JP6430208B2 - X-ray irradiation equipment - Google Patents

Description

  The present invention relates to an X-ray irradiation apparatus that is used for irradiating a subject with X-rays in an X-ray apparatus that irradiates the subject with X-rays to analyze and observe the subject.

  It is widely performed to perform analysis and observation by irradiating a sample with X-rays. For example, an X-ray fluorescence analyzer irradiates a subject with X-rays and detects fluorescent X-rays emitted from the subject accordingly. Since fluorescent X-rays have energy specific to the element, the element composition can be known based on the energy of the fluorescent X-ray, and the element can be quantified from the X-ray intensity. The X-ray diffractometer irradiates the subject with X-rays and detects diffracted X-rays emitted from the subject accordingly. By analyzing this diffracted X-ray, when the subject is a powder sample, the components constituting the sample can be identified and quantified, and the crystal size and crystallinity can be obtained. When the specimen is a single crystal sample, the three-dimensional structure of the sample molecule can be obtained. When the specimen is a vapor-deposited thin film, information such as density, crystallinity, crystal axis direction and period is obtained. be able to. Furthermore, an X-ray photoelectron spectrometer can perform composition analysis and state analysis on the very surface of a subject based on the energy spectrum of photoelectrons generated by irradiating the subject with X-rays.

  In the above-described X-ray apparatus that irradiates a subject with X-rays and performs analysis and observation of the subject, in order to increase the spatial resolution of the analysis and observation, the irradiation diameter of the X-rays irradiated to the subject Must be squeezed as small as possible. As is well known, unlike charged particle beams such as electron beams and ion beams, X-rays cannot be bent by an electric field or a magnetic field, and therefore cannot be condensed using an electromagnetic field lens. As summarized in 1, various condensing methods peculiar to X-rays have been proposed and put into practical use.

  A multicapillary lens is widely used in X-ray apparatuses such as a general fluorescent X-ray analyzer as a member for condensing X-rays with high efficiency.

  As disclosed in Non-Patent Document 1 and Patent Documents 1 and 2, etc., a multicapillary has a large number (several hundreds) of capillary tubes (capillaries) made of glass having a small diameter of about 2 to several tens μm. (About 1 million pieces) bundled into a single tube, and X-rays incident on the inside of one capillary travel while totally reflecting the inner wall surface of the glass at an angle less than the critical angle. This is an element that efficiently guides X-rays using the principle of the process. In general, in a multicapillary lens, at least one of the end portions thereof has an end surface in which each capillary is formed such that the central axes of many capillaries intersect at one point at a predetermined position outside the end surfaces of the end portions. It is the focal end face. As a result, X-rays emitted from an X-ray source that can be regarded as almost a point are captured with a large solid angle, and conversely, the X-rays guided through the capillaries are emitted so as to be converged to a substantially single point. Can do.

  As described above, the multicapillary lens can collect and guide X-rays with high efficiency, but sufficient performance cannot always be obtained in terms of reducing the area irradiated with the collected X-rays. The main reason for this is that the principle defocusing occurs in the multicapillary lens. That is, in the multi-capillary lens, as described above, X-rays travel while being totally reflected on the inner wall surface of one capillary, but the maximum incident angle that causes total reflection (the angle with respect to the reflecting surface is conventionally called the incident angle). Therefore, this definition also follows the definition) is a critical angle. Therefore, when X-rays are emitted from the end face of the capillary, the X-rays spread with an opening angle that maximizes the critical angle with respect to the central axis of the capillary. As a result, the irradiation region of the X-rays emitted from the point focal end face of the multicapillary lens is not an ideal point, and has a certain size.

  In addition, the end portion having the point focal point end surface is formed by heating and pulling a bundle of a large number of capillaries having the same inner diameter and parallel to each other. It is actually impossible to completely converge the central axis of a single point. There are not only defocuses that occur in principle, but also defocuses due to such manufacturing factors. Due to both factors that cannot be avoided theoretically and factors due to manufacturing limitations, the minimum focal size of a conventional multicapillary lens is usually about 20 to 30 μm at most, and the X-ray wavelength and focal length to be used are limited. However, it is about several μm, and it was difficult to realize an irradiation diameter smaller than this.

  On the other hand, an element capable of focusing X-rays to a smaller diameter in principle is a Fresnel zone plate (commonly abbreviated as FZP) described in Non-Patent Document 1. A Fresnel zone plate is a disk-shaped element that collects light using diffraction and interference, and is a kind of concentric circles in which shielding regions that shield X-rays and passing regions that allow X-rays to pass through are formed. It is a transmission type diffraction grating. In so-called synchrotron radiation using synchrotron radiation, X-rays with irradiation diameters of submicron to nano level are realized using such Fresnel zone plates. However, in a general X-ray apparatus used in a laboratory, it is difficult to realize X-rays with a very small irradiation diameter as described above even if a Fresnel zone plate is used. This is because, in general available Fresnel zone plates, X-rays incident on the Fresnel zone plate cannot be focused to one point unless the X-ray flux is almost perfect parallel light, whereas perfect or near parallel. This is because it is actually quite difficult to obtain an X-ray flux. That is, the poor parallelism of X-rays incident on the Fresnel zone plate is the main factor of defocusing.

  An X-ray focusing apparatus combining a multi-capillary lens and a Fresnel zone plate is disclosed in Patent Document 3, in order to reduce the focal spot size while taking advantage of the high X-ray collection efficiency of the multi-capillary lens as described above. 4.

