-rays are focused by an X-ray focusing means, for example, a confocal mirror. The sample can be irradiated with high-intensity X-rays while being in focus.

  Next, in the small-angle wide-angle X-ray measurement apparatus according to the present invention, it is preferable that the X-ray optical path from the X-ray source to the X-ray detection means is further maintained in a decompressed state, and further, the dark box It is desirable that the inside of the chamber is also maintained in a reduced pressure state. With this configuration, it is possible to prevent unnecessary scattered rays from being generated due to air scattering, and it is possible to obtain clear small-angle scattered ray images and wide-angle scattered ray images.

  According to the present invention, the phosphor and the light reflector constituting the wide-angle X-ray optical system are provided at a position that intersects with the X-ray optical axis of the small-angle X-ray optical system. Since each of the light reflectors is provided with an X-ray passage opening, the small-angle scattered radiation generated from the sample is detected using the small-angle optical system, and at the same time, the wide-angle scattered radiation generated simultaneously from the same sample is detected. Can be detected simultaneously. In addition, the diameter of the X-ray opening provided in the phosphor and the light reflector is a diameter that allows the maximum angle value (for example, 2θ = 5 °) in the small angle region, and is not larger than necessary. All of the lines can be detected without omission and the measurement accuracy of wide-angle X-ray scattering measurement can be improved.

(First embodiment)
Hereinafter, a small-angle wide-angle X-ray measurement apparatus according to the present invention will be described based on embodiments. Of course, the present invention is not limited to this embodiment. In the following description, the drawings are referred to. In the drawings, the components may be shown in different ratios from the actual ones in order to show the characteristic parts in an easy-to-understand manner.

  FIG. 1 shows an external configuration of an embodiment of a small-angle wide-angle X-ray measurement apparatus according to the present invention. FIG. 2 shows an X-ray optical system built in the X-ray measuring apparatus. FIG. 2 corresponds to a plan view of the apparatus shown in FIG. 1 and 2, a three-dimensional display indicated by XYZ indicates a three-dimensional space in which the small-angle wide-angle X-ray measurement apparatus is installed. The plane defined by XY is a so-called equator plane, and the Z direction is a latitude direction orthogonal to the equator plane. The equator plane is generally a horizontal plane, and the central axis (so-called optical axis) of X-rays incident on the sample and emitted from the sample is included in the equator plane.

  In FIG. 1, this small-angle wide-angle X-ray measurement apparatus has a sample stage 6 at a substantially central position, and a sample S as a measurement target is placed on the sample stage 6. As the sample S, a film sample, a fiber sample, a liquid sample, and other samples in various states are provided. The sample stage 6 is formed in a shape and structure suitable for the provided sample. An incident side optical system is installed on the left side of the sample stage 6, and a light receiving side optical system is installed on the right side of the sample stage 6.

  The incident side optical system includes an X-ray generation device 1, an X-ray condensing device 2, a first slit portion 3, a second slit portion 4, and a third slit portion 5. The light receiving side optical system includes a wide-angle X-ray optical system 7, a two-dimensional detector unit 8, and a CCD detector unit 9. Each of the above elements except for the X-ray generator 1 and the X-ray collector 2 is provided on a rail 12 provided on a base 11. Each element provided on the rail 12 can be fixedly arranged on the rail 12 with its position changed individually.

  A first decompression path 13a is provided between the first slit part 3 and the second slit part 4, and a second decompression path 13b is provided between the second slit part 4 and the third slit part 5, A third decompression path 13 c is provided between the wide-angle X-ray optical system 7 and the two-dimensional detector unit 8. The first decompression path 13a and the second decompression path 13b are tubes having a constant length and an airtight structure. The third decompression path 13c is formed of an accordion-like stretchable member, and can extend and contract along the rail 12 to change its length. This expansion / contraction movement takes into account the adjustment of the camera length. The inside of each decompression path is decompressed by a decompression device (not shown) such as a rotary pump and a turbo molecular pump, and set to a vacuum or a decompressed state close to vacuum. This decompression is a measure for preventing an increase in the background component in the measurement data due to the generation of unnecessary scattered radiation due to the air scattering phenomenon.

The correspondence between FIG. 1 and FIG. 2 will be described. An X-ray focal point F as an X-ray source is provided inside the X-ray generator 1, and X-ray condensing means is provided inside the X-ray collector 2. The X-ray condensing element 22 is provided, the first slit 23 is provided inside the first slit portion 3, the second slit 24 is provided inside the second slit portion 4, and the inside of the third slit portion 5. A third slit 25 is provided at the end. The sample S shown in FIG. 2 is supported by the sample stage 6 of FIG. The detector plate 26 and the direct beam stopper 27 shown in FIG. 2 are provided inside the two-dimensional detector unit 8 of FIG. In this specification, a region where X-rays travel from the X-ray focal point F to the detector plate 26 is referred to as an X-ray optical path, and a central axis of the X-ray optical path is referred to as an X-ray optical axis X1. The X-ray optical axis X1 is included in the equator plane XY.

