How to operate a spectrometer

Abstract

A method for operating a spectrometer includes positioning the crystal analyzer such that a first reciprocal vector corresponding to a first crystal plane of the crystal analyzer is coplanar with the source axis and the detector axis; performing a first scan by varying the first angle and the second angle such that a first angle between the source axis and the first crystal plane is substantially equal to a second angle between the detector axis and the first crystal plane; rotating the crystal analyzer such that a second reciprocal vector corresponding to a second crystal plane of the crystal analyzer is coplanar with the source axis and the detector axis; and performing a second scan by varying the first angle and the second angle such that the first angle is substantially equal to the second angle.

Description

[Technical Field]

[0001] Cross-references to related applications

[0001] This application claims priority from U.S. Provisional Patent Application No. 63 / 510,518, filed on 27 June 2023, which is incorporated herein by reference in its entirety.

[0002] Statements relating to federal government-commissioned research or development

[0002] This invention was made with federal government support under order number DE-NE0009158 granted by the U.S. Department of Energy. The Federal Government has certain rights in this invention. [Background technology]

[0003] background

[0003] Many X-ray spectrometers use a curved crystal analyzer (CCA) as a type of monochromator to selectively scatter X-rays emitted from or transmitted through a material sample under test. A CCA is typically made by adhesively attaching or bonding a silicon or germanium wafer to a concave glass lens or other concave form of glass lens. The crystallographic orientation of the wafer surface is selected so that the lattice spacing of crystal planes nominally parallel to the surface is appropriate via Bragg's law to produce positive interference (constructive interference) of X-rays within the energy or wavelength range of interest. However, using the same spectrometer to investigate the response of samples in different energy or wavelength ranges usually requires the use of a second CCA. The second CCA is selected so that the crystal planes nominally parallel to the surface of the second CCA have a different lattice spacing than the original CCA. Switching from a spectrometer to a CCA to investigate various wavelength or energy ranges can be cumbersome and time-consuming. [Overview of the project]

[0004] overview

[0004] A first example is a method for operating a spectrometer comprising a crystal analyzer defining a Rowland circle, a source configured to emit X-rays along a source axis, and a detector configured to detect X-rays traveling along a detector axis, the method being: positioning the crystal analyzer such that a first reciprocal lattice vector corresponding to a first crystal plane of the crystal analyzer is coplanar with the source axis and the detector axis; while the first reciprocal lattice vector is coplanar with the source axis and the detector axis, a first angle between the source axis and the first crystal plane is the first angle between the detector axis and the first The method includes: performing a first scan by varying the first angle and the second angle such that the first angle is substantially equal to the second angle with respect to the crystal plane; rotating the crystal analyzer so that the second reciprocal lattice vector corresponding to the second crystal plane of the crystal analyzer is coplanar with the source axis and the detector axis; and performing a second scan by varying the first angle and the second angle such that the first angle is substantially equal to the second angle while the second reciprocal lattice vector is coplanar with the source axis and the detector axis.

[0005]

[0005] A second example is a non-temporary computer-readable medium that stores instructions that, when executed by one or more processors of the spectrometer, cause the spectrometer to perform the method of the first example.

[0006]

[0006] A third example is a spectrometer comprising: a source configured to emit X-rays along a source axis; a detector configured to detect X-rays traveling along a detector axis; an analyzer stage configured to hold a crystal analyzer defining a Rowland circle, and configured to rotate the crystal analyzer about an analyzer axis that is coplanar with the source axis and the detector axis; and an alignment device, the alignment device comprising: a source stage configured to hold a source; a detector stage configured to hold a detector; and an angle meter, the angle meter configured to (i) adjust a fifth angle between the analyzer stage and the detector axis, and (ii) adjust a sixth angle between the analyzer stage and the source axis; the alignment device configured to move the source stage, the detector stage and / or the analyzer stage to adjust a first distance between the source and the analyzer stage along the source axis, and a second distance between the detector and the analyzer stage along the detector axis.

[0007]

[0007] Non-patent literature: Anthony J. Gironda et al., “Asymmetric Rowland circle geometries for spherically bent crystal analyzers in laboratory and synchrotron applications.” J.Anal.At.Spectrom., 2024, 39, 1375: https: / / pubs.rsc.org / en / content / articlelanding / 2024 / ja / d3ja00437f is incorporated herein by reference.

[0008] When the terms "substantially" or "about" are used in this specification, it means that "the recited features, parameters or values need not be achieved exactly, but deviations or variations (including, for example, tolerances, measurement errors, measurement accuracy limits, and other factors known to those skilled in the art) may occur in an amount that does not exclude the intended effect provided by the feature." In some of the examples disclosed herein, "substantially" or "about" means within + / - 0 to 5% of the recited value.

[0009] In addition to these aspects, other aspects, advantages and alternatives will also become apparent to those skilled in the art by reading the following detailed description, with reference to the accompanying drawings as necessary. Further, the summary of the invention and other descriptions and drawings provided herein are intended to illustrate the invention by way of example only, and thus it should be understood that numerous variations are possible.

