Xavier Thibault

MxCuBE: a synchrotron beamline control environment customized for macromolecular crystallography experiments

MxCuBE is a beamline control environment optimized for the needs of macromolecular crystallography. This paper describes the design of the software and the features that MxCuBE currently provides.

High-throughput sample handling and data collection at synchrotrons: embedding the ESRF into the high-throughput gene-to-structure pipeline

An automatic data-collection system has been implemented and installed on seven insertion-device beamlines and a bending-magnet beamline at the ESRF (European Synchrotron Radiation Facility) as part of the SPINE (Structural Proteomics In Europe) development of an automated structure-determination pipeline. The system allows remote interaction with beamline-control systems and automatic sample mounting, alignment, characterization, data collection and processing. Reports of all actions taken are available for inspection via database modules and web services.

Synchrotron radiation microtomography applied to investigation of paper

Some elements of the study of fibrous structure are presented in this paper. X-ray synchrotron microtomography is used to provide information about the three-dimensional structure. In this context a segmentation method is proposed to separate the different components of the porous material considered (paper).

Synchrotron 3D microtomography of halite aggregates during experimental pressure solution creep and evolution of the permeability

Pressure solution creep is one of the possible processes of mechano-chemical deformation that controls porosity and permeability variations in the upper crust. The three-dimensional geometry of the porous network of halite aggregates was imaged during compaction driven by pressure solution creep using X-ray synchrotron computed microtomography. This technique can be used to monitor individual grain contacts and whole aggregate textural changes during deformation. By reconstructing subvolumes, the 3D porosity of the aggregates was extracted. The time-resolved decrease in permeability during porosity reduction was calculated by solving the Stokes equations. The permeability remained isotropic and decreased from 2.1 to 0.15 Darcy after 18.2% compaction. Two microscopic mechanisms can explain the permeability reduction: grain indentation and pore connectivity reduction by precipitation on the free surface of pore throats.

Remote Access Experiments at the Macromolecular Crystallography Beamlines of the ESRF

Today, synchrotron-based macromolecular crystallography (SRMX) beamlines are increasingly automated with an emphasis on pushing data collection speeds and sample throughput rates to the highest reasonably possible values. While these facilities are designed to be user-friendly, somewhat paradoxically the speed with which single-crystal diffraction data can now be collected, and the resulting crystal structures solved, actually places a great deal of stress on many external users.

Technical Report: Automatic Experiments at the European Synchrotron Radiation Facility MX Beam-lines

During the last twenty years macromolecular crystallography (MX) has become the predominant tool for the investigation of structure/function relationships in biology. This is due to many technological advances and, in particular, improved access to synchrotron radiation (SR) sources, data from which has lead to ∼80% of the macromolecular crystal structures currently being deposited in the Protein Data Bank (PDB) (Figure 1, http://www.rcsb.org). The demand for synchrotron beam-time is also being fuelled by the funding of a number of structural genomics programmes [1], which, following an initial investment in protein production technology, have now contributed ∼1000 new structures to the PDB.

Evaluation of SiC-Particle Connectivity in Functionally Graded Al/SiCp Composites by Synchrotron Radiation Holographic Microtomography

Reliability of functionally graded metal matrix composites (FGMMCs) for automotive components is still dependent on the detailed knowledge of the mechanisms of the microstructural build-up, for instance on the mechanisms leading to the distribution and relative positions of the reinforcing particles. In order to assess the influence of the SiC particle size on the 3-D inter-particle connectivity in functionally graded Al/SiCp composites produced by centrifugal casting, X-ray microtomography experiments were performed at the ID19 beamline in ESRF (European Synchrotron Radiation Facility). The FGMMCs consisted of an Al-10Si-2Mg alloy matrix, reinforced by an average SiC particle volume fraction of 0.10; two different average sizes were used: 37 µm and 12 µm. The holographic modification of the X-ray CMT (Computer Micro- Tomography) method allowed to obtain neatly contrasted images, as opposed to classical CMT.Good agreement was found between the particle size evaluated by CMT and by laser interferometry. Particle clustering has been evaluated in number and volume, showing that a lower mean particle size is related to more clustering. Such an adverse effect relies on the importance of particle/liquid alloy surface tension. Also, the mean particle size has been evaluated as a function of particle number within a cluster: as expected, the larger a cluster, the larger the particles inside it.

Experimental Improvements ForMicro-tomography Of Paper And Board

Since early in this century, micro-tomography using an X-ray synchrotron source has aroused scientific interest to characterize the structure of paper. This paper shows improvements that have been made since the first micro-tomographic experiment. This concerns not only the X-ray beam preparation but also the paper sample preparation. To conclude this paper directions for the new developments are given.

Fast Acquisition High-resolution SynchrotronRadiation X-ray Microtomography ForAcademic And Industrial Purposes

The use of modern synchrotron radiation sources for monochromatic beam microtomography provides several new possibilities. These include, in addition to reduced signal-to-noise ratio, enhanced spatial resolution and phase contrast imaging, the quantitative measurements and the easy set-up of a sample environment for in-situ and/or real time experiments. Selected applications showing the improved capabilities, with special emphasis on industrially relevant topics, are presented.