Resonance-enhanced multiphoton ionization-photoelectron spectra of CO sub 2. I. Photoabsorption above the ionization potential

Journal Article · Sat Jun 15 04:00:00 EDT 1991 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.460146· OSTI ID:5797290

Wu, M; Taylor, D P; Johnson, P M ^[1]

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1. Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400 (US)

Photoabsorption above the first ionization potential of CO{sub 2} was observed at relatively low laser intensity, detected via resonant-enhanced multiphoton ionization-photoelectron spectra through several Rydberg states. This phenomenon can be explained by the presence of accidental resonances with long-lived autoionizing states which make photon absorption within the ionization continuum possible. Laser powers are too low for this to be explained in terms of a ponderomotive potential and conventional above-threshold ionization. This resonance-enhanced above-threshold absorption phenomenon is potentially useful in the study of excited and superexcited states. Photoelectron energies can be assigned to terminations on CO{sup +}{sub 2} ionic states at both the four- and five-photon levels, allowing measurement of states up to 22 eV. Two unassigned bands may represent terminations on a new state of CO{sup +}{sub 2}, with an ionization potential of 21.4 eV.

• DOE Contract Number: FG02-86ER13590
• OSTI ID: 5797290
• Journal Information: Journal of Chemical Physics; (USA), Journal Name: Journal of Chemical Physics; (USA) Vol. 94:12; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500 -- Photochemistry
640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
ELECTROMAGNETIC RADIATION
ELECTRON SPECTROSCOPY
ENERGY LEVELS
EXCITED STATES
IONIZATION
IONIZATION POTENTIAL
LASER RADIATION
MULTI-PHOTON PROCESSES
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PHOTOIONIZATION
RADIATIONS
RYDBERG STATES
SPECTROSCOPY