A high-performance compact X-ray absorption spectrometer

Abstract

The present invention provides a high-performance, compact X-ray absorption spectrometer, characterized by comprising an annular guide rail with three sliding modules mounted thereon. Each sliding module is equipped with an independent drive mechanism, each driving its corresponding sliding module to slide circumferentially along the annular guide rail. Each sliding module is equipped with a light source, a bent crystal analyzer, and a detector. Compared to existing technologies, the present invention boasts high photon collection efficiency, high mechanical stability, a compact motion scanning mechanism, and flexible acquisition modes.

Description

Technical Field

[0001] The present invention relates to an X-ray spectrometer, in particular to a high-performance compact X-ray absorption spectrometer. Background Art

[0002] X-ray absorption spectroscopy has element selectivity, site structural symmetry, and can detect element valence states, electronic and structural properties, as well as information such as spin, charge and orbital degrees of freedom. It has been widely used in characterizing energy, catalysis, chemical engineering, biology and other fields.

[0003] The X-ray Absorption Fine Structure (XAFS) spectrum typically spans the absorption edge from -50eV to +600eV. A wider energy range allows for higher precision in atomic bond lengths. XAFS spectra require scanning the energy of the incident light while simultaneously monitoring the intensity changes before and after the incident light passes through the sample.

[0004] At present, X-ray absorption spectrometers still have the following shortcomings:

[0005] 1. Monochromators based on flat crystals have high energy resolution, but a small spatial collection angle, resulting in low photon utilization efficiency. A brighter light source (such as synchrotron radiation) is usually required.

[0006] 2. The monochromator based on the bent crystal needs to ensure that the light source, crystal and detector perform scanning motion on a Rowland circle at the same time, and obtain monochromatic light of different energies at different spatial positions. The mechanical structures of the above items are too complicated for spatial point-to-point scanning.

[0007] 3. Curved crystal monochromator scanning is based on the principle of Bragg diffraction, and the scanning energy range depends on the angular range that can be scanned. Current technologies all use linear guides for spatial position scanning. However, the scanning angle range is limited by the length of the linear guide, resulting in a limited scanning energy range for the spectrometer.

[0008] 4. The current X-ray absorption spectrometers have poor versatility and cannot meet the requirements of switching between multiple light sources and multiple acquisition modes on the same X-ray absorption spectrometer. Summary of the Invention

[0009] The object of the present invention is to provide an X-ray absorption spectrometer with high photon collection efficiency, high mechanical stability, a compact motion scanning device and a flexible acquisition mode.

[0010] In order to achieve the above-mentioned object, the technical solution of the present invention is to provide a high-performance compact X-ray absorption spectrometer, which is characterized in that it includes an annular guide rail, on which three sliding modules are provided, and the three sliding modules are respectively provided with independent driving mechanisms, and each driving mechanism drives the corresponding sliding module to slide circumferentially along the annular guide rail; the three sliding modules are respectively provided with a light source, a bent crystal analyzer, and a detector, the centers of the light source and the bent crystal analyzer are connected by a connecting rod 1, and the centers of the detector and the bent crystal analyzer are connected by a connecting rod 2, the two ends of the connecting rod 1 are respectively hinged to the centers of the light source and the bent crystal analyzer to ensure the relative direction and angle of the light source and the bent crystal analyzer; the two ends of the connecting rod 2 are respectively hinged to the centers of the detector and the bent crystal analyzer to ensure the direction and angle of the detector and the bent crystal analyzer; a slit and a sample are sequentially provided at the front end of the detector, and the detector is connected to a signal processing system. The detector successively collects intensity data of X-rays before and after the sample is inserted, and the signal processing system calculates the difference between the intensity data read by the detector before and after the sample is inserted to obtain the X-ray absorption spectrum.

[0011] Preferably, the radius of curvature of the annular guide rail is greater than, equal to or less than (100%±20%)×R, where R is the radius of curvature of the Rowland circle of the bent crystal analyzer.

[0012] Preferably, a ring gear is provided on the annular guide rail; each of the drive mechanisms includes a drive motor and a drive gear provided on an output shaft of the drive motor, the drive gear being engaged with the ring gear; the three sliding modules perform a co-directional θ-2θ scanning mode or a reverse θ-θ scanning mode, where the co-directional mode means that the bent crystal analyzer and the detector have the same rotation direction or the light source and the bent crystal analyzer have the same rotation direction, and the reverse mode means that the light source and the detector have opposite rotation directions; the drive motors of the three drive mechanisms respectively adopt the same or different transmission ratios.

[0013] Preferably, the light source is an X-ray tube, a rotating target X-ray source, a laser plasma X-ray source, a liquid metal target X-ray source, a diamond microfocus X-ray source, a synchrotron radiation X-ray source or a free electron laser X-ray source.

[0014] Preferably, the bent crystal analyzer is a fully focusing bent crystal analyzer or a semi-focusing bent crystal analyzer, which uses a bent crystal as a monochromator to improve the utilization efficiency of monochromated photons; the bent crystal analyzer is spherical, hyperbolic or parabolic; the bent crystal analyzer is at least one piece; the bent crystal analyzer is made of single crystal material.

