Magnetic dipole transition rates in B-like and F-like titanium ions measured at a heavy-ion storage ring

The rates of the electric-dipole forbidden transitions between the fine str ucture levels of the ground state in B- and F-like ions of Ti have been mea sured optically at a heavy-ion storage ring. The lifetime results, (0.627 /- 0.010) ms for Ti17+ and (0.513 +/- 0.010) ms for Ti13+, are the most pre cise for any such transition yet and are in reasonable agreement with theor y. An isoelectronic comparison includes data from electron beam and Kingdon -type ion traps. (C) 1999 Elsevier Science B.V. All rights reserved.