Dislocation loop and tangle evolution of peak damage region in tungsten irradiated by heavy ion and deuterium plasma

Transmission electron microscope is widely used to investigate the defects induced by heavy ion irradiation and deuterium plasma exposure in tungsten, however, results differ greatly between in situ and near-bulk irradiation experiments. Here we adopt the back-thinned electropolishing and re-electropolishing method to study the microstructure in the peak damage region of heavy ion damaged tungsten. Transition from dislocation loops to complex dislocation tangles with increasing damage level is observed, and dislocation tangle decomposition and deuterium bubble formation under high-flux deuterium plasma exposure are also revealed. The results presented in this paper provide useful information for further investigation on irradiation defect evolution and the synergetic effect of displacement damage and deuterium behavior in W.