JPH0355890Y2 - - Google Patents

Description

[Detailed description of the invention] In an X-ray diffractometer, a normally plate-shaped sample is rotated to change the incident angle of X-rays, and the accompanying change in the intensity of diffracted X-rays is measured. Therefore, if a fixed slit is placed between the sample and the X-ray source,
As the sample rotates, the area of incidence of X-rays on its surface changes. For this reason, errors will occur if the sample is not completely uniform, and if the slit is removed and the X-rays are always incident on the entire surface of the sample, the X-rays protruding from the sample surface will increase the density and reduce measurement accuracy. descend. In order to eliminate such drawbacks, the X-ray device described in Japanese Patent Publication No. 53-28222 rotates the slit at an angular velocity that is slightly slower than the angular velocity at which the sample is rotated, thereby reducing the incidence of X-rays on the sample surface. The area is kept almost constant. However, as is clear from the curve shown in FIG. 5 in the above-mentioned publication, it is impossible to maintain the incident area accurately and constant. Therefore, the present invention has a simple structure and the X
The object of the present invention is to provide a slit device that can accurately keep the incident area of the line constant.

FIG. 1 is a cross-sectional view of an embodiment of the present invention, in which a flat sample 2 is attached to a rotating shaft 1 provided at the center of the goniometer, and an X-ray source 3 in a straight line perpendicular to the plane of the paper is applied to the sample. A line is incident. In addition, an X-ray detector 5 is provided which moves on a circular orbit 4 centered on the axis 1 and passing through the X-ray source 3 at an angular velocity twice that of the axis 1, and at an appropriate position between the X-ray source 3 and the sample 2. A slit 6 is arranged at. This slit 6 is attached to a shaft 7, and gears 8 and 9 of the same diameter fixed to the shafts 1 and 7 are meshed with the gear 10. Therefore, when the sample 2 is rotated as shown by the arrow a, the slit 6 is also rotated at the same angular velocity and in the same direction as shown by the arrow b.
The line detector 5 moves on the trajectory 4 as shown by the arrow c at twice the angular velocity. In addition, the X-rays emitted from the X-ray source 3 and passing through the slit 6 enter the sample 2 as indicated by the dotted arrow, and the diffracted X-rays are focused on the entrance window of the detector 5. By measuring the output of the detector, it is possible to observe the relationship between the incident angle θ of the X-rays on the sample 2 and the intensity of the diffracted X-rays.

Fig. 2 is a perspective view of the slit 6 in Fig. 1, in which an auxiliary plate ₆₂ is attached to the plate ₆₁ provided with a U-shaped cut, and a support shaft ₆₃ is fixed on the bisector of the slit. Both sides are bent at right angles to form shielding wings 6 ₄ and 6 ₅ when the slits are arranged parallel to the X-rays. Therefore, by fitting the support shaft 6 ₃ into the hole of the shaft 7 and fixing it with the screw 11, the slit 6
can be attached to the shaft 7 at any angle. FIG. 3 is an enlarged view of a part of FIG. 1, showing that the portion of the X-rays emitted from the X-ray source 3 that is sandwiched between the parallel edges p and q on both sides of the slit 6 passes through the slit. The slit 6 is fixed to the shaft 7 so that the light enters the sample 2 as indicated by the dotted arrow, and a straight line s passing through these points p and q is arranged parallel to the sample 2. In other words, since the sample 2 and the slit 6 rotate in the same direction at the same angular velocity as described above, the slit rotates as shown by the chain line 6' at the position where the incident angle of the X-rays on the sample 2 is zero, as indicated by the chain line 2'. When the slit is rotated as shown in FIG. The straight line is placed perpendicular to the X-ray, such as s''.

In the above-mentioned apparatus, points t and u in FIG. 3 indicate the centers of the slit 6 and the sample 2, respectively, and the slit and the sample rotate through these points about a straight line perpendicular to the plane of the paper, Moreover, the points t and u and the X-ray source 3 are arranged on a straight line. And as mentioned above, the edges p on both sides of the slit 6,
A straight line s passing through q is always parallel to the surface of the sample 2. Therefore, if the ratio of the distances from the X-ray source 3 to points t and u is k, then the incident range of the X-rays on the sample surface is determined by rotating the sample 2 and the slit 6 to change the incident angle θ of the X-rays from 0 to 90°. If the rotation angle changes by a degree, it will always be k times the rotation angle,
Hold a precisely constant value.

Further, FIG. 4 is a sectional view corresponding to FIG. 3 in which the slit 6 is formed by drilling a rectangular hole in one plate. In this case, the edges p and q on both sides of the slit form the corners of the opposite sides of the single plate. Therefore, the straight line s passing through points p and q is inclined with respect to the plate forming the slit, but by installing the slit so that this straight line s is parallel to the surface of the sample 2, Just like the embodiment shown in FIG. 3, the incident range of the X-rays on the sample surface is always exactly k times and maintains a constant value, regardless of its rotational angular position.

Note that in the above embodiment, divergent X-rays are incident on the sample, but when parallel X-rays are incident on the sample using a planar X-ray source, the value of k is only 1; Similar effects can be obtained by the present invention.

In addition, in the embodiments shown in FIGS. 3 and 4, the edge p of the slit is inclined with respect to the plate on which the slit is formed, so that when the straight line s is substantially perpendicular to the axis of the X-ray, the inner surface of the edge This prevents part of the X-rays from being blocked. However, since this amount of interruption is extremely small and may not be interrupted at all depending on the range of change in the observation angle, providing the above-mentioned "tilt" is not necessarily necessary.

As explained above, in the present invention, since the sample and the slit are rotated at the same angular velocity, the mechanism is simple and the operation for attaching the slit is easy. Moreover, the incident range of X-rays on the sample surface can be maintained accurately and constant regardless of its rotational angular position. Therefore, there is no fear that X-rays will protrude from the sample surface, and it is possible to prevent background from increasing and to perform accurate measurements.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an embodiment of the present invention, Fig. 2 is a perspective view of the slit in Fig. 1, Fig. 3 is an enlarged view of a part of Fig. 1, and Fig. 4 is a cross-sectional view of an embodiment of the present invention. FIG. 3 is a diagram corresponding to FIG. 3 of the embodiment. In the figure, 1 is a rotating shaft, 2 is a sample, 3 is an X-ray source, 4 is a circular orbit, 5 is an X-ray detector, 6 is a slit, 7 is a shaft,
8, 9, and 10 are gears, and 11 is a screw.

Claims (1)

[Scope of utility model registration request] In an X-ray diffractometer that measures the relationship between the incident angle and the diffracted X-ray intensity by injecting X-rays into a flat sample, a slit with parallel edges on both sides is inserted between the X-ray source and the sample as described above. a mechanism for driving the slit and the sample such that the edge of the slit is arranged so as to be orthogonal to the direction of change of the incident angle, and the incident angle of the X-rays to the slit changes in the same direction at the same angular velocity as the incident angle to the sample; and at a position where the angle of incidence of the X-rays on the sample is zero, the plane including the edges on both sides of the slit is parallel to the axis of the X-rays, and the angle of incidence of the X-rays on the sample is 90 degrees. A slit device in which the slit is attached to the drive mechanism such that the plane is disposed at right angles to the axis of the X-ray.