  In the X-ray focusing apparatus described in Patent Document 3, a Fresnel zone plate is disposed outside the point focal end face of the multicapillary lens, and X-rays that are converged to a certain extent after being emitted from the point focal end face of the multicapillary lens are Fresnel. The zone plate is narrowed down to one point. However, generally available Fresnel zone plates cannot focus X-rays that are not parallel bundles in this way, and for condensing, the shielding area and the passage area are conical circumferential surfaces in the plate thickness direction. A special Fresnel zone plate is required. Such Fresnel zone plates are very difficult to manufacture. Further, as described above, the X-rays passing through the capillaries in the multi-capillary lens are emitted from the emission end face to a certain extent, so even if the special Fresnel zone plate is obtained, The X-ray does not have an incident angle at which the X-ray can be collected at one point in the Fresnel zone plate, and it is inevitable that a fundamental defocusing occurs.

  On the other hand, in the X-ray focusing apparatus described in Patent Document 4, the end of the exit side has a smaller diameter than the end of the entrance side, and the central axes of the capillaries are parallel to each other at any end. A multi-capillary lens is used, and a general Fresnel zone plate is disposed outside the emission end face. In this configuration, it is possible to use a general Fresnel zone plate in which the shielding region and the passing region are each cylindrical in the thickness direction of the plate, but the multicapillary lens has a special shape. It is difficult to manufacture a capillary lens with high accuracy. Also in this X-ray focusing device, it is inevitable that the out-of-focus is caused by the above-described fundamental X-ray spread out of the multicapillary lens.

Japanese Examined Patent Publication No. 7-11600 Japanese Patent Publication No. 7-40080 JP 2007-93316 A JP 2010-276423 A

Japan Society for the Promotion of Science Microbeam Analysis 141st Committee, “Microbeam Analysis Handbook 1.2.3 X-ray Focusing”, Ohm Co., Ltd., issued June 30, 2014, p.85-92

  As described above, in order to achieve the purpose of narrowing the X-rays to a very small diameter, although the Fresnel zone plate is an excellent element in principle, an X-ray flux having sufficiently high parallelism is incident on the Fresnel zone plate. If this is not possible, the ability of the Fresnel zone plate cannot be fully exhibited. It is difficult to realize such a high parallelism X-ray flux with a relatively small and inexpensive apparatus, and it can be used for a general X-ray apparatus, and X-ray irradiation which can obtain submicron to nano level X-rays. The device has not existed before.

The present invention has been made to solve these problems, and the main object of the present invention is to irradiate a subject with X-rays with a smaller diameter than before while obtaining a relatively high X-ray intensity. An X-ray irradiation apparatus is provided.
Another object of the present invention is to provide an X-ray irradiation apparatus capable of irradiating a subject with an X-ray bundle having high parallelism while having a small and inexpensive configuration.

X-ray irradiation equipment according to the present invention has been made to solve the above problems,
a) an X-ray source emitting X-rays;
b) a collimator having two circular openings through which X-rays emitted from the X-ray source that are provided at a predetermined distance apart from each other on a linear axis passing through the X-ray source;
c) a plurality of bundled X-ray guiding capillaries each having a central axis that is straight and parallel to each other, and has substantially the same length and the same inner diameter, and includes two X-ray sources and two collimators. It has a central axis which coincides with straight axis passing through the opening, where one end faces the incident end face X-rays passing through the two openings Ru is incident is released the collimator from the X-ray source, the other A multicapillary whose end face is an emission end face for emitting X-rays substantially in parallel ;
The inside diameter of each thin tube of the multicapillary is smaller than the inside diameter of the two openings of the collimator .

In the present invention , the multicapillary has a structure in which a large number of straight tubular tubes are bundled, and each thin tube does not have a curved portion from the incident end surface to the output end surface. For this reason, the X-rays that have entered the thin tubes completely parallel to the central axis of the thin tubes never hit the inner wall of the tubes, that is, are not reflected and are emitted from the emission end face. In addition, a part of the X-rays having an incident angle within a predetermined angle (depending on the inner diameter and length of the thin tube) with respect to the central axis of the thin tube and not incident on the inner wall of the tube are emitted from the emission end face. To do. As described above, in general, multicapillary lenses guide X-rays using total reflection, but in reality, X-rays that hit the inner wall of a thin tube at an incident angle that is less than the critical angle are absorbed by the wall at a considerable rate. Therefore, the reflected X-ray is attenuated. Of course, X-rays incident on the capillary with an incident angle exceeding the critical angle do not pass through the capillary.

That is, in the multicapillary used in the present invention , the X-rays emitted from each capillary tube do not hit the inner wall surface of each capillary tube once, that is, pass through the capillary tube without being attenuated at all. X-rays that have been reflected by the inner wall surface of the thin tube at least once and have passed through the thin tube are included, but there is a sufficient difference in intensity between the X-rays that have passed without reflection and the X-rays that have been attenuated by reflection. Therefore, the X-ray bundle having high parallelism by the former is emitted from the emission end face with a large intensity. Thus, the multicapillary functions as a parallel filter that extracts X-rays having a high degree of parallelism among the X-rays emitted from the X-ray source .

In the present invention , the collimator functions as a first-stage coarse parallel filter, and the multicapillary functions as a second-stage fine parallel filter. For example, in a collimator in which two openings of the same diameter are arranged at a predetermined distance, only an X-ray having an incident angle (angle with respect to the central axis) determined by the diameter and the separation distance of the openings passes and has a larger incident angle. Even if it has passed through the opening of the front stage, the X-rays it has are shielded without passing through the opening of the rear stage. For example, the collimator opening diameter and separation distance can be determined so as to shield X-rays with an incident angle that may be reflected multiple times by the inner wall of the multicapillary when entering the multicapillary. For example, X-rays with relatively low parallelism can be prevented from entering the multicapillary .

