November 1999 issue
Design and implementation of a high-precision monitor for X-ray beam position, intensity and profile.
The layout and the instrumentation of the ROBL CRG beamline at the ESRF are described. ROBL is dedicated to radiochemistry research with X-ray absorption spectroscopy and materials research with X-ray diffraction and reflectometry.
A series of systematic property characterizations pertinent for the use of YB66 as a soft X-ray monochromator in the 1–2 keV region is reported.
A prototype pixel array detector is described for quantitative microsecond time-resolved X-ray imaging.
A CCD detector has been quantitatively studied for use in solution X-ray scattering, and showed that, for the most part, detector distortion and shading have little effect on SAXS analysis.
A new set-up for accurate structure determination at high pressure and high temperature has been developed at beamline ID30 of the ESRF. This new set-up allows fast collection of data suitable for structure refinement.
A simple and not too expensive cell for in situ investigations, at both high and low temperature, in transmission and fluorescence XAS spectroscopy is described. It was verified that the cell worked properly to obtain the in situ decomposition of an ammonium metatungstate sample to tungsten trioxide.
X-ray magnetic circular dichroism (XMCD) spectra can be obtained by switching the polarization helicity with a diamond quarter-wave plate. In these conditions a non-magnetic residual spectrum is superposed to the XMCD signal, the origins of which are analysed here.
High performance of polarization tunability and analysis of X-rays at SPring-8 is demonstrated by observing several magnetic effects. A diamond phase plate plays an essential role in regulating the polarization states.
Polarized X-ray absorption spectra of single crystals (0.2 × 0.2 × 0.2 mm) of carbonmonoxy myoglobin and its cryogenic photoproduct at T = 20 K have been collected in fluorescence mode. The data can be interpreted to provide insight into both the structural and electronic changes at the Fe-heme site level
Two-dimensional synchrotron radiation digital mammography is considered to be a powerful imaging modality for diagnosing breast tumors because it can detect microcalcifications and masses of soft tissue in breast specimens more clearly than the conventional mammography system under the same radiation dose.
Novel parabolic refractive X-ray lenses suitable for microanalysis, imaging and coherent scattering of hard X-rays are described.
A method for performing X-ray speckle-pattern correlation interferometry is explored. The summed small-angle scattering of two samples in series is simulated and tested for sensitivity to motion of one of the samples.
The design of an undulator beamline at the Advanced Photon Source optimized for performing coherent small-angle X-ray scattering is described. The beamline has been characterized by measuring and analysing static speckle patterns from isotropically disordered samples. The measured speckle widths and amplitudes are compared with a theory described herein and found to be in good agreement with its predictions.