[0015] Preferably, the single crystal material includes silicon, germanium, quartz, sapphire or highly oriented pyrolytic graphite.

[0016] Preferably, the detector is a silicon drift detector, a gas detector, a scintillator detector or a semiconductor detector.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. High photon collection efficiency: Using bent crystal as monochromator can obtain a larger spatial acceptance angle and improve the utilization efficiency of monochromated photons.

[0019] 2. High mechanical stability: A circular guide rail is used to fix the light source, crystal, and detector, ensuring that each component is mechanically fixed on the circular guide rail during scanning. This avoids scanning motion deviation and improves the motion accuracy and mechanical stability of the entire absorption spectrometer.

[0020] 3. Compact Motion Scanning Device: Utilizing a circular guide rail and sliding modules, the components can slide along the rail at wide angles, extending the scanning Bragg angle range from 20° to 85°, expanding the spectrometer's scanning energy range. The use of variable-length connecting rods ensures inherent directivity for the light source, crystal, and detector, resulting in a compact design and streamlined structure.

[0021] 4. Flexible acquisition mode: The sliding modules used move independently, making control easy. During scanning, one sliding module is fixed, and the other two sliding modules can move in the same direction or in the opposite direction, allowing for multiple scanning modes. For example, for high-power X-ray tubes or synchrotron radiation and free electron laser light sources, the light source point needs to remain stationary, while the crystal and detector scan in the same direction; whereas for low-power X-ray tubes, multiple crystal analyzers need to be switched, and the crystal analyzer can be left stationary while the light source and detector scan in the opposite direction. The multiple scanning modes of the present invention greatly expand the versatility of the X-ray absorption spectrometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A top view of the present invention;

[0023] Figure 2 It is a schematic diagram of the three-dimensional structure of the present invention. DETAILED DESCRIPTION

[0024] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0025] like Figure 1 and Figure 2As shown, the present invention provides a high-performance compact X-ray absorption spectrometer including a light source 1, a bent crystal analyzer 2, a detector 3, a ring guide 4, three sliding modules 5, a connecting rod 1 6-1, a connecting rod 2 6-2, a slit 7, a sample 8 and a signal processing system 9.

[0026] The light source 1, bent crystal analyzer 2, and detector 3 are respectively placed on three sliding modules 5, which are movably fixed to an annular guide rail 4. The radius of curvature of the annular guide rail 4 is equal to the radius of curvature of the Rowland circle of the bent crystal analyzer 2. The annular guide rail 4 is equipped with ring gears, and ring gears of different modules can be used according to actual needs. Each sliding module 5 is equipped with a motor, and the motors installed on the three sliding modules 5 have different transmission ratios. The drive gear on each motor output shaft meshes with the ring gear, allowing the three sliding modules 5 to slide circumferentially along the annular guide rail 4 under the drive of the corresponding motor.

[0027] The light source 1 and the center of the bent crystal analyzer 2 are connected via a second connecting rod 6-2, and the detector 3 and the center of the bent crystal analyzer 2 are connected via a first connecting rod 6-1.

[0028] Light source 1 can be an X-ray tube, rotating target X-ray source, liquid metal target X-ray source, diamond microfocus X-ray source, synchrotron radiation X-ray source, or free electron laser X-ray source. The curved crystal analyzer 2 can be spherical, hyperbolic, or parabolic; its material can be silicon, germanium, quartz, sapphire, or highly oriented pyrolytic graphite; it can be a fully focusing Johansson or semi-focusing Johann type. Using a curved crystal as a monochromator improves the utilization efficiency of monochromated photons.

[0029] Detector 3 can be a silicon drift detector, gas detector, scintillator detector, or semiconductor detector. A slit 7 and sample 8 are positioned at the front end of detector 3. Detector 3 is connected to a signal processing system 9. Detector 3 collects X-ray intensity data before and after the insertion of sample 8. Signal processing system 9 calculates the difference between the intensity data read by detector 3 before and after sample insertion to generate an X-ray absorption spectrum.

