Systematic analysis of different experimental approaches to measure electronic stopping of very slow hydrogen ions

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

卷:437

Article

Roth, D.¹  Celedon, C. E.^1,2,3,4  Goebl, D.¹  Sanchez, E. A.^2,3  Bruckner, B.¹  Steinberger, R.⁵  Guimpel, J.^2,3  Arista, N. R.^2,3  Bauer, P.¹ 

[1] Johannes Kepler Univ Linz, IEP AOP, Altenbergerstr 69, A-4040 Linz, Austria

[2] Ctr Atom Bariloche, San Carlos De Bariloche, Rio Negro, Argentina

[3] Inst Balseiro, San Carlos De Bariloche, Rio Negro, Argentina

[4] UTFSM, Dept Fis, Lab Colisiones Atom, Valparaiso, Chile

[5] Johannes Kepler Univ Linz, Zentrum Oberflachen & Nanoanalyt ZONA, Christian Doppler Lab Microscop & Spect Mat Chara, Altenbergerstr 69, A-4040 Linz, Austria

关键词: LEIS;    Electronic stopping;    Protons;    Nickel;    Transmission;    Backscattering;   

DOI  :  10.1016/j.nimb.2018.09.028

来源: Elsevier

【 摘 要 】

The electronic stopping cross section (SCS) of Ni for slow H+, H-2(+), D+ and D-2(+) ions has been investigated for different types of targets in two complementary experimental geometries, i.e., in transmission and back-scattering. To warrant sample purity, both a high purity nickel sheet and nanometer Ni layers were prepared in situ under ultra-high-vacuum conditions. In an alternative approach, ultra-thin samples were prepared ex-situ as self-supporting foils and as nanometer films on a polished substrate (silicon). Identical SCS results are obtained in backscattering using the in-situ prepared film and the high purity sheet. The ex-situ prepared targets contained considerable concentrations of impurities of low atomic numbers, whose contribution to the SCS can be rectified by applying Bragg's rule using TRIM stopping for the impurities. In this way for the ex-situ targets the accuracy of the resulting SCS data is improved considerably. Concordant stopping cross section data are obtained in both geometries. The achieved accuracy does, however, not permit to spot a possible influence of different impact parameter regimes explored in transmission and in backscattering geometries.

【 授权许可】

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