In the X-ray irradiation apparatus according to the present invention, X-rays with extremely high parallelism are multi-passed through a collimator which is a first-stage coarse parallel filter and a multi-capillary two-stage filter which is a second-stage fine parallel filter. The light exits from the exit end face of the capillary. Conventionally, such a parallel X-ray beam is an X-ray apparatus that irradiates a subject with a parallel X-ray beam generated by using a point / parallel type multicapillary lens, for example, a high-resolution X-ray diffraction analysis of a sample having a three-dimensional structure. Useful for wire devices.
In the present invention, it is preferable to further include a Fresnel zone plate disposed outside the emission end face of the multicapillary so that the central axis of the multicapillary coincides with the central axis.
In this configuration, an X-ray beam having high parallelism and relatively high intensity is incident on the Fresnel zone plate. This Fresnel zone plate is a general Fresnel zone plate that focuses parallel X-rays having a diameter less than or equal to the effective diameter at one point. As described above, in the X-ray irradiation apparatus according to the present invention, since the parallelism of the X-rays incident on the Fresnel zone plate is sufficiently high, the X-rays diffracted by the Fresnel zone plate are collected in a very small region. .

According to engagement Ru X-ray irradiation apparatus of the present invention, it will strength increases compared a compact device can be and parallelism obtain a very high X-ray flux. Thereby, a high-resolution diffraction spectrum can be obtained in high-resolution X-ray diffraction or the like where the parallelism of the irradiated X-ray flux is important.
Moreover, according to the preferable structure of the X-ray irradiation apparatus which concerns on this invention, although it is a small apparatus, it can irradiate intensively to a very small area | region X-ray with comparatively large intensity | strength. Accordingly, for example, by using the X-ray irradiation apparatus according to the present invention for an X-ray diffraction apparatus or a fluorescent X-ray analysis apparatus, it becomes possible to perform analysis and observation with high spatial resolution that cannot be realized conventionally. Moreover, since the multicapillary used in the present invention is simply a bundle of a large number of straight tubes, it is easy to manufacture and it is easy to ensure high dimensional accuracy. In the above configuration, the Fresnel zone plate does not require a special shape or structure. Therefore, it is easy to manufacture the apparatus and it is possible to realize low cost.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of the X-ray irradiation apparatus which is 1st Example of this invention. The fundamental block diagram which drawn the component required only for X-ray irradiation in the X-ray irradiation apparatus of 1st Example. The enlarged view of the straight tube | pipe type multicapillary in the X-ray irradiation apparatus of 1st Example. The enlarged view of the Fresnel zone plate in the X-ray irradiation apparatus of 1st Example. Explanatory drawing of the passage route at the time of an X-ray passing a collimator. Explanatory drawing of the passage route at the time of an X-ray passing through a capillary in a straight tube type multicapillary. The conceptual diagram of the wavelength distribution of the X-ray on the surface away from the Fresnel zone plate by the predetermined distance. The schematic block diagram which shows the modification in the case of obtaining the monochromatic X-ray in the X-ray irradiation apparatus of 1st Example. The schematic block diagram of the X-ray irradiation apparatus which is the 2nd, 3rd Example of this invention. The schematic block diagram of the X-ray irradiation apparatus which is the 4th, 5th Example of this invention. The structure schematic of the experimental apparatus for confirming the effect of this invention. The figure which shows the X-ray image obtained by the apparatus which remove | eliminated the collimator from the experimental apparatus shown in FIG. The figure which shows the X-ray image obtained by the apparatus which removed the straight tube | pipe type | mold multicapillary from the experimental apparatus shown in FIG. The figure which shows the X-ray image obtained by the experimental apparatus shown in FIG.

Hereinafter, embodiments of the X-ray irradiation apparatus according to the present invention will be described with reference to the accompanying drawings.
[First embodiment]
Figure 1 is a schematic structural diagram of an X-ray irradiation apparatus of the first embodiment, FIG. 1 is a principle block diagram depicting the components necessary only in the X-ray irradiation at the X-ray irradiation apparatus of the first embodiment is there.
As shown in FIG. 1, the X-ray irradiation apparatus 1A of the first embodiment includes an X-ray source 10, a collimator 20, a straight tube type multicapillary 30, and an X-ray shield chamber 50 as a housing. A Fresnel zone plate 40. The inside of the X-ray shield chamber 50 is filled with the atmosphere, and is supported on the vibration isolation table 60 by the chamber support 58. An X-ray exit opening 51 is formed in a part of the X-ray shield chamber 50, and the X-ray XL is emitted outside the X-ray shield chamber 50 through the X-ray exit opening 51. Although not shown, an X-ray apparatus such as an X-ray diffractometer or a fluorescent X-ray analyzer is installed outside the X-ray emission opening 51, and the X-ray XL taken out from the X-ray emission opening 51 is such an X-ray. The object (sample) set in the apparatus is irradiated.

  The X-ray source 10 includes, for example, an X-ray tube, and emits X-rays XL. As shown in FIG. 2, the X-ray source 10 can be regarded as a surface light source in which the X-ray emission surface 10a has a certain two-dimensional area. The diameter d1 of the surface 10a is larger than the effective diameter d4 of the Fresnel zone plate 40. Here, the energy of the wavelength of the X-ray emitted from the X-ray source 10 is, for example, 5 keV to 50 keV.