Brief Description of the Drawings

[0010] Brief Description of the Drawings [Figure 1]

[0010] A block diagram of a spectrometer according to an example. [Figure 2]

[0011] A schematic diagram of a spectrometer configured for operation in an asymmetric mode according to an example. [Figure 3A]

[0012] A schematic diagram of a spectrometer configured to perform an X-ray absorption fine structure (XAFS) scan according to an example. [Figure 3B]

[0013] A schematic diagram of a spectrometer configured to perform an X-ray emission spectroscopy (XES) scan according to an example. [Figure 4A]

[0014] A schematic diagram of an analyzer stage and a crystal analyzer according to an example. [Figure 4B]

[0015] A schematic diagram of an analyzer stage and a crystal analyzer according to an example. [Figure 4C]

[0016] This is a schematic diagram of an analyzer stage and crystal analyzer as an example. [Figure 5]

[0017] This is a schematic diagram of a spectrometer configured for operation in an asymmetric mode, as an example. [Figure 6]

[0018] This is a block diagram of one example of the method. [Figure 7A]

[0019] This is a schematic diagram of a spectrometer configured for operation in a symmetric mode, as an example. [Figure 7B]

[0020] This is a schematic diagram of a spectrometer configured for operation in an asymmetric mode, as an example. [Figure 8A]

[0021] This shows the degree of Johann error based on the location of X-rays incident on the crystal analyzer during operation in an example of a symmetrical configuration. [Figure 8B]

[0022] This example shows the degree of Johann error based on the location of X-rays incident on the crystal analyzer during operation in an asymmetric configuration. [Figure 9]

[0023] This example shows calculated and experimental results for (α,φ) corresponding to several crystal planes of a Si(551) crystal analyzer. [Modes for carrying out the invention]

[0011] Detailed explanation

[0024] There is a need for a method of operating a spectrometer that does not require the use of various curved crystal analyzers (CCAs) when investigating the response of samples within a wide wavelength or energy range. Accordingly, this disclosure includes such a spectrometer and a method of operating it.

[0012]

[0025] The spectrometer includes a source, such as an X-ray tube configured to emit X-rays along the source axis, and a detector, such as a silicon drift detector configured to detect X-rays traveling along the detector axis. The spectrometer also includes an analyzer stage configured to hold a crystal analyzer that defines a Rowland circle. The analyzer stage is configured to rotate the crystal analyzer about an analyzer axis that is coplanar with the source axis and the detector axis. The spectrometer also includes an alignment device, which includes a source stage configured to hold the source. The spectrometer also includes a detector stage configured to hold the detector. The spectrometer also includes an angle meter configured to (i) adjust the angle between the analyzer stage and the detector axis, and (ii) adjust the angle between the analyzer stage and the source axis. The alignment device is configured to move the source stage, the detector stage and / or the analyzer stage, and to adjust a first distance between the source and the analyzer stage along the source axis and a second distance between the detector and the analyzer stage along the detector axis.

[0013]

[0026] A method for operating a spectrometer includes positioning the crystal analyzer such that a first reciprocal vector corresponding to a first crystal plane of the crystal analyzer is coplanar with the source axis and the detector axis. The method further includes performing a first scan by varying a first angle such that a first angle between the source axis and the first crystal plane is substantially equal to a second angle between the detector axis and the first crystal plane, and by varying a second angle, while the first reciprocal vector is coplanar with the source axis and the detector axis. The method further includes rotating the crystal analyzer such that a second reciprocal vector corresponding to a second crystal plane of the crystal analyzer is coplanar with the source axis and the detector axis. The method also includes performing a second scan by varying a first angle such that a first angle is substantially equal to a second angle, and by varying a second angle, while the second reciprocal vector is coplanar with the source axis and the detector axis.

[0014]

[0024] Conventional X-ray spectrometers are typically used only in symmetric configurations where (i) the inlet or outlet slits of the source and detector are equidistant from the crystal analyzer, and (ii) the angle formed by the source axis and detector axis is bisected by a reciprocal lattice vector corresponding to a crystal plane nominally parallel to the surface of the crystal analyzer. In contrast, the first scan and / or second scan of the method described above are performed in an asymmetric configuration defined by the following conditions: (i) the inlet or outlet slits of the source and detector are not equidistant from the crystal analyzer, and (ii) the angle formed by the source axis and detector axis is bisected by a reciprocal lattice vector corresponding to a crystal plane that is not nominally parallel to the surface of the crystal analyzer.

[0015]

[0028] Asymmetric configurations offer at least three advantages. Firstly, an asymmetric configuration allows the use of a single crystal analyzer to investigate the response of a sample across a wide wavelength or energy range. Compared to a symmetric configuration, time is saved because multiple superimposed or unsupervised energy ranges can be investigated without removing the first crystal analyzer from the analyzer stage or inserting and calibrating a second crystal analyzer. For example, the entire energy range from 5 keV to 10 keV can be investigated simply by rotating a single crystal analyzer and properly positioning the source and detector prior to each new scan. Secondly, the Johann error can be significantly reduced or eliminated because the angle between the source axis and the center plane of the crystal analyzer can be kept very high. Thirdly, an asymmetric configuration can significantly increase the distance clearance between the source and the detector.

