中文摘要：

本文利用慢正电子束分析（SPBA）和透射电子显微镜（TEM）方法研究了钛膜内He相关缺陷的演化．实验结果表明：室温下，钛膜中的He主要形成均匀的小He泡．随着He浓度的增大，He泡的密度相应地增加．在973K高温退火后，在含高浓度He的钛膜样品中观测到大He泡的出现．实验结果表明迁移合并和较大He泡周围的级联融合共同作用导致了大He泡的形成．

英文摘要：

In this paper, the evolution of the He-related defects in the titanium film is experimentally investigated by combining slow positron beam analysis （SPBA） and transmission electron microscope （TEM） technique. The results indicate that small bubbles in the titanium film distribute uniformly at room temperature. With the increment of He concentration, the density of He bubbles in the sample increases correspondingly. Large bubbles are observed in the titanium film containing high He concentration after 973 K high temperature annealing, and it is found that both migration-coalescence and cascade-coalescence around the bigger He bubbles lead to the rapid growth of He bubbles.