scholarly journals TEXS: in-vacuum tender X-ray emission spectrometer with 11 Johansson crystal analyzers

2020 ◽  
Vol 27 (3) ◽  
pp. 813-826 ◽  
Author(s):  
Mauro Rovezzi ◽  
Alistair Harris ◽  
Blanka Detlefs ◽  
Timothy Bohdan ◽  
Artem Svyazhin ◽  
...  
Keyword(s):  
Vacuum Chamber ◽  
Solid Angle ◽  
High Vacuum ◽  
Core Hole ◽  
Innovative Design ◽  
X Ray ◽  
The Core ◽  
First Results ◽  
Sufficient Space

The design and first results of a large-solid-angle X-ray emission spectrometer that is optimized for energies between 1.5 keV and 5.5 keV are presented. The spectrometer is based on an array of 11 cylindrically bent Johansson crystal analyzers arranged in a non-dispersive Rowland circle geometry. The smallest achievable energy bandwidth is smaller than the core hole lifetime broadening of the absorption edges in this energy range. Energy scanning is achieved using an innovative design, maintaining the Rowland circle conditions for all crystals with only four motor motions. The entire spectrometer is encased in a high-vacuum chamber that allocates a liquid helium cryostat and provides sufficient space for in situ cells and operando catalysis reactors.

The Growth and Characterization of Germanium-Carbon Alloy Thin Films

1992 ◽  
Vol 270 ◽  
Author(s):  
Haojie Yuan ◽  
R. Stanley Williams
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Vacuum Chamber ◽  
Optical Band Gap ◽  
High Vacuum ◽  
Optical Absorption Spectroscopy ◽  
Alloy Thin Film ◽  
New Materials ◽  
X Ray

ABSTRACTThin films of pure germanium-carbon alloys (GexC1−x with x ≈ 0.0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) have been grown on Si(100) and A12O3 (0001) substrates by pulsed laser ablation in a high vacuum chamber. The films were analyzed by x-ray θ-2θ diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), conductivity measurements and optical absorption spectroscopy. The analyses of these new materials showed that films of all compositions were amorphous, free of contamination and uniform in composition. By changing the film composition, the optical band gap of these semiconducting films was varied from 0.00eV to 0.85eV for x = 0.0 to 1.0 respectively. According to the AES results, the carbon atoms in the Ge-C alloy thin film samples has a bonding configuration that is a mixture of sp2 and sp3 hybridizations.

scholarly journals A large-solid-angle X-ray Raman scattering spectrometer at ID20 of the European Synchrotron Radiation Facility

2017 ◽  
Vol 24 (2) ◽  
pp. 521-530 ◽  
Author(s):  
S. Huotari ◽  
Ch. J. Sahle ◽  
Ch. Henriquet ◽  
A. Al-Zein ◽  
K. Martel ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Raman Scattering ◽  
Solid Angle ◽  
European Synchrotron Radiation Facility ◽  
Electronic Excitations ◽  
Raman Scattering Spectroscopy ◽  
X Ray ◽  
Area Detector ◽  
Spectroscopic Tool

An end-station for X-ray Raman scattering spectroscopy at beamline ID20 of the European Synchrotron Radiation Facility is described. This end-station is dedicated to the study of shallow core electronic excitations using non-resonant inelastic X-ray scattering. The spectrometer has 72 spherically bent analyzer crystals arranged in six modular groups of 12 analyzer crystals each for a combined maximum flexibility and large solid angle of detection. Each of the six analyzer modules houses one pixelated area detector allowing for X-ray Raman scattering based imaging and efficient separation of the desired signal from the sample and spurious scattering from the often used complicated sample environments. This new end-station provides an unprecedented instrument for X-ray Raman scattering, which is a spectroscopic tool of great interest for the study of low-energy X-ray absorption spectra in materials under in situ conditions, such as in operando batteries and fuel cells, in situ catalytic reactions, and extreme pressure and temperature conditions.

