Synchronous radiation x-ray multi-method combined measurement system

Abstract

The present application relates to a kind of synchronous radiation X-ray multi-method combined measurement system, including light source, monochromator, slit, first ionization chamber, sample table for being placed for sample and second ionization chamber in the propagation direction of X-ray in first optical axis is sequentially arranged, the both sides of sample table are respectively equipped with fluorescence detector and high-resolution spectrometer, fluorescence detector and high-resolution spectrometer are all located on the second optical axis perpendicular to first optical axis;System further includes first data acquisition device and second data acquisition device, first data acquisition device is connected with first ionization chamber, for obtaining first photon number according to the current output by first ionization chamber, second data acquisition device is connected with second ionization chamber, for obtaining second photon number according to the current output by second ionization chamber.The synchronous radiation X-ray multi-method combined measurement system of the present application, HERFD-XAS spectrogram, XAS spectrogram and XRF spectrogram of sample can be obtained by once experiment, it is very convenient.

Description

Technical Field

[0001] This invention relates to the field of synchrotron radiation technology, and more specifically to a synchrotron radiation X-ray multi-method measurement system. Background Technology

[0002] Characterization techniques based on synchrotron radiation sources, such as X-ray diffraction (scattering), spectroscopy, fluorescence, and imaging, can acquire information on tissue structure, chemical elements, and stress / strain across nanometer to centimeter scales, providing technical support for the system characterization and evaluation of the service behavior and damage mechanisms of structural materials and components used in nuclear energy systems.

[0003] Various X-ray characterization techniques based on synchrotron radiation sources include HERFD-XAS (High Resolution Fluorescence Detection X-ray Absorption Spectroscopy), XAS (X-ray Absorption Spectroscopy), and XRF (X-ray Fluorescence Spectroscopy). For samples requiring analysis of component distribution, time-resolved absorption spectroscopy, and fine spectroscopic resolution, conventional XAS is used for absorption spectroscopy with some time resolution, HERFD-XAS is used for fine resolution of electronic and neighborhood structures, and XRF detection is used for component distribution analysis. These methods measure the HERFD-XAS, XAS, and XRF spectra of experimental samples using their respective measurement systems, thereby enabling the analysis and study of the experimental samples.

[0004] However, existing measurement systems can only acquire the spectrum of one method at a time. To obtain the HERFD-XAS, XAS, and XRF spectra of the same experimental sample, it is necessary to repeat the same experimental conditions three times, which is very troublesome and time-consuming. Summary of the Invention

[0005] The purpose of this invention is to provide a synchrotron radiation X-ray multi-method measurement system that can simultaneously perform HERFD-XAS, XAS and XRF methods, thereby obtaining the HERFD-XAS spectrum, XAS spectrum and XRF spectrum of the sample in a single experiment, which improves experimental efficiency and ensures the spatiotemporal consistency of the experiment.

[0006] To achieve the above objectives, this invention provides a synchrotron X-ray multi-method measurement system, comprising a light source, a monochromator, a slit, a first ionization chamber, a sample stage for sample placement, and a second ionization chamber arranged sequentially along a first optical axis along the X-ray propagation direction. A fluorescence detector and a high-resolution spectrometer are respectively mounted on both sides of the sample stage, both located on a second optical axis perpendicular to the first optical axis. The system further includes a first data acquisition device and a second data acquisition device. The first data acquisition device is connected to the first ionization chamber and is used to acquire a first photon count based on the current output from the first ionization chamber. The second data acquisition device is connected to the second ionization chamber and is used to acquire a second photon count based on the current output from the second ionization chamber, thereby acquiring the XAS spectrum of the sample using the second photon count and the first photon count. The fluorescence detector is configured to acquire a third photon count to acquire the XRF spectrum of the sample using the third photon count. The high-resolution spectrometer is configured to acquire a fourth photon count to acquire the HERFD-XAS spectrum of the sample using the fourth photon count and the first photon count.

[0007] Furthermore, it also includes a third ionization chamber and a third data acquisition device. The third ionization chamber is located downstream of the second ionization chamber and on the first optical axis. A standard sample located on the first optical axis is provided between the second ionization chamber and the third ionization chamber. The third data acquisition device is connected to the third ionization chamber and is used to obtain the fifth photon number based on the current output by the third ionization chamber.

[0008] Furthermore, the first data acquisition device, the second data acquisition device, and the third data acquisition device each include an amplifier, a VF converter, and a counter connected in sequence.

