JPH01262454A - Method of reading x-ray diffracted image from accumulation type fluorescent plate - Google Patents

Abstract

PURPOSE:To shorten the time for axis determination operations by executing reading with the picture element size larger than the picture element size for normal reading. CONSTITUTION:A denotes the reading method in the normal X-ray diffraction measurement. Namely, the X-ray diffracted image of the single crystal to be measured is recorded on an accumulation type fluorescent plate in the state in which the axis determination of said crystal is completed. This fluorescent plate is subjected to reading. Black dots 20 indicate the position of laser light on the fluorescent plate at each sampling time and sampling intervals are (a). B indicates the reading for the axis determination of the single crystal to be measured. Namely, the X-ray diffracted image for the axis determination is recorded on the fluorescent lamp and the sampling intervals (b) of this case are two-fold the (a). The reason for this increases lies in that the scanning speed of laser light is doubled in the X-direction and the Y-direction. A square 23 indicates the region where one reading position represents. The reading time thereof is shorted to 1/4 as compared to A. Since the reading is executed with the picture element size larger than the picture element size for the normal reading in such a manner, the reading time is shortened.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method in which excitation light is irradiated onto a stimulable fluorescent plate that records an X-ray diffraction image as a latent image, and the fluorescence generated therefrom is detected. This invention relates to an X-ray diffraction @ reading method, and particularly relates to a reading method for aligning a single crystal to be measured.

[Prior art] To read an X-ray diffraction image from this type of stimulable fluorescent screen,
An excitation beam such as a laser beam is scanned over a stimulable fluorescent screen,
The generated fluorescence is measured at predetermined sampling intervals. The pixel size for reading is determined depending on the resolution required for the X-ray diffraction image. In order to perform #l structure analysis of a single crystal, it is necessary to measure the diffraction intensity by the single crystal with high precision, and therefore, the pixel size needs to be small.

By the way, when performing crystal structure analysis using an X-ray diffraction image, if the axis of the single crystal to be measured is correctly aligned, subsequent processing will be easier and faster.

Here, "aligning" means accurately positioning a specific crystal axis of the single crystal to be measured in a predetermined direction with respect to the X-ray incident axis and the crystal rotation axis.

To perform this axis alignment, first, a preliminary X-ray diffraction measurement is performed on the single crystal set in the goniometer head. Using this diffraction pattern as a reference, the goniometer head is then finely adjusted to move the single crystal in the correct direction.

By repeating this kind of shafting work many times,
This completes the axis setup.

[Problems to be Solved by the Invention] In order to improve the accuracy of crystal structure analysis, the pixel size for reading is made small, so it takes a certain amount of time to read a stimulable fluorescent screen. On the other hand, in the above-mentioned axis setting operation, it is necessary to read one image of cumulative fluorescence many times, and the excitation light beam must be scanned each time.

Therefore, a lot of time was spent on the shafting work.

The present invention was developed in response to these circumstances, and its purpose is to provide a reading method that can shorten the time required for setting up the shaft.

[Means for Solving the Problems] In order to achieve the above object, the reading method of the present invention uses a reading method that uses a pixel size larger than the normal reading pixel size in order to align the single crystal to be measured. It is characterized by doing.

Another reading method according to the present invention is characterized in that reading is performed only in a central region narrower than the normal reading region in order to align the single crystal to be measured.

A further reading method according to the invention combines the two reading methods described above.

[Operation] The only information necessary for axis alignment is the diffraction pattern, and accurate diffraction intensity is not necessary. Therefore, by increasing the pixel size within the necessary range, the overall reading time can be shortened.

Furthermore, reading only the central area, which is narrower than the normal reading area, directly leads to a reduction in reading time. A diffraction pattern only in the central region is sufficient for alignment.

Furthermore, if the above two reading methods are combined, the reading time will naturally be further reduced. In other words, only the central area is read with a large pixel size.

[Example] Next, the present invention will be described in detail with reference to the drawings.

FIG. 4 is a perspective view showing an example of a reading device used in the reading method of the present invention. Planar stimulable fluorescent screen 1
A fluorescence reader is placed in front of the 0. This fluorescence reading device is of the X-Y two-dimensional scanning type, and includes an X stage that moves in the vertical direction and a Y stage that is mounted on the X stage and moves in the horizontal direction. A reflection mirror 11 is fixed to the X stage, and a reflection mirror 12 and an objective lens 13 are fixed to the Y stage.

Below the foul mirror 11 is another foul mirror 14,
This reflecting mirror 14 has a hole 15 opened therein. A laser generator 17 is located below the reflecting mirror 14, and a photomultiplier tube 16 is arranged in front of the reflecting mirror 14.

The output of the photomultiplier tube 16 is converted into a digital signal by an analog-to-digital converter, and at this time, the digital signal is held at a predetermined sampling time. To give a different example, the input analog signal is
The value is held as a digital signal for only 00nS (4 minutes).Then, after that, the hold is continued for only 10μs.Next, the input analog signal is integrated for another 100nS, and the value is held as a digital signal. The value is held as a digital signal.In this way, sampling is performed every 10 μs.