  The detector plate 26 is a flat plate-like X-ray detector in which a stimulable phosphor is provided in a layer with a uniform thickness on the X-ray detection surface. The direct beam stopper 27 is formed of a material that does not transmit X-rays, and is provided on the X-ray optical axis. The detector plate 26 accumulates an energy latent image at a position where the X-ray hits, and when the excitation excitation light (for example, laser light) is irradiated to the position, the accumulated energy latent image becomes light. It has the property of emitting. The direct beam stopper 27 prevents the detector plate 26 from being irradiated with a direct beam. When reading the scattered radiation image recorded on the detector plate 26, the detector plate 26 is removed from the small-angle wide-angle X-ray measuring apparatus, and the reading process is performed by a reader installed in another place.

  Although the internal structure of the CCD detector unit 9 shown in FIG. 1 is not shown in FIG. 2, for example, a phosphor screen having substantially the same area as the detector plate 26 is provided at a position behind the position where the detector plate 26 is arranged. A scattered radiation image is converted into a light image by the phosphor screen, the light image is guided to a planar CCD sensor by an optical fiber bundle, and a two-dimensional image signal corresponding to the scattered radiation image is generated by the CCD sensor; A CCD X-ray detector having the configuration described above can be arranged. In FIG. 1, the measurer selects either the two-dimensional detector unit 8 or the CCD detector unit 9 and performs measurement.

In FIG. 1, the X-ray generator 1 has a housing 16, and the housing 16 is provided around the X-ray focal point F. X-rays generated from the X-ray focal point F are extracted outside through an X-ray extraction window 17 provided in the housing 16. For example, as shown in FIG. 3, the X-ray generation apparatus 1 includes a rotor target (that is, a rotating counter cathode) 18 and a filament (that is, a cathode) 19 that faces the rotor target (that is, a rotating counter cathode). When the filament 19 is energized, thermoelectrons are emitted from the filament 19 and the thermoelectrons collide with the target 18. This collision area is an X-ray focal point F as an X-ray source . Cooling water flows inside the target 18. By rotating the target 18 and flowing cooling water through the target 18, the target 18 is prevented from being damaged due to the high temperature.

In the present embodiment, the surface of the target 18 is formed of Cu, and measurement is performed using a characteristic X-ray of CuKα. Further, the X-ray extraction angle α from the X-ray focal point F is about 6 °, and the focal point size d ₀ at a viewing angle of about 6 ° is set to 0.08 mmφ (or 0.08 mm × 0.08 mm). did. That is, it was decided to take out point-focused X-rays with a focal size of 0.08 mmφ. In FIG. 2, the X-ray extracted from the X-ray focal point F is irradiated to the sample S through the X-ray condensing element 22 and the first to third slits 23, 24 and 25. Then, secondary X-rays generated from the sample S are taken into the wide-angle X-ray optical system 7 or passed through the wide-angle X-ray optical system 7 and taken into the detector plate 26.

  Next, as shown in FIG. 4A, the X-ray condensing element 22 is formed by a first mirror 22a and a second mirror 22b which are a pair of X-ray reflecting mirrors joined at right angles to each other. ing. This X-ray condensing element 22 may be called a confocal mirror. The X-ray reflecting surfaces 29 of the first mirror 22a and the second mirror 22b are, as shown in FIG. 4B, a predetermined curved surface that can collect X-rays, such as a paraboloid, an ellipsoid, and the like. It has become. Depending on the shape of the curved surface, the incident X-rays can be shaped into a focused beam that converges to an appropriate point, or can be shaped into a parallel beam. In the present embodiment, it is assumed that the X-ray focusing element 22 forms X-rays into a focused beam. The condensing point of the focused beam is appropriately selected as necessary, but in this embodiment, the condensing point is set so as to condense at a position slightly behind the sample S in FIG. The condensing point may be matched with the sample S or may be matched with the detector plate 26.