[0009] Furthermore, it also includes an automatic gas distribution device, which includes a control device and a gas supply device storing gas. The gas supply device is connected to the first ionization chamber, the second ionization chamber, and the third ionization chamber through three input pipes, and each of the three input pipes is equipped with a solenoid valve and a flow meter connected to the control device.

[0010] Furthermore, the slit is defined by four movable blades.

[0011] Furthermore, the sample stage includes an X-axis displacement stage, a Z-axis displacement stage, a Z-axis rotation stage, an X-axis tilt stage, and a Y-axis roll stage arranged sequentially from bottom to top, and the sample is placed on the Y-axis roll stage.

[0012] Furthermore, a sample box is provided on the sample stage. The sample box includes a base and a shield. The base is placed on the sample stage, and the shield is disposed on the base. The shield has an internal cavity, in which the sample is located. The outer wall of the shield has an entrance hole, a transmission exit hole, a first fluorescence exit hole, and a second fluorescence exit hole that communicate with the cavity. The entrance hole and the transmission exit hole are aligned on the first optical axis, and the first fluorescence exit hole and the second fluorescence exit hole are aligned on the second optical axis.

[0013] Furthermore, the high-resolution spectrometer includes a detector and multiple crystals, with the detector located at the focal point of each crystal, the crystals distributed on an arc, and the middle one of the multiple crystals located on the second optical axis.

[0014] Furthermore, the crystal is a spherical curved crystal, and the detector is a surface detector or a single-unit silicon drift detector.

[0015] Furthermore, the incident angle between the X-rays and the sample is 45 degrees.

[0016] The synchrotron radiation X-ray multi-method measurement system of the present invention can simultaneously realize HERFD-XAS, XAS and XRF methods, so as to obtain the HERFD-XAS spectrum, XAS spectrum and XRF spectrum of the sample in a single experiment. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a synchrotron radiation X-ray multi-method measurement system according to an embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of the structure of a first data acquisition device according to an embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of the sample stage according to an embodiment of the present invention;

[0020] Figure 4 This is a top view of a sample box according to an embodiment of the present invention. Detailed Implementation

[0021] The preferred embodiments of the present invention are given below with reference to the accompanying drawings and described in detail.

[0022] In this embodiment of the invention, the X-axis and Y-axis are two mutually perpendicular directions in the horizontal plane, and the Z-axis is a vertical direction perpendicular to the horizontal plane.

[0023] like Figure 1As shown, this embodiment of the invention provides a synchrotron X-ray multi-method measurement system, including a light source 110, a monochromator 120, a slit 200, a first ionization chamber 310, a sample stage 400 for placing a sample 510, and a second ionization chamber 320 arranged sequentially along the first optical axis (i.e., the Y-axis) along the X-ray propagation direction. A fluorescence detector 600 and a high-resolution spectrometer 700 are respectively arranged on both sides of the sample stage 400. Both the fluorescence detector 600 and the high-resolution spectrometer 700 are located on the second optical axis (i.e., the X-axis) perpendicular to the first optical axis, and are used to receive fluorescence signals from the sample 510. The high-resolution spectrometer 700 is used to receive fluorescence signals from the sample. The light source 110 emits X-rays, and the monochromator 120 separates the X-rays into the desired monochromatic light. The monochromatic light passes through the slit 200 and the first ionization chamber 310 and then irradiates the sample 510 on the sample stage 400. The monochromatic light is transmitted from the sample 510 and sequentially enters the second ionization chamber 320 and the third ionization chamber 330. Simultaneously, sample 510 emits fluorescence under monochromatic light radiation, which is received by fluorescence detectors 600 and high-resolution spectrometers 700 on both sides of sample stage 400. The measurement system also includes a first data acquisition device and a second data acquisition device (neither shown in the figure). The first data acquisition device is connected to the first ionization chamber 310 (e.g., electrical or communication connection) and is used to acquire a first photon count based on the current output of the first ionization chamber 310. This first photon count is the number of monochromatic light photons that have passed through sample 510. The second data acquisition device is connected to the second ionization chamber 320 (e.g., electrical or communication connection) and is used to acquire a second photon count based on the current output of the second ionization chamber 320. This second photon count is the number of monochromatic light photons transmitted from sample 510. Fluorescence detector 600 can acquire a third photon count, which is the number of fluorescent photons detected by fluorescence detector 600. High-resolution spectrometer 700 can acquire a fourth photon count, which is the number of fluorescent photons detected by high-resolution spectrometer. The XAS spectrum (i.e., transmission method) of sample 510 can be obtained based on the first and second photon counts, the XRF spectrum (i.e., fluorescence method) of sample 510 can be obtained based on the third photon count, and the HERFD-XAS spectrum (i.e., fluorescence method) of sample 510 can be obtained based on the fourth and first photon counts. Therefore, this measurement system can simultaneously perform HERFD-XAS, XAS, and XRF methods, thus obtaining the HERFD-XAS, XAS, and XRF spectra of the sample in a single experiment.

