An improved model for the prediction of He bubbles driven W fuzz growth at different temperatures

Abstract

Based on our previous study (J. Nucl. Mater. 550 (2021) 152917), an improved model used to predict the W fuzz growth over W targets is presented by considering the complex physical processes, which are involved in He+ collisions in W fuzz layers, the growth of He bubbles in W bulk and W nanofibers, surface sputtering of W fuzz layers, and the tensile-stress driven cracking and instability of W nanofibers. By this model, we have modelled the He bubbles driven W fuzz growth over W targets at the temperatures of 1100 - 1830 K, which are consistent with the experimental measurements. Our study shows that the temperature is a very crucial parameter affecting W fuzz growth, and the temperature of 1400 - 1515 K significantly contributes to the W fuzz growth over W targets. An increase in temperature can contribute to the rapid growth of He bubbles, increase their radius, and decrease their density and the stability of W nanofibers, thus affecting the W fuzz growth.