[0016]

[0029] Figure 1 is a block diagram of the spectrometer 200. The spectrometer 200 includes a computing device 100. The computing device 100 includes one or more processors 102, a non-temporary computer-readable medium 104, a communication interface 106, and a user interface 108. The components of the computing device 100 are linked together by a system bus, network, or other connection mechanism 112.

[0017]

[0030] One or more processors 102 may be any type of processor, such as a microprocessor, field-programmable gate array, digital signal processor, or multicore processor, coupled to a non-temporary computer-readable medium 104.

[0018]

[0031] The non-temporary computer-readable medium 104 may be any type of memory, such as volatile memory like random access memory (RAM), dynamic random access memory (DRAM), or static random access memory (SRAM), or non-volatile memory like read-only memory (ROM), flash memory, magnetic or optical disk, or compact disk read-only memory (CD-ROM), among other devices used to store data or programs on a temporary or permanent basis.

[0019]

[0032] Additionally, the non-temporary computer-readable medium 104 may store instructions 111. Instructions 111 are executable by one or more processors 102 that cause the computing device 100 to perform any of the functions or methods described herein.

[0020]

[0033] The communication interface 106 may include hardware to enable communication within the computing device 100 and / or between the computing device 100 and one or more other devices. The hardware may include, for example, any type of input and / or output interface, a Universal Serial Bus (USB), PCI Express, a transmitter, a receiver, and an antenna. The communication interface 106 may be configured to facilitate communication with one or more other devices according to one or more wired or wireless communication protocols. For example, the communication interface 106 may be configured to facilitate wireless data communication of the computing device 100 according to one or more wireless communication standards such as the IEEE 801.11 standard, the ZigBee standard, or the Bluetooth® standard. As another example, the communication interface 106 may be configured to facilitate wired data communication with one or more other devices. The communication interface 106 may also include an analog-to-digital converter (ADC) or a digital-to-analog converter (DAC) that the computing device 100 can use to control various components of the computing device 100 or external devices.

[0021]

[0034] The user interface 108 may include any type of display component configured to display data. For example, the user interface 108 may include a touchscreen display. Alternatively, the user interface 108 may include a flat-panel display such as a liquid crystal display (LCD) or a light-emitting diode (LED) display. The user interface 108 may include one or more pieces of hardware used to provide data and control signals to the computing device 100. For example, the user interface 108 may include, in particular, a mouse or pointing device, a keyboard or keypad, a microphone, a touchpad, or a touchscreen, among other possible types of user input devices. Generally, the user interface 108 may enable an operator to interact with a graphical user interface (GUI) provided by the computing device 100 (e.g., displayed by the user interface 108).

[0022]

[0035] The spectrometer 200 further includes a radiation source 202, a detector 206, and an analyzer stage 210. The spectrometer 200 further includes an alignment device 221 including a radiation source stage 218, a detector stage 220, an angle measuring instrument 222, and one or more motors 224.

[0023]

[0036] Figure 2 is a schematic diagram of the spectrometer 200. The spectrometer 200 includes a source 202 configured to emit X-rays along the source axis 204. The X-rays emitted by the source 202 along the source axis 204 are generally divergent and uncollimated, but the X-rays are usually strongest along the source axis 204. The spectrometer 200 also includes a detector 206 configured to detect X-rays traveling along the detector axis 208. The spectrometer 200 also includes an analyzer stage 210 configured to hold a crystal analyzer 212 that defines a Rowland circle 214. The analyzer stage 210 is configured to rotate the crystal analyzer 212 about an analyzer axis 216 that is coplanar with the source axis 204 and the detector axis 208. The spectrometer 200 also includes a source stage 218. In some examples, the source stage 218 is configured to move the source 202 along the source axis 204 in the direction toward or away from the analyzer stage 210. In some examples, the angle detector 222 is configured to move the analyzer stage 210 along the source axis 204 in the direction of or away from the source 202. The spectrometer 200 also includes a detector stage 220. In some examples, the detector stage 220 is configured to move the detector 206 along the detector axis 208 in the direction of or away from the analyzer stage 210. In some examples, the angle detector 222 is configured to move the analyzer stage 210 along the detector axis 208 in the direction of or away from the detector 206. The spectrometer 200 also adjusts (i) the angle 225 between the analyzer stage 210 and the detector axis 208, and (ii) the angle θ between the analyzer stage 210 and the source axis 204. M The alignment device includes a double-circle angle detector 222 (shown in Figure 3) configured to adjust the distance ρ between the source 202 and the analyzer stage 210 along the source axis 204. The alignment device 221 (e.g., source stage 218, detector stage 220, angle detector 222, and / or one or more motors 224) is configured to move the source stage 218, detector stage 220, and / or analyzer stage 210 to adjust the distance d between the detector 206 and the analyzer stage 210 along the detector axis 208 in order to adjust the distance ρ between the source 202 and the analyzer stage 210 along the source axis 204.

[0024]

[0037] The diameter of the Rowland circle 214 is equal to the radius of curvature of the crystal analyzer 212. The crystal analyzer 212 can take the form of a spherically curved crystal analyzer. The Rowland circle 214 is tangent to the central plane of the crystal analyzer 212.

