JPS612100A - X-ray divergence angle limiter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an X-ray divergence angle limiter. For more details, see X
Single or multiple small hole or The present invention relates to an X-ray divergence angle limiter using a slit (hereinafter abbreviated as slit).

BACKGROUND ART Conventional X-ray generators employ a method in which electrons are accelerated at a predetermined voltage in a vacuum, transferred to a metal anticathode (or anode), and then taken out into the atmosphere through a beryllium window.

Here, 1X-rays are emitted in all directions from the position where individual electrons have lost their kinetic energy after colliding. Therefore, as long as the part where electrons collide has a finite area on the anticathode, a point in space away from the X-ray generation position can be reached from a direction within the range from that point to the finite area where the X-rays are generated. X-rays will be incident. Therefore, for various types of equipment that require parallel or nearly parallel X-ray flux,
There is no choice but to use an X-ray generating device with a limited upper limit of the ray generating area. In addition, in order to limit the divergence angle of X-rays, one or more of the X-ray generating device and the X-ray utilization equipment is equipped with a single or multiple slits, and the X-rays pass through the slits. There is no choice but to use an X-ray divergence angle limiter to extract only X-rays.

Therefore, X parallel or approximately parallel to #1 is
There was a problem in that it was impossible to irradiate the X-rays at the same time, and when the distance was increased, the intensity of the X-rays attenuated in inverse proportion to the square of the distance.

Purpose of the Invention The present invention aims to solve the above-mentioned conventional problems, and its purpose is to convert parallel or almost parallel X-rays (collectively referred to simply as parallel X-rays) into X-rays. It prevents the attenuation of X-ray intensity due to the distance between the radiation source and the sample, makes it possible to irradiate a wide sample area with X-rays, and at the same time, when the sample area is extremely small, it is possible to reduce the The object of the present invention is to provide an X-ray divergence angle limiter that can obtain X-ray intensity several tens of times higher than conventional ones by modification.

Structure of the Invention As a result of intensive research to achieve the above object, the present inventors found that the inner cross section is circular, elliptical, or polygonal, and the inner wall surface is a smooth surface that allows total reflection of X-rays. x consisting of one or more thin hollow tubes bundled in parallel
The above objective can be achieved by using a divergence angle limiter.
I found out that JP-A-6L-2too (2) 1chi. The present invention was completed based on this knowledge.

The gist of the present invention is that the inner cross section is circular, elliptical or polygonal,
The X-ray divergence angle limiter is composed of one or more thin hollow tubes bundled in parallel, each of which has a smooth inner wall surface capable of causing total reflection of X-rays.

To explain the X-ray divergence angle limiter of the present invention based on the drawings, FIGS. 1 and 2 are cross-sectional views of an embodiment of the X-ray divergence angle limiter (hereinafter simply abbreviated as limiter) of the present invention. be.

Figure 1 shows the case of a multi-tube bundle, and Figure 2 shows the case of a single tube. The broken line shown in FIG. 1 indicates the window portion from which X-rays are taken out in a conventional X-ray generator, 13 is the wall of the device, 12 is a beryllium window, and the left side of this window is a vacuum. Reference numeral 11 indicates an X-ray generating section on the anticathode. Although there are various forms of conventional X-ray generators, the X-ray extraction section is generally as shown in this drawing, and the limiter of the present invention can be used regardless of the form of the X-ray generator side. Can be joined.

1 is a hollow tube in which the restrictor of the present invention is connected to an X-ray generator; 4 is a hollow tube in which a controller is attached to the X-ray generator; the generated X-rays enter through the entrance port 5; The light exits from the exit port 6 while repeating total reflection within 'lQ' and '3.

The hollow tube 3 has an inner cross section of a circle, an ellipse, or a polygon, and its inner wall surface is smooth enough to allow total reflection of X-rays. The thinner the wall thickness is, the more efficiently the generated X-rays can be utilized.

The inner diameter φi of the hollow tube 3 is determined by the distance 11 from the X-ray generator 11 to the entrance port 5 and the critical angle Q for total reflection of the X-rays used. The following conditions are met. (See Figure 3) φ1≦2Qo-11 However, QC is in radian, and φi and 11 are in units of shank.

The inner diameter of the outer cylinder 2 is equal to or larger than the practical X-ray generation area. The X-ray generation region refers to the region where electrons on the anticathode collide, but in conventional X-ray generation equipment,
In some cases, X-rays are extracted from the same region at a low angle in the direction (6 to 10 degrees relative to the anticathode surface), so in that case, means the area of occurrence.

Next, the action of this restrictor will be explained with reference to FIG.

Figure 3-a is a schematic diagram of the conventional method in which a slit is provided in front of the sample in order to limit the divergence angle of the X-rays incident on the sample, and Figure 3-b is a schematic diagram of the limiter of the present invention. FIG. 3 is a schematic diagram showing the divergence angle of X-rays when used.