[0024] In some embodiments, the measurement system may further include a third ionization chamber 330 and a third data acquisition device. The third ionization chamber 330 is located downstream of the second ionization chamber 320 and on the first optical axis. A standard sample 520 is disposed between the second ionization chamber 320 and the third ionization chamber 330. Monochromatic light passing through the first ionization chamber 310 passes through the sample 510 and then through the standard sample 520 before entering the third ionization chamber 330. The third data acquisition device is connected to the third ionization chamber 330 (e.g., an electrical connection or a communication connection) and is used to obtain a fifth photon number based on the current output by the third ionization chamber 330, which is the number of photons of the monochromatic light after passing through the standard sample 520. The XAS spectrum of the standard sample 520 can be obtained by using the fifth photon number and the second photon number. The energy of the monochromatic light separated by the monochromator 120 can be corrected based on the XAS spectrum of the standard sample 520, so that the energy range of the monochromatic light is within the absorption edge range of the elements constituting the standard sample 520.

[0025] The first ionization chamber 310, the second ionization chamber 320, and the third ionization chamber 330 are all detectors that measure ionizing radiation using the ionization effect of ionizing radiation. The medium in the ionization chamber is a gas, and the output is an electric current. The gas may include one or more of nitrogen, argon, helium, and krypton. In some embodiments, to obtain XAS spectra with the best signal-to-noise ratio, the absorptivity of the first ionization chamber 310 may be set to 15%-25%, the absorptivity of the second ionization chamber 320 to 20%, and the third ionization chamber 330 may require complete absorption, i.e., an absorptivity of 100%. The absorptivity of the ionization chamber is related to the type and amount of gas introduced into the ionization chamber; therefore, the absorptivity of the ionization chamber can be changed by altering the type and amount of gas.

[0026] In some embodiments, the measurement system may include an automatic gas distribution device for filling the three ionization chambers with gas according to different incident energies and ionization chamber lengths to control their absorption rates. Specifically, the automatic gas distribution device may include a control device and a gas supply device (e.g., supplying nitrogen, argon, helium, or krypton). The gas supply device is connected to the three ionization chambers via three input pipes, each of which is equipped with a solenoid valve and a flow meter connected to the control device (e.g., electrical or communication connection), thereby controlling the gas type and quantity in the three ionization chambers through the control device. In an exemplary embodiment, the automatic configuration device may employ the automatic gas distribution system described in the utility model patent application with publication number CN202460571U.

[0027] like Figure 2As shown, the first data acquisition device includes an amplifier 810, a VF converter (voltage-to-frequency converter) 820, and a counter 830 connected in sequence. The amplifier 810 is connected to the output terminal of the ionization chamber and is used to amplify the current output from the ionization chamber and convert it into a voltage signal. The VF converter 820 is used to convert the voltage signal into a digital pulse frequency, and the counter 830 is used to count the digital pulse frequency to obtain the photon count. The second and third data acquisition devices have the same structure as the first data acquisition device, and will not be described in detail here.

[0028] In some embodiments, the size of the slit 200 is adjustable, thereby controlling the size of the monochromatic light and attenuating stray light. For example, the slit 200 may be defined by four blades that can be moved as needed (e.g., away from or closer to each other) to adjust the size of the slit 200.

[0029] In some embodiments, the sample stage 400 is a five-axis sample stage, capable of movement along five axes: X-axis, Z-axis, Roll axis (i.e., rotation around the Z-axis), Pitch axis (i.e., rotation around the X-axis), and Yaw axis (i.e., rotation around the Y-axis), thereby adjusting the five degrees of freedom position of the sample 510. Specifically, as... Figure 3 As shown, the sample stage 400 may include, from bottom to top, an X-axis displacement stage 410, a Z-axis displacement stage 420, a Z-axis rotary stage 430, an X-axis tilt stage 440, and a Y-axis roll stage 450. The sample 510 is placed on the Y-axis roll stage 450. The X-axis displacement stage 410, Z-axis displacement stage 420, Z-axis rotary stage 430, X-axis tilt stage 440, and Y-axis roll stage 450 can all be existing displacement stages, assembled to form a five-degree-of-freedom sample stage 400. Through the five-degree-of-freedom movement of the sample stage 400, the position of the sample 510 can be adjusted so that the sample 510 is aligned with monochromatic light (i.e., the sample 510 is adjusted to be on the first optical axis).

