Synthesis of superheavy nuclei in the Ca-48+Pu-244 reaction

In bombardment of Pu-244 With Ca-48, we observed a decay sequence consistin g of an implanted heavy atom, three subsequent a decays, and a spontaneous fission (SF), all correlated in time and position. The measured cu energies and corresponding time intervals were E-alpha = 9.71 MeV (Delta t = 30.4 s ), 8.67 MeV (Delta t = 15.4 min), and 8.83 MeV (Delta t = 1.6 min): for the SF (Delta t = 16.5 min), the total deposited energy was approximately 190 MeV. The a-particle energies together with the decay times and SF terminati ng the chain offer evidence of the decay of nuclei with high atomic numbers . This decay chain is a good candidate for originating from the a decay of the parent nucleus (289)114, produced with a cross section of about 1 pb.