In the drawings, the hollow tube is assumed to be circular.

In the figure, φ is the X-ray generation area, lj is the distance from the X-ray generation position to the entrance port of the restrictor, and s'2 is the length of the restrictor. In the usual case of installation, it is also the distance from the window to the sample. φ indicates the inner diameter of the hollow tube, which satisfies the relationship with the critical angle of total reflection of X-rays described above.

In Figure 3-a, /A=2φX/<1+”12)
In Fig. 3-S, /B-2φi/11, which is ≦2Qc1 from the condition of the hollow tube diameter φi.
However, depending on the wavelength of the X-ray and the density of the material used for the tube, in the case of ordinary glass or metal tubes, the wavelength is 1.5X.
For X-rays of about 7 to 3 x 10 radians.

As is clear from the comparison between Figure 3-a and Figure 3-b, if you try to obtain the same parallel X-ray flux as in Figure 3-b using the method of Figure 3-a using a slit, In this case, it is necessary to move the sample extremely far away from the X-ray source, or to make the plane of the X-ray generation region and the irradiation area on the sample as small as φ1 in FIG. 3. This is why the X-ray generation area of conventional X-ray generators is generally several tens of square meters or less.

In the case of FIG. 3-b using the restrictor of the present invention, the smaller the diameter of the hollow tube, the more parallel the X-ray flux can be obtained, and the X-ray intensity at the entrance is X-rays can be guided without attenuation due to total reflection by the inner wall of the hollow tube. Even in the embodiment where 12 is 800 units, especially when using a normal glass tube, the X-ray intensity ratio at the entrance and exit is 2.
:1, which is about 40 compared to about 80:1 in the conventional method using slits. This purpose can be easily achieved by attaching or incorporating an X-ray generating device having an X-ray generating area as wide as or larger than the contrast medium.

On the other hand, in various science and science experimental equipment that uses X-rays, when the sample or analysis area is extremely small, for example, an X-ray diffractometer,
When the diameter of the sample is 0.03 mm or less, the intensity of the diffracted X-rays is extremely weak, and the Xj! In an X-ray diffractometer using a 1-divergence angle limiter, it is not easy to obtain ρ[1 constant.

This is equivalent to the case where the slit is set to 0.03 # or less in FIG. 3-a. In such cases, among the conventional X-ray generators, an X-ray generator with a particularly small X-ray generating area (≦0.1φ), which is called a focal Xa generator, is used, and the present invention is used. When using a restrictor as shown in Figure 2, there is no limit to the distance between the X-ray generator and the sample, and the mechanism
'For the AXm source, use higher intensity X-rays.
No can be done. Therefore, analysis of minute samples or minute regions, which was previously impossible, becomes possible.

Effects of the Invention By using the restrictor of the present invention, as mentioned above, it is possible to prevent the intensity from decreasing in inverse proportion to the square of the distance from the There is no need to take it out. Therefore, the area of the sample that is irradiated with parallel or nearly parallel X-rays becomes larger.

For example, for applications such as lithography, an X-ray generator with a wide X-ray generation area equal to the sample surface is used, and the restrictor of the present invention is attached at an arbitrary angle to the anticathode surface to generate X-rays. By taking out the X-rays, a wide area can be simultaneously irradiated with parallel or nearly parallel X-ray fluxes.

In addition, even in the opposite case to the above, that is, when an extremely fine sample (for example, 0.05 tone or less) is irradiated with a parallel or almost parallel X-ray flux, the restrictor of the present invention can be installed. It is valid. In that case, the inner diameter φi of the hollow tube and the diameter φ of the X-ray generation area are equal to the diameter of the fine sample, and φ, ≦
If the hollow tube is installed so as to satisfy 2Qc-7+ and the hollow tube has less radiance, the sample can be irradiated with high-intensity X-rays very easily.

As mentioned above, it has excellent effects and can be used in various sciences,
We believe this will contribute to medical and industrial X-ray equipment.

[Brief explanation of drawings]

1 and 2 are cross-sectional views of embodiments of the X-ray divergence angle limiter of the present invention, with FIG. 1 showing a multi-tube bundle and FIG. 2 showing a single-tube configuration. Figure 3 is a schematic diagram showing the divergence angle of X-rays.
Figure 3-a shows the case where a slit is provided in front of the sample in the conventional method, and Figure 3-a shows the case in the restrictor of the present invention. 1: Cover for shielding divergent X-rays, 2: Peripheral cylinder, 3: Hollow tube, 4: Jig,
5: X-ray entrance port, 6: X-ray exit port,
7: Screw, 8: Screw holder, 11: X-ray generator, 12: Beryllium window, 13: Wall. Figure 1 Ward

Claims (1)

[Claims] An X-ray divergence angle limiter consisting of one or more thin hollow tubes whose inner cross section is circular, elliptical or polygonal and whose inner wall surface is smooth enough to cause total X-ray reflection. .