Radiative data for highly excited 3d8 4d levels in Ni II from laboratory measurements and atomic calculations
| Autor: | Lars Engström, Pascal Quinet, G. Malcheva, Patrick Palmeri, Henrik Hartman, Hampus Nilsson, Hans Lundberg, Krastan B. Blagoev, V. Fivet |
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| Rok vydání: | 2017 |
| Předmět: |
Photon
Atomic Physics (physics.atom-ph) techniques spectroscopic FOS: Physical sciences Astrophysics 7. Clean energy 01 natural sciences Physics - Atomic Physics Ion Ionization Naturvetenskap 0103 physical sciences atomic data Radiative transfer 010306 general physics 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Physics Laser ablation Astronomy and Astrophysics Polarization (waves) 3. Good health methods laboratory atomic Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Excited state Atomic physics Natural Sciences Excitation |
| DOI: | 10.48550/arxiv.1701.02480 |
| Popis: | This work reports new experimental radiative lifetimes and calculated oscillator strengths for transitions from 3d8 4d levels of astrophysical interest in singly ionized nickel. Radiative lifetimes of seven high-lying levels of even parity in Ni II (98400 -100600 cm-1) have been measured using the time-resolved laser-induced fluorescence method. Two-step photon excitation of ions produced by laser ablation has been utilized to populate the levels. Theoretical calculations of the radiative lifetimes of the measured levels and transition probabilities from these levels are reported. The calculations have been performed using a pseudo-relativistic Hartree-Fock method, taking into account core polarization effects. A new set of transition probabilities and oscillator strengths has been deduced for 477 Ni II transitions of astrophysical interest in the spectral range 194 - 520 nm depopulating even parity 3d8 4d levels. The new calculated gf-values are, on the average, about 20 % higher than a previous calculation by Kurucz (http://kurucz.harvard.edu) and yield lifetimes within 5 % of the experimental values. Comment: 17 pages |
| Databáze: | OpenAIRE |
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