Incorporation and Role of Nitrogen During Oxynitridation of Silicon Studied by Photoelectron Spectroscopy

1999 ◽  
Vol 567 ◽  
Author(s):  
Masayuki Suzuki ◽  
Yoji Saito
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Vacuum ◽  
Oxide Films ◽  
Silicon Surfaces ◽  
Gaseous Mixtures ◽  
X Ray ◽  
Initial Stage ◽  
Thermal Stability Of

ABSTRACTWe tried direct oxynitridation of silicon surfaces by remote-plasma-exited nitrogen and oxygen gaseous mixtures at 700°C in a high vacuum. The oxynitrided surfaces were investigated with in-situ X-ray photoelectron spectroscopy. With increase of the oxynitridation time, the surface density of nitrogen gradually increases, but that of oxygen shows nearly saturation behavior after the rapid increase in the initial stage. We also annealed the grown oxynitride and oxide films to investigate the role of the contained nitrogen. The desorption rate of oxygen from the oxynitride films is much less than that from oxide films. We confirmed that nitrogen stabilizes the thermal stability of these oxynitride films.

scholarly journals Modeling of Oxygen-Neon Dominated Accretion Disks in Ultracompact X-Ray Binaries: 4U 1626-67

2004 ◽  
Vol 194 ◽  
pp. 146-147 ◽  
Author(s):  
K. Werner ◽  
T. Nagel ◽  
S. Dreizler ◽  
T. Rauch
Keyword(s):  
Accretion Disks ◽  
Important Process ◽  
Gravitational Settling ◽  
X Ray ◽  
The Core ◽  
Synthetic Spectra ◽  
First Results ◽  
Low Mass ◽  
X Ray Binaries

AbstractWe report on first results of computing synthetic spectra from H/He-poor accretion disks in ultracompact LMXBs. We aim at the determination of the chemical composition of the very low-mass donor star, which is the core of a former C/O white dwarf. The abundance analysis allows to draw conclusions on gravitational settling in WDs which is an important process affecting cooling times and pulsational g-mode periods.

scholarly journals Exploring Deep-Rock Mechanics through Mechanical Analysis of Hard-Rock In Situ Coring System

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Jianan Li ◽  
Heping Xie ◽  
Ling Chen ◽  
Cong Li ◽  
Zhiqiang He
Keyword(s):  
Rock Mechanics ◽  
Hard Rock ◽  
Design Method ◽  
Drill Pipe ◽  
In Situ Stress ◽  
Drilling Depth ◽  
Innovative Design ◽  
The Core ◽  
Deep Rock

Exploration of deep-rock mechanics has a significant influence on the techniques of mining and rock mechanics. Rock coring technique is the basic method for all rock mechanics study. With the increase of the drilling depth and increasing strength of the hard rock, how to obtain high-quality rock core through various coring techniques is an eternal work. Here an innovative method is applied to design the new coring system to maximize the efficiency of operation. The stress conditions or parameters of rock core in the coring are analyzed, and the mechanism of the core with in situ stress is shown in this paper. The conflict of the core and coring tool chamber is proposed for the innovative design. The innovative design method is fulfilled by the theory of inventive problem solving (TRIZ). An improved coring system for the full-length core with in situ stress was obtained with the solutions of improved coring mechanism, cutting mechanism, and spiral drill pipe.

Study Of Al Surface Segregation In Icosahedral A162Cu25.5Fe12.5

1998 ◽  
Vol 553 ◽  
Author(s):  
M. GIL-GAVATZ ◽  
D. Rouxel ◽  
P. Pigeat ◽  
B. Weber ◽  
J.-M. Dubois
Keyword(s):  
Surface Segregation ◽  
Vacuum Chamber ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Electron Spectrometer ◽  
Temperature Dependent ◽  
Self Diffusion ◽  
Different Temperatures ◽  
High Vacuum Chamber

AbstractSurface segregation of aluminium was observed during oxidation experiments of icosahedral A162Cu25.5 Fel12.5, performed in-situ and at different temperatures in the ultra-high vacuum chamber of a scanning Auger electron spectrometer. Two regimes, below and above 770K, were observed in relation with severe segregation of Al atoms at the surface for T > 770K. We postulate that this temperature dependent segregation rate is representative of the aluminium transport towards the surface of the quasicrystal. By analogy with classical diffusion experiments, we can thus determine reasonable estimates of the activation energy for Al self-diffusion in this quasicrystal. The results are consistent with the existence of phason flips below 770K and thermal vacancies above this temperature.

