JP2019174245A - X-ray photography method and x-ray photography device - Google Patents

Abstract

To provide an X-ray photography method and X-ray photography device that can efficiently and stably acquire a dynamic phenomenon or a spectral imaging in a very short time and can be appropriately used for a non-repetitive phenomenon that occurs only once or for destructive inspection of an expensive or rare sample.SOLUTION: An image formation optical system 4 includes: an image formation optical element 41; and one or more separation optical surfaces 42 that are disposed on the downstream side of the image formation optical element, and reflect the light emitted from a partial region R1 of an outlet 41c of the image formation optical element and form an image at a position separate from that of the light emitted from another region. Thus, an X-ray image of a sample is acquired by detectors 50 at two or more positions.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an X-ray imaging method and an X-ray imaging apparatus suitable as a transmission X-ray microscope capable of examining the shape and properties of a sample in fields such as material science and life science. The present invention relates to an X-ray imaging method and an X-ray imaging apparatus capable of X-ray imaging and high-speed X-ray imaging.

  X-rays contribute to material evaluation in the development of new materials and analysis of life phenomena from cells to individuals. The progress of X-ray light sources has been remarkable, and analysis using short pulses, high intensity, and high controllability X-rays like the X-ray free electron laser, which is a large facility, can be performed at the laboratory level. Yes. When microscopic observation is performed using “X-rays” having a short wavelength, such as soft X-rays having a wavelength of about 1 to 10 nm and hard X-rays having a wavelength of about 0.01 nm to 1 nm, compared to using “visible light” having a long wavelength. High spatial resolution. Furthermore, by utilizing the fact that soft X-rays and hard X-rays have characteristic absorption-scattering characteristics with respect to atoms, it is possible to visualize the atomic distribution and its electronic state. If an imaging microscope is constructed using X-rays, a two-dimensional image can be obtained in the same way as visible light (see, for example, Patent Document 1).

  FIG. 20 is an explanatory diagram showing a schematic configuration of a conventionally used X-ray imaging apparatus 101 (X-ray microscope). Reference numeral 20 denotes an X-ray source, 3 denotes a sample, and 50 denotes a detector, which mainly includes an illumination optical system 102 including the X-ray source 20 and a condensing optical system 121, and an imaging optical system 104. As the condensing element 22 constituting the condensing optical system 121, for example, a spheroid mirror 60 is used, and as the imaging optical element 41, for example, a Walter type oblique incidence mirror 61 is used. A visible light lens cannot be used in the X-ray region. The Walter mirror, which is the Walter type oblique incidence mirror 61, is an imaging element using total reflection, and is composed of two mirrors of a rotating hyperboloid 610 and a rotating ellipsoid 611 as shown in the figure, and has a ring-shaped characteristic. Have a nice shape.

  By the way, when trying to acquire a dynamic image or an aerial image (spectral imaging) showing absorption specific to certain energy using such an X-ray imaging apparatus, conventional methods include a pump and a probe method. Observations are performed by repeating acquisitions called multiple times and switching of a spectroscope that cuts out certain energy from an X-ray light source a plurality of times. However, such a conventional method has a problem that it is impossible in the case of a non-repetitive phenomenon that occurs only once, and is not suitable for destructive inspection of expensive and rare samples. Furthermore, there have been fatal problems in research and development, which require a lot of time for measurement, and problems such as data dispersion due to instability of the light source.

JP-A-6-347600

  Therefore, in view of the above-mentioned situation, the present invention intends to solve the problem that a dynamic phenomenon or spectral imaging can be acquired efficiently and stably in a very short time, and it occurs only once. An object of the present invention is to provide an X-ray imaging method and an X-ray imaging apparatus that can be suitably used in the case of repetitive phenomena and in destructive inspection of expensive and rare samples.

