Mechanisms of helium nanobubble growth and defect interactions in irradiated copper: A molecular dynamics study

•For all values of bubble diameter and He/V<2, no defects nucleate around the nanobubbles within the irradiated copper for releasing the internal pressure of nanobubbles.•Punching-out of dislocation loops is observed only for D≥6nm and 2.5≤He/V ratio≤3.5, and Trainkaus equation is able to predict the critical pressure of punching-out of dislocation loop independent of the loop size.•Our developed EOS is able to predict the bubble pressure from the input bubble size, He/V ratio, and temperature.•Crystallization of the nanobubbles upon formation within the irradiate copper is only observed for D=2nm.