Measurements of cross sections for the fusion-evaporation reactions 244Pu(48Ca,xn)292-x114 and 245Cm(48Ca,xn)293-x116 -: art. no. 054607

We have studied the excitation functions of the reactions Pu-244(Ca-48,xn). Maximum cross sections for the evaporation of 3-5 neutrons in the complete-fusion reaction Pu-244+Ca-48 were measured to be sigma(3n)=2 pb, sigma(4n) =5 pb, and sigma(5n) = 1 pb. The decay properties of 3n-evaporation product (289)114, in the decay chains observed at low Ca-48 energy coincide well with those previously observed in the Pu-244+Ca-48 and Cm-248+Ca-48 reactions and assigned to (288)114. Two isotopes of element 114 and their descendant nuclei were identified for the first time at higher bombarding energies: (288)114 (E-alpha=9.95 MeV, T-1/2=0.6 s) and (287)114 (E-alpha = 10.04 MeV, T-1/2 =1 s). We also report on the observation of new isotopes of element 116, (290,291)116, produced in the Cm-245 + Ca-48 reaction with cross sections of about 1 pb. A discussion of self-consistent interpretations of all observed decay chains originating at Z=118, 146, and 114 is presented.