  As shown in FIG. 4B, the X-ray reflection surface 29 is formed by a laminated structure of a heavy element layer 30 and a light element layer 31. In the figure, only three layer pairs of the heavy element layer 30 and the light element layer 31 are shown, but in reality, hundreds to thousands of layer pairs are provided. As a heavy element constituting the heavy element layer 30, for example, tungsten (W), platinum (Pt), or nickel (Ni) can be used. Moreover, as a light element which comprises the light element layer 31, carbon (C) and silicon (Si) can be used, for example. In this embodiment, nickel is used as the heavy element and carbon is used as the light element. When a combination of nickel and carbon was employed, focused X-rays with high intensity could be obtained.

When X-rays generated from the X-ray focal point F are incident on the mirrors 22a and 22b, the wavelength of the X-rays is “λ”, the incident angle of the X-rays is “θ”, and the grating corresponds to the thickness of the layer pairs 30 and 31 If the surface spacing is “d”, the known Bragg diffraction conditions
2 dsin θ = nλ
When X is satisfied, diffracted X-rays are generated. In the above equation, “n” is the reflection order.

  In the present embodiment, the lattice plane distance d formed by the layer pairs 30 and 31 is such that the curved surface 29 satisfies the Bragg diffraction condition at an arbitrary position of the X-ray reflecting surface 29 with respect to a specific wavelength, for example, CuKα rays. It is formed in a state that changes continuously along. Such a multilayer film can be produced based on, for example, the method disclosed in Japanese Patent Application Laid-Open No. 60-7400. Since the X-ray reflection surface 29 of the mirrors 22a and 22b is thus formed by the plurality of layer pairs 30 and 31 that can diffract X-rays at each point, the X-ray reflection surface 29 is radiated from the X-ray focal point F. The diffracted X-ray becomes a focused X-ray beam and is emitted from the mirrors 22a and 22b. In addition, the focused X-ray beam has a very high intensity because it is a collection of the beams generated from each layer pair of the multilayer film.

  In FIG. 4A, the X-rays incident on the first mirror 22a and the second mirror 22b are repeatedly reflected between the mirrors 22a and 22b, and then emitted as a focused X-ray beam. In this case, since the first mirror 22a and the second mirror 22b are in a right-angled positional relationship, the cross-sectional shape of the emitted X-ray beam is a rhombus shape or a square shape.

  Note that the angular arrangement of the first mirror 22a and the second mirror 22b in the three-dimensional space XYZ is arbitrarily set as necessary. The mirror 22a and the second mirror 22b are tilted at an angle of 45 ° with respect to the vertical axis (Z axis) and the horizontal axis (Y axis), respectively. This is to facilitate the extraction of the parallel X-ray beam into the equator plane (XY plane). However, the first mirror 22a and the second mirror 22b may be provided in parallel with the Z axis and the Y axis, respectively.

In FIG. 4C, when the individual X-ray beams in the parallel X-ray beams emitted from the first mirror 22a and the second mirror 22b constituting the X-ray focusing element 22 are viewed, the individual X-ray beams are spread. Has an angle δ ₀ . The divergence angle δ ₀ is given as a peak width of the rocking curve, generally a half-value width, when the rocking curve is measured for the multilayer mirrors 22a and 22b. In this embodiment in which the layer pair of the multilayer film is formed of nickel, which is a heavy element, and carbon, which is a light element, the spread angle δ ₀ of the X-ray beam by the mirrors 22a and 22b itself is about 0.04 °. .

In FIG. 2, the point-focused X-rays generated from the X-ray focal point F and extracted at a predetermined focal point size are taken in from the X-ray entrance of the X-ray focusing element 22 while diverging. In this case, if the cross-sectional size of the diverging X-ray is too small than the opening area of the X-ray entrance of the X-ray condensing element 22, sufficient X-rays cannot be obtained, and if the X-ray cross-sectional size is too large. There is a disadvantage that more X-rays are wasted in the X-rays emitted from the X-ray focal point F. In the present embodiment, the X-ray focus F length _{L 1} of about 125mm to the center position of the X-ray focusing elements 22 (up to X-ray incidence port 85 mm) was set to, 1.3 mm × 1 the X-ray incidence port By setting to 3 mm, the X-ray emitted from the X-ray focal point F can be taken in by the X-ray focusing element 22 without being wasted, and a strong X-ray beam can be obtained. ing.

  Next, the first slit 23, the second slit 24, and the third slit 25 are all formed as circular pinholes. As the slit shape, there are a rectangular shape or a square shape in addition to the circular shape, but in the case of small-angle scattering measurement, a clear scattered radiation image can be obtained by using the circular slit. This is thought to be because unnecessary scattered rays are generated at the corners of a rectangular or square slit. The first slit 23 and the second slit 24 constitute a pinhole collimator. In other words, the X-rays emitted from the X-ray condensing element 22 are shaped into a parallel beam or a focused beam by suppressing the divergence by the cooperation of the first slit 23 and the second slit 24. The third slit 25 acts as a guard slit that prevents unwanted scattered rays from entering the sample S. As described above, by suppressing the dispersion of X-rays incident on the sample S by the slits 23, 24, and 25, and preventing unwanted scattered rays from entering the sample S, a small angle at the diffraction angle 2θ. It is possible to measure scattered radiation generated from the sample S in a region (for example, 0 ° <2θ ≦ 5 °).

