Femtosecond fragmentation of CS2 after sulfur 1s ionization: interplay between Auger cascade decay, charge delocalization, and nuclear motion

Autor: A. Naves de Brito, O. Björneholm, Alexandra Mocellin, O. Grånäs, E. S. Cardoso, Carl Caleman, F. Burmeister
Rok vydání: 2020
Předmět:
Zdroj: Journal of Physics B: Atomic, Molecular and Optical Physics. 53:244007
ISSN: 1361-6455
0953-4075
DOI: 10.1088/1361-6455/abc45d
Popis: We present a combined experimental and theoretical study of the fragmentation of molecular CS2 after sulfur 1s Auger cascade decay, consisting of electron–multi-ion coincidence spectra of charged fragments and theoretical simulations combining density functional theory and molecular dynamics. On the experimental side, a procedure for a complete determination of all sets of ions formed is described. For many of the fragmentation channels, we observed a higher charge in one of the sulfur atoms than the other atoms. Based on these observations and the theoretical simulations where the time scale of the nuclear motion and decay is taken into account, we propose that KLL Auger decay after the 1s core hole creation, via 2p double hole states, results in highly charged and strongly repulsive states with one localized core hole. These localized core holes are sufficiently long-lived that some will decay after fragmentation of the molecular ion, thereby efficiently impeding charge exchange between the fragments.
Databáze: OpenAIRE