The FERRUM project: Experimental transition probabilities from highly excited even 5s levels in Cr II
Engström, Lars; Lundberg, Hans; Nilsson, Hampus; Hartman, Henrik, et al. (2014). The FERRUM project: Experimental transition probabilities from highly excited even 5s levels in Cr II. Astronomy & Astrophysics, 570,
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Published
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English
Authors:
Engström, Lars
;
Lundberg, Hans
;
Nilsson, Hampus
;
Hartman, Henrik
, et al.
Department:
Atomic Physics
Lund Observatory - Has been reorganised
Abstract:
We report lifetime measurements of the five levels in the 3d(4)(a(5)D)5s e(6)D term in Cr II at an energy around 83 000 cm(-1), and log(gf) values for 38 transitions from the investigated levels. The lifetimes are obtained using time-resolved, laser-induced fluorescence on ions from a laser-produced plasma. Since the levels have the same parity as the low-lying states directly populated in the plasma, we used a two-photon excitation scheme. This process is greatly facilitated by the presence of the 3d(4)(a(5)D)4p z(6)F levels at roughly half the energy difference. The f-values are obtained by combining the experimental lifetimes with branching fractions derived using relative intensities from a hollow cathode lamp recorded with a Fourier transform spectrometer.
Keywords:
atomic data ;
methods: laboratory: atomic ;
techniques: spectroscopic ;
Astronomy, Astrophysics and Cosmology ;
Atom and Molecular Physics and Optics
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