[0025]

[0038] The radiation source 202 can take the form of an X-ray tube, a sample illuminated by the X-ray tube, or a synchrotron. In various examples, the sample under test may be positioned on the radiation source stage 218 together with the radiation source 202. The radiation source 202 includes an entrance slit 226 on the Rowland circle 214. The radiation source stage 218 is a platform configured to fix the radiation source 202 and prevent unintentional movement of the radiation source 202. A motor 224A is configured to move the radiation source stage 218 back and forth along the radiation source axis 204.

[0026]

[0039] The detector 206 may take the form of a silicon drift detector and include an exit slit 228 on the Rowland circle 214. In various examples, the sample under test may be positioned on the detector stage 220 together with the detector 206. The detector stage 220 is a platform configured to fix the detector 206 and prevent unintentional movement of the detector 206. A motor 224B is configured to move the detector stage 220 back and forth along the detector axis 208.

[0027]

[0040] The analyzer stage 210 is a platform configured to fix the crystal analyzer 212 and prevent unintentional movement of the crystal analyzer 212. Therefore, the analyzer stage 210 may include a tensioned clip to hold the crystal analyzer 212 in place. The motor 224C is configured to rotate the analyzer stage 210 and the crystal analyzer 212 around the analyzer axis 216.

[0028]

[0041] The angle measuring device 222 (shown in Figure 3) is a mechanical device configured to rotate the detector stage 220 and the radiation source stage 218 relative to the analyzer stage 210. One or more motors 224 are configured to operate the angle measuring device 222. For example, motor 224D is configured to adjust the angle 225, and motor 224E adjusts the angle θ M It is configured to adjust the distance ρ. In some examples, motor 224F is configured to move the analyzer stage 210 so that the distance ρ increases or decreases, and motor 224G is configured to move the analyzer stage 210 so that the distance d increases or decreases.

[0029]

[0042] Figures 3A and 3B illustrate the operation of the spectrometer 200 in two different modes. Figure 3A shows the spectrometer 200 performing X-ray absorption fine structure (XAFS) spectroscopy in transmission mode, where the spectrometer 200 generates a tunable intensity spectrum of the energy of the X-rays transmitted through the sample. As shown, the sample is positioned on the detector stage 220.

[0030]

[0043] Figure 3B shows the spectrometer 200 performing X-ray emission spectroscopy (XES) in emission mode. As shown, the sample is positioned on the source stage 218. This geometric shape also applies when the spectrometer 200 is used to perform wavelength-dispersive X-ray fluorescence spectroscopy (WD-XRF). In various examples, the spectrometer 200 can operate in emission mode, absorption mode, transmission mode, or fluorescence mode. In fluorescence mode, the sample is approximately on the Rowland circle 214, and the detector 206 is typically located on the Rowland circle 214.

[0031]

[0044] Figures 4A, 4B, and 4C are schematic diagrams of the analyzer stage 210 and the crystal analyzer 212. The analyzer stage 210 is configured to rotate the crystal analyzer 212 (see Figure 2) around the analyzer axis 216. Therefore, the angle of rotation φ defines a plane perpendicular to the analyzer axis 216.

[0032]

[0045] Referring to FIG. 2, the spectrometer 200 positions the crystal analyzer 212 such that the reciprocal lattice vector G corresponding to the crystal plane A at the center of the crystal analyzer 212 A lies in the same plane as the source axis 204 and the detector axis 208. Generally, the analyzer stage 210 rotates about the analyzer axis 216 manually or by using the motor 224C such that the reciprocal lattice vector G A lies in the same plane as the Rowland circle 214. In a specific example, the reciprocal lattice vector G A is G 5,5,1 which means that the spectrometer 200 positions the crystal analyzer 212 such that the 5,5,1 plane of the crystal analyzer 212 (e.g., silicon) is perpendicular to the Rowland circle 214. In an example where the spectrometer 200 operates in a symmetric configuration, the crystal plane A of the crystal analyzer 212 is nominally parallel to the central plane of the crystal analyzer 212. In other examples where the spectrometer 200 operates in an asymmetric configuration, the crystal plane A of the crystal analyzer 212 is not nominally parallel to the central plane of the crystal analyzer 212.

[0033]

[0046] Prior to and during performing the first scan, (i) the spectrometer 200 translates the source 202 and / or the crystal analyzer 212 such that the source axis 204 lies in the same plane as the detector axis 208 and the reciprocal lattice vector G A and (ii) the source distance ρ between the source 202 and the crystal analyzer 212 along the source axis 204 is substantially equal to the diameter D of the Rowland circle multiplied by the sine of the sum of (a) the angle θ formed by the source axis 204 and the crystal plane A B and (b) the angle α formed by the crystal plane A and the crystal plane C nominally parallel to the central plane of the crystal analyzer 212. This relationship is expressed by the following equation: ρ = Dsin(θ B + α). The spectrometer 200 can translate the source 202 by adjusting the positioning of the source stage 218 either manually or via the motor 224A. The spectrometer 200 can translate the crystal analyzer 212 by translating the analyzer stage 210, for example, by using the motor 224F.

