RU132900U1 - DEVICE FOR X-RAY ABSORPTION SPECTRAL ANALYSIS - Google Patents

Abstract

A device for X-ray absorption spectral analysis, containing an X-ray source based on an x-ray tube located on the same optical axis, a collimator, a monochromator and an absorber mounted on the basis of a goniometric attachment, the object of study, a monochromator and a detection unit located on the holders of the goniometric attachment, the engines of which are mechanically connected with holders, characterized in that a double-slot collimator is used as a collimator, in quality The acoustomonochromator installed on the first holder of the goniometric set-top box, on the second holder of which the research object and the detecting unit are located, the acousto-monochromator is connected to a broadband electromagnetic oscillator through an electric signal amplifier, and the x-ray source, goniometric attachment engines, and a broadband electromagnetic oscillator are selected as the monochromator. and the detection unit is connected to a computer.

Description

The utility model relates to the field of research or analysis of materials using x-ray radiation, namely to absorption spectrometry and can be used in physical instrumentation, x-ray analysis, in the oil and gas industry and in medical technology.

A device for x-ray absorption spectral analysis [D.I. Kochubey, “EXAFS-spectroscopy of catalysts”, VO “Nauka” Novosibirsk, 1992, p.83], which contains a synchrotron radiation source located on the same optical axis, an input collimator, which forms an x-ray beam and the first crystal of a double-crystal monochromator. The output collimator that monitors the ionization chamber, the test sample, and the total absorption ionization chamber are located on the same optical axis as the second crystal of the double-crystal monochromator parallel to the first axis. The fluorescence detector is perpendicular to the test sample. The crystals of a double-crystal monochromator are mechanically connected with stepper motors, which ensure their movement. The drive blocks of the stepper motors, the registration blocks of the ionization chambers and the fluorescence detector are connected to a computer.

This device is designed to work on beams of synchrotron radiation, which limits its use - only in synchrotron centers.

The closest adopted for the prototype is a device for x-ray absorption spectral analysis [a brochure for the device UNIVERSITY M8 company LLC Metrological channel VUF and MRI "]. An x-ray tube is used as a radiation source in this device, opposite the output window of which an input collimator is installed, which forms an x-ray beam. On the axis of propagation of the radiation beam in the holders of a goniometer of type θ-2θ, an object of study and two crystal monochromators are installed. The holders are mechanically connected to the goniometer's engines. A scintillation detector associated with the crystal at a Bragg angle is associated with each monochromator crystal. An output collimator is installed between the object of study and the monochromator crystals. An absorber is located behind the monochromator crystals on the propagation axis of the undiffracted beam.

This device uses standard monochromator crystals, which only partially reflect the corresponding energy line of the incident radiation beam in the diffraction direction. Part of the radiation does not diffract and, passing without deviating, remains in a non-monochromatized beam. As a result, part of the potentially useful signal is lost.

The objective of the utility model is to expand the arsenal of technical means for absorption spectral analysis of a substance.

The proposed device for x-ray absorption spectral analysis, as in the prototype, contains x-ray source based on an x-ray tube located on the same optical axis, a collimator, a monochromator and an absorber mounted on the basis of a goniometric attachment, and the object of study, a monochromator and a detection unit are placed on the holders goniometric set-top box, the engines of which are mechanically connected to the holders.

In contrast to the prototype, a double-slit collimator was used as a collimator, an acousto-monochromator installed on the first holder of a goniometric set-top box, on the second holder of which a research object and a detection unit were used, was used as a collimator. An acoustic monochromator is connected through an electric signal amplifier to a broadband electromagnetic oscillation generator. The X-ray source, goniometric set-top box motors, a broadband electromagnetic oscillation generator and a detection unit are connected to a computer.

Through the use of an acoustic monochromator in the proposed device, the effect of the complete transfer of x-ray radiation in the diffraction direction is realized [Mkrtchyan A.R., Navasardyan M.A., Gabrielyan R.G. et al. Complete specular reflection of Angstrom wavelength radiation on an ultrasonic superlattice in the case of Laue geometry // Letters in ZhTF. - 1983. - T. 9. - AT 11. - P.1181], since the acousto-monochromator allows you to reflect the energy line in the diffraction direction almost completely, in contrast to conventional crystalline monochromators, in which a significant part of the radiation energy line does not deviate in the diffraction direction. This allows you to increase the intensity of the diffracted radiation and, as a result, the useful signal recorded by the detection unit.

Thus, the proposed device for x-ray absorption spectral analysis in comparison with the prototype has a higher aperture and speed.

Figure 1 presents a functional diagram of a device for x-ray absorption spectral analysis.

