Behaviour of simplified nuclear waste glasses under gold ions implantation: A microluminescence study

Simplified nuclear borosilicate glasses doped with rare-earth elements were irradiated by gold ions. Thanks to fluorescence line narrowing spectroscopy (selective excitated photoluminescence), two major Eu3+ sites distributions were identified in the case of pre-irradiated samples due to the splitting of the 5D0 → 7F1 transition triplet. Evolution of europium ion environments under irradiation in these glasses was studied by non-selective microluminescence at room temperature. As well, spectroscopic studies demonstrated strong broadening in the distribution of the rare-earth environment for increasing irradiation doses. Determination of the luminescence asymmetric ratio allowed us to conclude that the symmetry of the sites is lowered by high energy nuclear deposits. Environment modifications under irradiation are attributed to a site distribution enlargement within the same two site distributions, a silicate and a borate one, and to lower symmetry mean sites.