  The collimator 20 to which the X-ray XL emitted from the X-ray source 10 first reaches is separated by a predetermined distance D2 on a predetermined central axis C passing through the X-ray source 10, and has two first and second circular shapes. Openings 21 and 22 are provided. The centers of the openings 21 and 22 coincide with the central axis C. In this embodiment, the number of openings is 2, and can be an appropriate number of 1 or more, but preferably 2 or more. The inner diameters of the two openings 21 and 22 are the same d2, and a part of the X-ray XL emitted from the X-ray source 10 first passes through the first opening 21 in the front stage, and a part of the X-ray XL is further in the second stage. Pass through two openings 22. When the X-ray XL passes through the openings 21 and 22, the X-ray XL that reaches outside the edges of the openings 21 and 22 is shielded by the collimator 20. As will be described in detail later, only X-rays that reach the inside of the two openings 21 and 22 having the same inner diameter can pass through the collimator 20, so that the X-ray XL is roughly collimated by passing through the collimator 20. Become.

  The straight tube type multicapillary 30 to which the X-ray XL that has passed through the collimator 20 reaches next is an aggregate of capillaries (capillaries) made of borosilicate glass that extends linearly along the central axis C. FIG. 3 is an enlarged view of the straight tube type multi-capillary 30, (a) is a plan view seen from the incident direction of the X-ray XL, and (b) is a cross-sectional view taken along line AA ′ in (a). .

  The straight tube type multi-capillary 30 includes a large number of cylindrical capillaries 31 having substantially the same inner diameter d3 (for example, d3 = about 3 μm to 10 μm) and the same length D4 inside a cylindrical light-shielding exterior body 32. It has a configuration stored in a bundled state. However, the number of capillaries 31 is much larger than that shown in FIG. 3, which is about several hundred to one million, and is approximately that of the straight-tube multicapillary 30 determined by the position of the capillaries 31 located on the outermost periphery. The effective diameter is at least larger than the effective diameter d4 of the Fresnel zone plate 40 described later. The straight tube type multi-capillary 30 is arranged so that the central axis (or the central axis of one capillary 31 closest to the center) coincides with the central axis C. Each capillary 31 extends linearly and parallel to each other from one end face (incident end face) 30a to the other end face (outgoing end face) 30b, and each capillary 31 passes X-ray XL while guiding it. As will be described in detail later, this straight tube type multi-capillary 30 has a function of extracting X-rays having a higher parallel degree than the collimator 20.

  The Fresnel zone plate 40 receives and collects the X-ray XL emitted from the emission end face 30 b of the straight tube type multi-capillary 30. 4A and 4B are enlarged views of the Fresnel zone plate 40, where FIG. 4A is a plan view viewed from the incident direction of the X-ray XL, and FIG. 4B is a cross-sectional view taken along line B-B ′ in FIG.

  The Fresnel zone plate 40 is a kind of transmissive diffraction grating in which the outer shape is substantially disk-shaped, and shielding regions 41 that shield X-rays and passing regions 42 that allow X-rays to pass through are alternately formed concentrically. . The interval between the passing regions 42 adjacent to each other in the radial direction is gradually narrowed from the center toward the outside, whereby the X-ray XL incident on the outer peripheral side is greatly bent by the diffraction. As a result, the X-ray XL incident in the range of the effective diameter d4 of the Fresnel zone plate 40 in parallel to the central axis converges to a single point F at a position away from the exit surface opposite to the entrance surface. The Fresnel zone plate 40 is arranged so that its central axis coincides with the central axis C.

  In the X-ray shield chamber 50, a rigid guide rail 54 extending in the traveling direction of the X-ray XL (the direction of the central axis C in FIG. 1) is provided on the two adjustment bases 53. A collimator adjustment base 55, a multicapillary adjustment base 56, and an FZP adjustment base 57 are attached to the rail 54 so that the position can be adjusted in the extending direction. The collimator adjustment table 55, the multicapillary adjustment table 56, and the FZP adjustment table 57 can adjust the inclination angles of the central axes of the collimator 20, the straight tube type multi-capillary 30, and the Fresnel zone plate 40 with respect to the central axis C. To support. Accordingly, the distance D1 between the X-ray source and the collimator 20, the distance D3 between the collimator 20 and the straight tube type multicapillary 30, and the distance D5 between the straight tube type multicapillary 30 and the Fresnel zone plate 40 are adjusted as appropriate. In addition, it is possible to finely adjust the inclination angles of the collimator 20, the straight tube type multi-capillary 30, and the Fresnel zone plate 40 with respect to the central axis C.

  As described above, in the X-ray irradiation apparatus 1A of the present embodiment, the collimator 20 and the straight tube type multi-capillary 30 are both elements for obtaining parallel X-rays, while the Fresnel zone plate 40 finely parallel X-rays. It is an element for narrowing down to a small diameter region. Next, the parallelization and focusing of X-rays will be described in detail with reference to FIGS. 5 and 6 in addition to FIGS. FIG. 5 is an explanatory view of a passage route when X-rays pass through the collimator 20, and FIG. 6 is an explanatory view of a passage route when X-rays pass through one capillary 31 in the straight tube type multicapillary 30.

  Since the diameters d2 of the two openings 21 and 22 are the same, the X-ray XL incident on the first opening 21 of the collimator 20 parallel to the central axis C passing through the centers of the openings 21 and 22 (that is, the inclination angle θ = X-rays that are 0) pass through the collimator 20. The inclination angle (angle with respect to the central axis C) of the X-ray XL passing through the collimator 20 depends on the distance D2 between the two openings 21 and 22 and the diameter d2 of the openings 21 and 22. That is, the inclination angle θ of the X-ray XL passing through the collimator 20 is maximized because the X-ray passes very close to the edge of the first opening 21 and sandwiches the central axis C as shown in FIG. In other words, it passes through the very vicinity of the edge on the opposite side of the second opening 22. Therefore, as the distance D2 between the two openings 21 and 22 is increased, the maximum inclination angle of the passing X-rays is reduced (that is, the parallelism is increased). The smaller the smaller, the smaller the maximum inclination angle of the X-rays that pass.

