[SY-B8] In-situ TEM of Formation Processes of Defects in Tungsten under Irradiation: Comparison between Electron and Self-ion Irradiations
Invited
Nuclear-fission and fusion materials are degraded primarily due to the accumulation of radiation-produced lattice defects, such as point defects (self-interstitial-atoms (SIAs) and vacancies) and point-defect clusters (dislocation loops and cavities). In order to precisely predict the lifetimes of nuclear materials, accurate understanding of the origins of the defect accumulation—generation of defects and their subsequent dynamics—is crucial.
In-situ transmission electron microscopy (TEM) is a powerful technique for probing defect dynamics, in response to external stimuli such as irradiation under heating or cooling. As the irradiation sources for the in-situ TEM, electrons and ions are available. In the electron irradiation, only point defects are generated as the primary damage via knock-on displacement. In contrast, in the ion irradiation, point-defect clusters are also generated as the primary damage, which is called “collision cascade”, like neutron irradiation.
In this presentation, we focus on the formation process of dislocation loops in tungsten under irradiation. Firstly we show our results on dynamic properties of SIAs [1] and SIA dislocation loops, which have been mainly obtained with high-voltage electron microscopes in Osaka University and Nagoya University in Japan. And, we provide our results on the formation processes of dislocation loops under self-ion irradiation, which have been obtained with an ion-accelerators combined microscope in the JANNuS-Orsay facility in France. Through the comparison between these results, we try to extract the effects of collision cascade on the formation processes of dislocation loops.
References
[1] T. Amino, K. Arakawa, and H. Mori, Scientific Reports 6 (2016) 26099.
In-situ transmission electron microscopy (TEM) is a powerful technique for probing defect dynamics, in response to external stimuli such as irradiation under heating or cooling. As the irradiation sources for the in-situ TEM, electrons and ions are available. In the electron irradiation, only point defects are generated as the primary damage via knock-on displacement. In contrast, in the ion irradiation, point-defect clusters are also generated as the primary damage, which is called “collision cascade”, like neutron irradiation.
In this presentation, we focus on the formation process of dislocation loops in tungsten under irradiation. Firstly we show our results on dynamic properties of SIAs [1] and SIA dislocation loops, which have been mainly obtained with high-voltage electron microscopes in Osaka University and Nagoya University in Japan. And, we provide our results on the formation processes of dislocation loops under self-ion irradiation, which have been obtained with an ion-accelerators combined microscope in the JANNuS-Orsay facility in France. Through the comparison between these results, we try to extract the effects of collision cascade on the formation processes of dislocation loops.
References
[1] T. Amino, K. Arakawa, and H. Mori, Scientific Reports 6 (2016) 26099.