[0034]

[0047] Furthermore, prior to and during the first scan, the spectrometer 200 (i) has the detector axis 208 aligned with the source axis 204 and the reciprocal lattice vector G A (ii) The detector distance d between the detector 206 and the crystal analyzer 212 along the detector axis 208 is such that (a) the angle θ formed by the detector axis 208 and the crystal plane A is such that (ii) the detector distance d between the detector 206 and the crystal analyzer 212 is such that (a) the detector axis 208 and the crystal plane A are on the same plane, and (ii) the detector distance d between the detector 206 and the crystal analyzer 212 along the detector axis 208 is such that (a) the detector distance θ is formed by the detector axis 208 and the crystal plane A. B The detector 206 and / or crystal analyzer 212 are translated so that they are substantially equal to the diameter D of the Rowland circle 214, which is obtained by multiplying the angle formed by crystal plane A and crystal plane C by the sine. This relationship is expressed by the following equation: d = Dsin(θ) B -α). The spectrometer 200 can move the detector 206 by adjusting the positioning of the detector stage 220, either manually or via the motor 224B. The spectrometer 200 can move the crystal analyzer 212 by moving the analyzer stage 210, for example, by using the motor 224G.

[0035]

[0048] Next, the spectrometer 200 measures the reciprocal lattice vector G A The first scan is performed while the source axis 204 and the detector axis 208 are on the same plane. Performing the first scan is performed when the angle θ between the source axis 204 and the crystal plane A is measured by the angle θ of the angle measuring instrument 222. B Varying the angle θ between the detector axis 208 and the crystal plane A B It is involved in causing these angles θ to vary. B The two angles are kept substantially equal to each other during the first scan. The first scan also involves the detector at an angle θ 206. B This involves detecting mono-X-rays from the crystal analyzer 212 while varying the temperature.

[0036]

[0049] In either a transmission or absorption configuration, the source 202 irradiates the crystal analyzer 212 with the first X-rays so that the second X-rays are emitted from the crystal analyzer 212 via Bragg reflection and incident on the sample. The detector 206 detects the second X-rays that pass through the sample.

[0037]

[0050] In the emission configuration, the source 202 irradiates the sample with first X-rays so that second X-rays are emitted by the sample and incident on the crystal analyzer 212. These X-rays can enter the Rowland circle through the entrance slit 226 on the source stage 218. Next, the detector 206 detects third X-rays reflected from the crystal analyzer 212 via Bragg reflection of the second X-rays.

[0038]

[0051] Regardless of the configuration of the first scan, the spectrometer 200 generates a tunable intensity spectrum of the X-ray energy detected by the detector 206. For example, the reciprocal lattice vector G A If this corresponds to the 5,1,1 plane of silicon, then the energy range of the first scan corresponds to approximately 8.3 keV to 9.4 keV.

[0039]

[0052] Figure 5 shows the spectrometer 200 performing the second scan. To initiate the second scan, the spectrometer 200 sets the reciprocal lattice vector G corresponding to the central crystal plane B of the crystal analyzer 212. B The crystal analyzer 212 is rotated around the analyzer axis 216 so that the reciprocal lattice vector G is on the same plane as the source axis 204 and the detector axis 208. Generally, the analyzer stage 210 is positioned such that the reciprocal lattice vector G B The analyzer axis 216 is rotated manually or by using the motor 224C so that it lies coplanar with the Rowland circle 214. In a specific example, the reciprocal lattice vector G B is G 3,5,-1 This means that the spectrometer 200 positions the crystal analyzer 212 such that the 3,5,-1 planes at the center of the crystal analyzer 212 (e.g., silicon) are perpendicular to the Rowland circle 214. In the example where the spectrometer 200 is operating in a symmetrical configuration, the crystal plane B of the crystal analyzer 212 is nominally parallel to the central plane of the crystal analyzer 212. In other examples where the spectrometer 200 is operating in an asymmetrical configuration, the crystal plane B of the crystal analyzer 212 is not nominally parallel to the central plane of the crystal analyzer 212.

[0040]

[0053] Prior to and during the second scan, (i) the source axis 204 is aligned with the detector axis 208 and the reciprocal lattice vector G B(i) The source distance ρ between the source 202 and the crystal analyzer 212 along the source axis 204 is such that (a) the angle θ formed by the source axis 204 and the crystal plane B is such that (ii) the source distance ρ between the source 202 and the crystal analyzer 212 is such that (a) the source axis 204 and the crystal plane B are coplanar, and (ii) the source distance ρ between the source 202 and the crystal analyzer 212 along the source axis 204 is such that (a) the source distance θ is formed by the source axis 204 and the crystal plane B. B (b) The spectrometer 200 moves the source 202 and / or the crystal analyzer 212 in parallel so that the diameter D of the Rowland circle is substantially equal to the sine of the sum of the angle α formed by the crystal plane B and the crystal plane C nominally parallel to the curvature center plane of the crystal analyzer 212. This relationship is expressed by the following equation: ρ = Dsin(θ) B (+α) The spectrometer 200 can move the radiation source 202 by adjusting the positioning of the radiation source stage 218, either manually or via the motor 224A. The spectrometer 200 can move the crystal analyzer 212 by moving the analyzer stage 210, for example, by using the motor 224F.