X-rays that have passed through the first opening 21 at an angle larger than the maximum inclination angle hit the wall around the second opening 22 and are shielded. However, as is apparent from FIG. 5, the X-ray that has passed through the first opening 21 at an angle smaller than the maximum inclination angle can pass through the second opening 22 within a predetermined range in the plane of the first opening 21. Therefore, a part of the incident X-ray XL passes through the collimator 20 and other X-rays are shielded. Therefore, the X-ray intensity distribution immediately outside the second opening 22 of the collimator 20 shows a high X-ray intensity in a range similar to the diameter d2 of the openings 21 and 22. The X-ray intensity gradually decreases toward the outside of the range, and the X-ray intensity becomes 0 outside the range determined by the maximum inclination angle. As described above, the collimator 20 extracts the X-ray XL having a rough parallelism substantially along the central axis C among the X-rays XL emitted from the X-ray source 10.

  The diameter d3 of each capillary 31 of the straight tube type multi-capillary 30 is the same from the entrance end face 31a to the exit end face 31b, and each capillary 31 has a linear shape parallel to the central axis C. As shown in FIG. 6A, when an X-ray XL that is completely parallel to the central axis C is incident on the capillary 31, the X-ray XL is never reflected, that is, not attenuated at all. Pass through. On the other hand, as shown in FIG. 6E, the X-ray XL having an incident angle larger than the critical angle and incident on the capillary 31 enters the wall surface when it hits the inner wall surface of the capillary 31 and is absorbed by the wall surface. Or pass through the wall surface and exit to the outside of the capillary 31. For this reason, the X-ray XL having such an incident angle is removed without passing through the capillary 31.

  Of the X-ray XL incident on the capillary 31 with an incident angle smaller than the critical angle, incident on the capillary 31 with an incident angle equal to or smaller than a predetermined angle θ1 depending on the inner diameter d3 and the length D4 of the capillary 31. A very small part of the X-ray XL passes through the capillary 31 without being reflected, that is, without being attenuated at all, as shown in FIG. 6B. On the other hand, most of the X-ray XL having the same incident angle hits the inner wall surface of the capillary 31 once as shown in FIG. 6C, and the totally reflected X-ray is emitted from the emission end face 31b of the capillary 31. . In principle, this reflection is total reflection, but in practice, the X-ray intensity is attenuated during reflection (because the reflection surface is not a perfect mirror surface). Therefore, the intensity of X-rays that have passed after being reflected once is clearly lower than the intensity of X-rays that have passed without being reflected.

  The X-ray XL incident on the capillary 31 with a larger incident angle even if it is less than the critical angle, after being repeatedly reflected on the inner wall surface of the capillary 31 as shown in FIG. The light is emitted from the emission end face 31 b of the capillary 31. Since the intensity is attenuated at each reflection, there is a significant difference in intensity between the X-rays that have passed through the capillary 31 through a plurality of reflections and the X-rays that have passed through the capillary 31 without being reflected at all. As described above, in the straight tube type multi-capillary 30, the X-ray XL passing through each capillary 31 and the inner wall surface of each capillary 31 are reflected at least once from the emission end face 30 b without being reflected by the inner wall surface of each capillary 31. Then, X-rays XL passing through the capillaries 31 are mixed and emitted, but there is a clear difference between the intensities of the two types of X-rays XL. Further, since the inner diameter d3 of the capillary 31 is extremely small, the predetermined angle determined from the inner diameter d3 and the length D4 is a very small value (close to 0). Therefore, it can be considered that only X-rays substantially parallel to the central axis of each capillary 31 pass, and this straight tube type multi-capillary 30 has an extremely high parallelism with respect to the central axis of the capillary 31. It functions as a filter that selectively passes only the line XL and shields the other X-rays XL.

  Furthermore, in this straight tube type multi-capillary 30, a large number of capillaries 31 are bundled as shown in FIG. 3 (a), so that only one of them is in a substantially circular cross section perpendicular to the optical axis (center axis C). It functions as a parallel filter for all (ie 360 °) radial directions. This can be said to be a significant advantage compared to the fact that a single solar slit, which is a parallel filter widely used in the past, functions as a parallel filter only in one direction.

As described above, the collimator 20 functions as a filter that selects X-rays with coarse parallelism, and the straight tube type multi-capillary 30 functions as a filter that selects X-rays with higher parallelism. As described above, in the X-ray irradiation apparatus 1A of this embodiment, the parallelism of the X-rays can be increased by the two-stage parallel filter, and X-rays with extremely high parallelism can be taken out and incident on the Fresnel zone plate 40. Usually, since the Fresnel zone plate 40 is manufactured using semiconductor manufacturing technology, its dimensional accuracy is very high. Since the X-rays are converged with such a high dimensional accuracy and using the diffraction effect, the X-rays can be converged in a very small region.

The size and focal length of the focal point F can be arbitrarily determined depending on the type of material constituting the Fresnel zone plate 40 and the interval of the annular pattern by the shielding region 41 and the passing region 42. Since it depends on the wavelength, it may be determined appropriately in consideration of the wavelength band of the X-ray to be used.
This point will be described with reference to FIGS. FIG. 7 is a conceptual diagram of the wavelength distribution of X-rays on a surface separated from the Fresnel zone plate 40 by a predetermined distance, and FIG. 8 shows a modified example in which monochromatic X-rays are obtained in the X-ray irradiation apparatus of the first embodiment. It is a schematic block diagram.

