Seniority Structure of 136 Xe 82

The level structure of the N = 82 nucleus Xe-136 was studied with the inelastic neutron scattering reaction followed by y -ray detection. A number of the spins and parities were reassigned, and many level lifetimes were determined for the first time using the Doppler-shift attenuation method. New shell-model calculations were also performed using both the full Z = 50-82 model space, and a reduced model space including only the 1d(5/2) and 0g(7/2) orbitals. This new information characterizing Xe-136 was used to identify the seniority structure of the low-lying levels and to assign (pi 0g(7/2))(nu=0)(4), (pi 0g(7/2))(nu=2)(4), (pi 0g(7/2))(nu=4)(4), (pi 1d(5/2))(pi 0g(7/2))nu=1(3), and (pi 1d(5/2))(2)(pi 0g(7/2))nu=0(2) configurations to describe all observed states below 2.8 MeV.