Angular Distributions of Deuterons from (p, d) Reactions in Light Nuclei. I. Nitrogen

Abstract

Deuterons have been observed from the reaction ${\mathrm{N}}^{14}(p, d){\mathrm{N}}^{13}$, produced by 18.7-Mev protons. The deuterons were distinguished from proton background by a thin NaI crystal in a scintillation counter with the crystal thickness equal to the deuteron range. The angular distribution of deuterons to the ${\mathrm{N}}^{13}$ ground state was fitted by a curve calculated from Butler's theory for an angular momentum transfer $l_n=1\mathrm{}$. This shows that the ground states of ${\mathrm{N}}^{13}$ and ${\mathrm{N}}^{14}$ have opposite parity and is consistent with the assignment of 1 + to the ${\mathrm{N}}^{14}$ ground state. The reduced width for the ground state transition is in qualitative agreement with that calculated using an independent-particle shell model with some indication that the ${\mathrm{N}}^{14}$ ground state is largely a $D$ state. The transition ${\mathrm{N}}^{14}(p, d){\mathrm{N}}^{13*}$ to the first excited state of ${\mathrm{N}}^{13}$ was not observed. The experimental upper limits on its cross section give upper limits of a few percent probability for admixtures of the configurations $p^8{s}^2$ and $p^8\mathrm{sd}$ in the ${\mathrm{N}}^{14}$ ground state. Application to the lifetime of ${\mathrm{C}}^{14}$ is discussed.