Core-level electron spectroscopy on the sodium dimer Na2plevel

Abstract

The lifetime broadening and molecular field splitting of the sodium dimer $2p$ core level is studied by x-ray photoelectron spectroscopy and by Auger electron spectroscopy. The lifetime of the Na $2p$ core hole has been determined to be $15\ifmmode\pm\else\textpm\fi{}8\phantom{\rule{0.3em}{0ex}}\mathrm{fs}$, much shorter than what has previously been reported for solid sodium. The molecular field splitting of this core level has been determined to be $42\ifmmode\pm\else\textpm\fi{}10\phantom{\rule{0.3em}{0ex}}\mathrm{meV}$. The Auger measurements have experimentally confirmed that the sodium dimer is a good example of when the Coulomb explosion mechanism determines the spectral shape.