Effect of dose rate on dislocation loop evolution in tungsten: Combination of defect generation rate and elastic interaction

Ion irradiation is often used to simulate neutron irradiation in reactor components, while the dose rate discrepancy makes it difficult to directly compare ion irradiation with neutron irradiation. A better understanding of dose rate effect is thus necessary to emulate neutron irradiation effect with ions. Here, based on in-situ 30 keV He+ irradiation in tungsten in TEM, we find that defect generation rate and elastic interaction are two key factors controlling dislocation loop evolution at different dose rates. By adjusting defect generation rate, the elastic interaction between the loops will play different roles. Finally, a schematical illustration is given to explain the different in loop density, size and spatial distribution caused by the combination of these two factors. Our results provide the underlying insights for understanding the dose rate effects of energetic ion irradiation.