Time-resolved Coulomb-explosion imaging of nuclear wave-packet dynamics induced in diatomic molecules by intense few-cycle laser pulses

Journal Article · Sat Jan 15 04:00:00 EST 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.83.013417· OSTI ID:21537012

Bocharova, I A; Thumm, U; Ray, D; Cocke, C L ^[1]; Alnaser, A S ^[2]; Niederhausen, T ^[3]; Litvinyuk, I V ^[1]

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1. J. R. Macdonald Laboratory, Kansas State University, Kansas 66506 (United States)
2. Department of Physics, American University of Sharjah, Sharjah (United Arab Emirates)
3. Departamento de Quimica, C-IX, Universidad Autonoma de Madrid, ES-28049 Madrid (Spain)

We studied the nuclear dynamics in diatomic molecules (N{sub 2}, O{sub 2}, and CO) following their interaction with intense near-IR few-cycle laser pulses. Using Coulomb-explosion imaging in combination with the pump-probe approach, we mapped dissociation pathways of those molecules and their molecular ions. We identified all symmetric and asymmetric breakup channels for molecular ions up to N{sub 2}{sup 5+}, O{sub 2}{sup 4+}, and CO{sup 4+}. For each of those channels we measured the kinetic energy release (KER) spectra as a function of delay between the pump and probe pulses. For both N{sub 2} and O{sub 2} the asymmetric (3,1) channel is only observed for short (<20 fs) delays and completely disappears after that. We interpret this observation as a signature of electron localization taking place in dissociating molecular tri-cations when their internuclear separation reaches about 2.5 times the equilibrium bond length. This is a direct confirmation that electron localization plays an essential role in the universal mechanism of enhanced ionization in homonuclear diatomic molecules. Using classical and quantum mechanical simulations of the time-dependent KER spectra, we identify the pathways and intermediate states involved in the laser-induced dissociation of those molecules.

• OSTI ID: 21537012
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 1 Vol. 83; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ASYMMETRY
BOND LENGTHS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATIONS
CHALCOGENIDES
CHARGED PARTICLES
COULOMB ENERGY
DIMENSIONS
DISSOCIATION
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY
IONIZATION
IONS
KINETIC ENERGY
LASER RADIATION
LENGTH
MEASURING METHODS
MECHANICS
MOLECULAR IONS
MOLECULES
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
QUANTUM MECHANICS
RADIATIONS
RESOLUTION
TIME DEPENDENCE
TIME RESOLUTION
TIMING PROPERTIES
WAVE PACKETS