The decay of the136I isomers to the energy levels of136Xe

The gamma ray spectra associated with the decay of the¹³⁶I isomers have been measured by means of a Ge(Li) detector. The iodine samples were produced by using the technique of on-line isotope separation of the fission products of a²³⁵U target at the R2-O reactor in Studsvik, Sweden. On the basis of the measured singles and Ge-Ge coincidence spectra a new level scheme was constructed for¹³⁶Xe. A comparison with theoretical calculations is included. The half-life analysis of the gamma peaks as well as the beta andK X-rays associated with mass 136 iodine showed that there exist three separate half-lives: 48 ± 2 s, 83 ± 3 s and 100 ± 3 s, the last one being not previously reported. The possibility of the existence of three isomeric states in¹³⁶I is discussed.