As a result of diligent investigations in view of the present situation, the present inventor has assumed that, in the case of X-rays with a short wavelength, a practically sufficient spatial resolution can be realized even with a small numerical aperture of the imaging optical element. The idea was to divide the exit aperture of the image optical element to obtain a plurality of images. If the aperture is divided in this way, the size of the aperture that gives one image is reduced, so that the spatial resolution of the image obtained is lower than when the aperture is not divided. As described above, sufficient spatial resolution may be obtained for each image.
Based on this assumption, as shown in FIG. 8 and Table 1, a Walter mirror is designed assuming the use of a soft X-ray having a wavelength of 4 nm as an imaging optical element, and the aperture in this Walter mirror is a portion as shown in FIG. As a result of verifying the imaging resolution when the aperture was set, it was confirmed that it was 100 nm on the basis of the Rayleigh resolution and exceeded the imaging resolution of the standard visible light microscope despite the small aperture.

  As a specific method for acquiring (detecting) a plurality of images by the aperture division, the inventor reflects light emitted from each of the divided exit areas on the downstream side of the imaging optical element. It has been devised to provide a separation optical surface that forms an image at a position different from that of light emitted from other regions, and the present invention has been completed. For example, a plane mirror can be used as the separation optical surface. If a flat mirror polished sufficiently flat is used, the image is not deteriorated by giving wavefront aberration to an existing imaging system. This makes it possible to acquire (detect) a plurality of the same or substantially the same image of the same sample simultaneously or substantially simultaneously.

That is, the present invention includes the following inventions.
(1) As an imaging optical system, an imaging optical element is provided, and light emitted from a part of the exit of the coupling optical element is reflected downstream of the imaging optical element to provide another An X-ray imaging method characterized by providing a single or a plurality of separation optical surfaces that form an image at a position different from the light emitted from the region, thereby obtaining an X-ray image of the sample at two or more positions.

  (2) The X-ray imaging method according to (1), wherein the imaging optical element is a Walter type oblique incidence mirror.

  (3) The X-ray imaging method according to (1) or (2), wherein the separation optical surface is a plane mirror section.

  (4) The partial area is one of divided areas obtained by dividing the exit of the imaging optical element into a plurality of areas along a circumferential direction around the element central axis. X-ray imaging method in any one of-(3).

  (5) Three or more of the divided regions are provided, and two or more of the divided regions are set as the partial regions, and the light emitted from each region is reflected and separated from the light emitted from other regions. The X-ray imaging method according to (4), wherein two or more of the mirror surfaces that are imaged at different positions are directed in different directions.

  (6) In the illumination optical system, different X-rays that generate X-rays having different wavelengths so that the wavelength of the light emitted from the partial region is different from the wavelength of the light from at least one other region. The X-ray imaging method according to any one of (1) to (5), wherein a wavelength generation unit is provided, thereby obtaining X-ray images of the same sample at different wavelengths at the two or more positions simultaneously.

  (7) The illumination optical system is provided with a time delay unit so that the light emitted from the partial region is delayed from the light from at least one other region, thereby the sample at the two or more positions. The X-ray imaging method according to any one of (1) to (5), wherein an X-ray image with a time shift is obtained.

  (8) As the imaging optical system, an imaging optical element is provided, and the light emitted from a part of the exit of the imaging optical element is reflected downstream of the imaging optical element. An X-ray imaging apparatus characterized in that a single or a plurality of separation optical surfaces for forming an image at a position different from the light emitted from the region is provided, thereby obtaining an X-ray image of the sample at two or more positions. .

  (9) The X-ray imaging apparatus according to (8), wherein the imaging optical element is a Walter type oblique incidence mirror.

  (10) The X-ray imaging apparatus according to (8) or (9), wherein the separation optical surface is a plane mirror unit.

  (11) The partial area is one of divided areas obtained by dividing the exit of the imaging optical element into a plurality of areas along a circumferential direction around the element central axis. X-ray imaging apparatus in any one of-(10).