  The sample S is supported by the sample stage 6 in FIG. The sample stage 6 includes, for example, a 4-axis rotation mechanism. By selecting an arbitrary axis of the four-axis rotation mechanism and rotating the sample S by a desired angle, a desired portion of the sample S can be placed on the X-ray optical axis X1. The sample stage 6 may have a configuration including a three-axis rotation mechanism.

In FIG. 2, the X-ray focal point F which is an X-ray source , the X-ray condensing element 22, the first slit 23, the second slit 24, the third slit 25, the sample S, and the detector plate 26 are small-angle X-ray scattering. A small-angle X-ray optical system for performing measurement is configured. The wide-angle X-ray optical system 7 is disposed on the X-ray optical path of the small-angle X-ray optical system. As shown in FIG. 5, the wide-angle X-ray optical system 7 includes a dark box 34 disposed across the X-ray optical path including the X-ray optical axis X <b> 1 and a detection unit 35 connected to the dark box 34. The dark box 34 is a box sealed so that light does not enter the inside. The inside of the dark box 34 is formed of, for example, an aluminum plate material subjected to matte black processing in order to prevent light reflection.

A fluorescent layer support 36 made of, for example, acrylic resin or glass is provided on the side wall portion of the dark box 34 on the sample S side, and a fluorescent layer 37 is formed in a layered manner with a constant thickness on the plane of the fluorescent layer support 36. Is provided. The fluorescent layer support 36 and the fluorescent layer 37 constitute a fluorescent plate 38 as a fluorescent material. The fluorescent layer 37 is a transmissive fluorescent layer, and an X-ray image received on the surface on the sample S side is displayed as a visible light image on the opposite surface. A circular X-ray opening 39 is provided at a portion where the fluorescent plate 38 intersects the X-ray optical axis X1. Further, a sheet-like light shielding member 40 such as black paper, a light-shielding polymer resin film, or the like is attached to the wall of the dark box 34 on the sample S side of the fluorescent plate 38. The light shielding member 40 is a member that blocks the passage of light and allows the passage of X-rays.

  Light reflectors 42 are provided at diagonal positions inside the dark box 34. In the present embodiment, the light reflecting plate 42 is inclined at an angle of approximately 45 ° with respect to the X-ray optical axis X1. The light reflecting plate 42 is formed by, for example, forming a thin film of light reflecting metal (for example, Al (aluminum)) in a uniform thickness on the surface of a support made of acrylic resin or glass. The light reflecting surface on which the metal thin film is formed faces the fluorescent plate 38. An X-ray opening 43 is provided at a portion where the light reflecting plate 42 intersects the X-ray optical axis X1. Is formed in an oval or oval shape that is circular when viewed from the X-ray optical axis X1.

A circular X-ray opening 44 is provided on the side wall of the dark box 34 on the detector plate 26 side. The X-ray opening 44 is shielded from light by an appropriate light shielding member. When small-angle X-ray scattering measurement is performed using a small-angle X-ray optical system including the X-ray focal point F, the X-ray focusing element 22, the slits 23 to 25, the sample S, and the detector plate 26 in FIG. In FIG. 2, the scattered radiation generated from the sample S sequentially passes through the X-ray opening 39 of the fluorescent plate 38, the X-ray opening 43 of the light reflecting plate 42, and the X-ray opening 44 on the side wall of the dark box 34. To reach and expose it. The portion of the detector plate 26 corresponding to the direct beam stopper 27 cannot receive scattered radiation as measurement data.

  The radius of the opening circle of each X-ray opening 39, 43, 44 is determined as follows. Since the X-ray opening 39 and the X-ray opening 44 are arranged at right angles to the X-ray optical axis X1, the maximum angle of the small-angle region to be measured in the small-angle X-ray scattering measurement is “β”, and the X-ray from the sample S If the distance to the opening 39 is L3, the radius of the opening circle of the X-ray opening 39 is “L3 × tan β”. If the distance from the sample S to the X-ray opening 44 is L5, the radius of the opening circle of the X-ray opening 44 is “L5 × tan β”. In general, the small-angle measurement region in the small-angle X-ray scattering measurement satisfies 0 ° <2θ (diffraction angle) ≦ 5 °, so β = 5 ° may be set. That is, the radius of the open circle of the X-ray openings 39 and 44 is a radius of a circle that allows the maximum angle value (5 °) in the small angle region (0 ° <2θ ≦ 5 °).

