The reaction 48Ca+238U→286112 studied at the GSI-SHIP

The fusion reaction of Ca-48 projectiles with U-238 target nuclei was studied at the velocity filter SHIP of GSI in Darmstadt. Two decay chains were measured, which fully confirm data that were previously assigned to the isotope (283)112 in experiments at the Flerov Laboratory in Dubna. Two other events are consistent with a 50% spontaneous-fission (SF) branch of this isotope. The mean value obtained for the half-life of (283)112 is (6.9(-2.3)(+6.9))s, the alpha energy is (9.520 +/- 0.015) MeV, and the total kinetic energy (TKE) of SF is (238 +/- 14) MeV. The half-life of the alpha decay daughter nucleus (279)Ds is (0.18(-0.07)(+0.32))s, and the TKE of SF is (210(-11)(+32) MeV. The cross-section deduced from all four events is (0.72(-0.35)(+0.58) pb , measured at an excitation energy of 34.6MeV of the compound nucleus (286)112.