The thermal conductivity of plasma-facing materials(PFM)exposed to intense radiation is a critical concern for the reliable usage of materials in fusion reactors.However,limited research has been performed regarding t...The thermal conductivity of plasma-facing materials(PFM)exposed to intense radiation is a critical concern for the reliable usage of materials in fusion reactors.However,limited research has been performed regarding the thermal conductivity of structures that rapidly change in a short time during collision cascade processes under irradiation.In this study,we employed the tight-binding(TB)method to investigate the electronic thermal conductivity(κ_(e))of tungsten-based systems during various cascading processes.We found thatκ_(e) values sharply decrease within the initial 0.3 picoseconds and then partially recover at a slow pace;this is closely linked to the evolution of defects and microstructural distortions.The increase in the initial kinetic energy of the primary knock-on atom and the presence of a high concentration of hydrogen atoms further decrease theκ_(e) values.Conversely,higher temperatures have a significant positive effect onκ_(e).Furthermore,the presence of a grain boundary∑5[001](130)substantially reducesκ_(e),whereas the absorption effect of point defects by the grain boundary has little influence onκ_(e) during cascades.Our findings provide a theoretical basis for evaluating changes in the thermal conductivity performance of PFMs during their usage in nuclear fusion reactors.展开更多
基金supported by the Collaborative Innovation Program of Hefei Science Center of CAS(No.2022HSC-CIP007)。
文摘The thermal conductivity of plasma-facing materials(PFM)exposed to intense radiation is a critical concern for the reliable usage of materials in fusion reactors.However,limited research has been performed regarding the thermal conductivity of structures that rapidly change in a short time during collision cascade processes under irradiation.In this study,we employed the tight-binding(TB)method to investigate the electronic thermal conductivity(κ_(e))of tungsten-based systems during various cascading processes.We found thatκ_(e) values sharply decrease within the initial 0.3 picoseconds and then partially recover at a slow pace;this is closely linked to the evolution of defects and microstructural distortions.The increase in the initial kinetic energy of the primary knock-on atom and the presence of a high concentration of hydrogen atoms further decrease theκ_(e) values.Conversely,higher temperatures have a significant positive effect onκ_(e).Furthermore,the presence of a grain boundary∑5[001](130)substantially reducesκ_(e),whereas the absorption effect of point defects by the grain boundary has little influence onκ_(e) during cascades.Our findings provide a theoretical basis for evaluating changes in the thermal conductivity performance of PFMs during their usage in nuclear fusion reactors.