  (12) Three or more of the divided regions are provided, and two or more of the divided regions are set as the partial regions, and the light emitted from each region is reflected and separated from the light emitted from other regions. The X-ray imaging apparatus according to (11), wherein two or more separation optical surfaces whose mirror surfaces are directed in different directions are formed at an image position.

  (13) The pyramid mirror or the truncated pyramid mirror having the two or more separation optical surfaces on the outer peripheral surface or the inner peripheral surface is provided coaxially so that the central axis coincides with the element central axis. X-ray imaging device.

  (14) In the illumination optical system, different X-rays that generate X-rays having different wavelengths so that the wavelength of the light emitted from the partial area is different from the wavelength of the light from at least one other area. The X-ray imaging apparatus according to any one of (8) to (13), wherein a wavelength generation unit is provided, thereby obtaining X-ray images of the same sample at different wavelengths at the two or more positions simultaneously.

  (15) The X-ray imaging apparatus according to (14), wherein the different wavelength generation unit includes a bandpass filter or a spectroscope.

  (16) The illumination optical system is provided with a time delay optical system so that the light emitted from the partial area is delayed from the light from at least one other area. The X-ray imaging apparatus according to any one of (8) to (13), wherein an X-ray image of a sample shifted in time is obtained.

  According to the X-ray imaging method and X-ray imaging apparatus according to the present invention as described above, a dynamic phenomenon or spectral imaging can be acquired efficiently and stably in a very short time. It is an innovative technique that opens the way to multi-spectral imaging and high-speed imaging. In particular, it can be suitably used in the case of a non-repetitive phenomenon that occurs only once or in the destructive inspection of expensive and rare samples. In this way, the present invention can acquire information that could not be acquired in a very short time, and can accelerate research and development widely from basic research to product development, as well as large X-ray facilities as well as laboratories. It is expected to be widely used as a tool for performing various X-ray analysis at the level.

(A), (b) is explanatory drawing which shows typical embodiment of the X-ray imaging apparatus concerning this invention, (c), (d) is the partial curved-surface mirror divided | segmented into the vertical direction along a mirror rotating shaft. Explanatory drawing which shows the exit opening of the modification comprised by this. Explanatory drawing which shows the modification reflected on an outer side with a plane mirror. Explanatory drawing which shows the modification which divided | segmented the opening into 3 or more using the some isolation | separation optical surface. Explanatory drawing which shows the modification which reflected all the division | segmentation area | regions of an exit with the isolation | separation optical surface, and eliminated the light imaged on an element central axis. Explanatory drawing which shows the modification which provided the pyramid mirror. (A), (b) is explanatory drawing which shows the example of the X-ray imaging apparatus which each implement | achieves multispectral imaging. Explanatory drawing which shows the example of the X-ray imaging apparatus which implement | achieves high speed imaging. Explanatory drawing which shows an example of the design plan of Walter Miller. Explanatory drawing which similarly shows an example of the design plan of Walter Miller. The figure which showed the mode of the propagation of the light from a certain point on a sample based on the ray tracing result. The figure which showed the mode of the propagation of the light from a certain point on a sample based on the ray tracing result. Explanatory drawing which shows the mounting plan of this invention which made soft X-ray object. Explanatory drawing which shows the other mounting plan of this invention for soft X-ray similarly. The figure which shows the original image set as a sample. FIG. 13 is a diagram illustrating an image formed by being reflected and imaged by a plane mirror in the implementation plan of FIG. 12 and an image formed at a position on the element central axis without being reflected. FIG. 14 is a diagram illustrating an image formed by being reflected by a plane mirror and an image formed at a position on the element central axis without being reflected in the implementation plan of FIG. 13. Explanatory drawing which shows the other example of the design plan of Walter Miller. Explanatory drawing which shows the mounting plan of this invention which made hard X-ray object. FIG. 19 is a diagram showing an image formed by being reflected by a flat mirror and an image formed at a position on the element central axis without being reflected in the implementation plan of FIG. 18. Explanatory drawing which shows the conventional X-ray imaging apparatus.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIGS. 1A and 1B, an X-ray imaging apparatus 1 according to the present invention includes an X-ray source 20 and an illumination optical system 2 having a condensing optical system 21 for condensing the X-ray source 20 on a material 3. And an imaging optical system 4 having the imaging optical element 41 and a detector 50, and in particular, as the imaging optical system 4, an outlet 41 c of the imaging optical element 41 is provided downstream of the imaging optical element 41. Among them, a separation optical surface 42 that reflects light emitted from a part of the region R1 and forms an image at a position different from the light emitted from the other region R01 is provided, and the image is formed through the separation optical surface 42. A detector 51 for detecting an X-ray image is provided, whereby an X-ray image of the sample 3 is obtained at two or more positions (in the example of FIG. 1, two positions of the detectors 50 and 51). It is an X-ray imaging apparatus suitable as a transmission type X-ray microscope.

