Radiative Lifetimes of Doubly Ionized Terbium

Radiative lifetimes of two short-lived levels (i.e. 4f⁸ (⁷F₆)6p^1/2 (6,1/2)_11/2,13/2) in Tb III are measured by time-resolved laser-induced fluorescence (LIF) technique with a two-step excitation process. Free Tb III ions are produced in a laser-induced plasma. Lifetime values are evaluated with a deconvolution procedure of the time-resolved fluorescence signal with the temporal shape of second-step excitation pulse (about 1ns). The lifetimes of the 4f⁸ (⁷F₆)6p^1/2 (6,1/2)_11/2 and 4f⁸ (⁷F₆)6p^1/2 (6,1/2)_13/2 levels are determined to be 1.9 (2) and 2.0 (2)ns, respectively.