DECAY SCHEME OF 13.3 H 123I

The decay scheme of 13.3 h 123I to levels of 123Te has been determined with the use of Ge(Li) and NaI(Tl) γ-ray detectors and coincidence equipment. Sources were produced by the 121Sb(α, 2n)123I reaction. A total of 14 γ-rays was observed and placed in the decay scheme. Excited states of 123Te were established at 159, 248 (117 d 123mTe), 440, 506, 688, 698, 784 and 895 keV. The upper limit for position decay of 123I is 0.01%. The 11 2- isomer 123mTe is fed in 0.010±0.005% of the decays of 123I. The levels of 123Te are fitted considerably better by the recent predictions by Kisslinger and Kumar than by the older calculations of Kisslinger and Sorensen. © 1968.