• 文献标题:   The role of radiative de-excitation in the neutralization process of highly charged ions interacting with a single layer of graphene
  • 文献类型:   Article
  • 作  者:   SCHWESTKA J, WILHELM RA, GRUBER E, HELLER R, KOZUBEK R, SCHLEBERGER M, FACSKO S, AUMAYR F
  • 作者关键词:   slow highly charged ion, graphene, xray emission
  • 出版物名称:   NUCLEAR INSTRUMENTS METHODS IN PHYSICS RESEARCH SECTION BBEAM INTERACTIONS WITH MATERIALS ATOMS
  • ISSN:   0168-583X EI 1872-9584
  • 通讯作者地址:   TU Wien
  • 被引频次:   2
  • DOI:   10.1016/j.nimb.2018.02.022
  • 出版年:   2018

▎ 摘  要

X-ray emission of slow (< 1 a.u.) highly charged Argon and Xenon ions is measured for transmission through a freestanding single layer of graphene. To discriminate against X-ray emission originating from the graphene's support grid a coincidence technique is used. X-ray emission of 75 keV Ar17+ and Ar18+ ions with either one or two K-shell vacancies is recorded. Using a windowless Bruker XFlash detector allows us to measure additionally Ar KLL and KLM Auger electrons and determine the branching ratio of radiative vs. non-radiative decay of Ar K-shell holes. Furthermore, X-ray spectra for 100 keV Xe22+-Xe35+ ions are compared, showing a broad M-line peak for all cases, where M-shell vacancies are present. All these peaks are accompanied by emission lines at still higher energies indicating the presence of a hollow atom during X-ray decay. We report a linear shift of the main M-line peak to higher energies for increasing incident charge state, i.e. increasing number of M-shell holes.