“Cartography” in 7-Dimensions at CHESS: Mapping of Structure in Real Space, Reciprocal Space, and Time Using High-Energy X-rays

2020 ◽  
Vol 33 (6) ◽  
pp. 11-16
Author(s):  
K. E. Nygren, ◽  
D. C. Pagan, ◽  
J. P. C. Ruff ◽  
E. Arenholz ◽  
J. D. Brock
Keyword(s):  
High Energy ◽  
Real Space ◽  
Reciprocal Space ◽  
X Rays ◽  
Space And Time

scholarly journals Beamline P02.1 at PETRA III for high-resolution and high-energy powder diffraction

2015 ◽  
Vol 22 (3) ◽  
pp. 675-687 ◽  
Author(s):  
Ann-Christin Dippel ◽  
Hanns-Peter Liermann ◽  
Jan Torben Delitz ◽  
Peter Walter ◽  
Horst Schulte-Schrepping ◽  
...  
Keyword(s):  
High Resolution ◽  
Powder Diffraction ◽  
Early Stage ◽  
Beam Quality ◽  
High Energy ◽  
Real Space ◽  
Photon Flux ◽  
X Rays ◽  
Ambient Conditions ◽  
X Ray

Powder X-ray diffraction techniques largely benefit from the superior beam quality provided by high-brilliance synchrotron light sources in terms of photon flux and angular resolution. The High Resolution Powder Diffraction Beamline P02.1 at the storage ring PETRA III (DESY, Hamburg, Germany) combines these strengths with the power of high-energy X-rays for materials research. The beamline is operated at a fixed photon energy of 60 keV (0.207 Å wavelength). A high-resolution monochromator generates the highly collimated X-ray beam of narrow energy bandwidth. Classic crystal structure determination in reciprocal space at standard and non-ambient conditions are an essential part of the scientific scope as well as total scattering analysis using the real space information of the pair distribution function. Both methods are complemented byin situcapabilities with time-resolution in the sub-second regime owing to the high beam intensity and the advanced detector technology for high-energy X-rays. P02.1's efficiency in solving chemical and crystallographic problems is illustrated by presenting key experiments that were carried out within these fields during the early stage of beamline operation.

High-energy X-ray diffuse scattering using Weissenberg flat-cone geometry

2000 ◽  
Vol 33 (4) ◽  
pp. 1046-1050 ◽  
Author(s):  
B. D. Butler ◽  
D. R. Haeffner ◽  
P. L. Lee ◽  
T. R. Welberry
Keyword(s):  
Diffuse Scattering ◽  
High Energy ◽  
Reciprocal Space ◽  
Irregular Shape ◽  
X Rays ◽  
Storage Phosphor ◽  
X Ray ◽  
Image Plate ◽  
X Ray Scattering ◽  
Disordered Crystal

A technique for the measurement of diffuse X-ray scattering on individual reciprocal-space planes using high-energy X-ray photons is described. The method is demonstrated using a disordered crystal of the compound TlSbOGeO4and compared to data collected with a sealed-tube Cu anode source. Measurements were made on a synchrotron undulator beamline at an energy of 45 keV using Weissenberg flat-cone geometry and a storage phosphor (image) plate to detect the scattered X-rays. Advantages of the method include: extension of the accessible diffraction space to both higherandlower wavevectors, the ability to use crystals of irregular shape without the need for complicated absorption corrections, less need to prepare sample surfaces carefully, and the ability to filter fluorescence simply.

scholarly journals Controllable CaF2 Nanosized Stripe Arrays on Si(001) Studied by X-ray and Electron Diffraction

Surfaces ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 97-105
Author(s):  
Sergey M. Suturin ◽  
Vladimir V. Fedorov ◽  
Alexander M. Korovin ◽  
Gleb A. Valkovskiy ◽  
Masao Tabuchi ◽  
...  
Keyword(s):  
Substrate Temperature ◽  
Atomic Layer ◽  
Grazing Incidence ◽  
High Energy ◽  
Reciprocal Space ◽  
X Rays ◽  
Reciprocal Space Mapping ◽  
Long Time ◽  
Fine Control ◽  
Oriented Parallel

