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This article describes a correction procedure for the removal of indirect background contributions to measured small‐angle X‐ray scattering patterns. The high scattering power of a sample in the ultra‐small‐angle region may serve as a secondary source for a window placed in front of the detector. The resulting secondary scattering appears as a sample‐dependent background in the measured pattern that cannot be directly subtracted. This is an intricate problem in measurements at ultra‐low angles, which can significantly reduce the useful dynamic range of detection. Two different procedures are presented to retrieve the real scattering profile of the sample. [ABSTRACT FROM AUTHOR]

The new technical features and enhanced performance of the ID02 beamline with the Extremely Brilliant Source (EBS) at the ESRF are described. The beamline enables static and kinetic investigations of a broad range of systems from ångström to micrometre size scales and down to the sub‐millisecond time range by combining different small‐angle X‐ray scattering techniques in a single instrument. In addition, a nearly coherent beam obtained in the high‐resolution mode allows multispeckle X‐ray photon correlation spectroscopy measurements down to the microsecond range over the ultra‐small‐ and small‐angle regions. While the scattering vector (of magnitude q) range covered is the same as before, 0.001 ≤ q ≤ 50 nm−1 for an X‐ray wavelength of 1 Å, the EBS permits relaxation of the collimation conditions, thereby obtaining a higher flux throughput and lower background. In particular, a coherent photon flux in excess of 1012 photons s−1 can be routinely obtained, allowing dynamic studies of relatively dilute samples. The enhanced beam properties are complemented by advanced pixel‐array detectors and high‐throughput data reduction pipelines. All these developments together open new opportunities for structural, dynamic and kinetic investigations of out‐of‐equilibrium soft matter and biophysical systems. [ABSTRACT FROM AUTHOR]

This article presents the main technical features and performance of the upgraded beamline ID02 at the ESRF. The beamline combines different small‐angle X‐ray scattering techniques in one unique instrument, enabling static and kinetic investigations from ångström to micrometre size scales and time resolution down to the sub‐millisecond range. The main component of the instrument is an evacuated detector tube of length 34 m and diameter 2 m. Several different detectors are housed inside a motorized wagon that travels along a rail system, allowing an automated change of the sample–detector distance from about 1 to 31 m as well as selection of the desired detector. For optional combined wide‐angle scattering measurements, a wide‐angle detector is installed at the entrance cone of the tube. A scattering vector (of magnitude q) range of 0.002 ≤ q ≤ 50 nm−1 is covered with two sample–detector distances and a single‐beam setting for an X‐ray wavelength of 1 Å. In the high‐resolution mode, two‐dimensional ultra‐small‐angle X‐ray scattering patterns down to q < 0.001 nm−1 can be recorded, and the resulting one‐dimensional profiles have superior quality as compared to those measured with an optimized Bonse–Hart instrument. In the highest‐resolution mode, the beam is nearly coherent, thereby permitting multispeckle ultra‐small‐angle X‐ray photon correlation spectroscopy measurements. The main applications of the instrument include the elucidation of static and transient hierarchical structures, and nonequilibrium dynamics in soft matter and biophysical systems. The technical features and performance of a new instrument for time‐resolved ultra‐small‐angle and coherent X‐ray scattering are presented. The instrument enables static and kinetic investigations from ångström to micrometre size scales and time resolution down to the sub‐millisecond range. Applications include elucidation of static and transient hierarchical structures in soft matter and biophysical systems. [ABSTRACT FROM AUTHOR]

The application of small-angle X-ray scattering (SAXS) to whole Escherichia coli cells is challenging owing to the variety of internal constituents. To resolve their contributions, the outer shape was captured by ultra-small-angle X-ray scattering and combined with the internal structure resolved by SAXS. Building on these data, a model for the major structural components of E. coli was developed. It was possible to deduce information on the occupied volume, occurrence and average size of the most important intracellular constituents: ribosomes, DNA and proteins. E. coli was studied after treatment with three different antibiotic agents (chloramphenicol, tetracycline and rifampicin) and the impact on the intracellular constituents was monitored. [ABSTRACT FROM AUTHOR]