Nuclear Energy Levels inC13,N13,N14,N15,O15, andF18fromHe3Induced Reactions

Abstract

The Rice Institute 5.5-Mev Van de Graaff accelerator and a magnetic spectrograph have been used to study reaction products produced by ${\mathrm{He}}^3$ bombardment of ${\mathrm{B}}^{11}$, ${\mathrm{C}}^{12}$, ${\mathrm{C}}^{13}$, ${\mathrm{N}}^{14}$, and ${\mathrm{O}}^{16}$. $Q$ values of 9.5, 9.3, 6.31, 5.68, 5.63, 5.49, 4.31, 3.67, and 3.29 Mev were observed for the ${\mathrm{B}}^{11}({\mathrm{He}}^3, p){\mathrm{C}}^{13}$ reaction, corresponding to excitations of from 3.7 to 9.90 Mev in ${\mathrm{C}}^{13}$. The energy levels at 7.69 and 8.87 Mev in ${\mathrm{C}}^{13}$, for which the $Q$ values were 5.49 and 4.31 Mev, were determined to have widths of approximately 75 and 175 kev, respectively. For the ${\mathrm{C}}^{13}({\mathrm{He}}^3, p){\mathrm{N}}^{15}$ reaction the observed $Q$ values were 5.38, 4.33, 3.50, 3.36, 3.09, 2.35, 2.09, 1.61 and 1.50 Mev. The ${\mathrm{O}}^{16}({\mathrm{He}}^3, p){\mathrm{F}}^{18}$ reaction revealed the existence of twelve states below 3.9 Mev of excitation in ${\mathrm{F}}^{18}$. These states occur at 0.943, 1.047, 1.089, 1.128, 1.708, 2.102, 2.521, 3.058, 3.130, 3.355, 3.724, and 3.843 Mev of excitation. The ground-state $Q$ values of the ${\mathrm{O}}^{16}({\mathrm{He}}^3, \alpha ){\mathrm{O}}^{15}$ and ${\mathrm{N}}^{14}({\mathrm{He}}^3, d){\mathrm{O}}^{15}$ reactions were determined to be 4.91 and 1.80 Mev, respectively, and the first excited state of ${\mathrm{O}}^{15}$ was observed at 5.17 Mev by means of the ${\mathrm{O}}^{16}({\mathrm{He}}^3, p){\mathrm{O}}^{15}$ reaction.