期刊
SURFACE SCIENCE
卷 678, 期 -, 页码 65-71出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.susc.2018.04.019
关键词
Quasi-elastic helium atom scattering; Qhas; Diffusion; Helium spin-echo; Wavepacket propagation
资金
- EPSRC [EP/E004962/1]
- Royal Society University Research Fellowship [UF090026]
- EPSRC [EP/E004962/1] Funding Source: UKRI
- Royal Society [UF090026] Funding Source: Royal Society
We use 2-D wavepacket calculations to examine the scattering of helium atoms from dynamic assemblies of surface adsorbates, and in particular to explore the validity of the widely used kinematic scattering approximation. The wavepacket calculations give exact results for quasi-elastic scattering that are closely analogous to time-of-flight (TOF) experiments and they are analysed as such. A scattering potential is chosen to represent 8 meV helium atoms scattering from sodium atoms adsorbed on a Cu(001) surface and the adsorbates in the model move according to an independent Langevin equation. The energy broadening in the quasi-elastic scattering is obtained as a function of parallel momentum transfer and compared with the corresponding results using the kinematic scattering approximation. Under most circumstances the kinematic approximation and the more accurate wavepacket method are in good agreement; however, there are cases where the two methods give different results. We relate these differences to pathological features in the scattering form-factor.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据