  In the conventional X-ray imaging apparatus, as shown in FIG. 20, the X-rays emitted from the exit (opening) of the imaging optical element 41 form one image on the optical axis farther downstream, and this position It is detected by the detector 50 provided in. On the other hand, in the present invention, as shown in FIG. 1, a part of the optical path of the X-rays emitted from the opening of the exit 41c is deflected by the separation optical surface 42 installed downstream of the opening, so An image is generated at a position different from the position of the detector 50 (the position of the detector 51). The images obtained by the detectors 50 and 51 are images of the same sample at the same timing.

  As described above, the present invention is an X-ray imaging apparatus capable of acquiring a plurality of X-ray images at a time by dividing the exit 41c of the imaging optical element 41 into regions and using them simultaneously. This is an innovative technique that can detect X-ray images of the same sample at the same timing at two or more positions, and can realize multispectral imaging and high-speed imaging in the X-ray region.

  As the X-ray source 20, soft X-rays or hard X-rays are preferably used. As for the illumination optical system 2, the condensing optical system 21, and the imaging optical element 41, a known optical system can be used in a conventional transmission X-ray imaging apparatus (X-ray microscope). In particular, for the imaging optical element 41, the Walter type oblique incidence mirror 61 is preferable. Since the Walter type oblique incidence mirror can be easily designed with a larger aperture than the others, it is particularly suitable for the present invention in which the aperture is divided. Fresnel zone plates and Advanced Kirkpatrick Baez mirrors can also be used.

  A typical Walter type oblique incidence mirror 61 shown in FIGS. 1 (a) and 1 (b) is a cylindrical Walter mirror extending over the entire circumference, but as indicated by (c) and (d) in FIG. Are composed of partially curved mirrors (half-split Walter grazing incidence mirror 61A, smaller Walter grazing incidence mirrors 61B and 61C) divided in the vertical direction in different angular regions, single or coaxial. Of course, a plurality of them may be arranged.

  As the separation optical surface 42, in this example, the plane mirror 70 having the plane mirror portion 7 is disposed at a position corresponding to the opening region R1 of the outlet 41c on the downstream side of the Walter type oblique incidence mirror 61. In addition, it is not limited to a plane mirror part, It can also comprise with a diffraction grating.

  The light emitted from the region R01 other than the region R1 forms an image at a position on the element central axis a (the position of the detector 50), which is the mirror rotation axis of the Walter type oblique incidence mirror 61, and is detected by the detector 50. . The light emitted from the region R <b> 1 is reflected by the plane mirror unit 7, forms an image at a different position (the position of the detector 51), and is detected by the detector 51. That is, the exit opening of the imaging optical element 41 (Walter type oblique incidence mirror 61) is divided into regions R1 and R01, and the light from the region R1 out of the light emitted from each region is separated into the optical surface 42 (planar mirror unit 7). ) Are separated and imaged at different positions, whereby images of the same sample 3 at the same timing are acquired (detected) at different positions.

