JP3762987B2 - X-ray condensing element - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
X-rays are widely used in industry, medicine, and the like, and their uses are expanding as the use technology advances. In order to obtain an X-ray profile optimal for the application field, an X-ray optical element is indispensable, and a condensing element is a basic element among them.
[0002]
In recent years, most of the light collecting elements use X-rays such as processing fields such as X-ray lithography, which are expected to be used, analysis fields represented by fluorescent X-ray analysis, medical fields represented by CT, etc. However, the conventional light collecting element is difficult to process and expensive. In order to provide a light collecting function by combining an inexpensive light collecting element, a high degree of alignment is required, and much labor is required.
[0003]
[Prior art]
The refractive index of a substance with respect to X-rays is almost the same as the X-ray refractive index in a vacuum, and the change in the X-ray propagation direction due to substance transmission is negligible. It is difficult to realize a transmission optical element such as a prism with X-rays. Diffractive optical elements such as Fresnel zone plates are inefficient and have a limited wavelength range of X-rays that work effectively as elements, making it difficult to construct an optical system that can handle X-rays in general.
Reflective optical elements can in principle control the direction of propagation for X-rays in general, but the reflectivity of the material is also small, so reflective optical elements that can withstand practical use are in comparison with visible light. Severe conditions are required.
[0004]
[Problems to be solved by the invention]
In order to obtain a sufficient reflectivity with respect to X-rays, it is necessary to make the X-rays incident at an oblique incidence of the reflective surface of the optical material (at an angle of about 0.2 to 0.5 degrees). Therefore, when an X-ray condensing element is realized, a simple spherical mirror has a large aberration at oblique incidence, and sufficient condensing cannot be performed. A toroidal mirror in which the curvature in the direction parallel to the incident surface and the direction perpendicular to the incident surface is changed to correct the aberration can collect light, but it is very difficult to process the surface shape of such a toroidal mirror. Although there is a method of providing a light collecting function by combining optical elements that are easy to process, each optical element requires a high degree of alignment, and the system becomes large due to the alignment jig, etc., which requires a lot of labor. did.
[0005]
[Means for Solving the Problems]
In order to solve the above problem, in the present invention, a reflective surface that is easy to process is integrally formed in the element. These reflecting surfaces are respectively responsible for vertical, horizontal, and front and rear light collection, and collect incident X-rays by these. The integration eliminates the need for complicated alignment between the reflecting surfaces, facilitates the processing of the light collecting element, and enables miniaturization.
[0006]
Embodiment
As a material for the mirror, a relatively heavy metal element or a material obtained by plating these elements on the inner surface of a base material processed into a condensing element shape is preferable. Alternatively, in the X-ray region, the higher the total number of electrons and the density of the element, the larger the difference in refractive index of the element / vacuum, and thus a higher reflectance can be expected. A multilayer film with light elements stacked alternately on the inner surface of a base material processed into a condensing element shape is good. Specific examples of the material include chromium, manganese, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, silver, gold, platinum, tantalum, iridium, rhenium, and tungsten. Thallium, osmium, and the like are possible as similar relatively heavy metal elements on the periodic table, but there is a problem of toxicity. Iridium and rhenium are rare, and tungsten has difficulty in workability. In implementation, it must be determined in consideration of the above-mentioned toxicity, easy availability, processability and the like.
[0007]
【Example】
FIG. 1 shows a conceptual diagram of an X-ray condensing element according to the present invention. The inner surface of the cylindrical hole formed on the condensing element is used as a mirror to reflect X-rays. In order not to impair the reflectivity, each cylindrical mirror is arranged so that X-rays are incident under oblique incidence conditions. Since each mirror collects X-rays in the vertical, horizontal, and front and rear directions, X-rays incident at a specified position and direction can be condensed.
[0008]
Further, by arranging the present optical element in an array as shown in FIG. 1-1, the present condensing element can be easily increased in area.
[0009]
【The invention's effect】
According to the present invention, X-rays can be condensed without complicated processing required for a conventional light condensing element or high-level alignment of the light condensing elements. Further, by integrating the light collecting element, a large area light collecting system can be configured.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of the present invention. FIG. 2 is a conceptual diagram of an integrated large area X-ray focusing system.

Claims (2)

An X-ray condensing element, wherein three cylindrical mirrors are integrally formed in a rectangular parallelepiped , and the vertical, horizontal, and front-rear condensing are performed by each mirror. An X-ray condensing element, wherein a plurality of the X-ray condensing elements according to claim 1 are stacked.

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