Adding uniaxial in-plane anisotropy to the otherwise four-fold Si(001) surface has for a long time been known to be possible via epitaxial deposition of a single atomic layer of calcium fluoride (CaF2), which forms an array of micron-long (110) oriented parallel stripes when the substrate temperature during the growth is kept in the range of 700–800 °C. As shown in the present paper, a fine control over dimensions and periodicity of the stripe array is possible through the introduction of a two-stage growth process at which the (110) orientation of the fluorite layer is settled at the high-temperature nucleation stage, while the stripes of controllable dimensions are formed at the second stage. By varying the substrate temperature at the second growth stage in the range of 800–400 °C, the stripe arrays with a periodicity from above 30 nm to below 10 nm can be fabricated with the height variation changing accordingly. Such variability can be of use in the applications in which the striped fluorite surface is used to influence the anisotropy of other functional (e.g., magnetically ordered or organic) materials grown on top. While large CaF2 stripes can be easily characterized by direct space techniques such as atomic force microscopy, the study of the shape and in-plane correlation between the stripes of a much smaller size is most effectively achieved through the use of grazing incidence reciprocal space techniques applied in the present paper. The discussed universal approach to 3D reciprocal space mapping utilizing scattering of X-rays and high-energy electrons offers a complementary way to study samples with arrays of long and narrow one-dimensional stripes at their surface.

scholarly journals Describing small angle scattering profiles by a limited set of intensities

2021 ◽  
Author(s):  
Thomas D Grant
Keyword(s):  
Small Angle ◽  
Structural Information ◽  
Real Space ◽  
Small Angle Scattering ◽  
Basis Functions ◽  
Reciprocal Space ◽  
X Rays ◽  
The Real ◽  
Size And Shape ◽  
Angle Scattering

Small angle scattering (SAS) probes the size and shape of particles at low resolution through the analysis of the scattering of X-rays or neutrons passing through a solution of particles. One approach to extracting structural information from SAS data is the indirect Fourier transform (IFT). The IFT approach parameterizes the real space pair distribution function (P(r)) of a particle using a set of orthogonal basis functions, which simultaneously determines the scattering profile (I(q)) using corresponding reciprocal space basis functions. This article presents an extension of an IFT algorithm proposed by Moore which used a trigonometric series to describe the basis functions, where the real space and reciprocal space basis functions are Fourier mates. We present an equation relating the Moore coefficients to the intensities of the SAS profile at specific positions. We provide a series of new equations that determine the size and shape parameters describing a particle from this distinct set of intensity values. We also derive an analytical real space regularizer to smooth the P(r) curve and ameliorate systematic deviations caused by series termination, commonly used in IFT methods though not described in Moore's original approach, which is particularly susceptible to such effects. The algorithm is provided as a script, denss.fit_data.py, as part of the DENSS software package for SAS, which includes both command line and interactive graphical interfaces.

Catalytic Adventures in Space and Time Using High Energy X-rays

2014 ◽  
Vol 18 (4) ◽  
pp. 134-148 ◽  
Author(s):  
Mark A. Newton ◽  
Marco Di Michiel ◽  
Davide Ferri ◽  
Marcos Fernàndez-Garcia ◽  
Andrew M. Beale ◽  
...  
Keyword(s):  
High Energy ◽  
X Rays ◽  
Space And Time

On High-Resolution Reciprocal-Space Mapping with a Triple-Crystal Diffractometer for High-Energy X-rays

1998 ◽  
Vol 5 (2) ◽  
pp. 82-89 ◽  
Author(s):  
K. D. Liss ◽  
A. Royer ◽  
T. Tschentscher ◽  
P. Suortti ◽  
A. P. Williams
Keyword(s):  
High Resolution ◽  
High Energy ◽  
Space Mapping ◽  
Reciprocal Space ◽  
X Rays ◽  
Reciprocal Space Mapping

