Beam and sample movement compensation for robust spectro-microscopy measurements on a hard X-ray nanoprobe

Static and in situ nanoscale spectro-microscopy is now routinely performed on the Hard X-ray Nanoprobe beamline at Diamond and the solutions implemented to provide robust energy scanning and experimental operation are described. A software-based scheme for active feedback stabilization of X-ray beam position and monochromatic beam flux across the operating energy range of the beamline is reported, consisting of two linked feedback loops using extremum seeking and position control. Multimodal registration methods have been implemented for active compensation of drift during an experiment to compensate for sample movement during in situ experiments or from beam-induced effects.

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Rapidin situX-ray position stabilizationviaextremum seeking feedback

Journal of Synchrotron Radiation ◽

10.1107/s1600577516000679 ◽

2016 ◽

Vol 23 (2) ◽

pp. 443-447 ◽

Cited By ~ 1

Author(s):

S. Zohar ◽

N. Venugopalan ◽

D. Kissick ◽

M. Becker ◽

S. Xu ◽

...

Keyword(s):

Extremum Seeking ◽

Quality Data ◽

Vertical Position ◽

Spatial Gradient ◽

Beam Position ◽

X Ray ◽

Large Intensity ◽

Recovery Times ◽

Vertical Beam

X-ray beam stability is crucial for acquiring high-quality data at synchrotron beamline facilities. When the X-ray beam and defining apertures are of similar dimensions, small misalignments driven by position instabilities give rise to large intensity fluctuations. This problem is solved using extremum seeking feedback control (ESFC) forin situvertical beam position stabilization. In this setup, the intensity spatial gradient required for ESFC is determined by phase comparison of intensity oscillations downstream from the sample with pre-existing vertical beam oscillations. This approach compensates for vertical position drift from all sources with position recovery times <6 s and intensity stability through a 5 µm aperture measured at 1.5% FWHM over a period of 8 hours.

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Nanometer Resolution XANES Imaging of in situ switched individual PC-RAM devices

MRS Proceedings ◽

10.1557/opl.2013.643 ◽

2013 ◽

Vol 1563 ◽

Cited By ~ 1

Author(s):

Jan H. Richter ◽

Alexander V. Kolobov ◽

Paul Fons ◽

Xiaomin Wang ◽

Kirill V. Mitrofanov ◽

...

Keyword(s):

Phase Change ◽

Photon Energy ◽

Absorption Edge ◽

Crystalline State ◽

Spatial Extent ◽

Cell Type ◽

Beam Position ◽

Fluorescence Response ◽

X Ray

ABSTRACTWe report on the study of single devices of phase-change (Ge2Sb2Te5) memory cells in line cell type devices. Devices were investigated employing an x-ray nanobeam of only about 150 nm diameter, which could be fully contained within the spatial extent of the active area within a single device cell. XANES spectra showing the device in the amorphous and crystalline state have been successfully collected after switching the device in situ at the synchrotron. By monitoring the fluorescence response of the sample constituent materials at a constant photon energy (corresponding to the Ge K-edge absorption edge) as a function of x-ray beam position on the sample 2D maps have been produced.

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Droplet-based in situ X-ray absorption spectroscopy cell for studying crystallization processes at the tender X-ray energy range

RSC Advances ◽

10.1039/c9ra06084g ◽

2019 ◽

Vol 9 (58) ◽

pp. 34004-34010 ◽

Cited By ~ 2

Author(s):

Jacinta Xto ◽

Reto Wetter ◽

Camelia N. Borca ◽

Christophe Frieh ◽

Jeroen A. van Bokhoven ◽

...

Keyword(s):

Energy Range ◽

Absorption Spectroscopy ◽

Time Resolved ◽

X Ray ◽

X Ray Absorption

We introduce a new in situ cell for time-resolved reactions involving aerosols/droplets using tender X-ray absorption spectroscopy and related methods.

