ROBL-II at ESRF: a synchrotron toolbox for actinide research

Abstract

ROBL-II provides four different experimental stations to investigate actinide and other alpha- and beta-emitting radionuclides at the new EBS storage ring of ESRF within an energy range of 3 to 35 keV. The XAFS station consists of a highly automatized, high sample throughput installation in a glovebox, to measure EXAFS and conventional XANES of samples routinely at temperatures down to 10 K, and with a detection limit in the sub-p.p.m. range. The XES station with its five bent-crystal analyzer, Johann-type setup with Rowland circles of 1.0 and 0.5 m radii provides high-energy resolution fluorescence detection (HERFD) for XANES, XES, and RIXS measurements, covering both actinide L and M edges together with other elements accessible in the 3 to 20 keV energy range. The six-circle heavy duty goniometer of XRD-1 is equipped for both high-resolution powder diffraction as well as surface-sensitive CTR and RAXR techniques. Single crystal diffraction, powder diffraction with high temporal resolution, as well as X-ray tomography experiments can be performed at a Pilatus 2M detector stage (XRD-2). Elaborate radioprotection features enable a safe and easy exchange of samples between the four different stations to allow the combination of several methods for an unprecedented level of information on radioactive samples for both fundamental and applied actinide and environmental research.

High-energy resolution X-ray spectroscopy at actinide M4,5 and ligand K edges: what we know, what we want to know, and what we can know

“…Fig. 2 shows a schematic drawing of the Johann-type point-focusing X-ray emission spectrometer 1,2 with five spherically bent crystal analyzers installed at the BM20 beamline 51 of ESRF. The spectrometer at the BM20 beamline can be operated with crystal analyzers with 0.5-m and 1-m bending radii 52 .…”

Application of multi-edge HERFD-XAS to assess the uranium valence electronic structure in potassium uranate (KUO3)

“…Uranium L 1 -and L 3 -edge XANES measurements were performed at BM20 (The Rossendorf Beamline) (Matz et al, 1999;Scheinost et al, 2021) of the European Synchrotron Radiation Facility (ESRF) operating at an electron beam energy of 6 GeV, in Grenoble, France. The incident energy was scanned using a Si(1 1 1) monochromator.…”

X-ray synchrotron radiation studies of actinide materials

“…The potential of XAS for elucidating the electronic structure of actinides was immediately recognized and a number of studies on actinide speciation in compounds and minerals followed (Silva & Nitsche, 1995;Conradson et al, 1998;Denecke, 2006). This body of experimental work stimulated the construction of dedicated beamlines, such as CAT-ACT at ANKA (Dardenne et al, 2009;Zimina et al, 2017) and ROBL-II at ESRF (Scheinost et al, 2021). Today, XAS experiments at state-ofthe-art spectrometers have been extended to the heaviest actinides available in macroscopic quantities, as recently demonstrated by a study of a coordination complex of 254 Es that used less than 200 ng of this highly radioactive isotope (half-life of $ 275.7 days) (Carter et al, 2021).…”