Dynamics of small mobile helium clusters near tungsten surfaces

被引：75

作者：

Hu, Lin ^{[1
]}

Hammond, Karl D. ^{[2
]}

Wirth, Brian D. ^{[2
]}

Maroudas, Dimitrios ^{[1
]}

机构：

[1] Univ Massachusetts, Dept Chem Engn, Amherst, MA 01003 USA

[2] Univ Tennessee, Dept Nucl Engn, Knoxville, TN 37996 USA

来源：

SURFACE SCIENCE | 2014年 / 626卷

关键词：

Plasma-exposed tungsten; Mobile helium clusters; Surface segregation; Diffusion; Surface structure and morphology; Molecular dynamics simulations; ELASTIC BAND METHOD; ENERGY;

D O I：

10.1016/j.susc.2014.03.020

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070305 [高分子化学与物理];

摘要：

We report the results of a systematic atomic-scale analysis of the dynamics of small mobile helium clusters in tungsten, near tungsten surfaces. These helium clusters are attracted to tungsten surfaces due to an elastic interaction force that drives surface segregation. As the clusters migrate toward the surface, trap mutation and cluster dissociation are activated at rates higher than in the bulk. These kinetic processes are responsible for important structural, morphological, and compositional features in plasma-exposed tungsten, including surface adatoms, near-surface immobile helium-vacancy complexes, and retained helium content. Detailed results are presented for di-helium and tri-helium clusters near low-Miller-index tungsten surfaces. (C) 2014 Elsevier B.V. All rights reserved.

引用

页码：21 / 25

页数：5

共 28 条

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