Effect of ballistic damage in UO$_2$ samples under ion beam irradiations studied by in situ Raman spectroscopy

G. Gutierrez (1) , Claire Onofri (1) , S. Miro (1) , M. Bricout (1) , F. Leprêtre (1)

1 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)

The damage induced in uranium dioxide (UO$_2$) during ion irradiation at low energy was studied by micro-Raman spectroscopy. Polycrystalline UO$_2$ samples were irradiated by 0.9-MeV I, 2-MeV Au at 25DC and by 4-MeV Kr ions at -160DC in a wide range of fluence. In situ Raman measurements reveal similar spectra evolution no matter the ion beam used. The T$_{2g}$ band centred at 445 cm$^{-1}$ related to the fluorine structure reveals a broadening with the irradiation damage increase. In addition, several bands ranging from 500 to 700 cm$^{-1}$, which are attributed to sub- or sur-stoichiometric structural defects, are observed at the first time of irradiation. Their intensities rise up with the irradiation fluence increase to a similar asymptotic relative values for all the irradiation conditions. The obtained Raman kinetics are compared with data from the literature on the microstructure evolution observed by Transmission Electronic Microscopy (TEM) and on the fraction of displaced atoms determined by Rutherford Backscattering Spectroscopy in channelling mode (RBS-C).

Mots clés: Raman spectroscopy UO2 radiation damage

Domaines: Physique Nucléaire Expérimentale [nucl-ex]; Physique Nucléaire Théorique [nucl-th]

G. Gutierrez, Claire Onofri, S. Miro, M. Bricout, F. Leprêtre. Effect of ballistic damage in UO$_2$ samples under ion beam irradiations studied by in situ Raman spectroscopy. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2018, 434, pp.45-50. ⟨10.1016/j.nimb.2018.08.010⟩. ⟨cea-02339665⟩