[0030] In some embodiments, sample 510 can be a radioactive sample. To avoid radiation interference, a sample box can be provided on the sample stage 400, and sample 510 can be placed in the sample box to shield against radiation. Figure 4As shown, the sample box includes a base 910 and a shield 920. The shield 920 is disposed on the base 910. The shield 920 (for example, made of tungsten) has a cavity 921 for accommodating the sample 510 inside. The outer wall of the shield 920 is provided with an entrance hole 922, a transmission exit hole 923, a first fluorescence exit hole 924 and a second fluorescence exit hole 925 communicating with the cavity 921. The entrance hole 922 and the transmission exit hole 923 are aligned with each other on the first optical axis, and the first fluorescence exit hole 924 and the second fluorescence exit hole 925 are aligned with each other on the second optical axis. During the experiment, monochromatic light enters the receiving cavity 921 through the light entrance aperture 922 and illuminates the sample 510. The monochromatic light transmitted through the sample 510 leaves the shield 920 through the transmission exit aperture 923 and enters the second ionization chamber 320. The fluorescence emitted by the sample 510 leaves the shield 920 through the first fluorescence exit aperture 924 and the second fluorescence exit aperture 925, respectively. The fluorescence of the first fluorescence exit aperture 924 is received by the fluorescence detector 600, and the fluorescence of the second fluorescence exit aperture 925 is received by the high-resolution spectrometer 700.

[0031] In some embodiments, the incident angle between the monochromatic light and the sample 510 can be 45 degrees. The position of the sample 510 can be adjusted by the sample stage 400 so that it forms a 45-degree angle with the first optical axis. In other embodiments, the sample can also be placed directly at a 45-degree angle to the sample stage 400.

[0032] like Figure 1 As shown, the high-resolution spectrometer 700 includes multiple crystals 710 and a detector 720. The multiple crystals 710 are distributed on an arc, with the central crystal 710 located on the second optical axis. The detector 720 is located at the focal point of each crystal 710. Each crystal 710 reflects and focuses the fluorescence signal from the sample 510 onto the detector 720, from which the fourth photon number is obtained. The spectrometer can be based on the Rowland circle principle, where the sample 510, multiple crystals 710, and detector 720 are all located on a Rowland circle with a diameter equal to the radius of curvature of the crystal 710. A multi-crystal spectrometer based on the Rowland circle structure has a simple structure and high resolution.

[0033] The number of crystals 710 can be selected as needed. The more crystals 710 there are, the more fluorescence photons the spectrometer can collect per unit time, and the higher the detection efficiency. In an exemplary embodiment, the high-resolution spectrometer 700 may include seven crystals 710, which are distributed on an arc, with the middle crystal 710 located on the second optical axis.

[0034] The crystal 710 can be a spherical curved crystal. The detector 720 can be a surface detector or a single-cell silicon drift detector.

[0035] In some embodiments, the high-resolution spectrometer 700 may further include a crystal adjustment mechanism and a detector adjustment mechanism. A plurality of crystals 710 are disposed on the crystal adjustment mechanism, which is used to adjust the position of the plurality of crystals 710. A detector 720 is disposed on the detector adjustment mechanism so that the position of the detector 720 can be adjusted by the detector adjustment mechanism.

[0036] In some embodiments, a vacuum channel is provided on the first optical axis so that X-rays can pass through the vacuum channel to irradiate the sample 510, ensuring that the X-rays are always in a low vacuum state and avoiding the sample signal being weakened by air impurities.

[0037] The steps of simultaneously implementing multiple methods using the measurement system of this invention are briefly described below:

[0038] First, the starting and ending energies of the monochromatic light are determined based on the element of interest (i.e. the element to be analyzed) of sample 510. The starting energy is usually 200 eV before the absorption edge of the element of interest, and the ending energy is usually 1000 eV after the absorption edge of the element of interest. Then, the monochromator 120 is scanned from the starting energy to the ending energy at a preset interval, which is one acquisition cycle. The HERFD-XAS spectrum, XAS spectrum and XRF spectrum of this acquisition cycle are obtained. Specifically, the monochromator first separates monochromatic light at the initial energy. After this monochromatic light illuminates the sample 510, the XAS spectrum data at the initial energy can be obtained by data collected by the first and second data acquisition devices. The HERFD-XAS spectrum data at the initial energy can be obtained by data collected by the high-resolution spectrometer 700 and the second data acquisition device. After scanning, the monochromator separates the monochromatic light at the next energy point and collects the XAS spectrum data and HERFD-XAS spectrum data at that energy point. This process continues until the XAS spectrum data and HERFD-XAS spectrum data at the termination energy are collected. For XRF spectrum data, it is only necessary to collect the XRF spectrum data once by the fluorescence detector 600 when the monochromator energy is greater than the absorption edge of the element to be analyzed. Then, by plotting each energy point as the x-axis and the XAS spectrum data and HERFD-XAS spectrum data at each energy point as the y-axis, the XAS spectrum and HERFD-XAS spectrum can be obtained.

