A simple approach to determine the polarization coefficient at synchrotron radiation stations

2014 ◽  
Vol 47 (4) ◽  
pp. 1449-1451 ◽  
Author(s):  
Sergei Sulyanov ◽  
Pavel Dorovatovskii ◽  
Hans Boysen
Keyword(s):  
Synchrotron Radiation ◽  
Simple Procedure ◽  
Glass Plate ◽  
Intensity Variation ◽  
Incident Beam ◽  
Azimuth Angle ◽  
Area Detector ◽  
Ccd Detector ◽  
Diffraction Angle ◽  
Polarization Coefficient

A simple procedure for the measurement of the degree of linear polarization at a synchrotron radiation station is described. The diffraction pattern from a glass plate set perpendicular to the incident beam is registered using a two-dimensional area detector. The intensity variation along the azimuth angle ρ at a constant diffraction angle is fitted to the theoretical cos2ρ dependence. The results of measurements performed at a synchrotron radiation station with a CCD detector on the beam from a bending magnet are presented.

Two Crystal Structures Towards the Discotic Columnar Mesophase of (1,4,8,11,15,18,22,25-Octahexylphthalocyaninato)nickel

1997 ◽  
Vol 53 (2) ◽  
pp. 231-240 ◽  
Author(s):  
M. Helliwell ◽  
A. Deacon ◽  
K. J. Moon ◽  
A. K. Powell ◽  
M. J. Cook
Keyword(s):  
Synchrotron Radiation ◽  
Conformational Changes ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
Area Detector ◽  
Ccd Detector ◽  
Slight Movement ◽  
Image Plate System

(1,4,8,11,15,18,22,25-Octahexylphthalocyaninato)nickel is a thermotropic liquid crystal, undergoing a transition to a discotic columnar mesophase at 418 K. Its crystals are weakly diffracting needles. Single-crystal X-ray diffraction studies at 103 K, using intense synchrotron radiation of wavelength 0.504 Å at Station F2, CHESS and the `Princeton 1k' CCD area detector, and at 295 K using a Cu Kα rotating anode diffractometer, have respectively shown that the symmetry of the crystals is increased from primitive monoclinic (space group P21/n) to C-centred monoclinic (space group C2/c) when the temperature is raised. Solution of the structure at each temperature shows that the increase in symmetry at 295 K arises from slight movement of the molecules, as well as increased thermal motion of the hexyl groups, and small conformational changes in these groups, indicating the first stage of the transition to the discotic columnar mesophase, when the hexyl groups are thought to become completely mobile. The quality of the refinement of the structure is indicative of what can now be realized by employing multipole wiggler synchrotron radiation and a CCD area detector, as well as cryocooling, for difficult small molecule samples. The temperature of the space group transition was determined at the Daresbury SRS, on Station 7.2, using a CCD detector to monitor an area of the diffraction pattern, whilst varying the temperature systematically. A gradual appearance of spots for h + k = 2n + l occurred between 205 and 195 K. Tests were also made using an image plate system at 195 and 293 K, which confirmed the transition from primitive to C-centred lattice symmetry with temperature. No other changes were apparent on the CCD or IP detectors.

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.

Kinematical two-dimensional multiple-diffraction intensity profiles. Application to ω–ψ scans of silicon and diamond obtained with synchrotron radiation

2001 ◽  
Vol 34 (2) ◽  
pp. 157-165 ◽  
Author(s):  
E. Rossmanith ◽  
A Hupe ◽  
R. Kurtz ◽  
H. Schmidt ◽  
H.-G. Krane
Keyword(s):  
Synchrotron Radiation ◽  
Incident Beam ◽  
Mosaic Structure ◽  
Two Dimensional ◽  
Diffraction Intensity ◽  
Multiple Diffraction ◽  
Crystal Sample ◽  
Diffraction Patterns ◽  
Kinematical Theory

In a previous paper by Rossmanith [J. Appl. Cryst.(2000),33, 1405–1414], expressions for the calculation of multiple-diffraction patterns observed in ω–ψ scans of Bragg reflections were derived within the framework of the kinematical theory, taking into account the divergence and wavelength spread of the incident beam, as well as the mosaic structure of the crystal sample. Agreement with CuKα experiments was demonstrated. In this paper, it is shown that the theoretical expressions are also suitable for synchrotron radiation experiments.