[0041]

[0054] Furthermore, prior to and during the second scan, the spectrometer 200 (i) has the detector axis 208 aligned with the source axis 204 and the reciprocal lattice vector G B (ii) The detector distance d between the detector 206 and the crystal analyzer 212 along the detector axis 208 is such that (a) the angle θ formed by the detector axis 208 and the crystal plane B is such that (ii) the detector distance d between the detector 206 and the crystal analyzer 212 is such that (a) the detector axis 208 and the crystal plane B are on the same plane, and (ii) the detector distance d between the detector 206 and the crystal analyzer 212 along the detector axis 208 is such that (a) the detector distance θ is formed by the detector axis 208 and the crystal plane B. B The detector 206 and / or crystal analyzer 212 are translated so that they are substantially equal to the diameter D of the Rowland circle 214, which is obtained by multiplying the angle difference between crystal plane B and crystal plane C by the sine. This relationship is expressed by the following equation: d = Dsin(θ) B -α). The spectrometer 200 can move the detector 206 by adjusting the positioning of the detector stage 220, either manually or via the motor 224B. The spectrometer 200 can move the crystal analyzer 212 by moving the analyzer stage 210, for example, by using the motor 224G.

[0042]

[0055] Next, the spectrometer 200 measures the reciprocal lattice vector G BA second scan is performed while the angle detector 222 is on the same plane as the source axis 204 and the detector axis 208. Performing the second scan is performed when the angle detector 222 is at the angle θ between the source axis 204 and the crystal plane B. B Varying the angle θ between the detector axis 208 and the crystal plane B B It is involved in causing these angles θ to vary. B During the second scan, the detectors 206 are kept substantially equal to each other. The second scan also involves the detectors 206 at an angle θ B This involves detecting mono-X-rays from the crystal analyzer 212 while varying the temperature.

[0043]

[0056] In either a transmission or absorption configuration, the source 202 irradiates the crystal analyzer 212 with the first X-rays so that the second X-rays are emitted from the crystal analyzer 212 via Bragg reflection and incident on the sample. The detector 206 detects the second X-rays that pass through the sample.

[0044]

[0050] In the emission configuration, the source 202 irradiates the sample with first X-rays so that second X-rays are emitted by the sample and incident on the crystal analyzer 212. The second X-rays can enter the Rowland circle through the entrance slit 226 on the source stage 218. Next, the detector 206 detects third X-rays reflected from the crystal analyzer 212 via Bragg reflection of the second X-rays.

[0045]

[0058] Regardless of the configuration of the second scan, the spectrometer 200 generates an intensity spectrum of the X-ray energy detected by the detector 206. For example, the reciprocal lattice vector G B If this corresponds to the 3,1,1 plane of silicon, then the energy range of the second scan corresponds to approximately 6.5 keV to 8.1 keV.

[0046]

[0059] Figure 6 is a block diagram of Method 300. As shown in Figure 6, Method 300 includes one or more operations, functions, or actions, as indicated by blocks 302, 304, 306, and 308. The blocks are shown in serial order, but these blocks may also be performed in parallel and / or in an order different from that described herein. Furthermore, various blocks may be combined into fewer blocks, divided into additional blocks, and / or removed, based on the desired implementation.

[0047]

[0060] In block 302, method 300 uses the reciprocal lattice vector G corresponding to the crystal plane A of the crystal analyzer 212. A This includes positioning the spectrometer 200 or the user's crystal analyzer 212 so that it is coplanar with the source axis 204 and the detector axis 208. The functionality related to block 302 is discussed above with reference to Figure 2-4.

[0048]

[0061] In block 304, method 300 is the reciprocal lattice vector G A While the source axis 204 and the detector axis 208 are on the same plane, the spectrometer 200 measures the angle θ between the source axis 204 and the crystal plane A. B The angle θ between the detector axis 208 and the crystal plane A is the angle θ between the detector axis 208 and the crystal plane A. B The angle θ between the source axis 204 and the crystal plane A is substantially equal to θ. B By varying the angle θ between the detector axis 208 and the crystal plane A, B This includes performing a first scan by varying the value. The functionality related to block 304 is discussed above with reference to Figure 2-4.

[0049]

[0062] In block 306, method 300 uses a spectrometer 200 or a user-defined reciprocal lattice vector G corresponding to crystal plane B of a crystal analyzer 212. B This includes rotating the crystal analyzer 212 so that it is coplanar with the source axis 204 and the detector axis 208. The functionality related to block 306 is discussed above with reference to Figure 2-5.

[0050]

[0063] In block 308, method 300 is performed by spectrometer 200, and the reciprocal lattice vector G B While the source axis 204 and the detector axis 208 are on the same plane, the angle θ between the source axis 204 and the crystal plane B B The angle θ between the detector axis 208 and the crystal plane B is the angle θ between the detector axis 208 and the crystal plane B. B The angle θ between the source axis 204 and the crystal plane B is substantially equal to θ. B By varying the angle θ between the detector axis 208 and the crystal plane B, B This includes performing a second scan by varying the value. The functionality related to block 304 is discussed above with reference to Figure 3-5.

