[en] The first lifetime measurements have been performed for six levels of doubly ionized thorium, an important cosmochronometer in astrophysics for estimating the age of the Galaxy. The levels, belonging to the 5f(2), 5f7p, 7s7p, and 6d7p configurations of Th III, have been measured by the time-resolved laser-induced fluorescence method and compared with relativistic Hartree-Fock calculations including configuration interaction and core-polarization effects. Taking advantage of the excellent agreement between theory and experiment, a first set of transition probabilities of astrophysical interest has been deduced for this ion from a combination of the experimental lifetimes and of the theoretical branching fractions.
Disciplines :
Earth sciences & physical geography
Author, co-author :
Biémont, Emile ; Université de Liège - ULiège > Département de physique > Physique nucléaire, atomique et spectroscopie
Palmeri, P.
Quinet, Pascal ; Université de Liège - ULiège > Département de physique > Physique nucléaire, atomique et spectroscopie
Zhang, Z. G.
Svanberg, S.
Language :
English
Title :
Doubly ionized thorium: Laser lifetime measurements and transition probability determination of interest in cosmochronology
Publication date :
10 March 2002
Journal title :
Astrophysical Journal
ISSN :
0004-637X
eISSN :
1538-4357
Publisher :
Univ Chicago Press, Chicago, United States - Illinois
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