Indexed by:期刊论文

Date of Publication:2020-10-01

Journal:JOURNAL OF NUCLEAR MATERIALS

Included Journals:SCIE

Volume:539

ISSN No.:0022-3115

Key Words:Ion irradiations; W fuzz; D retention; Plasma-facing material

Abstract:The retention of hydrogen isotopes in W is one of the main limiting factors affecting the design and development of next-step fusion reactors, such as the international thermonuclear experimental reactor (ITER). Here, we report on D retention behavior under the steady-state He/D ion irradiations of polycrystalline W. We find that the D retention behavior in the W bulk is completely suppressed by the growth of high surface-to-volume W fuzz layer (1.1-4.0 mm thick) over the surface. Our analyses show that due to their frequent collisions in the W fuzz layer, the dose of D ions greatly decreases when they collide into the W bulk beneath the fuzz layer. The W fuzz layer with a high surface-to-volume ratio becomes an effective shield against the ion driven diffusion processes. (C) 2020 Elsevier B.V. All rights reserved.