We have measured the mass and kinetic-energy distributions of fragments from the spontaneous fission (SF) of ${}_{104}{}^{262}{}_{}{}^{}\mathrm{Rf}$. The ${}_{104}{}^{262}{}_{}{}^{}\mathrm{Rf}$ was produced via the ${}_{}{}^{244}{}_{}{}^{}\mathrm{Pu}$${(}^{22}$Ne,4n) reaction with a production cross section of ∼0.7 nb using 114.4-MeV projectiles. The kinetic energies and times of the coincident fission fragments were measured using our rotating wheel system. From these data the half-life, mass, and kinetic-energy distributions were derived. The total kinetic-energy (TKE) distribution appears to consist of a single component with a most probable pre-neutron-emission TKE of 215±2 MeV. The mass distribution is symmetric with a full width at half maximum of about 22 mass numbers. These results are consistent with trends observed for other trans-berkelium spontaneously fissioning isotopes. We determined the half-life to be 2.1±0.2 s by measuring its spontaneous fission decay. We also attempted to observe the alpha decay of ${}_{104}{}^{262}{}_{}{}^{}\mathrm{Rf}$ by searching for alpha decay correlated in time with SF from the alpha daughter, 1.2-ms ${}_{}{}^{258}{}_{}{}^{}\mathrm{No}$. We observed no such decays and have set an upper limit of 0.8% (68% confidence level) on the alpha decay branch of ${}_{104}{}^{262}{}_{}{}^{}\mathrm{Rf}$. © 1996 The American Physical Society.

• Received 19 January 1996

DOI:https://doi.org/10.1103/PhysRevC.53.2893