Energy levels of the nucleus ${\mathrm{C}}^{15}$ have been measured by measuring the kinetic energies of proton groups produced in the bombardment of thin beryllium targets with 2-Mev lithium ions, causing the reaction ${\mathrm{Be}}^9({\mathrm{Li}}^7, p){\mathrm{C}}^{15}$. The energy levels found were at 0.62, 2.48, 3.08, 4.26, 5.93, 6.58, and 8.18 Mev above the ground state. A continuum of particles was interpreted as due partly to ${\mathrm{Be}}^9({\mathrm{Li}}^7, pn){\mathrm{C}}^{14}$. The ground state and the lowest levels were compared with levels in ${\mathrm{N}}^{15}$; the presence of the lowest $T=\frac{3}{2}$ level at 11.61 Mev in ${\mathrm{N}}^{15}$ was confirmed. Comparison with the low-lying levels in ${\mathrm{O}}^{17}$ revealed similarity suggested by the analogous shell structures of the two nuclei ${\mathrm{C}}^{15}$ and ${\mathrm{O}}^{17}$.

• Received 8 July 1957

DOI:https://doi.org/10.1103/PhysRev.108.421