58 ESRF

2020 was truly an exceptional year with the inauguration of the Extremely Brilliant Source (EBS) on one hand, and the COVID-19 pandemic on the other. The pandemic triggered reflections about new access modes for beam-time and the importance of automating simple tasks like sample- exchange and alignment. By the end of 2020, most beamlines were equipped with software and hardware allowing users to control experiments remotely with beamline staff. Three new Eiger2 detectors were installed on ID02, ID10 and ID17 with Si or CdTe sensors. The increase in beam intensity and the higher acquisition speed from the fast detectors are producing a tremendous amount of data and work on real-time data analysis is in progress.

The small-angle scattering beamline ID02 came online soon after the beam was delivered for experiments. Prior to the restart, the installation and software integration of the new Eiger2 4M SAXS/USAXS detector were completed. Using the new LIMA server, the detector can acquire up to 1000 frames/sec with 8 bit data. The data- reduction pipeline, DAHU, is now debugged and able to produce azimuthally averaged data almost on the fly during fast time-resolved measurements. X-ray photon correlation spectroscopy (XPCS) is also working well with 20 times more flux and with the fast Eiger-500k detector taking up to 22 000 frames/sec. Despite the restrictions, a large number of remote user experiments and industrial mail-in services were carried out. During the year, many high- quality publications came from experiments performed prior to the shutdown. To further improve the coherence, a refurbishment of the monochromator is foreseen during the winter shutdown.

ID09, the time-resolved beamline, received new high-power slits and attenuators that are adapted to the very hot EBS beam. The two heat-load choppers, which are essential for isolating single X-ray pulses from the white beam, underwent major upgrades with improved monitoring of the water flow, disc temperature, air pressure, humidity, etc. The air pressure in the air bearings of the PIC chopper was increased to 8 bar to prevent leaks into the bearing from the water cooling of the rotor. A new high-speed chopper from KFA Jülich was installed and tested in December, allowing to increase the frequency

of pump-probe experiments to 3 kHz, whereby the beam intensity is tripled (ph/s). The Von Hamos spectrometer received 16 new analysers, which will double the count rate in X-ray emission experiments. On the theory side, the intensity of emission lines, stimulated off-resonance by the pink undulator beam, can now be predicted very precisely, which makes it easier to optimise the experimental parameters. Examples of time- resolved scattering work from ID09 can be found in articles on pages 63 and 73.

The soft interfaces and coherent scattering beamline ID10 is now fully operational on the new EBS source. The new source provides significantly higher coherent flux and reduction in the horizontal beam size. Many experiments were performed in mail-in and remote-control user mode with assistance from staff. The beamline operates with the new beamline control software BLISS. The new Eiger 4M detector with a CdTe sensor is now available on both end-stations. It is used for coherent X-ray diffraction imaging (CXDI), XPCS and surface scattering (GISAXS, GIWAXS, GID). This detector is an enormous benefit for the exploitation of the increased EBS brilliance, especially at higher energies. The surface scattering user community will now get access to a reactor for CVD growth of 2D nanomaterials on liquid metal catalysts. The reactor, built in the context of the European project LMCat: 2020-FETOPEN, is currently used by staff for in-situ growth and characterisation of graphene on molten copper. Two examples of studies with the XPCS technique are shown in articles on pages 64 and 66.

The biomedical beamline ID17 is almost fully back in operation and has welcomed users, mostly via remote access. In terms of upgrades, the new Eiger2 CdTe 1M detector for monochromatic CT imaging was delivered and successfully commissioned, as well as a single Laue crystal that reduces the focal spot size on the sample by almost one order of magnitude. The Biomedical Facility opened its doors again and the L1 and L2 confinement biology labs underwent a major upgrade in terms of equipment and capacity. As in previous years, the main body of publications resulting from work on ID17 were in the field of biomedical imaging and X-ray radiotherapy. This year s highlights comprise a study on combining synchrotron microbeam radiation therapy with conventional X-ray therapy fractionated in time (page 67) and the high-

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