  The plane mirror 70 has the plane mirror unit 7 disposed on the inside thereof, reflects the light emitted from the exit region R1 to the inside, and is different from the position on the element center axis a (the position of the detection unit 50) (the detection unit 51). The image is formed at the position (1) and detected by the detector 51. Here, “reflect inside” means that the direction of reflection is closer to the element center axis a than the incident direction.

  Thus, the plane mirror 70 only needs to be arranged at a position corresponding to the region R1 on the downstream side of the imaging optical element, and since it has a simple structure and does not require alignment accuracy, it can be realized at a very low cost. The handleability is also good. In this example, the light is reflected inward by the flat mirror 70. However, as shown in FIG. 2, by disposing the flat mirror 70 and reflecting it outward, a position different from the position on the element central axis a (detection). It is of course possible to form an image at the position of the container 51). “Reflect outside” means that the incident direction is closer to the element center axis a than the direction of reflection. Although not shown, it may be reflected in a circumferential direction around the element central axis, neither inside nor outside.

  Also, as shown in FIG. 3, a plurality of separation optical surfaces 42 are used to divide the aperture into three or more (in this example, exit regions R1, R2, R05, R06), and two or more of the divided regions (R1) , R2) are reflected in different directions by the corresponding separation optical surfaces 42, 42, and each position (detection) is different from the light emitted from other regions (R05, R06). It is also a preferred embodiment to form an image at each position of the containers 51 and 52. Thereby, three or more images can be acquired simultaneously. For example, as shown in FIG. 9, if the circumferential angular width per opening is set to 12 degrees, 360 ° / 12 ° = 30, and 30 images can be captured simultaneously. Here, each separation optical surface 42 is provided with a flat mirror 70 that reflects light inward, but a part or all of it may be a flat mirror that reflects light outward.

  Although a plurality of three or more images can be obtained simply by providing a plurality of plane mirrors 70 in this way, such plane mirrors 70 do not require alignment accuracy and reduce the number of parts of the alignment system. Can do. Further, even if a cylindrical Walter mirror as shown in FIGS. 1A and 1B is used as the imaging optical element 41, it can be reflected and imaged at an accurate position by simple alignment of each plane mirror 70. Can do.

  Further, as shown in FIG. 4, it is of course possible to reflect all of the divided areas (R3, R4) at the exit by the separation optical surface 42 so as to eliminate the light imaged on the element center axis a. In the figure, (b) is an example in which the region is divided into two (R3, R4), but it may be divided into four (R5 to R8) as shown in (c) or other numbers. Further, in this case, as shown in FIG. 5, it is also preferable to provide a truncated pyramid mirror 71 having a plurality of plane mirror portions 7 on the outer peripheral surface and reflect the light from each region to the outside by each plane mirror portion 7. It is a form. According to this, the number of parts can be reduced compared with the case where a plurality of plane mirrors are provided.

A pyramid mirror may be used instead of the pyramid mirror 71. Alternatively, a plurality of similar planar mirror portions 7 may be provided on the inner peripheral surface instead of the outer peripheral surface, and the inner peripheral surface may reflect light from each region to the inside using a truncated pyramid shaped cylindrical mirror. The truncated pyramid mirror 71 is provided coaxially so that the central axis thereof coincides with the element central axis a, but is not limited to this.
In the above description, the light emitted from the divided area at the exit is reflected once by the separation optical surface 42 and imaged. However, a plurality of separation optical surfaces 42 are reflected on the optical path of the light and reflected multiple times. You may comprise so that it may image-form.

  FIG. 6A shows an example of an X-ray imaging apparatus that realizes multispectral imaging. Specifically, the illumination optical system 2 is different so that the wavelength of the light in a part of the region reflected by the separation optical surface 42 is different from the wavelength of the light from at least one other region. A different wavelength generator 23 for generating X-rays of wavelengths is provided, whereby X-ray images of different wavelengths of the same sample can be obtained simultaneously at two or more positions (positions of detectors 51 and 52). This is a great advantage when testing a sample destructively or observing a sample that changes over time.

