Nuclear Reactions Produced by Nitrogen on Nitrogen

Excitation functions for the reactions (1) ${\mathrm{N}}^{14}$(${\mathrm{N}}^{14}$, ${\mathrm{N}}^{13}$)${\mathrm{N}}^{15}$ and (2) ${\mathrm{N}}^{14}$(${\mathrm{N}}^{14}$, ${\mathrm{O}}^{15}$)${\mathrm{C}}^{13}$ were determined from thick-target yields obtained with 26-Mev nitrogen ions on AgCN. The cross section for both reactions at 25 Mev is about 5 millibarns. As the energy decreases, the cross section for reaction (1) decreases more rapidly than for reaction (2). Neither ${\mathrm{N}}^{13}$ nor ${\mathrm{O}}^{15}$ was observed from the proton bombardment of ${\mathrm{Al}}^{27}$ at proton energies which lead to the same excitation in the compound nucleus. Further, it was found that reaction (1) proceeds through the ground states of ${\mathrm{N}}^{13}$ and ${\mathrm{N}}^{15}$ in more than 90% of the cases. The angular distribution of ${\mathrm{N}}^{13}$ in reaction (1) was measured for nitrogen energies of 16.3, 19.2, 21.1, and 23.3 Mev. The peak of the distribution at 23 Mev is at 50 deg in the center-of-mass system. As the energy decreases, the angle at which the peak occurs increases. It is concluded that these reactions take place through a stripping process.