Fifteen Years of Radionuclide Research at the KIT Synchrotron Source in the Context of the Nuclear Waste Disposal Safety Case

Abstract

For more than 120 years, systematic studies of X-ray interaction with matter have been the basis for our understanding of materials—both of natural or man-made origin—and their structure-function relationships. Beginning with simple radiographic imaging at the end of the 19th century, X-ray based analytical tools such as X-ray diffraction, X-ray fluorescence and photoemission or X-ray absorption techniques are indispensable in almost any field of chemical and material sciences—including basic and applied actinide and radionuclide studies. The advent of dedicated synchrotron radiation (SR) sources in the second half of the last century has revolutionized the analytical power of X-ray probes, while—with increasing number of SR facilities—beamline instrumentation followed a trend towards increasing specialization and adaption to a major research topic. The INE-Beamline and ACT station at the KIT synchrotron source belong to the exclusive club of a few synchrotron beamline facilities—mostly located in Europe—dedicated to the investigation of highly radioactive materials. Since commissioning of the INE-Beamline in 2005, capabilities for synchrotron-based radionuclide and actinide sciences at KIT have been continuously expanded, driven by in-house research programs and external user needs.

Insight into the structure–property relationship of UO2nanoparticles

“…Thanks to its high sensitivity, it can easily detect even the tiniest oxidation state impurities, which are present in many uranium oxides (U 4 O 9, U 3 O 8 , U 3 O 7 ). 9,10,46,[66][67][68][69] The HERFD method at the An M 4 edge probes An 3d-5f electronic transitions and is thus highly effective for the detection of the 5f electron configuration and for oxidation state identification. 9,10,39,40,46,66 Moreover, the shapes of the recorded data on various mixed uranium oxides are so distinct 66,67 that recorded HERFD spectra on uranium systems can be straightforwardly analyzed by a fingerprint approach to detect the presence of U 4 O 9 /U 3 O 8 impurities in UO 2 NPs.…”

“…The HERFD spectra at the U M 4 edge were collected at the CAT-ACT beamline of the KARA (Karlsruhe research accelerator) facility in Karlsruhe, Germany. 46 The incident energy was selected using the [111] reflection from a double Si crystal monochromator. Estimated flux at the sample position was in the order of 10 9 ph/sec at an incident energy of 3.8 keV.…”

Understanding the local structure of Eu3+- and Y3+-stabilized zirconia: insights from luminescence and X-ray absorption spectroscopic investigations

“…The pellets were placed in a polyethylene confinement for the EXAFS measurements. The measurements were performed at the INE-Beamline [73,74] at the KIT synchrotron source, Karlsruhe, Germany, at the Zr-K-and Y-K-edge at room temperature in transmission mode. The storage ring operating conditions were 2.5 GeV and 80-120 mA.…”

Signatures of technetium oxidation states: a new approach

“…The Tc L3 edge XANES spectra were recorded at the INE-Beamline of the KARA (Karlsruhe research accelerator) facility in Karlsruhe, Germany. 24 This bending magnet beamline operates with a collimating first mirror and a toroidal refocusing second mirror, both Rh-coated to reduce higher harmonics and to condense the photon flux at the sample position, and a fixed-exit double crystal monochromator. 25 An energy range from 2635 eV to 2823 eV was scanned using Si(111) crystals with a varying step size down to 0.1 eV in the edge region.…”