Alpha Decays Impact on Nuclear Glass Structure

International audienceThis paper reviews the main results on the long-term behavior of SON68 nuclear glass towards alpha decay accumulation. The effects of the radiation damage induced by alpha decay were investigated by doping a glass with a short-lived actinide $^{244}$Cm, by using ionic irradiations and by molecular dynamic simulations. The analysis of the behavior of the glass structure subjected to ballistic effects with various spectroscopic studies has identified some local order changes around born and silicon atoms. Moreover a modification of the medium-range order has also been demonstrated through changes in the bond angles between network formers and broadening of the ring size distributions, indicating increasing disorder of the glass structure. This structural evolution induced by alpha decays would be driven by the reconstruction of the glass disorganized by displacement cascades of the recoil nuclei, freezing a glass structure with a higher fictive temperature. This “ballistic disordering (BD) fast quenching” event induce a new glassy state characterized by a higher enthalpy state