ISOMERIC TRANSITIONS BETWEEN SHAPE COEXISTING STATES IN IODINE ISOTOPES WITH A = 115, 119 AND 121

Applying delayed gamma - r.f. coincidences and generalized centroid-sh ift analysis, nanosecond isomers in some odd-A iodine isotopes are stu died in-beam. The reactions (Cd(C, p2n))-Cd-106-C-12 and (Sn(Li, 3n))- Sn-116-Sn-118-Li-6 have been used. The following half-lives were deter mined: T1/2(565 keV) = 0.50 +/- 0.10 ns and T1/2(837 keV) = 0.90 +/- 0 .20 ns in 115I, T1/2(687 keV) = 5.50 +/- 0.50 ns and T1/2(2418 keV) = 4.0 +/- 0.50 ns in 119I as well as T1/2(812 keV) = 0.35 +/- 0.20 ns an d T1/2(445 keV) < 0.10 ns in I-121. A systematics of the absolute prob abilities for the transitions deexciting the pi g9/2 9/2+ and pi1/2 11 /2(1)- band heads in I-115-125 is presented and discussed.