Decay ofI133to Levels inXe133

Abstract

The decay of ${}_{}{}^{133}{}_{}{}^{}\mathrm{I}$ was studied by a combination of lithium-drifted germanium and scintillation-coincidence techniques. Radiations identified were: gamma rays of energies (and intensities) 250 (0.1), 263 (0.18), 340 (0.3), 360 (0.3), 422 (0.40), 509.8 (2.50), 529.4 (100), 617.0 (0.30), 679 (1.0), 706.8 (1.7), 768 (0.59), 821 (0.22), 856.0 (1.4), 875.3 (5.8), 912 (0.40), 1052 (0.72), 1062 (0.16), 1234 (1.7), 1297 (2.7), and 1350 keV (0.16); and beta rays of energies 1540, 1230, 890, and 500 keV. A ${}_{}{}^{133}{}_{}{}^{}\mathrm{Xe}$ level scheme was constructed with states at 233, 529.4, 679, 875.3, 1052, 1235, 1296.9, 1349.4, 1385.2, and 1591.4 keV. The ${}_{}{}^{133}{}_{}{}^{}\mathrm{I}$ half-life was remeasured as 20.8±0.2 h.