Lifetimes are reported for the 6s6p P-1,3(1), 6s6d D-1(2) and 6s7s S-1
(0) levels in Hg-like T1 II, measured using beam-foil excitation. The
values obtained were tau(P-1(1)) = 0.59 +/- 0.02 ns, tau(P-3(1)) = 39
+/- 2 ns, tau(D-1(2)) = 6.5 +/- 0.5 ns, and tau(S-1(0)) = 3.0 +/- 0.4
ns. Isoelectronic trends for line strengths of the resonance and inter
combination transitions are studied through comparisons with earlier m
easurements for Hg I-Bi IV.