Production of 256Lr in the 249,250,251Cf + 11B, 243Am + 18O, and 248Cm + 14N reactions

Production cross-sections of the isotope 256 Lr in the 249,250,251 Cf + 11 B, 243 Am + 18 O ,a nd 248 Cm + 14 N reac- tions were measured using a He/KCl gas-jet transport sys- tem and a rotating wheel �� -particle detection apparatus. The �� -particle energy of 256 Lr was distributed from 8.3 to 8.7 MeV and its half-life, �� 1/2, was measured to be 28± 1 s. The maximum cross sections in the 249 Cf ( 11 B, 4�� ) 256 Lr and 243 Am( 18 O, 5�� ) 256 Lr reactions were determined to be 122 ± 36 nb at the beam energy of 63 MeV and 26 ± 7 nb at 96 MeV, respectively. In the 248 Cm( 14 N, 6�� ) 256 Lr reac- tion, the cross section was measured to be 27 ± 10 nb at 91 MeV.