  Since the X-ray opening 43 is inclined with respect to the X-ray optical axis X1, when the distance from the sample S to the center of the X-ray opening 43 is L4, the X-ray opening 43 is perpendicular to the X-ray optical axis X1. The X-ray opening 43 is formed in an elliptical shape or an elliptical shape so that the apparent opening circle has a radius of “L4 × tan β”. That is, the radius of the opening circle of the X-ray opening 43 is also the radius of the circle that allows the maximum angle value (5 °) in the small angle region (0 ° <2θ ≦ 5 °).

  An imaging lens 46 is provided inside a cylindrical connecting portion 45 that connects the dark box 34 and the detecting portion 35. Further, a two-dimensional CCD (Charge coupled device) sensor 47 which is a two-dimensional X-ray detector is provided inside the detection unit 35. This two-dimensional CCD sensor is formed by arranging a plurality of CCD elements in a matrix on a plane. In the present embodiment, the number of pixels and the arrangement of the CCD elements are 512 × 512 pixels. The CCD sensor 47 is an element that outputs a light receiving position and a received light amount of light received in a two-dimensional area as electric signals. A cooling device 48 is provided on the surface opposite to the light receiving surface of the two-dimensional CCD sensor 47. The cooling device 48 is an element for enabling the CCD sensor 47 to be exposed for a long time by suppressing the occurrence of dark current in the CCD sensor 47. The cooling device 48 is realized, for example, by using a Peltier element, using a liquid refrigerant, utilizing heat radiation from fins or the like.

  Next, in FIG. 1, the dark box 34 of the wide-angle X-ray optical system 7 is connected to the third decompression path 13c. When the interior of the third decompression path 13c is decompressed, the interior of the dark box 34 is also decompressed simultaneously. Therefore, the dark box 34 is formed in an airtight structure and has a structure having sufficient strength that does not break even when the outside is in an atmospheric pressure state and the inside is in a vacuum state.

  Hereinafter, the measurement using this measuring apparatus will be described. This measuring apparatus can simultaneously perform small-angle X-ray scattering measurement and wide-angle X-ray scattering measurement. Hereinafter, these measurements will be described individually. In the small angle X-ray scattering measurement, a small angle region of 0 ° <2θ (diffraction angle) ≦ 5 ° is a measurement range, and in the wide angle X-ray scattering measurement, a wide angle region of 5 ° ≦ 2θ ≦ 50 ° is a measurement range. I will decide.

  First, small-angle X-ray scattering measurement is performed as follows. In FIG. 2, the distance from the sample S to the detector plate 26, the so-called camera length L2, is set to a long distance, for example, 1 m. Then, a point-focused X-ray including CuKα ray is taken out from the X-ray focal point F, and the X-ray is reflected by the first mirror 22a and the second mirror 22b which are constituent elements of the X-ray condensing element 22 to a specific point. The beam is shaped so as to be condensed. In this case, the X-rays are not X-rays partially cut by the slits, but are obtained by diffraction by the mirrors 22a and 22b, and are very strong X-rays. This high-intensity X-ray enters the sample S in a state where divergence is suppressed by the first slit 23 and the second slit 24. At this time, the third slit 25 prevents unnecessary scattered rays from entering the sample S.

Thus, when X-rays with high intensity and suppressed divergence are incident on the sample S, the small-angle region (0 ° <2θ ≦ 5 °) is caused by the nano (10 ⁻⁹ m) structure included in the sample S. Scattered rays are generated at an angular position of the scattering angle (diffraction angle) 2θ inherent to the sample. In FIG. 5, the scattered rays pass through the X-ray openings 39, 43, and 44 in the wide-angle X-ray optical system 7 and reach the detector plate 26 to form an X-ray scattered ray image. By performing a reading process on the detector plate 26 holding the X-ray scattered radiation image by the reader, scattered radiation data relating to the sample S can be obtained, and by analyzing the scattered radiation data, the inside of the sample S is analyzed. Nanoscale (10 ⁻⁹ m) structure, more specifically, a molecular level structure (macro structure of 1 nm to 100 nm) to an atomic level structure (microstructure of 0.2 nm to 1 nm) can be evaluated.