  The different wavelength generation unit 23 generates illumination light having different wavelengths using a solid filter or a spectroscope and supplies the illumination light to each aperture. The use of white light sources such as synchrotron radiation and multispectral light sources such as higher harmonics is assumed. In this example, a bandpass filter 63 is used as the different wavelength generation unit 23. In the present invention, since it is possible to perform shooting with a single shot, it is possible to acquire a spectral image in which time synchronism is ensured.

  That is, two light whose wavelengths are changed by the bandpass filter 63 are simultaneously incident on the sample 3 from different directions, and the transmitted light is imaged at different positions through the imaging optical element 41 and the separation optical surface 42, The information “image” of a different wavelength is detected by the detector at each position. For example, light having a wavelength of 2 nm and light having a wavelength of 4 nm are simultaneously incident to obtain a 2 nm image and a 4 nm image. Substances have different absorption coefficients depending on the wavelength. The details of the substance can be determined from the difference in the observed image due to the absorption coefficient.

  Conventionally, since an image is obtained by changing the wavelength, the obtained images are images having different timings. On the other hand, in the present invention, an image of light of each wavelength can be acquired simultaneously. Depending on the number of divisions, images of many wavelengths can be acquired simultaneously. Since X-ray light sources such as high-order harmonics and synchrotron radiation emit multi-wavelength X-rays, light of a plurality of wavelengths can be obtained through a filter as in this example.

  FIG. 6B shows an X-ray emitted from the diffraction grating 64 at a different angle for each energy, instead of the bandpass filter 63, as the different wavelength generator 23, and the mirror array 65 and the spheroid mirror. This is an example of irradiating the observation target (sample 3) at a different angle by 62.

  FIG. 7 shows an example of an X-ray imaging apparatus that realizes high-speed imaging. Specifically, the illumination optical system 2 is provided with a time delay optical system 24 so that light emitted from a part of the region is delayed from light from at least one of the other regions. An X-ray image of the sample shifted in time at the position (in this example, the position of the detectors 51 and 52) is obtained. Using this method, dynamics in high-speed areas such as picoseconds and femtoseconds that cannot be captured by conventional high-speed electric cameras using pulsed light sources such as X-ray free electron laser (FEL) and higher harmonics. Can be understood as a spatial image for the first time. The time resolution of photographing can be freely adjusted by the configuration of the illumination optical system 2 in the first half, and photographing can be performed under conditions suitable for the phenomenon desired by the user. This method eliminates all mechanical and electrical operations that are used in the conventional method, and can achieve complete single-shot shooting.

  In addition, by combining the apparatus configurations of FIGS. 6 and 7, it is possible to simultaneously realize observation at multiple wavelengths while acquiring dynamics as a moving image.

  The embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and can of course be implemented in various forms without departing from the gist of the present invention.

(Ray tracing simulation)
In order to confirm that the design of the X-ray imaging apparatus of the above-described embodiment is actually possible, a ray tracing simulation was performed. 10 (a), (b), FIG. 11 (a) and FIG. 11 (b) show the light from a certain point on the sample 3 in the examples of FIG. 1, FIG. 2, FIG. 4 (c) and FIG. It is the figure which showed the mode of propagation based on the ray tracing result. The lattice pattern portion indicates the Walter type oblique incidence mirror 61, the dark black line segment on the downstream side indicates the plane mirror portion 7, and the gray color indicates the light beam.

  It can be seen that the light beam propagated from the sample position is divided by the plane mirror section, and the divided light beam groups form images at different positions. Here, a Walter mirror having a shape design that cannot actually be used for display is used. Actually, the Walter mirror used in the X-ray imaging apparatus of the present invention has a larger magnification and a smaller oblique incidence angle of the light beam on the mirror.

