Estimation of the lifetime of small helium bubbles near tungsten surfaces - A methodological study

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:383

Article

Cui, Jiechao¹  Wu, Zhangwen¹  Hou, Qing¹ 

[1] Sichuan Univ, Inst Nucl Sci & Technol, Key Lab Radiat Phys & Technol, Chengdu 610064, Peoples R China

关键词: Molecular dynamics;    Helium bubble;    Lifetime;    Plasma material interaction;    Multiscale simulations;   

DOI  :  10.1016/j.nimb.2016.07.001

来源: Elsevier

【 摘 要 】

Under low energy and high flux/fluence irradiation of helium (He) atoms, the formation and bursting of He bubbles on tungsten (W) surfaces play important roles in the morphological evolution of component surfaces in fusion reactors. Microscopically, the bursting of He bubbles is a stochastic process, and He bubbles have statistically average lifetimes. In the present paper, a molecular dynamics-based method was developed to extract, for the first time, the lifetime of He bubbles near tungsten surfaces. It was found that He bubble bursting can be treated as an activated event. Its frequency or, equivalently, the average lifetime of bubbles follows the Arrhenius equation. For a given bubble size, the activation energy exhibits a good linear dependence with the depth, and the pre-exponential factor obeys the Meyer Neldle rule. These results are useful for establishing a model in multi-scale simulations of the morphological evolution of component surfaces in fusion reactors. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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