The counter ratio method has been used to investigate neutron thresholds in the ($d, n$) reactions on ${\mathrm{B}}^{10}$, ${\mathrm{B}}^{11}$, ${\mathrm{C}}^{12}$, and ${\mathrm{C}}^{13}$. Thresholds were found corresponding to excited states in ${\mathrm{C}}^{11*}$ at 8.107, 8.430, and 8.660 Mev; in ${\mathrm{C}}^{12*}$ at 15.100 Mev; in ${\mathrm{N}}^{13*}$ at 2.37 Mev; and in ${\mathrm{N}}^{14*}$ at 5.683 Mev. Resonances in the reaction ${\mathrm{C}}^{12}(d, n)$ were found at 3.01 and 3.36 Mev and in the reaction ${\mathrm{C}}^{13}(d, n)$ at 1.80, 2.45, and 3.46 Mev. The absolute cross sections for the reactions ${\mathrm{B}}^{10}(d, n)$, ${\mathrm{B}}^{11}(d, n)$, and ${\mathrm{C}}^{13}(d, n)$ were measured.

• Received 21 July 1955

DOI:https://doi.org/10.1103/PhysRev.100.847