(Imaging simulation by ray tracing)
(Specific design plan for soft X-rays)
Next, FIGS. 12 to 16 design an X-ray imaging apparatus that assumes actual use in order to show a specific implementation plan of the present invention for soft X-rays, and further form an image by ray tracing. The result of the simulation is shown. The design assumed the use of soft X-rays having a wavelength of 4 nm, that is, photon energy of 310 eV. The design of the Walter mirror is the same as that shown in FIGS.

  12 is a dimensional diagram of a specific X-ray imaging apparatus that realizes the example of FIG. 1, and FIG. 13 is a dimensional diagram of the X-ray imaging apparatus that realizes the example of FIG. In both cases, a single plane mirror is inserted and the opening is divided into two.

  FIG. 15 shows an image formed by being reflected by a plane mirror using the system of FIG. 12 (with plane mirror reflection) and an image formed at a position on the element central axis without being reflected by the plane mirror (plane mirror). (Without reflection). FIG. 16 shows an image formed by being reflected by a plane mirror using the system of FIG. 13 (with plane mirror reflection) and an image formed at a position on the element central axis without being reflected by the plane mirror ( Each of them shows no flat mirror reflection). FIG. 14 shows an original image set as a sample.

  It can be seen that the same image is obtained with and without plane mirror reflection, except that the direction of the image is reversed depending on the presence or absence of reflection. It can be seen that a plurality of images can be obtained without causing image degradation due to wavefront aberration by performing aperture division using a plane mirror.

(Specific design plan for hard X-ray)
Next, FIGS. 17 to 19 design an X-ray imaging apparatus that assumes actual use in order to show a specific implementation plan of the present invention for hard X-rays, and further form an image by ray tracing. The result of the simulation is shown. The design assumed the use of a hard X-ray having a wavelength of 0.12 nm, that is, a photon energy of 10 keV. The design of the Walter mirror is shown in FIG.

  When X-rays are reflected by an oblique incidence mirror, a sufficient reflectance cannot be obtained unless the wavelength is incident on the mirror at a shallower angle. When hard X-rays having a short wavelength are used, the oblique incident angle must be designed shallower than when soft X-rays are targeted. Therefore, the Walter mirror is longer and thinner, and the aperture dividing plane mirror is designed to be longer in the element central axis direction. Here, the material of the reflecting surface is ruthenium instead of nickel used for the soft X-ray Walter mirror. This is because ruthenium has a higher reflectance in the hard X-ray region. On the other hand, when hard X-rays are used, the spatial resolution is improved because the wavelength is shorter than that of soft X-rays.

  FIG. 18 is a dimensional diagram of a specific X-ray imaging apparatus that realizes the example of FIG. 1, and shows a case where a single plane mirror is inserted and the opening is divided into two. FIG. 19 shows an image reflected and imaged by a plane mirror using the system of FIG. 18 (with plane mirror reflection) and an image (plane mirror) imaged at a position on the element central axis without being reflected by the plane mirror. (Without reflection). Except for the fact that the direction of the image is reversed depending on the presence or absence of reflection, it can be seen that the same image is obtained with and without plane mirror reflection. As in the case of soft X-rays, it can be seen that a plurality of images can be obtained by performing aperture division using a plane mirror without causing image degradation due to wavefront aberration.