Micro-X-Ray Fluorescence Analysis on a Synchrotron Radiation Wiggler Beam Line

1991 ◽  
Vol 35 (B) ◽  
pp. 995-1000
Author(s):  
J.V. Gilfrich ◽  
E.F. Skelton ◽  
S.B. Qadri ◽  
N.E. Moulton ◽  
D.J. Nagel ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
National Laboratory ◽  
Incident Beam ◽  
Fluorescence Analysis ◽  
High Energy ◽  
Brookhaven National Laboratory ◽  
Beam Line ◽  
X Rays ◽  
X Ray ◽  
Electron Orbit

AbstractIt has been well established over recent years that synchrotron radiation possesses some unique features as a source of primary x-rays for x-ray fluorescence analysis. Advantage has been taken of the high intensity emanating from the bending magnets of storage rings to develop x-ray microprobes utilizing apertures or focussing optics, or both, to provide a beam spot at the specimen of the order of micrometers. The use of insertion devices wigglers and undulatora, can further increase the available intensity, especially for the high energy photons. Beam Line X-17C at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory, accepts the unmodified continuum radiation from a superconducting wiggler in the storage ring. Some initial XRF measurements have been made on this beam line using apertures in the 10 to 100 micrometer range. The fluorescent radiation was measured by an intrinsic Ge detector having an energy resolution of 300 eV at 15 kev, and located at 90° to the incident beam in the plane of the electron orbit. In samples containing many elements, detection limits of a few ppm were achieved with 100 μm beams.

Statistical measures of spottiness in diffraction rings

2013 ◽  
Vol 47 (1) ◽  
pp. 166-172 ◽  
Author(s):  
Bridget Ingham
Keyword(s):  
Carbon Dioxide ◽  
Size Distribution ◽  
Intensity Variation ◽  
Incident Beam ◽  
Mean Square ◽  
X Ray Diffraction ◽  
X Ray ◽  
Statistical Measures ◽  
Diffraction Patterns

Spotty diffraction rings arise when the size distribution of crystallites illuminated by the incident beam includes crystallites that are large compared with the size of the beam. In this article, several statistical measures are used in conjunction to quantify spottiness and relate it to a crystallite size distribution: the number of peaks, the normalized root mean square intensity variation and the fractal dimension. These are demonstrated by way of example using synchrotron X-ray diffraction patterns collected duringin situcorrosion of mild steel in carbon dioxide-saturated aqueous brine.

Low-Temperature Synchrotron Radiation Study of a Twinned Disordered Crystal of Bis(4,4'-bromophenyl)-61,61-diyl Methano Fullerene C60

1998 ◽  
Vol 54 (2) ◽  
pp. 174-179 ◽  
Author(s):  
B. B. Iversen ◽  
A. Darovsky ◽  
R. Bolotovsky ◽  
P. Coppens
Keyword(s):  
Synchrotron Radiation ◽  
Low Temperature ◽  
Satisfactory Description ◽  
Area Detector ◽  
Chemical Crystallography ◽  
Synchrotron Radiation Diffraction ◽  
Radiation Technique ◽  
Indispensable Tool ◽  
Disordered Crystal

Synchrotron radiation diffraction measurements at 100 (5) K have been carried out on bis(4,4′-bromophenyl)-61,61-diyl methano fullerene C60 using area detector technology. In order to obtain a satisfactory description of the data it is necessary to introduce both a twinning model of the crystal and a disorder model consisting of two different isomers of the title compound. The study provides the first solid-state characterization of a 6–5 isomer of a methano fullerene. For the 6–6 isomer the geometry is in good agreement with recent literature on methano fullerenes. Unfortunately, the present study cannot resolve the bond lengths in the transannular region. The fact that the structure can be solved from diffraction data measured on a minute poorly scattering crystal shows that the low-temperature single-crystal synchrotron radiation technique is an indispensable tool in chemical crystallography.

Asymmetric Diffraction with Parallel-Beam Synchrotron Radiation

1992 ◽  
Vol 36 ◽  
pp. 609-616
Author(s):  
Hideo Toraya ◽  
Ting C. Huang ◽  
Yan Wu
Keyword(s):  
Synchrotron Radiation ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Incident Angle ◽  
Large Angle ◽  
Incident Beam ◽  
Sample Surface ◽  
Parallel Beam ◽  
Advantages And Disadvantages ◽  
Scanning Technique

AbstractIn this paper, the advantages and disadvantages of using the asymmetric 2θ scanning technique with a fixed incident angle α are described. Vertical-scan powder diffractometers with long horizontal parallel slits with an aperture of 0.05° and parallel-beam synchrotron radiation with λ = 1.54 Å and α = 10°, 2°, and 1° were used to collect α-Al2O3, silver behenate CH3(CH2)20COOAg, and Si powder diffraction patterns. The synchrotron radiation data were analyzed by profile fitting, and the results were compared with those obtained by the conventional θ-2θ scanning technique. As expected, significantly higher intensities were obtained from the asymmetric diffraction data with α = 10°. At smaller α = 2° and 1°, however, the intensities were reduced because of a smaller effective beam height. The peak positions remained practically unchanged for the data obtained with α = 10°, but displaced toward higher 2θ angles for α = 2° or lower, and, consequently a refractive-index correction was needed. Profile shape was slightly broadened and became more Lorentzian in asymmetric diffraction with highly oblique incidence of the beam. The change in shape was, however, negligibly small. The results showed that intensive and reliable powder diffraction data can be obtained from asymmetric diffraction by fixing the incident beam at a sufficiently large angle to fully illuminate the available sample surface.

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