CN-121978141-A - High-resolution desk type X-ray spectrometer and X-ray absorption spectrum testing method

CN121978141ACN 121978141 ACN121978141 ACN 121978141ACN-121978141-A

Abstract

The invention discloses a resolution desk type X-ray spectrometer and an X-ray absorption spectrum testing method, and relates to the technical field of spectrum measurement. The high-resolution bench X-ray spectrometer comprises a sample signal source, an index crystal, a detector and a detector, wherein the sample signal source is positioned in a multiple Roland circle and is used for generating X-rays, the index crystal is a curved crystal, the surface shape of the index crystal is defined by an index equation, different points on a curved surface of the crystal have different curvature radiuses and correspond to Roland circles with different radiuses, each point on the index crystal is tangent to the corresponding Roland circle, the index crystal is used for monochromatizing and focusing the X-rays incident from the sample signal source, and the detector is positioned on a surface formed by imaging points corresponding to each Roland circle and is used for receiving the X-rays monochromatized and focused by the index crystal and outputting corresponding light intensity signals. Therefore, through the cooperative coordination of the index crystal and the dolomitic circle structure, the X-ray absorption spectrum test with high light receiving efficiency, high spectrum resolution and wide energy spectrum range can be realized, and the comprehensive performance of the desk spectrometer is improved.

Inventors

WANG SHUN
CHEN QINGQING
Mei Bingbao
Yu can
LIU SHOUJIE
XIAO HAILONG

Assignees

安徽吸收谱仪器设备有限公司

Dates

Publication Date: 20260505
Application Date: 20260409

Claims (10)

1. A high-resolution desk-top X-ray spectrometer is characterized by comprising a sample signal source, an index crystal and a detector; The sample signal source is positioned inside the multiple-rowland circle and is used for generating X rays; The surface shape of the index crystal is defined by an index equation, so that different points on a curved surface of the crystal have different curvature radiuses and correspond to Roland circles with different radiuses, each point on the index crystal is tangent to the corresponding Roland circle, and the index crystal is used for monochromatizing and focusing the X-rays incident from the sample signal source; The detector is positioned on a surface formed by corresponding imaging points on each Roland circle, and is used for receiving the X-rays after monochromatization and focusing of the index crystal and outputting corresponding light intensity signals.
2. The high resolution table X-ray spectrometer of claim 1, wherein the sample signal source comprises an X-ray tube and a sample carrier: the sample bearing piece is arranged in front of the emergent point of the X-ray tube and is used for placing a sample; And X-rays generated by the X-ray tube are absorbed by the sample and then irradiated to the index crystal.
3. The high resolution table X-ray spectrometer of claim 1, wherein the exponential crystal has a radius of curvature on the meridian plane that is greater than a radius of curvature on the sagittal plane, resulting in an asymmetric curvature distribution.
4. The high resolution table X-ray spectrometer of claim 1, wherein the exponential crystal adopts a low-index crystal plane.
5. The high resolution table X-ray spectrometer of claim 1, wherein the detector comprises a detector body and a CMOS photosensitive element; the CMOS photosensitive element is arranged at the front end of the detector main body and is used for receiving the X-rays subjected to monochromatization and focusing of the index crystal, converting the received X-ray signals into electric signals and transmitting the electric signals to the detector main body so that the detector main body outputs light intensity signals representing the intensity of the X-rays.
6. The high resolution table X-ray spectrometer of claim 1, the high-resolution desk-top X-ray spectrometer is characterized in that the high-resolution desk-top X-ray spectrometer further comprises: And the controller is respectively connected with the sample signal source, the detector and the index crystal and is used for adjusting the distance between the sample signal source and the detector and/or adjusting the crystal face of the index crystal according to the test requirement so as to obtain data in different energy ranges.
7. An X-ray absorption spectrum testing method for a high resolution table X-ray spectrometer according to any of claims 1 to 6, wherein a sample signal source in the high resolution table X-ray spectrometer comprises an X-ray tube and a sample carrier, the sample carrier being arranged in front of an exit point of the X-ray tube, the method comprising the steps of: In response to the sample carrier being provided with a sample, starting the X-ray tube, enabling the compound-color X-rays generated by the X-ray tube to irradiate the sample, enabling the compound-color X-rays to be absorbed and attenuated by the sample and then enter the index crystal, and obtaining a first light intensity signal which is output by the detector and corresponds to the X-rays after monochromatization and focusing of the index crystal; In response to the sample carrier not placing a sample, starting the X-ray tube, enabling the multi-color X-rays generated by the X-ray tube to be incident to the index crystal, and acquiring a second light intensity signal which is output by the detector and corresponds to the X-rays after monochromatization and focusing of the index crystal; and obtaining X-ray absorption spectrum data according to the first light intensity signal and the second light intensity signal.
8. The method of claim 7, wherein obtaining X-ray absorption spectrum data from the first light intensity signal and the second light intensity signal comprises: calculating an absorption coefficient according to the formula μ (E) =ln (P0/P1), wherein P0 is the second light intensity signal, P1 is the first light intensity signal, μ (E) is the absorption coefficient; performing energy calibration, background subtraction and normalization on the absorption coefficient to obtain a normalized absorption spectrum; and extracting an XAFS oscillation function from the normalized absorption spectrum to obtain the X-ray absorption spectrum data.
9. The method for testing an X-ray absorption spectrum according to claim 7, wherein, before acquiring the first light intensity signal and the second light intensity signal, the method further comprises: The distance between the sample signal source and the detector is adjusted according to the energy range required for the test.
10. The method for testing an X-ray absorption spectrum according to claim 7, wherein, before acquiring the first light intensity signal and the second light intensity signal, the method further comprises: the crystal face of the exponential crystal is adjusted according to the energy range required for the test.

