Lawrence Berkeley National Laboratory

Forty-six decay chains, assigned to the decay of 115288, were produced using the Am243(Ca48,3n)115288 reaction at the Lawrence Berkeley National Laboratory 88-in. cyclotron. The resulting series of α decays were studied using α-photon and α-x-ray spectroscopies. Multiple α-photon coincidences were observed in the element 115 decay chain members, particularly in the third- and fourth-generation decays (presumed to be Rg280 and Mt276, respectively). Upon combining these data with those from 22 115288 decay chains observed in a similar experiment, updated level schemes in Mt276 and Bh272 (populated by the α decay of Rg280 and Mt276, respectively) are proposed. Photons were observed in the energy range expected for K x rays coincident with the α decay of both Rg280 and Mt276. However, Compton scattering of higher-energy γ rays and discrete transitions are present in the K x-ray region preventing a definitive Z identification to be made based on observation of characteristic K x-ray energies.