  When X-rays having different wavelengths A, B, and C are incident on the Fresnel zone plate 40, the diffraction angles differ depending on the wavelengths, and thus the focal lengths of the respective wavelengths are different. Since the X-rays of the wavelengths B and C are not focused at the focal position of the X-rays of the wavelength A, the X-ray flux is not sufficiently reduced. On the other hand, the optical axis that is also the central axis C1 of the Fresnel zone plate 40 does not change depending on the wavelength. Therefore, as shown in FIG. 7, the irradiation ranges of X-rays with different wavelengths are overlapped at the center, and only X-rays with some wavelengths reach the peripheral part.

  X-rays emitted from an X-ray source used in a general X-ray apparatus include an X-ray having a strong peak energy (for example, wavelength A) determined by a target material and a set acceleration voltage, and moderate continuous energy ( For example, X-rays having wavelengths B and C). Therefore, when an X-ray image is observed on the surface of the focal position with respect to the X-ray of the wavelength A, the blur due to the X-rays of the wavelengths B and C is added to the image of the focal size of the wavelength A, that is, a very small image. Inevitable. Therefore, when irradiation with X-rays having a specific wavelength, that is, monochromatic light is necessary, the configuration shown in FIG. 8 may be adopted.

  That is, in this X-ray irradiation apparatus, a flat plate crystal (spectral element) 70 is installed between the straight tube type multicapillary 30 and the Fresnel zone plate 40, and only X-rays of a specific wavelength extracted by the flat plate crystal 70 are used. Is incident on the Fresnel zone plate 40. As described above, since the parallelism of the X-rays emitted from the emission end face 30b of the straight tube type multi-capillary 30 is sufficiently high, accurate monochromation can be easily performed using the plate crystal crystal 70, for example, the wavelength A Only high parallel X-rays can enter the Fresnel zone plate 40. As a result, it is possible to irradiate a very small region with monochromatic X-rays.

  Returning to the X-ray irradiation apparatus of the first embodiment, the description will be continued. In the X-ray irradiation apparatus of the first embodiment, the distance D5 between the emission end face 30b of the straight tube type multi-capillary 30 and the Fresnel zone plate 40 may be determined as follows. That is, the closer the exit end face 30b and the Fresnel zone plate 40 are, the more the X-rays emitted from the exit end face 30b are reflected at least once by the inner wall surface of the capillary 31, that is, the parallelism is relatively inferior. X-rays easily reach the range of the effective diameter d4 of the Fresnel zone plate 40. Since such X-rays are not ideal as incident X-rays for the Fresnel zone plate 40, it is desirable to eliminate them as much as possible. Therefore, in the X-ray irradiation apparatus 1A of the present embodiment, the emission end face has an angle equal to or larger than the predetermined angle θ1 determined by the inner diameter d3 and the length D4 of the capillary 31 that may be totally reflected by 1 degree or more. The distance D5 is set such that the X-rays emitted from 30b do not reach the range of the effective diameter d4 of the Fresnel zone plate 40. As a result, the parallelism of the X-rays incident on the Fresnel zone plate 40 can be further increased, and the irradiation diameter of the X-rays at the focal point F can be reduced.

  If the second opening 22 of the collimator 20 and the incident end face 30a of the straight tube type multi-capillary 30 are too close, the X-ray XL having a large inclination with respect to the central axis C is likely to enter the incident end face 30a. Although the X-ray XL having such a large incident angle is removed by the straight tube type multi-capillary 30, a part of such undesired X-rays is reflected on the inner surface of the outer package 32 or scattered on the outer surface of the capillary 31. Or may appear on the emission end face 30b. Therefore, by increasing the distance D3 between the second opening 22 of the collimator 20 and the incident end face 30a of the straight tube type multi-capillary 30 to a certain extent or more, the central axis C of the X-rays XL passing through the second opening 22 is increased. It is better to avoid the X-ray XL having a large inclination with respect to the incident end face 30a. Specifically, the distance D3 may be about 100 mm or more. However, it is not appropriate to increase this distance unnecessarily in order to reduce absorption and scattering by the atmosphere.

  As described above, in the X-ray irradiation apparatus 1A of the present embodiment, it is possible to irradiate the X-ray XL intensively on a very small diameter region. In this X-ray irradiation apparatus 1A, although X-rays are not collected from a wide range of X-ray sources as in the X-ray focusing apparatuses described in Patent Documents 3 and 4, for example, X-rays are collected. Since X-rays that are never reflected in the process, that is, not attenuated, are effectively used, high-intensity X-rays can be intensively irradiated.

  Next, an X-ray irradiation apparatus according to another embodiment of the present invention will be described with reference to FIGS. In these drawings, the same components as those in the first embodiment are denoted by the same reference numerals.

[Second Embodiment]
FIG. 9A is a schematic configuration diagram of the X-ray irradiation apparatus 1B of the second embodiment.
In the X-ray irradiation apparatus 1B of the second embodiment, a point-parallel type multicapillary 120 is disposed instead of the collimator 20 in the X-ray irradiation apparatus 1A of the first embodiment, and is not a surface light source but a point light source. An X-ray source 110 is used. The X-ray source 110 emits X-rays XL radially from an X-ray emitting unit 110a that can be regarded as a point light source. The multicapillary 120 is narrowed so that the inner diameter of each capillary gradually decreases toward the end face on the incident end face 120a, unlike the straight-tube multicapillary 30 at the subsequent stage, and the central axes of the many capillaries are X-rays. It is formed so as to overlap (that is, become a focal point) at the emission part 11a. As a result, the X-ray XL emitted from the X-ray emission part 11a is taken into the multicapillary 120 with a large solid angle, and the X-ray is guided while repeating total reflection on the inner wall surface of each capillary, and is substantially parallel to the emission end face 120b. Is emitted. In principle, since the X-ray XL emitted from the emission end face 120b has a maximum critical angle spread, the multicapillary 120 functions as a coarse parallel filter, like the collimator 20 in the first embodiment.