[0039] The synchrotron radiation X-ray multi-method measurement system of this invention can simultaneously perform HERFD-XAS, XAS and XRF methods, thereby obtaining the HERFD-XAS spectrum, XAS spectrum and XRF spectrum of the sample in a single experiment, which is very convenient.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. Various variations can be made to the above embodiments of the present invention. That is, all simple and equivalent changes and modifications made based on the claims and description of this invention fall within the protection scope of the claims of this patent. All aspects not described in detail in this invention are conventional technical content.

Claims

1. A synchrotron X-ray multi-method measurement system, characterized in that, The system comprises a light source, a monochromator, a slit, a first ionization chamber, a sample stage for placing a sample, and a second ionization chamber, arranged sequentially along a first optical axis along the X-ray propagation direction. A fluorescence detector and a high-resolution spectrometer are respectively located on opposite sides of the sample stage, both situated on a second optical axis perpendicular to the first optical axis. The system further includes a first data acquisition device and a second data acquisition device. The first data acquisition device is connected to the first ionization chamber and is used to acquire a first photon count based on the current output from the first ionization chamber. The second data acquisition device is connected to the second ionization chamber and is used to acquire a second photon count based on the current output from the second ionization chamber, thereby obtaining an XAS spectrum of the sample using the second photon count and the first photon count. The fluorescence detector is configured to acquire a third photon count to obtain an XRF spectrum of the sample using the third photon count. The high-resolution spectrometer is configured to acquire a fourth photon count to obtain a HERFD-XAS spectrum of the sample using the fourth photon count and the first photon count. The high-resolution spectrometer includes a detector and multiple crystals. The detector is located at the focal point of each crystal, and the crystals are distributed on an arc. The middle one of the multiple crystals is located on the second optical axis.

2. The synchrotron X-ray multi-method measurement system according to claim 1, characterized in that, It also includes a third ionization chamber and a third data acquisition device. The third ionization chamber is located downstream of the second ionization chamber and on the first optical axis. A standard sample located on the first optical axis is provided between the second ionization chamber and the third ionization chamber. The third data acquisition device is connected to the third ionization chamber and is used to obtain the fifth photon number based on the current output by the third ionization chamber.

3. The synchrotron X-ray multi-method measurement system according to claim 2, characterized in that, The first data acquisition device, the second data acquisition device, and the third data acquisition device each include an amplifier, a VF converter, and a counter connected in sequence.

4. The synchrotron X-ray multi-method measurement system according to claim 2, characterized in that, It also includes an automatic gas distribution device, which includes a control device and a gas supply device storing gas. The gas supply device is connected to the first ionization chamber, the second ionization chamber and the third ionization chamber through three input pipes, and each of the three input pipes is equipped with a solenoid valve and a flow meter connected to the control device.

5. The synchrotron X-ray multi-method measurement system according to claim 1, characterized in that, The slit is defined by four movable blades.

6. The synchrotron X-ray multi-method measurement system according to claim 1, characterized in that, The sample stage includes, from bottom to top, an X-axis displacement stage, a Z-axis displacement stage, a Z-axis rotation stage, an X-axis tilt stage, and a Y-axis roll stage, and the sample is placed on the Y-axis roll stage.

7. The synchrotron X-ray multi-method measurement system according to claim 1, characterized in that, The sample stage is provided with a sample box, which includes a base and a shield. The base is placed on the sample stage, and the shield is disposed on the base. The shield has an internal cavity, in which the sample is located. The outer wall of the shield has an entrance hole, a transmission exit hole, a first fluorescence exit hole, and a second fluorescence exit hole that communicate with the cavity. The entrance hole and the transmission exit hole are aligned on the first optical axis, and the first fluorescence exit hole and the second fluorescence exit hole are aligned on the second optical axis.

8. The synchrotron X-ray multi-method measurement system according to claim 1, characterized in that, The crystal is a spherical curved crystal, and the detector is a surface detector or a single-unit silicon drift detector.

9. The synchrotron X-ray multi-method measurement system according to claim 1, characterized in that, The incident angle between the X-rays and the sample is 45 degrees.

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