Nanostructure formation on tungsten exposed to low-pressure rf helium plasmas: A study of ion energy threshold and early stage growth

被引：91

作者：

Baldwin, M. J. ^{[1
]}

Lynch, T. C. ^{[1
]}

Doerner, R. P. ^{[1
]}

Yu, J. H. ^{[1
]}

机构：

[1] UCSD, Energy Res Ctr, La Jolla, CA 92093 USA

来源：

JOURNAL OF NUCLEAR MATERIALS | 2011年 / 415卷 / 01期

关键词：

SURFACE;

D O I：

10.1016/j.jnucmat.2010.10.050

中图分类号：

T [工业技术];

学科分类号：

120111 [工业工程];

摘要：

Nanostructure formation on W targets is explored as a function of He+ impact energy, epsilon(i), in the range 20 <= epsilon(i) <= 57 eV. Six targets are exposed at 1120 K for 6 h to pure He plasmas, generated by a low-pressure rf Helicon source. One target is additionally exposed to Ar plasma pre-treatment. It is found that He ions of impact energy 32-37 eV are necessary for nanostructure formation to be observed in this type of plasma, as determined by SEM. At 57 eV a nanostructured surface forms readily (similar to that observed by Baldwin and Doerner, Nuclear Fusion 48 (2008) 035001 in the PISCES-B device), but growth is retarded in the Ar pre-treatment case. Thermal desorption shows that nanostructuring is accompanied by increased trapping of He in degenerate vacancies and clusters, but is reduced by a factor of 8 as a result of Ar pre-treatment. (C) 2010 Elsevier B.V. All rights reserved.

引用

页码：S104 / S107

页数：4

共 15 条

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Helium induced nanoscopic morphology on tungsten under fusion relevant plasma conditions [J].