JPH0695080B2 - X-ray diffractometer - Google Patents

Description

Detailed Description of the Invention a. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray diffractometer of a type that does not perform angular scanning and is suitable for use at a production site.

B. 2. Description of the Related Art X-ray diffractometers are used for stress measurement of structures, determination and identification of samples, and the like, but conventional X-ray diffractometers are angle scanning types that move an X-ray detector on a goniometer. It took a considerable amount of time to measure one sample, and was unsuitable for processing a large number of samples or inspecting materials that are continuously running. It takes a long time to measure, because one X-ray detector is used, so when measuring the X-ray intensity at one angular position, X-rays emitted in the other direction contribute to the measurement. This is because the angle scanning speed must be reduced in order to obtain the S / N ratio required for measurement.

As an X-ray detector having a position detecting function, that is, an X-ray detector capable of measuring a one-dimensional distribution of X-ray intensity, a large number of electrode wires are stretched in parallel in a gas chamber at a constant interval and The type that makes X-rays incident in the direction is commercialized under the name of PSPC, etc. If such an X-ray detector is used, the position and intensity profile of diffracted X-rays can be obtained without performing angular scanning. It is possible to measure, and the time required for measurement can be shortened, but it is troublesome to use because it requires constant circulation of argon methane mixed gas etc. in the gas chamber for maintenance. Although it is difficult to apply, it can be applied for research purposes, but it is not suitable for daily quality control at production sites.

C. Problems to be Solved by the Invention Although scintillation detectors and proportional counters have a long track record of stable performance and ease of maintenance, etc., they are sufficiently reliable, but they do not have a position detection function. The X-ray diffractometer used is an angle scanning type, and it takes time to measure. A detector with a position detection function is troublesome to maintain and is not suitable for daily use in the field. In general, an X-ray detector having position resolution has a delicate structure, is difficult to use, is less reliable, and is more expensive than an X-ray detector having no position resolution. The present invention provides an X-ray diffractometer using a detector such as a scintillation detector or a proportional counter which is easy to use and reliable, but has no positional resolution, and does not require angular scanning and can perform quick measurement. It is what

D. Means for Solving Problems A plurality of X-ray detectors having no position resolution are closely arranged over a certain angle range of one circumference, and a plurality of such X-ray detector arrays are set, and each set of X-ray detectors is detected. The detectors were overlapped with each other in the arrangement circumferential direction of the X-ray detectors little by little, and the measured portion of the sample surface was positioned on a common center line connecting the centers of the arrangement circumferences of these X-ray detectors.

E. Operation If the diameter of the detectors arranged on one circle is d, the array pitch is p, and the radius of the circle is R, the angular distance of the adjacent detectors to the center of the circle is p / R. Is. Detector row is N
When stacking rows by shifting them slightly, if the offset angle between adjacent detectors on the circumference is p / (NR), the angle between adjacent detectors on one circumference is equally divided, The X-ray detector is arranged at each division position, which is the same as the arrangement of the X-ray detector at the angular pitch of p / (NR). The pitch p on one circumference cannot be smaller than the diameter d of the X-ray detector,
As described above, by overlapping the detector arrays so as to be offset from each other, the substantial array pitch can be made smaller than the diameter d of the detector, and the X-ray detector performs the angular scanning over a certain angular range with a desired angular resolution. It is possible to measure the X-ray intensity at once without performing.

F. Embodiment The drawings show an embodiment of the present invention. FIG. 1A is a front view of an array of X-ray detectors, and B is a view of this array as seen from the direction of arrow V. C is the array circumference of the X-ray detector, O is the center, radius R is 400 mm, D is the X-ray detector, the diameter is 10 mm, and the array pitch is 12 mm. As shown in FIG. 1B, there are three X-ray detector rows. The angle between the array pitch of X-ray detectors and the center of the circumference in one detector row is
The angle of deviation of the X-ray detector D between adjacent rows is 1.5 °.
The angle resolution of the group of X-ray detectors D is 0.5 ° in this embodiment.

An X-ray source used in an X-ray diffractometer is usually one in which an electron beam is linearly focused on a target, and such an X-ray source is also used in the present invention. The electronic focus line on the target of the X-ray source has a length of about 40 mm. In FIG. 2, X is the above-mentioned X-ray source, Sl is a solar slit, and the focus line of the electron beam in the X-ray source extends in the chain line direction. The solar slit Sl is parallel to this focus line and has a flat X shape.
A line beam B is formed, and a linear X-ray irradiation area A on the sample S is irradiated with this X-ray beam B. An arrow θ indicates the diffraction angle measurement direction of the diffracted X-rays, the array circumference C of the X-ray detectors D extends along this direction, and the three X-ray detector rows are arranged in the X-ray irradiation area A as shown in the figure. Are arranged parallel to each other with their centers offset in the longitudinal direction.

