Interaction of nitrogen ions with beryllium surfaces

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

卷:340

Article; Proceedings Paper

Dobes, Katharina¹  Koeppen, Martin²  Oberkofler, Martin³  Lungu, Cristian P.⁴  Porosnicu, Corneliu⁴  Hoeschen, Till³  Meisl, Gerd³  Linsmeier, Christian²  Aumayr, Friedrich¹ 

[1] TU Wien, Assoc EURATOM OAW, Inst Appl Phys, Vienna, Austria

[2] Forschungszentrum Julich GmbH, Inst Energy & Climate Res Plasma Phys, D-52425 Julich, Germany

[3] Max Planck Inst Plasma Phys, D-85748 Garching, Germany

[4] Natl Inst Laser Plasma & Radiat Phys, Bucharest, Romania

关键词: Plasma wall interaction;    Sputtering;    Erosion;    Beryllium;   

DOI  :  10.1016/j.nimb.2014.06.025

来源: Elsevier

【 摘 要 】

The interaction of energetic nitrogen projectiles with a beryllium surface is studied using a highly sensitive quartz crystal microbalance technique. The overall mass change rate of the beryllium sample under N-2(+) ion impact at an ion energy of 5000 eV (i.e. 2500 eV per N) is investigated in situ and in real-time. A strong dependency of the observed mass change rate on the nitrogen fluence (at constant flux) is found and can be attributed to the formation of a nitrogen-containing mixed material layer within the ion penetration depth. The presented data elucidate the dynamics of the interaction process and the surface saturation with increasing nitrogen fluence in a unique way. Basically, distinct interaction regimes can be discriminated, which can be linked to the evolution of the surface composition upon nitrogen impact. Steady state surface conditions are obtained at a total cumulative nitrogen fluence of similar to 80 x 10(16) N atoms per cm(2). In dynamic equilibrium, the interaction is marked by continuous surface erosion. In this case, the observed total sputtering yield becomes independent from the applied nitrogen fluence and is of the order of 0.4 beryllium atoms per impinging nitrogen atom. (C) 2014 Elsevier B.V. All rights reserved.

【 授权许可】

Free