A molecular dynamics study of diamond exposed to tritium bombardment for fusion applications

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

卷:269

Article; Proceedings Paper

Dunn, A. R.¹  Duffy, D. M.¹  Stoneham, A. M.¹ 

[1] UCL, London Ctr Nanotechnol, London WC1H 0AH, England

关键词: Diamond;    Tritium;    Fusion;    Divertor;    Plasma facing material;    High flux;   

DOI  :  10.1016/j.nimb.2010.12.009

来源: Elsevier

【 摘 要 】

Diamond, with its low atomic number and high thermal conductivity, is being assessed as a possible plasma facing material within a fusion reactor. Molecular dynamics simulations using the AIREBO potential were performed simulating the exposure of diamond to a plasma in conditions similar to those of the divertor region of a tokamak. Diamond surfaces at temperatures of 300 and 600 K were bombarded with 15 eV tritium at a high flux (10(29) ions m(-2) s(-1)). A layer-by-layer etching process was observed which, with the lack of any tritium diffusion though the remaining diamond structure, was responsible for limiting damage, and thus tritium retention, to the top 4-5 diamond layers. Analysis of this damaged region also showed a large amount of residual structure suggesting that bombardment below the physical sputtering threshold (similar to 30 eV) may not lead to amorphisation of the surface. (C) 2010 Elsevier B.V. All rights reserved.

【 授权许可】

Free