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

摘要

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