Beta-delay Neutron Emission from Heavy Nitrogen Isotopes

Beta-delayed neutrons from the decay of $^{19,20}$N and most recently $^{22}$N have been measured for the first time using neutron time-of-flight spectroscopy. The nuclei were produced by projectile fragmentation reactions and the decays observed in a batch-mode experiment using plastic scintillators and germanium detectors. The half-lives, total neutron emission probability, and the branching to bound and neutron-unbound states were determined in the present work. The $\beta-\gamma$, $\beta-n$, and $\beta-n-\gamma$ coincidence data were used to construct level schemes for the oxygen daughters and the two lighter isotopes compare well to the results of other determinations. The results do not compare well to USD shell model calculations.