We have confirmed the 1974 report of the discovery of element 106 by Ghiorso et al. The 0.9-s ${}_{}{}^{263}{}_{}{}^{}106$ was produced at the Lawrence Berkeley Laboratory 88-Inch Cyclotron via the ${}_{}{}^{249}{}_{}{}^{}\mathrm{Cf}$${(}^{18}$O,4n${)}^{263}$106 reaction using a beam of 95-MeV ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$ ions. Positive identification of ${}_{}{}^{263}{}_{}{}^{}106$ was made by observing its α decay followed closely in time by the α decay of the ${}_{}{}^{259}{}_{}{}^{}\mathrm{Rf}$ daughter. Our rotating wheel system was used in a special parent-daughter mode with six pairs of detectors. The ${}_{}{}^{263}{}_{}{}^{}106$ half-life, α-decay energy, and production cross section are consistent with those measured by Ghiorso et al. The half-life and α-decay energies of the ${}_{}{}^{259}{}_{}{}^{}\mathrm{Rf}$ daughter events are also consistent with those previously published.

• Received 21 September 1993

DOI:https://doi.org/10.1103/PhysRevLett.72.1423