The FERRUM project: metastable lifetimes in Cr II
2012 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 420, no 2, 1636-1639 p.Article in journal (Refereed) Published
Parity forbidden radiative transitions from metastable levels are observed in spectra of low-density astrophysical plasmas. These lines are used as probes of the physical conditions, made possible due to the long lifetime of their upper level. In a joint effort, the FERRUM project aims to obtain new and accurate atomic data for the iron-group elements, and part of this project concerns forbidden lines. The radiative lifetimes of the metastable energy levels 3 d4(a 3 D)4 s c4 D 5/2 and 3 d4(a 3 D)4 s c4 D 7/2 of singly ionized chromium have been measured. The experiment has been performed at the ion storage ring CRYRING. We employed a laser-probing technique developed for measuring long lifetimes. In this article, we present the lifetimes of these levels to be t5/2= 1.28(16) s and t7/2= 1.37(7) s, respectively. A comparison with previous theoretical work shows good agreement and the result is discussed in a theoretical context.
Place, publisher, year, edition, pages
2012. Vol. 420, no 2, 1636-1639 p.
atomic data, methods: laboratory, techniques: spectroscopic, astronomical data bases: miscellaneous
Atom and Molecular Physics and Optics
Research subject Physics
IdentifiersURN: urn:nbn:se:su:diva-67023DOI: 10.1111/j.1365-2966.2011.20152.xISI: 000299417600056OAI: oai:DiVA.org:su-67023DiVA: diva2:469139
FunderSwedish Research Council, 2006-3085Swedish Research Council, 2008-3736