On the other hand, wide-angle X-ray scattering measurement is performed as follows simultaneously with small-angle X-ray scattering measurement. In FIG. 2, the distance L3 from the sample S to the fluorescent layer 37 of the fluorescent plate 38 is set to an appropriate distance within 40 cm ≦ L3 ≦ 50 cm. In FIG. 5, when X-rays enter the sample S, the scattering angle (diffraction angle) inherent to the sample in a wide angle region (5 ° ≦ 2θ) due to the sub-nano (10 ⁻¹⁰ m) structure included in the sample S. ) Scattered rays (diffracted rays) are generated at an angular position of 2θ. In FIG. 5, the scattered rays enter the fluorescent layer 37 of the fluorescent plate 38, are converted into a visible light image by the action of the fluorescent layer 37, and are displayed on the back surface (right side in the drawing). This visible light image is reflected by the light reflecting plate 42 and formed on the light receiving surface of the two-dimensional CCD sensor 47 by the action of the lens 46. The CCD sensor 47 reads a visible light image based on a predetermined scanning reading method and generates diffraction line data. By analyzing the diffraction line data, the sub-nanoscale (10 ⁻¹⁰ m) structure inside the sample S can be evaluated.

  The time for which the sample S is irradiated with X-rays is several minutes. During this few minutes, the CCD sensor 47 is exposed and accumulates an image. In general, as the exposure time for the CCD sensor becomes longer, the dark current increases and accurate data cannot be obtained. However, in this embodiment, the CCD sensor is cooled, so that it can withstand long exposure. A preferable cooling temperature was about −50 ° C. The reading time by the CCD sensor 47 after image storage is usually several seconds. Although not particularly shown in FIG. 5, it is desirable to provide a mechanical shutter between the lens 46 and the CCD sensor 47. It is desirable to open the mechanical shutter during image accumulation and close the mechanical shutter so that external light does not enter the CCD sensor 47 during reading.

  As described above, small-angle scattered ray data and wide-angle scattered ray data can be obtained simultaneously when the sample S is placed under exactly the same common conditions. As a result, the internal structure of the sample S can be accurately evaluated. Although not specifically shown in FIGS. 1 and 2, the sample S can be equipped with ancillary equipment such as a load applying device, a temperature control device, a humidity control device, and the like. The load applying device is a device that can apply a tensile or compressive load to the sample S. The temperature control device is a device that can control the temperature of the sample S by increasing or decreasing it. The humidity control device is a device that can control the humidity around the sample S by increasing or decreasing it.

  The conventional small-angle X-ray scattering measurement apparatus does not include the wide-angle X-ray optical system 7 in FIG. If it is desired to perform wide-angle scattering measurement with this small-angle X-ray scattering measurement device, it is possible to perform wide-angle scattering measurement by changing the camera length L2 from a long distance such as 1 m to a short distance capable of measuring a wide-angle region. is there. Otherwise, the sample S must be mounted on a dedicated wide-angle X-ray measuring device to perform wide-angle X-ray measurement. When trying to acquire small-angle scattered ray data and wide-angle scattered ray data while changing the conditions for the sample using the various accessory devices described above, a conventional measurement method is adopted in which the camera length is changed or the measuring device is changed. If this is the case, it is impossible to obtain these two types of data while the sample S is accurately placed under common conditions. On the other hand, according to the present embodiment, two types of data, small-angle scattered ray data and wide-angle scattered ray data, can be obtained under exactly the same conditions. Therefore, very accurate analysis can be performed based on these data. It becomes possible.

  On the other hand, in a conventional small-angle wide-angle X-ray measuring apparatus having a structure in which two panel sensors are juxtaposed with an X-ray optical axis in between, a scattered radiation image corresponding to the interval between the panel sensors is shown in FIG. Since it was not obtained, it was difficult to perform sufficiently accurate evaluation. On the other hand, in the present embodiment, the wide-angle scattered radiation generated from the sample S in FIG. 2 is received by the fluorescent layer 37 having a small X-ray opening 39 at the center, so that the wide-angle scattered radiation is spread over a wide area. An image can be acquired and therefore an accurate assessment can be made with respect to wide angle scattering.

  Incidentally, the two-dimensional CCD sensor 47 shown in FIG. 5 does not need to be a CCD sensor having a specific structure, but a back-illuminated CCD sensor is preferably used. This back-illuminated CCD sensor is a CCD sensor having a structure in which a surface opposite to a surface on which a plurality of CCD elements and their associated wirings are formed is very thin and the back surface functions as a light receiving surface. If the surface on which the wiring is formed is used as the light receiving surface, the light entering the portion on which the wiring is formed is not detected as data and is only consumed wastefully, so that the efficiency is poor. On the other hand, if the back surface of the CCD sensor is used as the light receiving surface, all received light can be detected as data, so that an X-ray image can be detected accurately.

