Characterizations with the MARS beamline (synchrotron SOLEIL) of materials irradiated in nuclear reactors

Abstract

International audienceMARS (Multi-Analyses on Radioactive Samples) is the X-ray bending magnet beamline of the French synchrotron facility SOLEIL dedicated to the study of radioactive matter. The MARS beamline aims at extending the possibilities of synchrotron based X-ray characterizations towards a wider variety of radioactive elements (et61537;et61484;et61472;et61538;et61484;et61472;et61543; and n emitters). Thus, its specific and innovative infrastructure has been optimized to carry out analyses on radioactive materials with activities up to 18.5 GBq per sample. This beamline, which has been built thanks to a close partnership and support by the CEA, has been designed to provide X-rays in the energy range of 3.5 keV to 35 keV. Three main techniques are progressively proposed on MARS beamline transmission and high-resolution powder X-ray diffraction (respectively T-XRD and HR-XRD), X-ray absorption spectroscopy (XAS) and X-ray fluorescence (XRF).After the preliminary experiences performed on un-irradiated samples, this presentation deals with recent results obtained on the MARS beamline, thanks to very powerful and useful improvements brought to the experimental set-up of the beamline and to various materials irradiated in nuclear reactors Oxide dispersion-strengthened (ODS) steels at high doses and also Zr based alloys irradiated in Pressurized Water Reactors up to 7 PWR cycles.Results concerning secondary phases evolutions as a function of irradiation doses for both ODS and Zr based alloys will be presented using XRD, but also experiences using XAS especially on ODS will be given.Finally, future prospects and main objectives concerning the evolution of the beamline and studies on irradiated materials will be discussed