Photoionization Energies and Oscillator Strengths of Helium and Helium-like Ions

Journal Article · Mon Oct 17 00:00:00 EDT 2005 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2128336· OSTI ID:20719557

Faye, N A.B.; Ndao, A S; Konte, A; Biaye, M; Wague, A ^[1]

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1. Laboratoire Atomes Lasers (ICTP-Affiliated Centre), Departement de Physique, Universite Cheikh Anta Diop de Dakar (Senegal)

We first studied the resonant photoionization of helium-like ions, such as C4+, N5+, and O6+, and determined the wave functions, the excitation energies, and the partial and total widths of the autoionizing states of these ions lying under the n = 3 thresholds of the residual ion. For more detailed analysis of the theory, and a better comprehension of the internal dynamics of atomic resonances and electronic phenomena of correlation, we extended these calculations to other helium-like ions, under higher thresholds (n = 4 and 5) of the hydrogen ions H-, and of Li+, C4+, N5+, and O6+. We were also interested in oscillator strengths. These parameters are important for interpreting the spectra and diagnosing astrophysical and laboratory plasmas, as well as for analyzing the spectra coming from space and determining the composition and relative abundance from the various elements of the stellar and interstellar environment. We sought a better comprehension of the coupling between autoionizing and continuum states and of the phenomena of electronic correlations. We used the method of diagonalization that has been used below the n = 2 threshold of the residual ion. The results are important for astrophysicists and physicists studying matter-radiation interaction and for the invention of new laser systems. We also measured laser-induced chlorophyll fluorescence (LICF) emission spectra of the leaves of some tropical plants using a compact fiber-optic fluorosensor with a continuous-wave violet diode laser as the exciting source and an integrated digital spectrometer to analyze the state of stress of the plants.

• OSTI ID: 20719557
• Journal Information: AIP Conference Proceedings, Vol. 795, Issue 1; Conference: 2. IUPAP international conference on women in physics, Rio de Janeiro (Brazil), 23-25 May 2005; Other Information: DOI: 10.1063/1.2128336; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
CARBON IONS
CATIONS
CHLOROPHYLL
ELECTRON CORRELATION
ELEMENT ABUNDANCE
EMISSION SPECTRA
EXCITATION
EXCITED STATES
FLUORESCENCE
HELIUM IONS
HYDROGEN IONS
IONIZATION POTENTIAL
LASERS
LITHIUM IONS
NITROGEN IONS
OSCILLATOR STRENGTHS
OXYGEN IONS
PHOTOIONIZATION
PLANTS
WAVE FUNCTIONS