The technique of observing neutron thresholds in ($p, n$) and ($d, n$) reactions has been applied to the reactions ${\mathrm{O}}^{16}(d, n){\mathrm{F}}^{17}$ and ${\mathrm{N}}^{14}(d, n){\mathrm{O}}^{15}$. A nuclear resonance absorption magnetometer, in conjunction with a 90° magnetic analyzer, was used to accurately measure the bombarding energies. The ${\mathrm{Li}}^7(p, n){\mathrm{Be}}^7$ threshold was used as the primary calibration. The energy of the first excited state of ${\mathrm{F}}^{17}$ was found to be 0.499±0.003 Mev; excited states in ${\mathrm{O}}^{15}$ were found at 6.20±0.03, 6.841±0.009, and 6.909±0.009 Mev. Ten broad resonances in the forward yield of neutrons from the reaction ${\mathrm{O}}^{16}(d, n){\mathrm{F}}^{17}$ have been found in the range of bombarding energies from 1.8 to 4.3 Mev. The cross section for the ${\mathrm{N}}^{14}(d, n){\mathrm{O}}^{15}$ reaction increases with the deuteron energy in the range 1.1 to 4.5 Mev; a sharp rise in the cross section begins at a bombarding energy of 2.1 Mev. The absolute cross sections for the ${\mathrm{O}}^{16}(d, n){\mathrm{F}}^{17}$ and ${\mathrm{N}}^{14}(d, n){\mathrm{O}}^{15}$ reactions were measured.

• Received 6 June 1955

DOI:https://doi.org/10.1103/PhysRev.100.46