(Second Embodiment)
FIG. 6 shows another embodiment of the small-angle wide-angle X-ray measurement apparatus according to the present invention. This figure shows a configuration corresponding to FIG. 2 in the previous embodiment. In FIG. 6, the same reference numerals as those in FIG. 2 denote the same members, and description of those members will be omitted. In this embodiment, the wide-angle X-ray optical system is modified with respect to the embodiment shown in FIG. As shown in FIG. 7, the wide-angle X-ray optical system 57 used in the present embodiment has a dark box 64 whose section is not rectangular. The dark box 64 is connected to the detection unit 35 via the connection unit 45 as in the embodiment of FIG. A two-dimensional CCD sensor 47 and a cooling device 48 are provided in the detection unit 35, and an imaging lens 46 is provided in the connection unit 45.

  A light reflecting plate 42 is provided on the side wall portion of the dark box 64 on the sample S side, and a light shielding member 40a is further provided on the outer side. The light reflecting plate 42 has a light reflecting surface on the inner surface side, and reflects a light image toward the lens 46 and the CCD sensor 47. In this case, the light reflecting plate needs to hardly absorb X-rays, and the support is preferably made of a thin polymer material. A fluorescent plate 68 is provided on the side wall portion of the dark box 64 on the detector plate 26 side, and a light shielding member 40b is provided on the outside thereof. The fluorescent plate 68 is formed by the fluorescent layer support 36 and the fluorescent layer 67 supported by the fluorescent layer support 36. The fluorescent layer 67 is an element that converts X-rays into light in the same manner as the fluorescent layer 37 shown in FIG. 5, whereas the fluorescent layer 37 in FIG. 5 generates light in the transmission direction, whereas the fluorescence of the present embodiment. The layer 67 generates light in the reflection direction (that is, the direction toward the sample S).

  Also in the present embodiment, X-ray passage openings 59 and 60 are provided in the central portion of the light reflecting plate 42 and the fluorescent plate 68 (that is, the portion intersecting the X-ray optical axis X1). As in the case of the X-ray openings 39, 43, and 44 in the embodiment shown in FIG. 5, the opening diameters of the opening 59 and the opening 60 are the maximum angle value “β” in the small angle region desired to be measured, and the sample S To the openings 59 and 60 thereof.

  In the present embodiment, the small-angle scattered radiation generated from the sample S reaches the detector plate 26 through the X-ray openings 59 and 60 in the dark box 64 and exposes it. On the other hand, the wide-angle scattered rays generated from the sample S pass through the light reflecting plate 42 and reach the fluorescent layer 67 to be converted into light. This light image is reflected by the reflecting surface of the light reflecting plate 42, is imaged on the light receiving surface of the CCD sensor 47 by the imaging lens 46, and is read two-dimensionally by the CCD sensor 47. By reading with the CCD sensor 47, wide-angle scattered radiation data is generated.

  In the embodiment shown in FIG. 5, the fluorescent plate 38 is arranged on the sample S side and the light reflecting plate 42 is arranged on the detector plate 26 side. However, as in the present embodiment, the fluorescent plate 68 is arranged on the detector plate 26 side. In addition, the light reflecting plate 42 can be disposed on the sample S side.

(Other embodiments)
The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the embodiments, and various modifications can be made within the scope of the invention described in the claims.
For example, in the embodiment shown in FIG. 2, the small-angle scattered radiation is detected by the detector plate 26, but the small-angle scattered radiation can also be detected by using the CCD detector unit 9 shown in FIG.

In the embodiment of FIG. 2, the focused beam or the parallel beam is formed by suppressing the divergence of the X-ray emitted from the X-ray focal point F as the X-ray source by the X-ray focusing element 22. Small-angle X-ray scattering measurement can be performed only by suppressing the divergence of incident X-rays to the sample S by the three slits 23, 24, and 25 without using the line condensing element 22. In addition, a graphite monochromator may be arranged in place of the X-ray condensing element 22 in FIG. Although the graphite monochromator does not have a condensing function, X-rays generated from the X-ray focal point F are monochromatized (a process for selectively extracting characteristic lines of specific wavelengths), thereby measuring small-angle scattered rays and wide-angle scattered rays. The background in the measurement can be lowered and a sharp scattered radiation peak can be generated.

  Note that it is possible to perform small-angle X-ray scattering measurement by extracting line-focused X-rays from the X-ray generator. The present invention can also be configured by attaching a wide-angle X-ray optical system to this apparatus. However, in this case, since the scattered radiation image becomes unclear due to the overlapping of the scattered radiation in the line focus direction (for example, the latitude direction), it is necessary to compensate the obtained data by calculation.

