title: Charge resonance enhanced ionization of CO2 probed by laser Coulomb explosion imaging.
abstract: The process by which a molecule in an intense laser field ionizes more efficiently as its bond length increases towards a critical distance R(c) is known as charge resonance enhanced ionization (CREI). We make a series of measurements of this process for CO(2), by varying pulse duration from 7 to 200 fs, in order to identify the charge states and time scales involved. We find that for the 4+ and higher charge states, 100 fs is the time scale required to reach the critical geometry <R(CO)> ≈ 2.1 Å and <θ(OCO)> ≈ 163° (equilibrium CO(2) geometry is <R(CO)> ≈ 1.16 Å and <θ(OCO)> ≈ 172°). The CO(2)(3+) molecule, however, appears always to begin dissociation from closer than 1.7 Å indicating that dynamics on charge states lower than 3+ is not sufficient to initiate CREI. Finally, we make quantum ab initio calculations of ionization rates for CO(2) and identify the electronic states responsible for CREI.
authors: J. R. Macdonald Laboratory, Physics Department, Kansas State University, Manhattan, 66503, USA.
authors: Irina
authors: I
authors: Bocharova
authors: Reza
authors: R
authors: Karimi
authors: Emmanuel F
authors: EF
authors: Penka
authors: Jean-Paul
authors: JP
authors: Brichta
authors: Philippe
authors: P
authors: Lassonde
authors: Xiquan
authors: X
authors: Fu
authors: Jean-Claude
authors: JC
authors: Kieffer
authors: André D
authors: AD
authors: Bandrauk
authors: Igor
authors: I
authors: Litvinyuk
authors: Joseph
authors: J
authors: Sanderson
authors: François
authors: F
authors: Légaré