Total fusion cross section excitation functions for the /sup 12/C+/sup 24/Mg and /sup 12/C+/sup 26/Mg systems have been measured in the energy range 20< or =E/sub lab/<60 MeV by detection of the evaporation residues. The excitation function for /sup 12/C+/sup 24/Mg is found to show evidence of oscillatory structures with peak to valley difference of approx.5--10% while that for /sup 12/C+/sup 26/Mg is relatively smooth. The maximum fusion cross section for /sup 12/C+/sup 24/Mg is observed to be approx.1180 mb compared to approx.1280 mb for /sup 12/C+/sup 26/Mg. The cross sections for /sup 12/C+/sup 26/Mg show evidence of a change in behavior at a bombarding energy significantly below the energy at which the cross section saturates. The results are discussed in the context of previous measurements and predictions of macroscopic and microscopic fusion models.

Total fusion cross section excitation functions for the $^{12}\mathrm{C}$ + $^{24}\mathrm{Mg}$ and $^{12}\mathrm{C}$ + $^{26}\mathrm{Mg}$ systems have been measured in the energy range $20\ensuremath{\le}{E}_{\mathrm{lab}}<60$ MeV by detection of the evaporation residues. The excitation function for $^{12}\mathrm{C}$ + $^{24}\mathrm{Mg}$ is found to show evidence of oscillatory structures with peak to valley difference of \ensuremath{\sim}5-10% while that for $^{12}\mathrm{C}$ + $^{26}\mathrm{Mg}$ is relatively smooth. The maximum fusion cross sectin for $^{12}\mathrm{C}$ + $^{24}\mathrm{Mg}$ is observed to be \ensuremath{\sim}1180 mb compared to \ensuremath{\sim}1280 mb for $^{12}\mathrm{C}$ + $^{26}\mathrm{Mg}$. The cross sections for $^{12}\mathrm{C}$ + $^{26}\mathrm{Mg}$ show evidence of a change in behavior at a bombarding energy significantly below the energy at which the cross section saturates. The results are discussed in the context of previous measurements and predictions of macroscopic and microscopic fusion models.NUCLEAR REACTIONS Fusion measurement, ${\ensuremath{\sigma}}_{\mathrm{fus}}(E)$: $^{12}\mathrm{C}$ + $^{24}\mathrm{Mg}$, $20\ensuremath{\le}{E}_{\mathrm{lab}}\ensuremath{\le}63$ MeV; $^{12}\mathrm{C}$ + $^{26}\mathrm{Mg}$, $20\ensuremath{\le}{E}_{\mathrm{lab}}\ensuremath{\le}56$ MeV; measured ${\ensuremath{\sigma}}_{\mathrm{elastic}}(\ensuremath{\theta})$, ${\ensuremath{\sigma}}_{\mathrm{fusion}}(\ensuremath{\theta})$ at ${E}_{\mathrm{lab}}=20, 24, 30, 41, 48, 56, \mathrm{and} 60$ MeV for $^{12}\mathrm{C}$ + $^{24}\mathrm{Mg}$, and at 20, 30, 42, and 56 MeV for $^{12}\mathrm{C}$ + $^{26}\mathrm{Mg}$.

The $^{24}\mathrm{Mg}$($^{12}\mathrm{C}$,${\ensuremath{\alpha}}_{0,1}$)$^{32}\mathrm{S}$ reaction has been investigated in the energy range ${E}_{\mathrm{lab}}=24\ensuremath{-}36$ MeV. Excitation curves taken at forward (0\ifmmode^\circ\else\textdegree\fi{}) and backward (173\ifmmode^\circ\else\textdegree\fi{}) angles show striking dissimilarities in both the ${\ensuremath{\alpha}}_{0}$ and ${\ensuremath{\alpha}}_{1}$ channels. Complete angular distributions in the ${\ensuremath{\alpha}}_{0}$ channel taken at selected energies do not resemble the square of a single Legendre polynomial over the full angular range. It is concluded that previous spin assignments to suggested isolated resonances using this reaction cannot be substantiated.NUCLEAR REACTIONS $^{24}\mathrm{Mg}$($^{12}\mathrm{C}$,$\ensuremath{\alpha}$)$^{32}\mathrm{S}$, ${E}_{\mathrm{lab}}=24\ensuremath{-}36$ MeV, measured $\ensuremath{\sigma}(E,\overline{\ensuremath{\vartheta}})=0\ifmmode^\circ\else\textdegree\fi{}$, $\overline{\ensuremath{\vartheta}}=173\ifmmode^\circ\else\textdegree\fi{}$, $\ensuremath{\sigma}(\ensuremath{\vartheta})$ at selected energies.

The total fusion cross section for the system /sup 15/N+/sup 27/Al has been measured over an energy range 27 MeV< or =E/sub lab/< or =70 MeV by detection of the fusion-evaporation residues. In addition elastic scattering was measured at six energies and fitted by optical model calculations. The fusion cross section for the system saturates at 1150 +- 50 mb. The data can be well described by the model of Glas and Mosel, using a reasonable set of parameters. The model of Horn and Ferguson also describes the data well if an appropriate charge radius is used. Comparison is made between these results and the fusion cross sections for /sup 16/O+/sup 26/Mg and /sup 18/O+/sup 24/Mg, which lead to the same compound nucleus. The results for /sup 15/N+/sup 27/Al are quite similar to those for /sup 18/O+/sup 24/Mg, and the differences between the fusion cross sections for these two systems and those for /sup 16/O+/sup 26/Mg may be evidence for an entrance channel effect.