The $\beta$-decay of ${}^{18}\mathrm{N}$ has been studied using $\beta \text{−}n$ and $\beta \text{−}\gamma$ coincidence methods. The ${}^{18}\mathrm{N}$ ions were produced by the fragmentation of the $E/A=68.8$ MeV ${}^{22}\mathrm{Ne}$ beam on a thick beryllium target. A newly constructed neutron detector system with wide energy detection range and low-energy detection threshold was used. The 619 ± 2 ms half-life of the ${}^{18}\mathrm{N}$ $\beta$-decay was found to be in very good agreement with the previous measurements. Transitions to 11 $\beta$-delayed neutron emitting states in ${}^{18}\mathrm{O}$ have been observed with a total branching ratio of 6.98 ± 1.46%. The Gamow-Teller $\beta$-decay strengths of ${}^{18}\mathrm{N}$ to these levels were deduced and compared with the shell model calculations. The intensities of the strong $\gamma$-ray transitions in ${}^{18}\mathrm{O}$ were found to be consistent with recent work.

• Received 2 September 2005

DOI:https://doi.org/10.1103/PhysRevC.72.064327