The near threshold structure of the unbound N=7 isotones 10Li and 9He has been investigated using proton removal and breakup from intermediate energy (35 MeV/nucleon) secondary beams of 11Be and 14,15B. The coincident detection of the beam velocity 9
Li and 8He fragments and neutrons permitted the relative energy of the in-flight decay of 10Li and 9He to be reconstructed. Both systems were found to exhibited virtual s-wave strength near threshold together with a higher-lying resonance.
The structure of the unbound nuclei 9He, 10Li and 13Be has been explored using breakup and proton-knockout from intermediate energy 11Be and 14,15B beams. In the case of both N=7 isotones, virtual s-wave strength is observed near threshold together w
ith a higher-lying resonance. A very narrow structure at threshold in the 12Be+n relative energy spectrum is demonstrated to arise from the decay of the 14Be*(2+), discounting earlier reports of a strong virtual s-wave state in 13Be.
The low-lying level structure of the unbound system $^{16}$B has been investigated via single-proton removal from a 35 MeV/nucleon $^{17}$C beam. The coincident detection of the beam velocity $^{15}$B fragment and neutron allowed the relative energy
of the in-flight decay of $^{16}$B to be reconstructed. The resulting spectrum exhibited a narrow peak some 85 keV above threshold. It is argued that this feature corresponds to a very narrow ($Gamma ll $100 keV) resonance, or an unresolved multiplet, with a dominant $pi (p_{3/2})^{-1} otimes u (d_{5/2}^3)_{J=3/2^+}$ + $pi (p_{3/2})^{-1} otimes u (d_{5/2}^2,s_{1/2})_{J=3/2^+}$ configuration which decays by d-wave neutron emission.
