Oxygen and nitrogen contained as a gas in a cloud chamber were bombarded by 14.1-Mev neutrons. From the disintegrations of these nuclei the following data have been collected: ($a$) the range-energy relations of ${\mathrm{C}}^{13}$ in the energy range 0-5 Mev, and the range-energy curve of ${\mathrm{B}}^{11}$ from 0-7 Mev; ($b$) the excited states of the nuclei ${\mathrm{C}}^{13}$, ${\mathrm{B}}^{11}$, ${\mathrm{N}}^{15}$, and ${\mathrm{N}}^{16}$; ($c$) the angular distributions of the alpha-particles emitted in the ${\mathrm{O}}^{16}(n,\alpha ){\mathrm{C}}^{13}$ and ${\mathrm{N}}^{14}(n,\alpha ){\mathrm{B}}^{11}$ reactions; ($d$) the cross sections for some of the reactions taking place.

• Received 26 May 1952

DOI:https://doi.org/10.1103/PhysRev.87.716