Description

High-resolution desk type X-ray spectrometer and X-ray absorption spectrum testing method Technical Field The invention relates to the technical field of spectrum measurement, in particular to a high-resolution desk type X-ray spectrometer and an X-ray absorption spectrum testing method. Background In recent years, the development of X-ray spectroscopy technology is rapid, and advanced characterization means such as X-ray absorption fine structure spectrum (XAFS, X-ray Absorption Fine Structure) based on synchrotron radiation and the like become important research directions for guiding advanced material design and revealing catalyst reaction mechanism. The XAFS technology can analyze the local coordination environment and bond length of atoms in the material, and provides unique structural information for the fields of material science, catalytic chemistry, energy devices and the like. Synchrotron radiation light sources are electromagnetic radiation emitted in a tangential direction of a track when charged particles (typically electrons) move in a magnetic field at a curved line near the speed of light. Compared with the traditional laboratory X-ray tube, the synchrotron radiation light source has extremely high brightness (several orders of magnitude higher than the traditional light source), a wide continuous spectrum (covering the wave band from far infrared to hard X-rays), excellent collimation and good polarization, and is known as a super microscope for researching the microstructure of substances. By virtue of these unique advantages, synchrotron radiation light sources thoroughly change the characterization means of the microstructure of the substance, and thus the XAFS technique can fully exert its analytical capabilities. However, the development of synchrotron radiation light sources is accompanied by significant limitations. First, the resource scarcity is that although the global synchrotron radiation light source has been developed to the fourth generation (diffraction limit light source), the construction cost is expensive and the allocation is extremely tight. Secondly, the timeliness is poor, researchers often need to wait for months to obtain experimental time of several days, and the experimental time is in serious conflict with the requirement of rapid iteration and high-frequency test in modern scientific research. The wide popularization of XAFS in scientific research and industrial application is severely limited by the scarcity of synchrotron radiation light source machines. To compensate for these limitations of synchrotron radiation light sources, table X-ray spectrometers have been developed rapidly. However, existing bench-top X-ray spectrometers that can be deployed in the laboratory suffer from the following drawbacks: On one hand, the traditional curved crystal (such as plane, cylindrical surface, conical surface and spherical crystal) has the defects of low photon collection rate, lack of Rowland round structure, astigmatism caused by paraxial approximation, john error and the like, so that the traditional curved crystal has obvious limitations on spectral resolution, energy spectrum range and sensitivity to light source size, and on the other hand, the high-index crystal face crystal used by the traditional curved crystal has obviously lower diffraction intensity than the low-index crystal face crystal due to the common influence of atomic scattering factors, structural factors and temperature factors, so that the detection sensitivity and signal-to-noise ratio of the instrument are limited. Therefore, there is an urgent need to develop a set of table-type X-ray spectrometers capable of achieving accurate point source imaging over a large crystal shape, with extremely high spectral resolution and high diffraction intensity, to perfect laboratory-level X-ray spectroscopy testing capabilities. Disclosure of Invention The invention aims to provide a resolution desk type X-ray spectrometer and an X-ray absorption spectrum testing method, so as to realize X-ray absorption spectrum testing with high light receiving efficiency, high spectrum resolution and wide energy spectrum range and improve the comprehensive performance of the desk type spectrometer. In a first aspect, an embodiment of the present invention provides a high resolution table X-ray spectrometer, including a sample signal source, an exponential crystal and a detector, where the sample signal source is located inside a multiple rowland circle and is used for generating X-rays, the exponential crystal is a curved crystal, the surface shape of the exponential crystal is defined by an exponential equation, so that different points on a curved surface of the crystal have different radii of curvature and correspond to rowland circles with different radii, each point on the exponential crystal is tangential to a corresponding rowland circle, the exponential crystal is used for monochromatizing and focusing the X-rays i