Excited States inB10

Energy levels in ${\mathrm{B}}^{10}$ have been investigated by observing the neutrons from the ${\mathrm{Be}}^9(p, n){\mathrm{B}}^9$ reaction and the $\gamma$ rays from the ${\mathrm{Be}}^9(p, \alpha \gamma ){\mathrm{Li}}^6$ reaction in the range of bombarding energy from 2 Mev to 5 Mev. At $E_p=2.562\mathrm{}\pm 0.006$ Mev both the neutrons and the $\gamma$ rays are resonant. The width of the $\gamma$-ray peak is 38±3 kev while the width of the neutron peak is 85±10 kev. The results are analyzed in terms of two ${\mathrm{B}}^{10}$ states at 8.89 Mev which probably are the analogs to the 7.37- and 7.54-Mev states in ${\mathrm{Be}}^{10}$. The neutron reduced widths for the ${\mathrm{B}}^{10}$ states are in good agreement with those for the ${\mathrm{Be}}^{10}$ states (which is to be expected on the basis of charge symmetry of nuclear forces) if the neutron and $\gamma$-ray resonances have $J=3^{+}$, $T=1\mathrm{}$ and $J=2^{+}$, $T=1\mathrm{}$, respectively. In addition, a broad resonance in the neutron yield at $\theta =90\mathrm{}°$ near 3.2 Mev indicates a wide level ($\Gamma \approx 0.7$ Mev) in ${\mathrm{B}}^{10}$ at 9.5 Mev. Angular distributions of the neutrons have been measured and total cross sections obtained at bombarding energies of 2.56, 2.92, 3.06, 3.56, and 4.56 Mev.