The yield of the reaction ${\mathrm{Li}}^6(\alpha , \gamma ){\mathrm{B}}^{10}$ was measured as a function of bombarding energy from 0.7 up to 3.8 Mev. Five levels in ${\mathrm{B}}^{10}$ were found at excitation energies of 4.77, 5.11, 5.16, 5.91, and 6.02 Mev. Only the levels at 4.77 and 5.16 Mev have been observed previously in this reaction. Resonance widths, cross sections, branching ratios, and angular distributions are given for the levels. Spin assignments of $2^{+}$ (or possibly $3^{+}$) to the 4.77-Mev level and $4^{+}$ to the 6.02-Mev level are indicated by the evidence. For the other levels many spins are ruled out but definite assignments cannot be given.

• Received 22 August 1957

DOI:https://doi.org/10.1103/PhysRev.108.1506