Excited States in ${\mathrm{Be}}^7$ and ${\mathrm{Be}}^8$

The neutron-threshold method has been used to observe the neutrons emitted in the deuteron bombardment of both ${\mathrm{Li}}^6$ and ${\mathrm{Li}}^7$. From the bombardment of ${\mathrm{Li}}^6$, two broad thresholds were observed corresponding to levels in ${\mathrm{Be}}^7$ at excitation energies of 6.5 Mev ($\Gamma =1.2\mathrm{}$ Mev) and 7.2 Mev ($\Gamma =0.5\mathrm{}$ Mev). Four thresholds were observed in the bombardment of ${\mathrm{Li}}^7$, corresponding to excited-state energies in ${\mathrm{Be}}^8$ of 16.07 Mev, 16.65 Mev, 17.60 Mev, and 18.19 Mev.