The laser beam emitted from the laser generator 17 passes through the hole 15 of the anti-fouling mirror 14, passes through the reflective mirror 11, the reflective mirror 12, and the objective lens 13, and then reaches the stimulable fluorescent plate 10.
corresponds to The fluorescence generated at that time returns along the same path and is finally detected by the photomultiplier tube 16. This reading is performed with an X-Y two-dimensional scan.

The stimulable fluorescent screen used in this example is barium fluorobromide (B) doped with divalent europium ions.
aFBr: Eu") powder crystal phosphor is coated on a plastic film. The laser beam used for reading is a He-Ne laser beam (wavelength: 633 nm).
>, and the generated fluorescence has a peak at a wavelength of 390 nm.

FIG. 2 shows the reading method in regular X-ray diffraction measurements. That is, when the axis alignment of the single crystal to be measured is completed, its X-ray diffraction image is recorded on a stimulable phosphor screen, and reading is performed on this stimulable phosphor screen. A black circle 20 in this figure indicates the position of the laser beam on the stimulable fluorescent screen at each sampling time. That is, it shows the position where fluorescence is read. The laser beam is scanned horizontally, and the sampling interval in the horizontal direction is a. When the laser beam reaches the end of the stimulable fluorescent screen, the distance a
, and then scanned in the opposite direction. Squares separated by vertical and horizontal straight lines 21 and 22 in the figure represent areas represented by one reading position. In this example, 200
For a stimulable phosphor screen with dimensions of mm x 200 mm, the read pixel size is 105 μm x 105 μm. That is, a=105 μm. The beam diameter of the laser beam is narrowed down to 105 μm in accordance with this pixel size.

FIG. 1 shows the reading for the alignment of the single crystal to be measured. That is, an X-ray diffraction image for axis alignment is recorded on a stimulable fluorescent screen, and reading is performed on this stimulable fluorescent screen. The difference from the case in FIG. 2 is that the sampling interval is twice a. This increases the scanning speed of the laser beam by 2 in the X and Y directions.
This is because it is doubled. Therefore, the pixel size is
The size is 210 μm x 210 μm. That is, b=2
It is 10 μm. A square 23 indicated by a broken line represents an area represented by one reading position.

With this reading method, compared to the one in Figure 2,
Reading time has been reduced to one-fourth.

Of course, it is also possible to double the scanning speed only in the X direction or only in the Y direction, in which case the reading time will be doubled.
It will be shortened to 1/2.

Hey, in the example in Figure 1, the pixel size is doubled, but
Of course, this can be made into any multiple.

FIG. 3 shows another example of the reading method when setting up the shaft. In this example, only the central region 30 of the stimulable fluorescent screen 10 is read. In this area 30, the same reading method as shown in FIG. 2 is performed. In this example, 200
For a stimulable fluorescent screen with dimensions mm x 200 mm, io
The center area 30 of ommxroomm is set. This reduces the reading time to one-fourth.

In fact, for rough alignment, the central region 30 is
There is no problem even if the size is about 50 mm x 50 mm, and in this case, the reading time is shortened to one-sixteenth of that in FIG. 2. Incidentally, it goes without saying that the dimensions of the central region can be any arbitrary dimension other than these values.

Furthermore, the reading methods of FIG. 1 and FIG. 3 can be combined. In other words, only the central region is read,
Moreover, reading is performed with twice the pixel size. In this way, reading time is significantly reduced. Of the several shafting operations, the first one often does not require much precision, so such a reading method can also be adopted.

[Effects of the Invention] As explained above, in the invention of claim 1, in order to align the single crystal to be measured, reading is performed with a pixel size larger than the regular reading pixel size, so the reading time is reduced. is shortened.

Further, according to the second aspect of the invention, in order to align the single crystal to be measured, reading is performed only in the central area narrower than the normal reading area, so that the PAc and reading time are shortened.

Roughly speaking, in the invention of claim 3, since the above-mentioned two reading methods are combined, the reading time is significantly shortened.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing an example of the present invention, Fig. 2 is an explanatory diagram showing a regular reading method, Fig. 3 is an explanatory diagram showing another example of the present invention, and Fig. 4 is an explanatory diagram showing an example of the present invention. FIG. 2 is a perspective view showing an example of a reading device. a... regular pixel size b... large pixel size 10... stimulable fluorescent screen 30... central area

Claims (3)

[Claims] (1) In an X-ray diffraction image reading method in which a stimulable fluorescent plate that records an X-ray diffraction image as a latent image is irradiated with excitation light and the fluorescence generated therefrom is detected, the axis of the single crystal to be measured is A reading method characterized by performing reading at a pixel size larger than the regular reading pixel size in order to perform vertical reading. (2) In an X-ray diffraction image reading method in which excitation light is irradiated onto a stimulable fluorescent plate that records the X-ray diffraction image as a latent image and the fluorescence generated therefrom is detected, the axis of the single crystal to be measured is A reading method characterized in that reading is performed only in a central area narrower than the regular reading area in order to perform vertical alignment. (3) In an X-ray diffraction image reading method in which an excitation light beam is irradiated onto a stimulable fluorescent plate that records an X-ray diffraction image as a latent image, and the fluorescence generated therefrom is detected, the axis of the single crystal to be measured is A reading method characterized in that reading is performed only in a central area that has a pixel size larger than the regular reading pixel size and is narrower than the regular reading area in order to perform the vertical reading.