Angular correlation study of 129I populated in the decay of 129Te

From coincidence measurements on γ-γ cascades following the decay of ${}^{129}{Te}^m$ the existence of a 1047-keV level in ¹²⁹I is well established. Angular correlation measurements for several cascades give the following values: 281-251-keV cascade:,A₂₂= 0.238±0.015,,A₄₄= 0.014±0.026;209-251-keV cascade:,A₂₂= 0.234±0.012,,A₄₄= 0.011±0.022;281-278-keV cascade:,A₂₂=-0.048±0.014,,A₄₄=-0.014±0.023;209-278-keV cascade:,A₂₂=-0.059±0.011,,A₄₄= 0.018±0.018;624-209-keV cascade:,A₂₂=-0.270±0.065,,A₄₄= 0.047±0.095;624-460-keV cascade:,A₂₂= 0.151±0.009,,A₄₄= 0.003±0.012;624-478-keV cascade:,A₂₂=-0.290±0.025,,A₄₄=-0.002±0.036;343-460-keV cascade:,A₂₂=-0.341±0.058,,A₄₄= 0.033±0.080. These values, together with nuclear orientation data, uniquely determine the spin of the excited states at 278 keV (3/2) and 860 keV (3/2). The mixing ratios δ(E2/M1) for the different transitions are obtained.[RADIOACTIVITY ¹²⁹Te from ¹²⁸Te(n,γ); measured γγ coin, γγ(θ). ¹²⁹I deduced levels, J, γ-mixing ratios. Enriched target, Ge(Li), Na(Tl) detectors.]