SU842522A1 - X-ray spectrometer - Google Patents

Description

The invention relates to devices for precision X-ray diffraction studies of the structural perfection of single crystals. A X-ray spectrometer is known, which contains an X-ray source, a crystal monochromator, a collimator, an analyzer crystal, and a detector fl. The closest to the proposed is an X-ray spectrometer containing an X-ray source, two fortified in the crystal holder of a monochromator crystal located between them a collimator one of which is mounted on the goniometer, analyzer crystal and detector 2. The disadvantages of the known devices are high requirements mutual adjustment and fine adjustment in the course of operation of the used flat monochromator crystals and loss of radiation intensity as a result of collimation. The purpose of the invention is to increase the luminosity due to the bending of the chryshallamonochromator. The goal is achieved by the fact that, in an X-ray spectrometer, containing an X-ray source, two monochromator crystal-mounted crystal-carriers with a collimator located between them, one of which is mounted on a goniometer, an analyzer crystal and a detector, a crystal holder mounted on a goniometer-monochromator made in the form of a frame, the ends of which are fixed in racks, and the central part is connected through a screw and a spring with a bracket rigidly fixed on the goniometer. FIG. 1 shows the scheme of the proposed device; in fig. 2 is a crystal holder circuit; in fig. 3 is a section A-A in FIG. in fig. 4 - crystal holder, side view. In the device, monochromator crystals 1 and 2 and crystal analyzer 3 are arranged so that the X-ray beam reflected from crystal monochromator 1 is directed to a curved monochromator crystal 2 and then to the surface of analyzer crystal 3. Crystal monochromator 2 is fixed in the crystal holder, made in the form of a frame 4, the ends of which are fixed in racks 5, and the central part is connected through a screw 6 and spring 7 with a rigidly fixed bracket 8.

The crystal monochromator 2 is fixed in the central part of the frame, the deformation of the plates which lie in the same plane with it is determined by the ratio of the rigidity of these plates and the regulating spring deforming them 7. This gives with a given degree of accuracy (0.1-0.01) parallelism diffracted along the surface of the crystal monochromator 3 radiation In addition, the selected method of force control of the bend of the crystal monochromator 2 provides the necessary accuracy and stability of the instrument's working (absolute error of the bending radius lK 10-20 s m at R 100-150 m).

The bending radius is determined by the formula 1. |, OGo Go-Up |

where LO is the distance of the imaginary radiation source (diffracted at the first iinocKOM monochromator crystal, from a curved monochromator crystal in the direction of the incident beam;

The TO and Tn are the direction cosines of the incident and reflected rays from the curved crystal.

In this case, a sharp narrowing of the angular divergence of the diffracting beam occurs without losing its intensity, normalized with respect to the intensity of the radiation reflected from the first flat monochromator crystal.

The device works as follows.

The X-ray beam is incident on a flat monochromator crystal 1, which is placed in a reflecting position using rotation mechanisms. A diffracted monochromator crystal 1 beam passes through

slit collimator and is reflected from a curved monochromator crystal 2, installed in the reflecting position, taking into account the specified bending condition. The transition to other values of diffraction angles and radiation wavelengths is carried out in a known manner.

The proposed device allows to increase the intensity of the diffracted radiation by 5-10 times, which increases the speed of precision analysis of the defective structure of single crystals.

Claims (2)

Invention Formula An X-ray spectrometer containing an X-ray source, two monochromator-mounted crystal monochromators with a collimator located between them, one of which is mounted on a goniometer, an analyzer crystal and a detector, characterized in that, in order to increase luminosity due to crystal bending monochromator, 11 A crystal holder of a monochromator crystal mounted on a goniometer is made in the form of a frame, the ends of which are fixed in racks, and the central part is connected through a screw and a spring with a rigid ukreg lennym on a goniometer arm. Sources of information taken into account in the examination 1.Lida A., Kohra K. Separate mechurement of the cristals with a triple cristal 0 diffractometer. - Zarap Appl. Phys 1978, 17, 968. 2. USSR author's certificate I 48733, cl. G 01 N 23/20, 1973 (prototype). 8. S (rig 3