FIG. 3 shows the entire apparatus of this embodiment. Reference numeral 1 denotes an arm rotatable about a point O, which is pivotally supported by the base body 2, and the X-ray tube X is fixed to the base body 2. Sl is a solar slit attached to the X-ray tube X, and the arm 1 is designed to measure the rotation angle with reference to the direction of the solar slit Sl. That is, the arm 1 is a goniometer of the X-ray diffractometer. A solar slit 3 is fixed to the arm 1. This solar slit has an X-ray detector group 4 arranged behind it.
In the set of individual solar slits corresponding to each X-ray detector D, each of the individual slits is fixed in the direction of the rotation center line of the arm 1. The configuration of the X-ray detector group 4 is the first
As shown in the figure, the individual X-ray detectors are arranged. Seven X-ray detectors are arranged in a line, and the entire detector group 4 covers an angular range of about 10 °, and the angular resolution is 0.5.
It is ゜.

The output pulse of each X-ray detector of the detector group 4 is counted by the counter group 6 through the signal processing circuit group 5 such as amplification waveform shaping, and is taken into the data processing device 7. The data processing device 7 operates as follows.

First, a correction operation for variations in the characteristics of each X-ray detector. In this operation, one diffracted X-ray peak of an arbitrary sample is measured in advance by each X-ray detector of the detector 4 while rotating the arm 1. If there is no variation in the characteristics of each X-ray detector or uneven X-ray illuminance in the X-ray irradiation area of the sample surface, the profile of the diffracted X-ray peak obtained by each X-ray detector will be the same shape. Due to variations, the peak top heights of the profiles measured with each X-ray detector are different. The data processing device 7 obtains the average of the peak heights, obtains the ratio between the peak heights obtained by each X-ray detector and this average value, and stores this in the memory as a correction coefficient, and the actual sample At the time of measurement, the output data of each X-ray detector is multiplied by this correction coefficient to obtain correct measurement data.

Another operation is an interpolation calculation of measurement data. Since the measurement data is obtained every 0.5 °, an interpolation calculation is performed using the corrected data to determine the precise angular position on the peak of the diffraction X-ray peak. The interpolation calculation algorithm is arbitrary, for example, using 4 data at intervals of 0.5 ° and a minimum of 2
A quadratic curve is used to represent the range of the diffraction line profile over 2 ° by multiplication. Instead of such an interpolation calculation, the arm 1 may be rotated within a range of 0.5 ° and angular scanning may be performed within a range of 0.5 ° to obtain continuous data as a whole.

In the above example, the X-ray detector group is fixed on the arm 1. However, by making it possible to adjust the position in the radial direction on the arm,
The angular resolution may be variable within a certain range.

G. Effects According to the present invention, an X-ray detector having a position detecting function that is difficult to use and troublesome for maintenance is not used, and a normal scintillation detector or a proportional coefficient tube that does not have a position detecting function that is reliable and easy to use is used. Since an X-ray detector such as
There are few failures, no special operation or precautions (such as keeping gas in circulation or gas pressure management) is required, stable measurement can be performed for a long period of time, and angle scanning is not required. Since it is free to perform scanning in an appropriate angle range), the mechanical part also has a long life, and it is possible to measure a certain angle range at the same time. Therefore, when measuring the same S / N ratio, the conventional angle scanning method is used. Since one measurement can be performed in a very short time compared to the above, inspection of materials transferred one after another can be performed in the flow of the production process, and a large number of X
By arranging the X-ray detectors in multiple rows and arranging the X-ray detectors in each row slightly offset, the effective array pitch of the X-ray detectors was made smaller, so a sufficient angle was obtained without increasing the goniometer radius. Since the resolution can be obtained, the apparatus can be downsized, and in combination with the above-mentioned high speed, stability, reliability, and ease of use, an X-ray diffractometer which is very suitable for use in a production site can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing the arrangement of X-ray detectors in the present invention, FIG. 2 is a perspective view for explaining the relationship between the X-ray detector arrangement in the present invention and the entire X-ray diffraction apparatus, and FIG. 3 is the present invention. 3 is a front view of one embodiment and a block diagram of a data processing system. FIG. D ... X-ray detector, X ... X-ray source, Sl ... Solar slit on X-ray source side, B ... X-ray beam, A ... X on sample surface
Line irradiation area, S ... Sample, 1 ... Rotating arm, 2 ... Substrate,
3 …… Solar slit on the detector side, 4 …… X-ray detector group,
6 ... Counter group, 7 ... Data processing device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenichi Imamura, 1st Nishinokyo Kuwabara-cho, Nakagyo-ku, Kyoto City, Kyoto Prefecture Shimazu Corporation Sanjo Plant (72) Inventor Hiroshi Konan 1st Nishinokyo-Kuwabara-cho, Nakagyo-ku, Kyoto City, Kyoto Prefecture Shimadzu Sanjo Factory (56) References JP 54-25785 (JP, A) JP 58-50453 (JP, A)

Claims (1)

[Claims] 1. A plurality of X-ray detectors having no position resolution are arranged close to each other on one circumference, and a plurality of such X-ray detector rows and adjacent X-ray detectors are provided. The X-rays are arranged in parallel with each other so that the mutual positional relationship of the detectors is shifted in the circumferential direction by a value obtained by dividing the arrangement pitch of the X-ray detectors on one circumference by the number of the plurality of rows. A detector group,
An X-ray diffraction device in which the X-ray irradiation area of the sample is located on the center line of the circumference of the X-ray detector array of this X-ray detector group.