Photoionization of an autoionizing level of atomic oxygen

Journal Article · Tue Jan 01 04:00:00 EST 1991 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.43.282· OSTI ID:5989823

Pratt, Stephen T. ^[1]; Dehmer, Patricia M. ^[1]; Dehmer, Joseph L. ^[1]

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1. Argonne National Laboratory (ANL), Argonne, IL (United States)

Direct evidence for the photoionization of an autoionizing level of atomic oxygen is presented. Atomic oxygen is produced in the 1s²2s²2p^{4 1}D₂ level by photodissociation of NO₂ or N₂O and excited to the (²D°)3p ¹P₁ and ¹F₃ levels by two-photon absorption. These levels lie above the O^{+ 4}S°_3/2 ionization threshold but are forbidden to autoionize in LS coupling. Although the autoionization rates are thus very small, photoelectron spectra demonstrate that both levels do autoionize into the ⁴S°_3/2 continuum. At laser intensities of ~ 3 X 10⁹ W/cm², photoionization of the ¹F₃ level competes effectively with autoionization. The implications of this work for high-intensity multiphoton ionization studies of above-threshold ionization and multiple ionization are discussed.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Assistant Secretary for Energy Research, Office of Health and Environmental Research
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5989823
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 1 Vol. 43; ISSN 1050-2947; ISSN PLRAAN
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
AUTOIONIZATION
D STATES
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY LEVELS
IONIZATION
LASER RADIATION
MULTI-PHOTON PROCESSES
NONMETALS
OXYGEN
PHOTOIONIZATION
RADIATIONS