[Third embodiment]
FIG. 9B is a schematic configuration diagram of the X-ray irradiation apparatus 1C of the third embodiment.
In the X-ray irradiation apparatus 1C of the third embodiment, instead of the collimator 20 in the X-ray irradiation apparatus 1A of the first embodiment, a multicapillary 220 whose incident end face 220a is larger than the emission end face 220b is disposed. An X-ray source 210 that is a surface light source having a large emission surface 210a is used. The capillaries constituting the multicapillary 220 have funnel-shaped incident end surfaces, efficiently capture X-rays XL emitted from the X-ray exit surface 210a, and substantially parallelize while increasing the density of the X-rays XL. The light exits from the exit end face 220b. Also in this case, since the X-ray XL advances while repeating total reflection on the inner wall surface of the capillary, in principle, the X-ray XL emitted from the emission end face 120b has a maximum critical angle spread. Therefore, the multicapillary 220 functions as a coarse parallel filter, like the collimator 20 in the first embodiment.

[Fourth embodiment]
Fig.10 (a) is a schematic block diagram of X-ray irradiation apparatus 1D of 4th Example.
In the X-ray irradiation apparatus 1D of the fourth embodiment, the collimator 20 in the X-ray irradiation apparatus 1A of the first embodiment is omitted, and the X-ray XL emitted from the X-ray emission surface 10a of the X-ray source 10 is directly The light enters the incident end face 30 a of the straight tube type multi-capillary 30. As described above, since the straight tube type multicapillary 30 functions as a filter for selecting X-rays with extremely high parallelism, even if the collimator 20 is omitted, a sufficiently high parallelism X-ray XL is taken out and the Fresnel zone plate. 40 can be incident. Thereby, even in the configuration of the fourth embodiment, it is possible to irradiate the region having a small diameter with the X-ray XL.

[Fifth embodiment]
FIG.10 (b) is a schematic block diagram of the X-ray irradiation apparatus 1E of 5th Example.
In the X-ray irradiation apparatus 1E of the fifth embodiment, instead of omitting the collimator 20 in the X-ray irradiation apparatus 1A of the first embodiment, a multi-capillary 320 having the same configuration as the straight tube type multi-capillary 30 is used as an X-ray source. 10 and the straight tube type multi-capillary 30. In this configuration, the first-stage multicapillary 320 functions as a coarse parallel filter, but this also allows X-ray XL with sufficiently high parallelism to be extracted and incident on the Fresnel zone plate 40.

  As described above, in the X-ray irradiation apparatus according to various embodiments of the present invention, a combination of the straight tube type multi-capillary 30 and the Fresnel zone plate 40 is used to collectly irradiate a small diameter region with X-rays. Is possible.

[Experimental example]
Next, experimental results performed to confirm the X-ray convergence effect in the X-ray irradiation apparatus 1A of the first embodiment will be described.
FIG. 11 is a schematic diagram of the configuration of the experimental apparatus used in this experiment.
In this experimental apparatus, the X-ray source 10 includes a point light source 15, a tube 16 in which a window 16a is formed, a shielding plate 17 in which an opening 17a is formed, and a copper foil 18 provided so as to cover the opening 17a. Consists of including. A part of the X-ray XL emitted radially from the point light source 15 passes through the window 16a, and further part thereof passes through the opening 17a. The X-ray XL emitted from the opening 17a while passing through the copper foil 18 can be regarded as a surface light source having an opening area of the opening 17a.

  A collimator 20 and a straight tube type multicapillary 30 are arranged on a central axis C coinciding with the center axis of the opening 17a, and the X-ray XL is paralleled by passing through the collimator 20 and the straight tube type multicapillary 30 in order. It becomes. The diameter (d2) of the openings 21 and 22 of the collimator 20 is 1 mm, and the distance (D2) between the openings 21 and 22 is 50 mm. In this experimental apparatus, the Fresnel zone plate is omitted, and the X-ray XL emitted from the emission end face 30b of the straight tube type multicapillary 30 is introduced into the two-dimensional detector 80, and an X-ray image by the reached X-ray XL is obtained. I tried to get it.

  11 obtained by removing the collimator 20 from the experimental apparatus shown in FIG. 11, setting the distance between the shielding plate 17 and the incident end face 30a of the straight tube type multicapillary 30 to 180 mm, and the imaging magnification of the two-dimensional detector 80 to be 1. A line image is shown in FIG. 12A to 12D are X-ray images when the distance between the emission end face 30b of the straight tube type multi-capillary 30 and the two-dimensional detector 80 is set to 35 mm, 70 mm, 140 mm, and 340 mm, respectively. . In FIG. 12 (the same applies to FIGS. 13 and 14 to be described later), the portion with the higher X-ray intensity is displayed brighter (whiter).

  As a comparative example, the straight multi-capillary 30 is removed from the experimental apparatus shown in FIG. 11, the distance between the shielding plate 17 and the first opening 21 of the collimator 20 is 30 mm, and the imaging magnification of the two-dimensional detector 80 is 1 ×. The X-ray image obtained as is shown in FIG. 13A to 13C are X-ray images when the distance between the second opening 22 of the collimator 20 and the two-dimensional detector 80 is set to 35 mm, 70 mm, and 140 mm, respectively.

