Through the reorganisation of the Experiments Division in July 2015, the high energy beamlines have been brought together within the Structure of Materials Group. The Microtomography Beamline, ID19, has joined the group, while beamlines ID01 and ID03 now belong to the X-ray Nanoprobe Group and Complex Systems and Biomedical Sciences Group, respectively. This new portfolio of high-energy X-ray techniques strengthens our capability to study complex heterogeneous devices and new advanced materials such as rechargeable batteries, catalytic materials, as well as serving complementary scientific communities including palaeontology, environmental research and cultural heritage.

From the Materials Science Beamline, ID11, in addition to the articles selected for this chapter, there is also an article on full-field X-ray orientation microscopy in the Enabling Technologies chapter, describing the recently developed six-dimensional framework for diffraction contrast tomography that allows the combined reconstruction of the shape and local orientation of single grains inside the sample. This year, ID11 took over several experiments which would normally have been performed at ID15, for example some XRD-CT and a high-energy experiment on the POLAR detector [1]. The 3DXRD station continues to run well with a full suite of detectors for near-field and far-field diffraction where it is possible to carry out simultaneous diffraction and imaging studies with micrometre scale spatial resolution. The installation of a new end-station for nano-focussing experiments is currently taking place allowing for the mapping of materials with around 100 nm resolution.

The refurbishment of ID15 began in December 2014 and the beamline will be reopened for users in the spring 2016 proposal round. The canted straight section houses the Engineering Materials Science and Materials Chemistry branch ID15A as well as the High Pressure Diffraction branch ID15B, relocated from ID09A, part of the Matter at Extremes Group. ID15A will offer two new end-stations, which have been developed for stress/strain measurements in the field of metallurgy and high speed tomography, and for time and space resolved materials chemistry. Both experimental hutches will share the main optical components. The Engineering Materials Science instrument will benefit from an improved flux of collimated X-rays in the range 50–150 keV. An additional high-energy monochromator inside the experimental hutch can deliver energies up to 750 keV. The improved instrument will provide an optimised setup for combined diffraction and micro tomography studies, offering both polychromatic and monochromatic beam conditions. Various sample environments (cryostats, high temperature ovens, stress rigs) are available to emulate real service conditions of advanced materials used today in high-end technological appliances. The end-station focussed on Materials Chemistry will feature a variety of sample environments and ancillary probes (mass, infra-red and fluorescence spectroscopy) in addition to a much more intense focal spot down to 1x1 µm2, delivered by the completely redesigned primary and secondary optics. The station is to be equipped with a photon counting Pilatus3 X CdTe pixel detector that will be shared with ID31. This detector is optimised for high-energy X-ray diffraction and features a maximum frame rate of 500 fps. Coupling more intense focused beams with this high-speed, high-efficiency and low-noise detector will make it possible to carry out non-spatially resolved diffraction studies of irreversible chemical processes on the timescale of milliseconds, and two and three dimensionally spatially resolved studies (XRD-CT, PDF-CT) on the timescale of seconds and minutes, respectively.

The users of the Microtomography Beamline, ID19, will benefit from many developments completed during 2015: the monochromator is now operational in both Bragg-Bragg and Laue-Laue geometries giving access to photon energies up to 200 keV; the accumulation mode is implemented for PCO-edge and FReLoN detectors for high dynamical range tomography of highly absorbing samples; new optical configurations based on Hasselblad photographic lenses are available for medium and high resolution tomography; the implementation of jpeg2000 data compression for radiographs and reconstructed data provides a 10-fold reduction in the final data size with negligible loss in quality; larger usable beams up to 75 mm are available. Furthermore, a Shimadzu HPV-X high speed camera was purchased for acquisition speeds up to single bunch imaging as well as an image-intensified camera PIMAX4 by Princeton Instruments for shock and impact studies. In addition to the selected articles, one should note the paper by Babel et al. [2] about the characterisation of dendrite morphologies in rapidly solidified droplets and the paper by Smith et al. [3] about the advances in virtual dental histology on early hominids.

The high resolution Powder Diffraction Beamline, ID22, has now commissioned its Perkin Elmer large area detector for complementary studies to the standard high-resolution configuration. The implementation of this detector was accompanied by the installation of a monochromatic-beam transfocator equipped with 185 aluminium refractive lenses manufactured in house. This detector can be used for checking for preferred orientation and graininess, for faster measurements on weakly scattering samples, and for one-shot PDF analysis, which is much quicker than the high resolution scanning mode that remains an option for highest quality data. Thanks to this 2D detector, ID22 and ID11 were able to help cover experiments that might normally be performed at ID15, unavailable to users during its refurbishment, such as looking at the behaviour of bio-alcohol reforming catalysts under reaction conditions.

The High-energy Beamline for Buried-interface Structures and Materials Processing, ID31, was known as upgrade beamline project UPBL2 during the Upgrade Phase I Programme. Beamline components were installed during spring 2015, and after commissioning, the beamline was ready to take first users in autumn 2015, as foreseen. ID31 offers a portfolio of hard X-ray characterisation techniques including reflectivity, wide-angle diffraction both in transmission and grazing incidence geometry, small-angle X-ray scattering, imaging methods, and auxiliary techniques coupled with a great versatility in choice of beam size and detectors optimised for high energy X-rays. The first large area, high-energy single-photon counting detector, Pilatus3 2M CdTe, was commissioned just before the winter break. This detector, to be shared with ID15A, allows measurements of weak signals next to strong ones with best possible signal-to-noise ratio for photon energies up to 100 keV. Currently, this long beamline is working with a multilayer monochromator with 0.36% bandpass in the energy range 20-70 keV. A bent Laue-Laue monochromator with adjustable bandpass over the energy range 50 to 150 keV will be installed during spring 2016. The installation of a new small gap and short period undulator, U14, and a new instrument with extended nanofocusing capabilities at high photon energies is scheduled later in 2016.

These improvements together with better detectors and sample environments constitute a revolutionary enhancement in performance for an ever increasing community of users from academia and industry. The highlights from ESRF and CRG beamlines selected for 2015 demonstrate how synchrotron X-ray characterisation techniques have been applied for the study of both real devices under operating conditions and idealised model systems under precisely controlled environments.

V. Honkimäki
 

References

[1] H.L. Xiao et al., Calibration of gamma-ray burst polarimeter POLAR, arXiv:1512.02784v1 [astro-ph.IM] 9 Dec 2015.
[2] M. Bedel et al., Characterization of dendrite morphologies in rapidly solidified Al–4.5 wt.%Cu droplets, Acta Materialia 89, 234–246 (2015).
[3] T.M. Smith et al., Dental ontogeny in pliocene and early pleistocene hominins, PLoS ONE 10(2): e0118118 (2015).