TI-II TRANSITION-PROBABILITIES AND RADIATIVE LIFETIMES IN TI+ AND THESOLAR TITANIUM ABUNDANCE

Transition probabilities of 100 Ti-II emission lines, originating from 7 different atomic levels, have been determined by combining branchin g fractions with radiative lifetimes. The branching fractions were mea sured using Fourier transform spectroscopy on a hollow cathode. The ra diative lifetimes of these 7 - and 35 additional - levels were measure d using time resolved laser-induced fluorescence on a slow Ti ion beam . The transition probabilities of 21 very weak lines have been used to derive a solar titanium abundance of a(Ti) = log(N(Ti)/N(H)) + 12 = 5 .04 +/- 0.04 dex, which is insensitive to the solar model. This value is in disagreement with the meteoritic titanium abundance (4.93 +/- 0. 02).