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Spectral Decomposition of X-ray Absorption Spectroscopy Datasets: Methods and Applications

Crystals ◽

10.3390/cryst10080664 ◽

2020 ◽

Vol 10 (8) ◽

pp. 664 ◽

Cited By ~ 1

Author(s):

Andrea Martini ◽

Elisa Borfecchia

Keyword(s):

Absorption Spectroscopy ◽

Multivariate Curve Resolution ◽

Beam Position ◽

X Ray ◽

External Variables ◽

Spectral Profiles ◽

X Ray Absorption ◽

Further Development ◽

Selection Of

X-ray absorption spectroscopy (XAS) today represents a widespread and powerful technique, able to monitor complex systems under in situ and operando conditions, while external variables, such us sampling time, sample temperature or even beam position over the analysed sample, are varied. X-ray absorption spectroscopy is an element-selective but bulk-averaging technique. Each measured XAS spectrum can be seen as an average signal arising from all the absorber-containing species/configurations present in the sample under study. The acquired XAS data are thus represented by a spectroscopic mixture composed of superimposed spectral profiles associated to well-defined components, characterised by concentration values evolving in the course of the experiment. The decomposition of an experimental XAS dataset in a set of pure spectral and concentration values is a typical example of an inverse problem and it goes, usually, under the name of multivariate curve resolution (MCR). In the present work, we present an overview on the major techniques developed to realize the MCR decomposition together with a selection of related results, with an emphasis on applications in catalysis. Therein, we will highlight the great potential of these methods which are imposing as an essential tool for quantitative analysis of large XAS datasets as well as the directions for further development in synergy with the continuous instrumental progresses at synchrotron sources.

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Diamond In-Line Monitors for Synchrotron Experiments

MRS Proceedings ◽

10.1557/proc-590-125 ◽

1999 ◽

Vol 590 ◽

Cited By ~ 3

Author(s):

P. Bergonzo ◽

D. Tromson ◽

A. Brambilla ◽

C. Mer ◽

B. Guizard ◽

...

Keyword(s):

Chemical Vapour ◽

In Situ Monitoring ◽

Light Sources ◽

Beam Position ◽

Position Resolution ◽

X Ray ◽

High Position ◽

Photo Detectors ◽

Beam Instabilities

ABSTRACTDiamond polycrystalline films have been synthesised using the Chemical Vapour Deposition (CVD) technique in order to fabricate new types of photo-detectors for the characterisation of x-ray light sources as encountered in synchrotron experiments. Since diamond exhibits a low absorption to low energy x-ray photons, these devices allow beam position monitoring with very little beam attenuation at photon energies as low as 2 keV. We present here diamond based new devices for four different applications, including (i) semitransparent beam intensity and (ii) position monitors with high position resolution (< 2 µm), (iii) beam profile monitors with 20 µm pitch resolution, and (iv) ultra-fast diamond detectors (response time < 100 ps) that enable the intensity and temporal monitoring of fast x-ray pulses. These devices can be used for in-line characterisation of synchrotron beam line experiments for permanent in-situ monitoring of beam instabilities during experiments as well as for synchrotron machine diagnostics.

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The TES beamline (8-BM) at NSLS-II: tender-energy spatially resolved X-ray absorption spectroscopy and X-ray fluorescence imaging

Journal of Synchrotron Radiation ◽

10.1107/s1600577519012761 ◽

2019 ◽

Vol 26 (6) ◽

pp. 2064-2074 ◽

Cited By ~ 7

Author(s):

Paul Northrup

Keyword(s):

Energy Range ◽

Fluorescence Imaging ◽

Absorption Spectroscopy ◽

Small Sample ◽

Energy Calibration ◽

Helium Atmosphere ◽

X Ray ◽

Spatially Resolved ◽

X Ray Absorption

The tender-energy X-ray spectroscopy (TES) beamline at the National Synchrotron Light Source II (NSLS-II) is now operational for general users. Its scientific mission includes static and in situ X-ray fluorescence imaging and spatially resolved X-ray absorption spectroscopy for characterization of complex heterogeneous, structured and dynamic natural or engineered materials and systems. TES is optimized for the tender-energy range, offering routine operations from 2.0 to 5.5 keV, with capabilities to reach down to 1.2 or up to 8 keV with configuration change. TES is designed as an extended X-ray absorption fine-structure microprobe (EXAFS microprobe) for applications of micrometre-scale EXAFS spectroscopy to heterogeneous samples. Beam size is user-tunable from ∼2 to 25 µm. Energy may be scanned on-the-fly or in traditional step scanning. Importantly, the position of the microbeam at the sample location does not move significantly during energy scanning or when changing energy across the entire routine energy range. This enables full EXAFS of a particle or domain the same size as the probe beam, and measurement of the same spot at different energies. In addition, there is no measureable drift in energy calibration (repeatability) scan-to-scan and over 24 h. This is critical where simultaneous calibration measurements are generally not feasible, and for speciation mapping where precise and stable control of incident energy is essential. The sample environment is helium atmosphere at room pressure with infrastructure for in situ electrochemistry and catalysis in small sample cells or microreactors. As the first bend-magnet beamline at NSLS-II, noteworthy commissioning aspects are described. Example measurements are presented to illustrate its capabilities.

