Electron Spectroscopy of Planetary Atoms.

Abstract

We present time-of-flight spectra of autoionizing electrons ejected from doubly excited planetary atoms in strontium with high angular momenta of both electrons $(6fn\ensuremath{\ell},n\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}16,\ensuremath{\ell}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}10)$. ``Apparent'' branching ratios for electron emission into various final channels (not corrected for unknown angular distributions) are reported. They include novel radiative-to-autoionization cascade process. To our knowledge these results represent the first comprehensive investigation of the internal decay dynamics of a highly excited, quasibound three-body Coulomb system.