[0051]

[0064] Figure 7A shows spectrometer 200 configured for performing XAFS in a symmetric configuration. In the symmetric configuration, the Bragg angle θ B The angle θ is the angle between the source axis 204 and the nominally parallel crystal plane C with respect to the central plane of the crystal analyzer 212. M It is equal to.

[0052]

[0065] Figure 7B shows the spectrometer 200 configured for performing XAFS in an asymmetric configuration. In the asymmetric configuration, the Bragg angle θ B The angle is θ M It is not equal to. The asymmetric configuration allows for a Bragg angle such as 65° while the X-rays from source 202 are incident on crystal analyzer 212 at a high angle such as 90°. This high incident angle on crystal analyzer 212, combined with the reduced or eliminated Johann error despite the use of a Bragg angle much smaller than 90°, can result in a high signal intensity.

[0053]

[0066] Figure 8A shows the significant Johann error that occurs with respect to X-rays incident on a crystal analyzer located more than approximately 10 mm from the center when operating in a symmetrical configuration.

[0054]

[0067] Figure 8B shows that the Johann error is close to zero for X-rays incident on the crystal analyzer at a distance of less than approximately 40 mm from the center when operating in an asymmetric configuration.

[0055]

[0068] Figure 9 shows the calculated and experimental results of (α,φ) corresponding to several crystal planes of the Si(551) crystal analyzer. The asymmetric angle α corresponds to the radial direction, and the rotation angle φ corresponds to the azimuthal direction. For example, the 733 crystal plane of the Si(551) crystal analyzer corresponds to approximately α=25° and φ=120°.

[0056]

[0069] While various exemplary embodiments and exemplary forms have been disclosed herein, other embodiments and exemplary forms will be apparent to those skilled in the art. The various exemplary embodiments and exemplary forms disclosed herein are for illustrative purposes only and are not intended to limit them, and the true scope and spirit are shown by the following claims.

Claims

1. A method for operating a spectrometer comprising a crystal analyzer that defines a Rowland circle, a source configured to emit X-rays along the source axis, and a detector configured to detect X-rays traveling along the detector axis, the method being: Positioning the crystal analyzer such that the first reciprocal lattice vector corresponding to the first crystal plane of the crystal analyzer lies on the same plane as the source axis and the detector axis; The first scan is performed by varying the first angle and the second angle such that the first angle between the source axis and the first crystal plane becomes substantially equal to the second angle between the detector axis and the first crystal plane, while the first reciprocal lattice vector is coplanar with the source axis and the detector axis; Rotating the crystal analyzer such that the second reciprocal lattice vector corresponding to the second crystal plane of the crystal analyzer lies on the same plane as the source axis and the detector axis; and The second scan is performed by varying the first angle and the second angle such that the first angle becomes substantially equal to the second angle, while the second reciprocal lattice vector is coplane with the source axis and the detector axis. A method that includes this.

2. The method according to claim 1, wherein the crystal analyzer is a spherical curvature crystal analyzer.

3. The method according to claim 1 or 2, wherein the diameter of the Rowland circle is equal to the radius of curvature of the crystal analyzer.

4. The method according to any one of claims 1 to 3, wherein the radiation source includes an X-ray tube or a synchrotron.

5. Performing the first scan further: Irradiating the sample with first X-rays using the radiation source such that second X-rays are emitted from the sample and incident on the crystal analyzer; and The third X-ray reflected from the crystal analyzer via the Bragg reflection of the second X-ray is detected using the detector. The method according to any one of claims 1 to 4, including the method described in any one of claims 1 to 4.

6. The method according to claim 5, wherein the first scan and the second scan each include performing X-ray emission spectroscopy (XES).

7. The method according to claim 5, wherein the first scan and the second scan each include performing wavelength-dispersive X-ray fluorescence spectroscopy (WD-XRF).

8. Performing the first scan further: Irradiating the crystal analyzer with the first X-rays using the source such that the second X-rays are emitted from the crystal analyzer via Bragg reflection and incident on the sample; and The second X-rays passing through the sample are detected using the detector. The method according to any one of claims 1 to 4, including the method described in any one of claims 1 to 4.

9. The method according to claim 8, wherein the first scan and the second scan each include performing X-ray absorption fine structure (XAFS) analysis.

10. The method according to any one of claims 1 to 9, wherein the radiation source includes an inlet slit on the Rowland circle.

11. The method according to any one of claims 1 to 10, wherein the detector includes an inlet slit on the Rowland circle.

12. The method according to any one of claims 1 to 11, wherein the first scanning is performed by translating the source and / or the crystal analyzer such that (i) the source axis is coplanar with the detector axis and the first reciprocal lattice vector, and (ii) the source distance between the source and the crystal analyzer along the source axis is substantially equal to the diameter of the Rowland circle multiplied by the sine of the sum of (a) the first angle and (b) the third angle formed by the first crystal plane and the third crystal plane nominally parallel to the curved surface of the crystal analyzer.

13. The method according to claim 12, wherein the second scanning comprises (i) translating the source and / or the crystal analyzer such that the source axis is coplanar with the detector axis and the second reciprocal lattice vector, and (ii) the source distance is substantially equal to the diameter of the Rowland circle multiplied by the sine of the second sum of (a) the first angle and (b) the fourth angle formed by the second crystal plane and the third crystal plane.