A device for X-ray absorption spectral analysis contains an X-ray source 1 (II) located on the same optical axis and based on an X-ray tube, a double-slot collimator 2 (SC), an acousto-monochromator 3 (AM) mounted on a holder (not shown in FIG. 1) of a goniometric set-top box 4 (GP) and an absorber 5 installed on the basis of a goniometric prefix.

Behind the acoustomonochromator 3 (AM) in the diffraction direction on the second holder (not shown in FIG. 1) of the goniometric attachment 4 (GP), an object of study 6 and a detection unit 7 (DB) are installed. The holders are mechanically connected to the engines (not shown in FIG. 1) of the goniometric attachment 4 (GP).

The acoustic monochromator 3 (AM) is connected through an electric signal amplifier 8 (US) to a broadband electromagnetic oscillation generator 9 (SH). X-ray source 1 (AI), goniometric set-top box motors 4 (GP), broadband electromagnetic oscillation generator 9 (SH) and detection unit 7 (DB) are connected to computer 10 (PC) through the appropriate control drivers.

As the radiation source 1 (II) can be used x-ray tube type BSV-29. The double-slot collimator 2 (SC) is a pair of lead plates with slits cut through them. The plates are mounted so that the slots are parallel to each other and perpendicular to the direction of propagation of the x-ray beam. Acoustic monochromator 3 (AM) is made according to the patent AM 2719 A, G21K 1/00, publ. 02/25/2013. The absorber 5 is a solid lead plate with a recess in the Central part. Detection unit 7 (DB) can be made on the basis of the BDER-KI-11K energy-dispersive X-ray detector and a spectrometric path assembled in the EUROMECHANIKA standard from the UIS-04, BNV-07, BNN-03 and BPA-02 modules manufactured by NPTs CJSC "ASPECT" (Dubna). As a goniometric 4 (GP) set-top box, a goniometer of the θ-2θ type, for example, GUR-8, can be used. As an electric signal amplifier 8 (CSS), the BBA100 amplifier from Rohde & Schwarz can be selected. As a broadband generator of electromagnetic waves 9 (SH) can be used generator WW5061 production Tabor Electronics Ltd. with a working frequency range from 0.1 MHz to 25 MHz.

X-ray radiation from the radiation source 1 (II) passes through a double-slit collimator 2 (SC). A collimated x-ray beam with a continuous spectrum passes through an acousto-monochromator 3 (AM), a part of the beam not satisfying the Bragg condition is absorbed by the absorber 5, and the other part is deflected in the diffraction direction. A beam of monochromatic x-ray radiation is passed through the object of study 6 and recorded by the detection unit 7 (DB). Using the stepper motors of a goniometric attachment 4 (GP), the holder with the acoustic monochromator 3 (AM) installed on it and the holder with the object of study 6 and the detection unit 7 (DB) mounted on it are simultaneously rotated, while the radiation energy that passes through the object of study 6 varies according to Bragg’s law, and detection unit 7 (DB) records spectrometric information, which is the dependence of the intensity of transmitted radiation on its energy. A broadband electromagnetic oscillation generator 9 (SH) generates an electric signal, which is amplified by an electric signal amplifier 8 (US) and is fed to an acoustic monochromator 3 (AM), exciting an acoustic field in it. Computer 10 (PC), using a set of programs, manages the parameters of the X-ray source 1 (AI), the goniometric set-top box 4 (GP) engines, the acoustic field parameters in the acoustic monochromator 3 (AM) created by the broadband electromagnetic oscillator 9 (SH), collecting and recording spectrometric information by the detecting unit 7 (DB).

According to the resonance intensity dips from the received by the detecting unit 7 (DB), the dependence of the intensity of the transmitted radiation on its energy determines the composition and concentration of the substance in the volume of the object of study 6. The composition of the substance is determined by the position of the dips on the energy scale, and the concentration by the dependence of the absorption coefficient on the concentration of the substance in the volume of the object of study 6.

Claims (1)

A device for X-ray absorption spectral analysis, containing an X-ray source based on an x-ray tube located on the same optical axis, a collimator, a monochromator and an absorber mounted on the basis of a goniometric attachment, the object of study, a monochromator and a detection unit located on the holders of the goniometric attachment, the engines of which are mechanically connected with holders, characterized in that a double-slot collimator is used as a collimator, in quality The acoustomonochromator installed on the first holder of the goniometric set-top box, on the second holder of which the research object and the detecting unit are located, the acousto-monochromator is connected to a broadband electromagnetic oscillator through an electric signal amplifier, and the x-ray source, goniometric attachment engines, and a broadband electromagnetic oscillator are selected as the monochromator. and the detection unit is connected to a computer.

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