New highly excited states of ${}^{10}\mathrm{Be}$ observed in charged particle decay

Highly excited states of ${}^{10}\mathrm{Be}$ are formed by the bombardment of ${}^7\mathrm{Li}$ targets by ${}^7\mathrm{Li}$ beams at 34 and 50.9 MeV from the Florida State University Tandem/LINAC accelerator facility. The states are observed in three-body final state reactions by coincidence measurement of the vector momenta of two of the three particles and reconstruction of the decay energies. We observe decays involving ${}^7\mathrm{Li},$ ${}^8\mathrm{Li},$ ${}^9\mathrm{Li},$ and ${}^6\mathrm{He}$ in their ground states, first excited states, and in some cases second excited states. Fifteen of the 18 excitations observed are proposed as possible new states of ${}^{10}\mathrm{Be}.$ A few $\alpha$-particle decays of excited boron isotopes are also reported.