14. The method according to any one of claims 1 to 13, wherein the first scanning is performed by translating the detector and / or the crystal analyzer such that (i) the detector axis is coplanar with the source axis and the first reciprocal lattice vector, and (ii) the detector distance between the detector and the crystal analyzer along the detector axis is substantially equal to the diameter of the Rowland circle multiplied by (a) the first angle minus (b) the sine of the difference between the first crystal plane and the third crystal plane nominally parallel to the curved surface of the crystal analyzer.

15. The method according to claim 14, wherein the second scanning comprises (i) translating the detector and / or the crystal analyzer such that the detector axis is coplanar with the source axis and the second reciprocal lattice vector, and (ii) the detector distance is substantially equal to the diameter of the Rowland circle multiplied by (a) the first angle minus (b) the sine of the second difference between the fourth angle formed by the second and third crystal planes.

16. The method according to any one of claims 1 to 15, wherein performing the first scan includes detecting monochromatic X-rays from the crystal analyzer while varying the first angle and the second angle.

17. The method according to any one of claims 1 to 16, wherein the second scanning includes detecting monochromatic X-rays from the crystal analyzer while varying the first and second angles.

18. The method according to any one of claims 1 to 17, wherein positioning the crystal analyzer such that the first reciprocal lattice vector lies coplane with the source axis and the detector axis includes rotating the crystal analyzer about a rotation axis that lies coplane with the source axis and the detector axis.

19. Performing the first scan includes detecting X-rays within a first energy range, The method according to any one of claims 1 to 18, wherein performing the second scan includes detecting X-rays in a second energy range that does not overlap with the first energy range.

20. The method according to claim 1, wherein performing the first scan includes operating the spectrometer in emission mode, absorption mode, transmission mode, or fluorescence mode.

21. The method according to claim 1, wherein performing the second scan includes operating the spectrometer in emission mode, absorption mode, transmission mode, or fluorescence mode.

22. The method according to any one of claims 1 to 21, wherein rotating the crystal analyzer such that the second reciprocal lattice vector lies coplane with the source axis and the detector axis includes rotating the crystal analyzer about a rotation axis that lies coplane with the source axis and the detector axis.

23. The method according to any one of claims 1 to 22, wherein the detector includes a silicon drift detector.

24. A non-temporary computer-readable medium that, when executed by one or more processors of a spectrometer, stores instructions causing the spectrometer to perform the method according to any one of claims 1 to 23.

25. A radiation source configured to emit X-rays along its source axis; A detector configured to detect X-rays traveling along the detector axis; An analyzer stage configured to hold a crystal analyzer that defines a Rowland circle, the analyzer stage configured to rotate the crystal analyzer about an analyzer axis that is coplanar with the source axis and the detector axis; and Alignment device A spectrometer comprising: A source stage configured to hold the aforementioned source; A detector stage configured to hold the detector; and An angle measuring instrument configured to (i) adjust a fifth angle between the analyzer stage and the detector axis, and (ii) adjust a sixth angle between the analyzer stage and the source axis. A spectrometer comprising, wherein the alignment device is configured to move the source stage, the detector stage and / or the analyzer stage to adjust a first distance between the source and the analyzer stage along the source axis and a second distance between the detector and the analyzer stage along the detector axis.

26. The spectrometer according to claim 25, wherein the spectrometer is configured to perform the method described in any one of claims 1 to 23.

27. The spectrometer according to claim 25 or 26, wherein the alignment device further includes a first motor configured to move the source stage along the source axis.

28. The spectrometer according to any one of claims 25 to 27, wherein the alignment device further includes a second motor configured to move the detector stage along the detector axis.

29. The spectrometer according to any one of claims 25 to 28, wherein the angle measuring instrument includes one or more motors configured to adjust the fifth angle and the sixth angle.

30. The spectrometer according to any one of claims 25 to 29, wherein the alignment device includes a third motor configured to move the analyzer stage along the source axis.

31. The spectrometer according to any one of claims 25 to 30, wherein the alignment device includes a fourth motor configured to move the analyzer stage along the detector axis.

32. The spectrometer according to any one of claims 25 to 31, further comprising a fifth motor configured to rotate the analyzer stage about the analyzer axis.

33. The spectrometer according to any one of claims 25 to 32, wherein the crystal analyzer is a spherical curved crystal analyzer.

34. The spectrometer according to any one of claims 25 to 33, wherein the diameter of the Rowland circle is equal to the radius of curvature of the crystal analyzer.

35. The spectrometer according to any one of claims 25 to 34, wherein the radiation source includes an X-ray tube or a synchrotron.

36. The spectrometer according to any one of claims 25 to 35, wherein the radiation source includes an entrance slit on the Rowland circle.

37. The spectrometer according to any one of claims 25 to 36, wherein the detector includes an exit slit on the Rowland circle.

38. The spectrometer according to any one of claims 25 to 37, wherein the detector includes a silicon drift detector.

39. One or more processors; and A computer-readable medium that, when executed by one or more of the aforementioned processors, stores instructions causing the spectrometer to perform the method according to any one of claims 1 to 23. A spectrometer according to any one of claims 24 to 38, further comprising:

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