The energy spectra of deuterons from the ($\alpha , d$) reaction on ${\mathrm{C}}^{12}$, ${\mathrm{N}}^{14}$, ${\mathrm{N}}^{15}$, ${\mathrm{O}}^{16}$, ${\mathrm{Ne}}^{20}$, ${\mathrm{Mg}}^{24}$, ${\mathrm{Mg}}^{26}$, ${\mathrm{Si}}^{28}$, ${\mathrm{S}}^{32}$, ${\mathrm{Ar}}^{40}$, and ${\mathrm{Ca}}^{40}$ have been observed. These reactions were induced by alpha particles ranging in energy from 42 to 53 MeV. All the energy spectra were dominated by one or more preferentially populated levels. Evidence that these levels have a common configuration is obtained from (a) the relationship between their $Q$ values of formation and the mass number of the recoil nuclei, and (b) the similarity of their angular distributions. It is proposed that the levels preferentially populated are of a ${[J_T+{\left(j_p{j}_n\right)}_{J^{\prime }}]}_J$ configuration, with the proton-neutron pair captured in the $d_{\frac{5}{2}}$ or $f_{\frac{7}{2}}$ shell, and that the maximum final spin (5, 6, or 7) is favored. A self-consistent energy-level scheme for the low-lying levels of ${\mathrm{Sc}}^{42}$ is also proposed.

• Received 11 August 1965

DOI:https://doi.org/10.1103/PhysRev.141.1021