Neutrons from the Proton Bombardment ofB10

The ${\mathrm{B}}^{10}(p, n){\mathrm{C}}^{10}$ reaction has been investigated at 30, 60, 90, 120, and 150 degrees in the laboratory system by the method of proton recoils in thick photographic emulsions. The mean energy of the incident protons was 17.2±0.15 Mev. The results indicate a ground-state $Q$ value of -4.35±0.2 Mev, yielding a mass defect of 18.6 Mev for ${\mathrm{C}}^{10}$ in good agreement with beta decay results. The data also indicate a level in ${\mathrm{C}}^{10}$ at 3.34±0.2 Mev and partly resolved levels at excitation energies ≳5 Mev. The angular distributions of the neutrons to the ground state and to the 3.34-Mev state are shown.