Effect of Electron-Ion Coupling on Radiation Damage Simulations of a Pyrochlore Waste Form.

Greathouse, J. A. ; Croziere, P. S. ; Ismail, A. E. ; Foiles, S. M.

Technical Information Center Oak Ridge Tennessee

关键词: Electron-ion coupling;    Pyrochlore;    Waste forms;    Atoms;    Defects;   

RP-ID  :  DE2010974414

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

We have performed molecular dynamics simulations of cascade damage in the gadolinium pyrochlore Gd(sub 2)Zr(sub 2)O(sub 7), comparing results obtained from traditional methodologies that ignore the effect of electron-ion interactions with a 'two-temperature model' in which the electronic subsystem is modeled using a diffusion equation to determine the electronic temperature. We find that the electron-ion interaction friction coefficient (gamma)(sub p) is a significant parameter in determining the behavior of the system following the formation of the primary knock-on atom (here, a U(sup 3+) ion). The mean final U(sup 3+) displacement and the number of defect atoms formed is shown to decrease uniformly with increasing (gamma)(sub p); however, other properties, such as the final equilibrium temperature and the oxygen-oxygen radial distribution function show a more complicated dependence on (gamma)(sub p).