It is a perspective view which shows the external appearance of one Embodiment of the small angle wide angle X-ray measuring apparatus which concerns on this invention. It is a top view which shows the X-ray optical system inside the small angle wide angle X-ray measuring apparatus of FIG. It is a perspective view which shows an example of an X-ray source. It is a figure which shows an example of an X-ray condensing element. It is a top view which shows an example of a wide angle X-ray optical system. It is a top view which shows other embodiment of the small angle wide angle X-ray measuring apparatus which concerns on this invention. It is a top view which shows the other example of a wide angle X-ray optical system. It is a figure which shows an example of the result of the measurement using the conventional small angle wide angle X-ray measuring apparatus.

Explanation of symbols

1. 1. X-ray generator, 2. X-ray focusing device; First slit part,
4). 2. second slit part; 5. Third slit part Sample stage, 7. Wide-angle X-ray optical system,
8. Two-dimensional detector unit, 10. CCD detector unit Base,
12 Rails, 13a-13c. Decompression pass, 16. housing,
17. X-ray extraction window, 18. Rotor target, 19. filament,
22. X-ray focusing element, 22a. First mirror, 22b. The second mirror,
23-25. Slit, 26. Detector plate, 27. Direct beam stopper,
29. X-ray reflecting surface, 30. Heavy elements, 31. Light elements, 34. Dark box, 35. Detection unit,
36. 36. fluorescent layer support Phosphor layer, 38. Fluorescent plate, 39. X-ray aperture,
40. Light shielding member, 40a, 40b. Light shielding member, 42. Light reflector, 43. X-ray aperture,
44. X-ray aperture, 45. Connection part, 46. Imaging lens, 47. Two-dimensional CCD sensor,
48. Cooling device, 57. Wide-angle X-ray optical system, 59, 60. X-ray aperture, 64. Dark box,
67. Fluorescent layer, 68. Fluorescent screen, A. Data unacquisition area, d0. Focus size,
F. X-ray focus, α. X-ray extraction angle, X1. X-ray optical axis

Claims (7)

A small-angle X-ray optical system that irradiates a sample with X-rays emitted from an X-ray source and detects scattered rays generated from the sample within a small-angle region by an X-ray detection unit;
A wide-angle X-ray optical system that is provided between the sample and the X-ray detection means and detects scattered rays generated from the sample within a wide-angle region;
The wide-angle X-ray optical system is
A phosphor that is provided on an X-ray optical path between the sample and the X-ray detection means, and converts an X-ray image into a visible light image;
A light reflector for reflecting the visible light image formed on the phosphor,
A light detection means for detecting a visible light image reflected by the light reflector,
An X-ray aperture is provided in each of the phosphor and the light reflector at a portion that intersects the X-ray optical path, and the X-ray aperture has an aperture diameter that allows a maximum angle value of the small angle region. A small-angle wide-angle X-ray measuring device. The small-angle wide-angle X-ray measurement apparatus according to claim 1,
A dark box surrounding the phosphor and the light reflector;
A small-angle wide-angle X-ray measurement apparatus, wherein an X-ray opening is provided in the dark box at a portion intersecting with the X-ray optical path, and the X-ray opening has an opening diameter that allows a maximum angle value of the small-angle region. .   3. A small-angle wide-angle X-ray measurement apparatus according to claim 1, wherein the light detection means is a two-dimensional CCD optical sensor. In the small angle wide angle X-ray measuring apparatus according to any one of claims 1 to 3,
The small-angle wide-angle X-ray measuring apparatus, wherein the phosphor is disposed at right angles to the X-ray optical axis, and the light reflector is inclined with respect to the X-ray optical axis. In the small angle wide-angle X-ray measuring apparatus according to any one of claims 1 to 4,
A small-angle wide-angle X-ray measurement apparatus, wherein the phosphor is disposed closer to the sample than the light reflector. In the small angle wide angle X-ray measuring apparatus according to any one of claims 1 to 5,
The small angle X-ray optical system is:
An X-ray generator that includes the X-ray source and extracts point-focused X-rays from the X-rays generated by the X-ray source ;
A small-angle wide-angle X-ray measurement apparatus, comprising: an X-ray condensing unit that is disposed between the X-ray source and the sample and condenses the X-rays extracted from the X-ray source. In the small angle wide angle X-ray measuring apparatus according to any one of claims 1 to 6,
Means for holding the X-ray optical path from the X-ray source to the X-ray detection means in a reduced pressure state;
A small-angle wide-angle X-ray measurement apparatus characterized in that the inside of the dark box is also maintained in a reduced pressure state.

Images