Interatomic Coulombic decay following Ne1sAuger decay in NeAr

Abstract

Using momentum-resolved electron-ion multicoincidence spectroscopy, we have investigated interatomic Coulombic decay (ICD) in the heteronuclear NeAr dimer following Ne $1s$ Auger decay. The measured intensity ratio for the three ICD transitions Ne${}^{2+}$($2{s}^{\ensuremath{-}1}2{p}^{\ensuremath{-}1} {}^{1}P$)Ar to Ne${}^{2+}$($2{p}^{\ensuremath{-}2} {}^{1}S$)--Ar${}^{+}$($3{p}^{\ensuremath{-}1}$), Ne${}^{2+}$($2{s}^{\ensuremath{-}1}2{p}^{\ensuremath{-}1} {}^{1}P$)Ar to Ne${}^{2+}$($2{p}^{\ensuremath{-}2} {}^{1}D$)-Ar${}^{+}$($3{p}^{\ensuremath{-}1}$), and Ne${}^{2+}$($2{s}^{\ensuremath{-}1}2{p}^{\ensuremath{-}1} {}^{3}P$)Ar to Ne${}^{2+}$($2{p}^{\ensuremath{-}2} {}^{3}P$)-Ar${}^{+}$($3{p}^{\ensuremath{-}1}$) reasonably agree with predictions. The kinetic energy release distribution for the fragmentation to Ne${}^{2+}$($2{p}^{\ensuremath{-}2} {}^{1}D$)-Ar${}^{+}$($3{p}^{\ensuremath{-}1}$) after the ICD transition from singlet Ne${}^{2+}$($2{s}^{\ensuremath{-}1}2{p}^{\ensuremath{-}1} {}^{1}P$)Ar state, which is a mirror image of the kinetic energy distribution of the emitted ICD electrons, suggests that the corresponding ICD rate is roughly two times lower than predicted by ab initio calculations.