The Basic Physical Principles of Ion, Electron, and X-Ray Detectors and Their Application to Microanalysis

1985 ◽  
Vol 43 ◽  
pp. 154-157
Author(s):  
A.J. Tousimis
Keyword(s):  
Ion Beam ◽  
Depth Resolution ◽  
Sample Surface ◽  
High Energy ◽  
X Rays ◽  
X Ray ◽  
Electrons And Ions ◽  
Spatial Depth ◽  
Minimum Surface Area ◽  
Physical Principles

An integral and of prime importance of any microtopography and microanalysis instrument system is its electron, x-ray and ion detector(s). The resolution and sensitivity of the electron microscope (TEM, SEM, STEM) and microanalyzers (SIMS and electron probe x-ray microanalyzers) are closely related to those of the sensing and recording devices incorporated with them.Table I lists characteristic sensitivities, minimum surface area and depth analyzed by various methods. Smaller ion, electron and x-ray beam diameters than those listed, are possible with currently available electromagnetic or electrostatic columns. Therefore, improvements in sensitivity and spatial/depth resolution of microanalysis will follow that of the detectors. In most of these methods, the sample surface is subjected to a stationary, line or raster scanning photon, electron or ion beam. The resultant radiation: photons (low energy) or high energy (x-rays), electrons and ions are detected and analyzed.

Ab initio structure determination of cytochrome c6 by combined reciprocal space-real space approach

2003 ◽  
Vol 218 (1) ◽  
Author(s):  
K. Chowdhury ◽  
S. Ghosh ◽  
M. Mukherjee
Keyword(s):  
Cytochrome C ◽  
Ab Initio ◽  
Structure Determination ◽  
Direct Method ◽  
Real Space ◽  
Reciprocal Space ◽  
Cytochrome C6 ◽  
Ab Initio Structure ◽  
Space Approach

AbstractThe direct method program SAYTAN has been applied successfully to redetermine the structure of cytochrome c

scholarly journals The interstellar medium in young supernova remnants: key to the production of cosmic X-rays and $\gamma $-rays

2021 ◽  
Vol 366 (6) ◽  
Author(s):  
Hidetoshi Sano ◽  
Yasuo Fukui
Keyword(s):  
Interstellar Medium ◽  
Supernova Remnants ◽  
Cosmic Ray ◽  
High Energy ◽  
X Rays ◽  
Interstellar Gas ◽  
High Energy Radiation ◽  
Dense Cores ◽  
The Relationship ◽  
Turbulent Velocity Field

AbstractWe review recent progress in elucidating the relationship between high-energy radiation and the interstellar medium (ISM) in young supernova remnants (SNRs) with ages of ∼2000 yr, focusing in particular on RX J1713.7−3946 and RCW 86. Both SNRs emit strong nonthermal X-rays and TeV $\gamma $ γ -rays, and they contain clumpy distributions of interstellar gas that includes both atomic and molecular hydrogen. We find that shock–cloud interactions provide a viable explanation for the spatial correlation between the X-rays and ISM. In these interactions, the supernova shocks hit the typically pc-scale dense cores, generating a highly turbulent velocity field that amplifies the magnetic field up to 0.1–1 mG. This amplification leads to enhanced nonthermal synchrotron emission around the clumps, whereas the cosmic-ray electrons do not penetrate the clumps. Accordingly, the nonthermal X-rays exhibit a spatial distribution similar to that of the ISM on the pc scale, while they are anticorrelated at sub-pc scales. These results predict that hadronic $\gamma $ γ -rays can be emitted from the dense cores, resulting in a spatial correspondence between the $\gamma $ γ -rays and the ISM. The current pc-scale resolution of $\gamma $ γ -ray observations is too low to resolve this correspondence. Future $\gamma $ γ -ray observations with the Cherenkov Telescope Array will be able to resolve the sub-pc-scale $\gamma $ γ -ray distribution and provide clues to the origin of these cosmic $\gamma $ γ -rays.

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