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X-ray spectroscopy for chemistry in the 2-4 keV energy regime at the XMaS beamline: ionic liquids, Rh and Pd catalysts in gas and liquid environments, and Cl contamination in γ-Al2O3

Journal of Synchrotron Radiation ◽

10.1107/s1600577515016148 ◽

2015 ◽

Vol 22 (6) ◽

pp. 1426-1439 ◽

Cited By ~ 14

Author(s):

Paul B. J. Thompson ◽

Bao N. Nguyen ◽

Rachel Nicholls ◽

Richard A. Bourne ◽

John B. Brazier ◽

...

Keyword(s):

Ionic Liquids ◽

Energy Range ◽

Materials Science ◽

X Rays ◽

Pd Catalysts ◽

X Ray ◽

Operational Energy ◽

Overall Performance ◽

Chemical Character

The 2–4 keV energy range provides a rich window into many facets of materials science and chemistry. Within this window, P, S, Cl, K and CaK-edges may be found along with theL-edges of industrially important elements from Y through to Sn. Yet, compared with those that cater for energies aboveca.4–5 keV, there are relatively few resources available for X-ray spectroscopy below these energies. In addition,in situoroperandostudies become to varying degrees more challenging than at higher X-ray energies due to restrictions imposed by the lower energies of the X-rays upon the design and construction of appropriate sample environments. The XMaS beamline at the ESRF has recently made efforts to extend its operational energy range to include this softer end of the X-ray spectrum. In this report the resulting performance of this resource for X-ray spectroscopy is detailed with specific attention drawn to: understanding electrostatic and charge transfer effects at the SK-edge in ionic liquids; quantification of dilution limits at the ClK- and RhL3-edges and structural equilibria in solution; in vacuum deposition and reduction of [RhI(CO)2Cl]2to γ-Al2O3; contamination of γ-Al2O3by Cl and its potential role in determining the chemical character of supported Rh catalysts; and the development of chlorinated Pd catalysts in `green' solvent systems. Sample environments thus far developed are also presented, characterized and their overall performance evaluated.

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The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071107 ◽

1973 ◽

Vol 31 ◽

pp. 132-133 ◽

Cited By ~ 1

Author(s):

R. E. Herfert

Keyword(s):

Surface Characterization ◽

Analytical Techniques ◽

X Ray Diffraction ◽

Depth Of Penetration ◽

X Ray ◽

The Past ◽

Transmission Electron ◽

Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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Quantitative x-ray microanalysis and thickness determination using ζ factor

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100165367 ◽

1996 ◽

Vol 54 ◽

pp. 580-581

Author(s):

M. Watanabe ◽

Z. Horita ◽

M. Nemoto

Keyword(s):

Diffusion Couple ◽

Extrapolation Method ◽

Thin Specimen ◽

Beam Position ◽

X Ray ◽

Thickness Determination ◽

Experimental Limitation ◽

X Ray Absorption

X-ray absorption in quantitative x-ray microanalysis of thin specimens may be corrected without knowledge of thickness when the extrapolation method or the differential x-ray absorption (DXA) method is used. However, there is an experimental limitation involved in each method. In this study, a method is proposed to overcome such a limitation. The method is developed by introducing the ζ factor and by combining the extrapolation method and DXA method. The method using the ζ factor, which is called the ζ-DXA method in this study, is applied to diffusion-couple experiments in the Ni-Al system.For a thin specimen where incident electrons are fully transparent, the characteristic x-ray intensity generated from a beam position, I, may be represented as I = (NρW/A)Qωaist.

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