DESCRIPTION OF SYMBOLS 1, 1A-1G X-ray imaging apparatus 2 Illumination optical system 3 Sample 4 Imaging optical system 7 Flat mirror part 20 X-ray source 21 Condensing optical system 22 Condensing element 23 Different wavelength production | generation part 24 Time delay optical system 41 Imaging Optical element 41c Exit 42 Separation optical surface 50, 51, 52 Detector 60 Spheroid mirror 61, 61A, 61B Walter type oblique incidence mirror 62 Spheroid mirror 63 Bandpass filter 64 Diffraction grating 65 Mirror array 70 Flat mirror 71 Pyramid Table mirror 101 X-ray imaging apparatus 102 Illumination optical system 104 Imaging optical system 121 Condensing optical system 610 Rotating hyperboloid 611 Rotating ellipsoid

Claims (16)

As an imaging optical system,
While providing an imaging optical element,
Separation optics that reflects light emitted from a part of the exit of the coupling optical element on the downstream side of the imaging optical element and forms an image at a position different from the light emitted from the other area One or more surfaces are provided,
Thereby, an X-ray image of the sample is obtained at two or more positions.
X-ray imaging method.   The X-ray imaging method according to claim 1, wherein the imaging optical element is a Walter type oblique incidence mirror.   The X-ray imaging method according to claim 1, wherein the separation optical surface is a plane mirror unit. The partial area is one of divided areas obtained by dividing the exit of the imaging optical element into a plurality of areas along a circumferential direction around the element central axis.
The X-ray imaging method according to claim 1. Provide three or more of the divided areas,
Two or more of the divided regions are defined as the partial regions, and the mirror surfaces are different from each other, reflecting the light emitted from each region to form an image at a position different from the light emitted from other regions. Provided two or more of the above facing the direction,
The X-ray imaging method according to claim 4. A different wavelength generation unit that generates X-rays having different wavelengths so that the wavelength of light emitted from the partial region is different from the wavelength of light from at least one other region in the illumination optical system. Provided,
Thereby, X-ray images with different wavelengths of the same sample at the two or more positions are simultaneously obtained.
The X-ray imaging method according to claim 1. In the illumination optical system, a time delay unit is provided so that light emitted from the partial area is delayed from light from at least one other area,
Thereby, an X-ray image of the sample shifted in time at the two or more positions is obtained.
The X-ray imaging method according to claim 1. As an imaging optical system,
While providing an imaging optical element,
Separation in which light emitted from a part of the exit of the imaging optical element is reflected downstream from the imaging optical element to form an image at a position different from the light emitted from the other area Provide one or more optical surfaces,
Thereby, an X-ray image of the sample is obtained at two or more positions.
X-ray imaging device.   The X-ray imaging apparatus according to claim 8, wherein the imaging optical element is a Walter type oblique incidence mirror.   The X-ray imaging apparatus according to claim 8, wherein the separation optical surface is a plane mirror unit. The partial area is one of divided areas obtained by dividing the exit of the imaging optical element into a plurality of areas along a circumferential direction around the element central axis.
The X-ray imaging apparatus of any one of Claims 8-10. Provide three or more of the divided areas,
Two or more of the divided regions are defined as the partial regions, and the mirror surfaces are different from each other, reflecting the light emitted from each region to form an image at a position different from the light emitted from other regions. Two or more separation optical surfaces facing the direction were provided,
The X-ray imaging apparatus according to claim 11.   The X-ray imaging according to claim 12, wherein a pyramid mirror or a truncated pyramid mirror having the two or more separation optical surfaces on an outer peripheral surface or an inner peripheral surface is provided coaxially so that a central axis coincides with an element central axis. apparatus. A different wavelength generation unit that generates X-rays having different wavelengths so that the wavelength of light emitted from the partial region is different from the wavelength of light from at least one other region in the illumination optical system. Provided,
Thereby, X-ray images with different wavelengths of the same sample at the two or more positions are simultaneously obtained.
The X-ray imaging apparatus of any one of Claims 8-13.   The X-ray imaging apparatus according to claim 14, wherein the different wavelength generation unit includes a bandpass filter or a spectroscope. In the illumination optical system, a time delay optical system is provided so that light emitted from the partial area is delayed from light from at least one other area,
Thereby, an X-ray image of the sample shifted in time at the two or more positions is obtained.
The X-ray imaging apparatus of any one of Claims 8-13.