CORE-HOLE EFFECT IN THE Ce L3 X-RAY ABSORPTION SPECTRA OF CeO2 AND CeFe2: NEW EXAMINATION BY USING RESONANT X-RAY EMISSION SPECTROSCOPY

2013 ◽  
Vol 27 (16) ◽  
pp. 1330012 ◽  
Author(s):  
A. KOTANI
Keyword(s):  
Absorption Spectra ◽  
Ground State ◽  
Theoretical Calculations ◽  
Emission Spectra ◽  
Core Hole ◽  
Final State ◽  
X Ray ◽  
The Core ◽  
X Ray Absorption ◽  
Hole Effect

We consider two different resonant X-ray emission spectra for Ce compounds: Ce 3d to 2p X-ray emission (denoted by 3d-RXES) and valence to 2p X-ray emission (v-RXES), both of which follow the Ce 2p to 5d resonant excitation. We propose that the comparison of the 3d- and v-RXES spectra is a new powerful method of directly detecting the core-hole effect in the final state of Ce L 3 X-ray absorption spectra (XAS). We applied this method to recent experimental RXES spectra for CeO 2 and CeFe 2, and showed unambiguously that the core-hole effect should be essential in the XAS of both materials. This result is confirmed by theoretical calculations, which reproduce well the experimental RXES and XAS spectra. We conclude that the ground state of CeO 2 is in the mixed state of 4f0 and [Formula: see text] configurations, where [Formula: see text] is a ligand hole, instead of a pure 4f0 configuration which was proposed recently by first-principles energy band calculations. Also, we conclude that the double peaks observed in L 3 XAS of CeFe 2 are caused by the 4f0 and 4f1 configurations, which are mixed in the ground state but separated in energy by the large core-hole potential in the final state of XAS.

A scanning Kelvin probe for synchrotron investigations: thein situdetection of radiation-induced potential changes

2011 ◽  
Vol 19 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Bekir Salgin ◽  
Dirk Vogel ◽  
Diego Pontoni ◽  
Heiko Schröder ◽  
Bernd Schönberger ◽  
...  
Keyword(s):  
High Performance ◽  
Structural Changes ◽  
Kelvin Probe ◽  
X Ray ◽  
Scanning Kelvin Probe ◽  
Wide Range ◽  
First Results ◽  
Radiation Induced ◽  
Set Up

A wide range of high-performance X-ray surface/interface characterization techniques are implemented nowadays at every synchrotron radiation source. However, these techniques are not always `non-destructive' because possible beam-induced electronic or structural changes may occur during X-ray irradiation. As these changes may be at least partially reversible, anin situtechnique is required for assessing their extent. Here the integration of a scanning Kelvin probe (SKP) set-up with a synchrotron hard X-ray interface scattering instrument for thein situdetection of work function variations resulting from X-ray irradiation is reported. First results, obtained on bare sapphire and sapphire covered by a room-temperature ionic liquid, are presented. In both cases a potential change was detected, which decayed and vanished after switching off the X-ray beam. This demonstrates the usefulness of a SKP forin situmonitoring of surface/interface potentials during X-ray materials characterization experiments.

scholarly journals Analysis of a measurement scheme for ultrafast hole dynamics by few femtosecond resolution X-ray pump–probe Auger spectroscopy

2014 ◽  
Vol 171 ◽  
pp. 93-111 ◽  
Author(s):  
Bridgette Cooper ◽  
Přemysl Kolorenč ◽  
Leszek J. Frasinski ◽  
Vitali Averbukh ◽  
Jon P. Marangos
Keyword(s):  
Auger Spectroscopy ◽  
X Rays ◽  
Core Hole ◽  
Pump Probe ◽  
X Ray ◽  
Molecular Systems ◽  
The Core ◽  
Probe Delay ◽  
Valence Region ◽  
Hole Migration

Ultrafast hole dynamics created in molecular systems as a result of sudden ionisation is the focus of much attention in the field of attosecond science. Using the molecule glycine we show through ab initio simulations that the dynamics of a hole, arising from ionisation in the inner valence region, evolves with a timescale appropriate to be measured using X-ray pulses from the current generation of SASE free electron lasers. The examined pump–probe scheme uses X-rays with photon energy below the K edge of carbon (275–280 eV) that will ionise from the inner valence region. A second probe X-ray at the same energy can excite an electron from the core to fill the vacancy in the inner-valence region. The dynamics of the inner valence hole can be tracked by measuring the Auger electrons produced by the subsequent refilling of the core hole as a function of pump–probe delay. We consider the feasibility of the experiment and include numerical simulation to support this analysis. We discuss the potential for all X-ray pump-X-ray probe Auger spectroscopy measurements for tracking hole migration.

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