  Comparing FIG. 12 and FIG. 13, the outline of the X-ray image is clearer when only the straight tube type multicapillary 30 is used (FIG. 12) than when only the collimator 20 is used (FIG. 13). At the same time, it can be seen that the uniformity of the strength within the contour is high. From this, it can be confirmed that the straight tube type multi-capillary 30 has a remarkably high effect of increasing the parallelism of the X-ray XL as compared with the collimator 20, that is, the ability as a parallel filter is high. Note that blurring is observed in the contour of the image at (c) the detector distance of 140 mm and (d) the detector distance of 340 mm in FIG. 12, which is considered to be mainly caused by scattering of X-rays by the atmosphere.

  FIG. 14 is a view showing an X-ray image in the experimental apparatus shown in FIG. 11, that is, an X-ray image when the collimator 20 and the straight tube type multi-capillary 30 are used together. In this case, the distance (D1) between the shielding plate 17 and the first opening 21 of the collimator 20 is 30 mm, and the distance (D3) between the second opening 22 of the collimator 20 and the incident end face 30a of the straight tube type multicapillary 30 is set. The distance between the output end face 30b of the straight tube type multi-capillary 30 and the two-dimensional detector 80 is 35 mm to 140 mm, and the imaging magnification of the two-dimensional detector 80 is set to 1. 14A to 14C are X-ray images when the distance between the emission end face 30b of the straight tube type multi-capillary 30 and the two-dimensional detector 80 is 35 mm, 70 mm, and 140 mm, respectively.

From FIG. 14, by using the collimator 20 and the straight tube type multi-capillary 30 in combination, X-rays are irradiated with a higher intensity to a smaller area than when only the straight tube type multi-capillary 30 is used (FIG. 12). I understand that From this, it can be confirmed that the parallelism of the X-rays is further enhanced by the combined use of the collimator 20 and the straight tube type multi-capillary 30.
In the X-ray irradiation apparatus 1A of the first embodiment, X-rays with extremely high parallelism can be introduced into the Fresnel zone plate 40, so that the high X-ray convergence of the Fresnel zone plate 40 is effectively utilized. Utilizing this, it becomes possible to focus X-rays on a minute area.

  In addition, it can be seen from the above experimental results that the straight tube type multi-capillary 30 has a higher ability to parallelize X-rays than the collimator 20, so that the combined use of the collimator 20 and the straight tube type multi-capillary 30 is not possible. However, as in the fourth embodiment, it can be understood that the X-rays can be efficiently condensed in a minute region simply by omitting the collimator 20 and combining the straight tube type multi-capillary 30 and the Fresnel zone plate 40. In addition, as in the second, third, and fifth embodiments, in the case where a multicapillary having various configurations is used instead of the collimator 20, similarly, X-rays can be efficiently condensed in a minute region. It is.

  Furthermore, each of the above embodiments is an X-ray irradiation apparatus that collects X-rays in a minute region, but the above configuration can also be used when an X-ray bundle having high parallelism is required. That is, as described above, the combination of the collimator 20 and the straight tube type multicapillary 30 makes it possible to obtain an X-ray bundle having sufficient strength and extremely high parallelism. For example, in the high-resolution X-ray diffraction analysis of a substance having a three-dimensional structure, the spatial resolution improves as the parallelism of the irradiated X-ray flux increases. Therefore, in such an X-ray apparatus, for example, the Fresnel zone plate 40 is omitted in the X-ray irradiation apparatus 1A of the first embodiment, and the X-ray XL emitted from the emission end face 30b of the straight tube type multi-capillary 30 is directly emitted as X-rays. It is preferable to use an X-ray irradiation apparatus which is taken out of the X-ray shield chamber 50 through the opening 51.

  In addition, since each of the above-described embodiments is an example of the present invention, it is a matter of course that modifications, corrections, or additions as appropriate within the scope of the present invention are included in the scope of the claims of the present application.

1A, 1B, 1C, 1D, 1E ... X-ray irradiation apparatus 10, 110, 210 ... X-ray source 10a, 210a ... X-ray emission surface 110a ... X-ray emission unit 20 ... Collimator 21 ... First opening 22 ... Second opening 30 ... Straight multi-capillary 30a, 31a, 120a, 220a ... Incident end face 30b, 31b, 120b, 220b ... Outlet end face 31 ... Capillary 32 ... Exterior body 40 ... Fresnel zone plate 41 ... Shielding area 42 ... Passing area 50 ... X Line shield chamber 51... X-ray emission opening 53. Adjustment table 54. Rigid guide rail 55. Collimator adjustment table 56. Multicapillary adjustment table 57. FZP adjustment table 58. , 220, 320 ... multicapillary

Claims (2)

a) an X-ray source emitting X-rays;
a collimator having two openings, a circular shape b) X-rays emitted from said X-ray source provided apart from each other by a predetermined distance in the linear axis line passing through the X-ray source passes,
c) a plurality of bundled X-ray guiding capillaries each having a central axis that is straight and parallel to each other, and has substantially the same length and the same inner diameter, and includes two X-ray sources and two collimators. It has a central axis which coincides with straight axis passing through the opening, where one end faces the incident end face X-rays passing through the two openings Ru is incident is released the collimator from the X-ray source, the other A multicapillary whose end face is an emission end face for emitting X-rays substantially in parallel;
An X-ray irradiation apparatus , wherein an inner diameter of each thin tube of the multicapillary is smaller than an inner diameter of two openings of the collimator . The X-ray irradiation apparatus according to claim 1,
An X-ray irradiation apparatus , further comprising: a Fresnel zone plate disposed outside the emission end face of the multicapillary so that the central axis of the multicapillary coincides with the central axis.