[0030] During X-ray absorption spectroscopy measurements, light source 1 emits X-rays, which are then monochromatized by the bent crystal analyzer 2. By moving the slide module 5 relative to the circular guide 4, scanning motions of varying energies are performed. For high-power X-ray tubes, synchrotron radiation, and free electron laser sources, light source 1 may remain stationary while the bent crystal analyzer 2 and detector 3 perform co-directional θ-2θ scanning motions. For example, while light source 1 remains stationary, the bent crystal analyzer 2 rotates clockwise by an angle of θ, while the detector 3 rotates clockwise by an angle of 2θ. Alternatively, while light source 1 remains stationary, the bent crystal analyzer 2 rotates counterclockwise by an angle of θ, while the detector 3 rotates counterclockwise by an angle of 2θ. For low-power X-ray tubes, multiple bent crystal analyzers 2 need to be switched. Alternatively, the bent crystal analyzer 2 can be kept stationary while the light source 1 and detector 3 perform counter-rotating θ-θ scanning motions. For example, while the light source 1 remains stationary, the bent crystal analyzer 2 rotates clockwise by an angle θ, while the detector 3 rotates counterclockwise by an angle θ. Alternatively, while the light source 1 remains stationary, the bent crystal analyzer 2 rotates counterclockwise by an angle θ, while the detector 3 rotates counterclockwise by an angle θ. For situations where the detector cannot be moved, the detector 3 can be kept stationary while the light source 1 and bent crystal analyzer 2 perform co-directional θ-2θ scanning motions. For example, while the detector 3 remains stationary, the bent crystal analyzer 2 rotates clockwise by an angle θ, while the light source 1 rotates clockwise by an angle 2θ. Alternatively, while the detector 3 remains stationary, the bent crystal analyzer 2 rotates counterclockwise by an angle θ, while the light source 1 rotates counterclockwise by an angle 2θ.

[0031] Detector 3 collects X-ray intensity data before and after sample 8 is inserted. After sample 8 is inserted, it absorbs the monochromatic X-rays, and the remaining light is detected by detector 3. The signal from detector 3 is finally connected to signal processing system 9, which calculates the difference between the intensity data read by detector 3 before and after sample insertion to obtain the X-ray absorption spectrum.

Claims

1. A high performance compact X-ray absorption spectrometer, characterized in that: The invention comprises an annular guide rail (4), three sliding modules (5) are provided on the annular guide rail (4), and the three sliding modules (5) are respectively provided with independent driving mechanisms. Each driving mechanism drives the corresponding sliding module (5) to slide along the annular guide rail (4) in the circumferential direction. During scanning, one sliding module (5) is fixed, and the other two sliding modules (5) move in the same direction or in the opposite direction to realize multiple scanning modes. The three sliding modules (5) are respectively provided with a light source (1), a bent crystal analyzer (2), and a detector (3). The light source (1) and the bent crystal analyzer (2) are respectively provided with a light source (1) and a bent crystal analyzer (2). ) is connected to the center of the light source (1) and the bent crystal analyzer (2) through a connecting rod (6-1), and the centers of the detector (3) and the bent crystal analyzer (2) are connected through a connecting rod (6-2). The two ends of the connecting rod (6-1) are respectively hinged to the center of the light source (1) and the bent crystal analyzer (2), ensuring the relative direction and angle of the light source (1) and the bent crystal analyzer (2); the two ends of the connecting rod (6-2) are respectively hinged to the center of the detector (3) and the bent crystal analyzer (2), ensuring the direction and angle of the detector (3) and the bent crystal analyzer (2); the front end of the detector (3) is sequentially provided with narrow The slit (7) and the sample (8) are connected to the detector (3) and the signal processing system (9). The detector (3) collects the intensity data of the X-ray before and after the sample (8) is inserted. The signal processing system (9) calculates the difference between the intensity data read by the detector (3) before and after the sample is inserted to obtain the X-ray absorption spectrum; the annular guide rail (4) is equipped with an annular gear, and annular gears of different modules are used according to actual needs. Each sliding module (5) is equipped with a motor. The motors equipped on the three sliding modules (5) have With different transmission ratios, the driving gear on each motor output shaft meshes with the ring gear, so that the three sliding modules (5) can slide in the circumferential direction along the ring guide rail (4) under the drive of the corresponding motor; the three sliding modules (5) perform a co-directional θ-2θ scanning mode or a reverse θ-θ scanning mode, the co-directional mode means that the bending crystal analyzer (2) and the detector (3) rotate in the same direction or the light source (1) and the bending crystal analyzer (2) rotate in the same direction, and the reverse mode means that the light source (1) and the detector (3) rotate in opposite directions; The light source (1) is a rotating target X-ray source, a laser plasma X-ray source, a liquid metal target X-ray source, a diamond microfocus X-ray source, a synchrotron radiation X-ray source or a free electron laser X-ray source.

2. A high performance compact X-ray absorption spectrometer according to claim 1, characterized in that: The curvature radius of the annular guide rail (4) is greater than, equal to, or less than (100%±20%)×R, where R is the curvature radius of the Rowland circle of the bent crystal analyzer (2).

3. A high performance compact X-ray absorption spectrometer according to claim 1, characterized in that: The bent crystal analyzer (2) is a fully focusing bent crystal analyzer or a semi-focusing bent crystal analyzer, and uses a bent crystal as a monochromator, thereby improving the utilization efficiency of monochromated photons; the bent crystal analyzer (2) is a sphere, a hyperbola or a paraboloid; the bent crystal analyzer (2) is at least one piece; and the bent crystal analyzer (2) is made of a single crystal material.

4. A high performance compact X-ray absorption spectrometer according to claim 3, characterized in that: The single crystal material includes silicon, germanium, quartz, sapphire or highly oriented pyrolytic graphite.

5. The high performance compact X-ray absorption spectrometer according to claim 1, characterized in that: The detector is a silicon drift detector, a gas detector or a scintillator detector.

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