Observation of enhanced excitation of I{sub 2}{sup 2+} by strong laser fields

Journal Article · Wed Feb 15 04:00:00 EST 2006 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.73.023418· OSTI ID:20974613

Gibson, G N; Coffee, R N; Fang, L ^[1]

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1. Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States)

Using pump-probe spectroscopy with ultrashort laser pulses, we see an enhancement of the charge-asymmetric dissociation (CAD) channel (I{sub 2}{sup 2+})*{yields}I{sup 2+}+I, over a narrow range of internuclear separation. The enhancement of the CAD channel appears to come from the excitation of the symmetric ground state dissociation channel (I{sup +}+I{sup +}) for two reasons. First, there is a depletion in the symmetric channel at approximately the same pump-probe delay as the asymmetric enhancement. Second, for a fixed delay, the asymmetric channel increases as a function of probe intensity while the symmetric channel decreases. In addition, we find that the kinetic energy of the extra I{sup 2+}+I ions decreases for increasing delay. To explain this dependence of the kinetic energy release on delay, we introduce model potential energy curves. Based on these curves, we conclude that the excitation is produced by a resonant three-photon transition within I{sub 2}{sup 2+} rather than by ionization of I{sub 2}{sup +}.

• OSTI ID: 20974613
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 2 Vol. 73; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ASYMMETRY
DISSOCIATION
ELECTROMAGNETIC FIELDS
EXCITATION
EXCITED STATES
GROUND STATES
IODINE
IODINE IONS
KINETIC ENERGY
LASER RADIATION
MULTI-PHOTON PROCESSES
PHOTOLYSIS
PHOTON-MOLECULE COLLISIONS
PHOTONS
POTENTIAL ENERGY
PUMPING
REACTION KINETICS
SPECTROSCOPY
SURFACES