The neutron-rich isotope ${}^{218}\mathrm{Bi}$ has been produced in proton-induced spallation of a uranium carbide target at the ISOLDE facility at CERN, extracted from the ion source by the pulsed-release technique and resonant laser ionization, and its $\beta$ decay is studied for the first time. A half-life of $33\left(1\right)\mathrm{s}$ was measured and is discussed in the self-consistent continuum-quasi particle-random-phase approximation framework that includes Gamow-Teller and first-forbidden transitions. A level scheme was constructed for ${}^{218}\mathrm{Po}$, and a deexcitation pattern of stretched $E2$ transitions $8^{+}\to 6^{+}\to 4^{+}\to 2^{+}\to 0^{+}$ to the ground state is suggested. Shell-model calculations based on the Kuo-Herling interaction reproduce the experimental results satisfactorily.

• Received 9 October 2003

DOI:https://doi.org/10.1103/PhysRevC.69.044305