Helium bubble formation in nuclear glass by in-situ TEM ion implantation

The effect of helium implantation fluences on He bubble nucleation and growth mechanisms in nuclear borosilicate glass has been characterized using in-situ transmission electron microscopy experiments. Observations of implanted glass at 143 K indicate that a helium concentration of around 3 at.% is required to nucleate a significant density of nanosized bubbles. He bubble growth is observed for concentration higher than the number of host sites (>4 at.%). These results highlight the large capacity of the glassy network for incorporating helium atoms.