FLNR JINR experiments on synthesis of superheavy nuclei with Ca-48 beam

The investigations of the decay properties and formation cross sections of the heaviest isotopes of the 110 and 112 elements with atomic numbers 276, 277 and 282, 283, respectively, were performed at the FLNR JINR with the us e of the intense internal and extracted Ca-48 beams. Th-232 and U-238 targe ts were used for the experiments. With the use of U-238 target at the beam energy E-targ. = 231+/-3 MeV (EC = 31 MeV) two spontaneous fission events w ere detected, that corresponds to the cross section - 5.0 +/- 2 pb. The res ult could be explained as spontaneous fission of the even-odd isotope (283) 112 With half life T-1/2 = 117(-48)(+283) seconds. The probability of a dec ay of (283)112 is not excluded and the possible branching ratio could be b( alpha) approximate to b(sf) approximate to 50 %.