SU894502A1 - X-ray spectrum for investigating monocrystal structural perfection - Google Patents

Description

(54) X-RAY SPECTROMETER FOR INVESTIGATION OF STRUCTURAL PERFECTION OF SINGLE CRYSTALS

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The invention relates to X-ray diffraction and can be used to study single crystals by X-ray radiation from high-power stationary sources of radiation.

X-ray sources based on X-ray tubes with rotating anode 1 are known.

Such sources have significant dimensions and weight, so that they are fixed in the diffractometric apparatus. However, when designing multi-crystal X-ray spectrometers, it is more advantageous from the point of view of the design of the spectrometer itself to use a moving (rotary) source, which makes it easy to go to work with other reflection orders from the monochromator crystal on which the primary beam of the source falls. without significant restructuring (rearrangement) of other elements of the spectrometer.

However, the sources used in such spectrometers are thin, which significantly increases the research time and reduces the functionality of the spectrometers due to

insufficient intensity of the primary. x-ray beam.

The closest to the present invention is an X-ray spectrometer for the study of the structural perfection of single crystals, containing a rotary x-ray source, two rotary x-rays installed along the X-ray beam.

10 monochromator crystals, a rotating holder of the monocrystal under investigation, radiation detectors, the second Junochromator crystal being installed with the possibility of its center

15 turns on the path of a beam reflected by the first crystal with a monochromator 2.

A disadvantage of the known spectrometer is the difficulty of tuning when using powerful stationary

20 radiation sources.

The purpose of the invention is expansion. functional capabilities and control of the spectrometer setup using high-power stationary radiation sources.

The goal is achieved by eM, which is in an X-ray spectrometer containing the installed along the way. X-ray beam two turning

30 crystals, radiation detectors, the second monochromator crystal installed with the possibility of its center of rotation on the path reflected by the first crystal monochromator beam, the second monochromatic crystal mounted on a turntable, whose rotation passes through the axis of rotation of the first monochromator crystal, and the holder the single crystal is mounted on the platform with the possibility of its linear movement in the direction perpendicular to the direction of the beam reflected by the second crystal-myochromator . In addition, a third rotary monochromator mounted on the same platform with the holder of the single crystal under investigation is additionally introduced into the spectrometer. At the same time, the third crystal monochromator is installed with an additional ability to rotate around the axis around the gate of the holder of the single crystal under study. FIG. the spectrograph spectrometer is shown; n & 2 - f & 5th X-ray and X-ray spectrum Treycrystal hipp felt contains a fixed stationary source and is equipped with a single monochromator 2, a single crystal chromium 2, a usable rotation of a holder, 3, a second crystal, and an ischerometer and Ichrochee Ichrochee, and Ichrochem 5. Derzhak-spruce 5 with a monochromator crystal 4, set in leu5 on a turning 6, the turn of which coincides with the axis of the gate de | The first 3-mAHOxPOMatopa 2. MO-3 Christopher 7 is mounted on an all-round holder 8, mounted on a platform 9, which can be mounted along a guide 10 in a direction that is perpendicular from the second core to the core pattern of the core. . The radiation diffracted by the monocrystal 7 is recorded with the help of detector ii, which is installed with the possibility of rotation relative to the axis of rotation of the holder 8 of the explosive single crystal 7. Additional detectors can be introduced into the spectrometer for tuning purposes (not shown). In the four-crystal version, a third crystal monochromator 12 is inserted into the spectrometer, which can be mounted directly on the holder 8 of the monocrystal 7 under investigation or on its own rotating holder 13 mounted on the holder All holders 3, 5, 8, 13 are equipped, as is adopted in diffractometric equipment, by means of adjusting the crystals by moving them in two mutually perpendicular directions as, for example, implemented in a known device. The spectrometer works as follows. The x-ray beam from the stationary source 1 is incident on the first crystal-monochromator 2 installed in the reflecting position, for example, using a detector (not shown). Reflected from a crystal monochromator 2 x. the x-ray beam falls on the second crystal monochromator 4, installed parallel to the monochromator 2 using the turntable 6 and the rotary holder 5. In this case, the direction reflected by the second crystal monochromator 4 of the x-ray beam will be parallel to the primary beam and offset from it by an amount equal to CsinZe, where E is the distance between the axes of rotation of the holders 3 and 5, and 0 is the diffraction angle. Then, the research single crystal 7 by moving the platform 9 along the guide 10 is set so that the x-ray beam reflected by the second crystal monochromator 4 passes through the axis of rotation of the holder 8. In this position, the single crystal 7 is studied by the radiation diffracted by the detector 11. allows the use of reflections in almost the whole range of Bragg angles from 0 to 90 °. In this case, the restrictions on small angles are determined in the presence of a completely unshielded surface of crystals of monochromators 2, 4 and the monocrystal-g- under study. tal 7 is only the angle of total external reflection of x-rays, and at large angles is the geometric dimensions of monochromator crystals 2, 4c with the frames in which they are fixed, and the dimensions of the detector ii. In this spectrometer, crystal studies can be implemented using Borrman diffraction. In this case, thick perfect single crystals are used as monochromator crystals 2, 4, which are mounted with the help of holders 3, 5 and platform 6 in the position of consecutive Borrman diffraction. The crystal under study is also installed on passage with the aid of the holder 8. This spectrometer is very compact, since the required travel path of the platform 9 along the guide 10 does not exceed the distance between the axes of rotation of the first 2 and second 4 monochromator crystals. Additional functionality arises when a third monochromator 12 crystal mounted on a common axis of rotation with the crystal under test 7 is introduced into the spectrometer. dual beam diffraction. In addition, the third monochromator crystal 12 can be installed in an antiparallel position with the second monochromator 4 crystal with the help of a pivoting holder 13 / holder 8 of the monocrystal 7 under investigation (for this purpose, the crystal 7 can rotate independently d) axes, which allows for research in antiparallel geometry.

Thus, the spectrometer described above allows a wide range of research to be carried out using a stationary x-ray source and maintaining structural simplicity.

Claims (3)

1. X-ray spectrum for the study of the structural perfection of single crystals, containing two rotary monochromators installed along the X-ray beam, a rotatable holder of the single crystal under study, radiation detectors, the second crystal of the monochromator being installed with the center of rotation of the first crystal reflected by the first crystal A beam monochromator, in contrast to the fact that, in order to expand the functionality and simplify the adjustment of the spectrometer when using Vania powerful stationary radiation sources, a second crystal monochromator is mounted on a turntable, which pivot axis extends through the pivot axis of the first monochromator crystal, and the test of the single crystal holder mounted on the platform o the possibility of its linear movement in the direction perpendicular to the direction of the reflection of the second monochromatic crystal of the beam. 2. The spectrometer according to claim 1, d. T. And g 5 the fact that it additionally entered into the third turn of the institute of the crystal-mono-sspr ator, installed on one of the p sfors. holder of the explosive crystal ..;. 3. Spectrum according to claim 2, distinguishing Fem. that the third crystal M) r yuhrOF ator is installed with the possibility of a double twist around the axis of rotation of the holder of an explosive single crystal. S Sources vifo; 4ation / taken into account in the examination 1. Rusakov and. And.. X-ray of leytall. N., Atomizdat, 1977, p. 34-35. 0 2. Kovalchu M.V. et al. Three-crystal X-ray spectrometer for investigating structural perfection of real crystals. 1976, 1, p. 194-196 (prototype). Phi1.1 fB 2 at 12/0 X W