In 2017, imaging with nanobeams has seen an increase in the portfolio of techniques made available to users. This has been supplied both by an incremental improvement of existing techniques, making them more user-friendly to non-experts, and by the extension of available sample environments, allowing for new in situ or operando experiments. It can also be noted that important investments in new detectors and data handling strategies have had a positive impact on the acquisition rate and quality offered by the XNP beamlines.

On beamline ID01, a software tool for easy online data analysis of scanning diffraction data has been developed by the ESRF Data Analysis unit, allowing users to treat terabytes of data during their stay – and even during measurements – and to receive optimised feedback. This is of great utility in the perspective of higher data rates enabled by the implementation of a 2 Megapixel detector developed by the ESRF in collaboration with the PSI in Switzerland. It can record scanning data at several hundred Hz and will be able to follow acquisition rates of up to 10 kHz in the future. Furthermore, the last elements of the ID01 beamline upgrade were put into operation in 2017. A KB mirror setup, operational between 7 and 11 keV, as well as between 19 and 21 keV, supplies beams of 150 x 250 nm2 with photon fluxes of up to 1011 ph/s and an energy resolution between 10–4 and 3*10–3. Full field diffraction microscopy is now offered as a new technique on ID01, the first end-station offering this technique to users.  

To enable scanning micro-diffraction and  micro-SAXS/WAXS with energy variation at ID13, a sub-micron beam (150x300 nm2) produced by a fixed curvature KB mirror has been integrated into the beamline’s microbranch in collaboration with the ESRF Optics group (R. Barrett et al.). It serves as an alternative focusing optics to the existing Be-CRL transfocator. The system has already been used for several very successful user experiments, mostly investigating texture effects in biomineralised or bioinspired samples. In addition, this optics has been employed for promising first tests aiming at 3D SAXS tomography with micron resolution.

First successful tests of a nanobeam-compatible, in situ wedge-indentation sample environment have been performed in collaboration with Kubec, Keckes et al. (MI-1216 long-term proposal). This setup is designed to be used in transmission on thin hard condensed matter or polymer specimens. It is expected to be available for ID13 users in the second part of 2018. A second high-performance computer dedicated to online data analysis of large EIGER 4M data volumes is scheduled to be operational from the beginning of next year.

At the nanoimaging beamline ID16A, X-ray nanotomography is now routinely used in fluorescence, holography and ptychography mode, both at room temperature and under cryogenic conditions. All techniques exploit an intense nanofocus with a sub-13 nm size – the smallest worldwide – at a high energy of 33.6 keV. X-ray ptychography was sped up significantly at the level of acquisition and processing: software enhancements now provide optimal scanning paths and faster GPU-based reconstruction, while a GaAs pixel detector achieves lowest dose at high spatial resolution. Several studies combine the nanoimaging capabilities of the beamline with complementary techniques at other ESRF beamlines such as ID13, ID17 and ID19, or exploit correlative soft and hard X-ray microscopy. There is an increasing demand for cryo-imaging. A majority of the accepted proposals during the last round aims at imaging frozen-hydrated biological samples. This configuration has been optimised to avoid parasitic fluorescence background from the cryogenic environment. Finally, from next year on, cryo-correlative light and X-ray microscopy will complement the workflow.

The optimisation of beamline ID16B has been started in order to take full advantage of the future EBS. In this respect, a new seven-element XRF detector has recently been installed and tested, providing unprecedented count rate capabilities. Moreover, a new KB mirror system optimised for XAS measurements is ready to be implemented in the experimental set-up and will undoubtedly improve the beamline capabilities. In situ/operando experiments are now routinely performed at ID16B, involving most techniques available at the beamline (XRF, XRD, XEOL,XBIC, nanotomography) and many different sample environments such as high-pressure cells, furnaces, electrochemical cells, operando batteries, electrically connected nanowires, etc. After miniaturisation to fit with severe spatial constraints, more and more sophisticated environments (such as a tensile testing machine within a HT furnace) can be integrated to investigate complex dynamical phenomena by fast nanotomography.

At ID21, the refurbishment of the scanning X-ray microscope has started. The ultimate goal is to provide a smaller and more stable beam (~100 nm), over an extended energy range (2-11 keV), and faster XRF and XANES acquisitions. User friendliness and cryo-microscopy, which are important strengths at ID21, will be maintained and further developed. During a four-month shutdown (December 2017 – March 2018), the first two optics hutches will be almost emptied, and later re-equipped with new instruments, in particular a new pair of mirrors for harmonic rejection, new slits and beam viewers. Later in 2018, the first prototype of the new double crystal monochromator, specially designed for spectroscopy, will be installed and commissioned. As an unfortunate side-effect, the infrared end-station had to be definitively shut down, and the diffraction end-station will be temporarily unavailable until the refurbishment of the experiment hutch. However, some beam time will be preserved for user operation in 2018 on the scanning X-ray microscope.


T. Schülli