Energy levels of ${\mathrm{B}}^9$ have been investigated by the ${\mathrm{B}}^{10}({\mathrm{He}}^3, \alpha ){\mathrm{B}}^9$ reaction. Alpha-particle groups leading to the ground, 2.37-Mev and 2.83-Mev states of ${\mathrm{B}}^9$ have been found. There is no evidence for any well-defined state between the ground state and 2.37-Mev state of ${\mathrm{B}}^9$. The ${\mathrm{O}}^{16}({\mathrm{He}}^3, \alpha ){\mathrm{O}}^{15}$ reaction has been studied in the neighborhood of 5-Mev excitation in ${\mathrm{O}}^{15}$ and excited states have been found at 5.247- and 5.195-Mev energy in ${\mathrm{O}}^{15}$.

• Received 22 December 1958

DOI:https://doi.org/10.1103/PhysRev.114.1114