Comparison of fusion cross sections for theB10+O16andC12+N14systems

The fusion cross sections for the ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}$ + ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ and ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ + ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ systems are compared for bombarding energies up to 18 MeV/nucleon. The energy spectra, angular distributions, and relative yields of the evaporation residues are analyzed in terms of simple kinematic considerations and Hauser-Feshbach calculations. Simultaneous determinations of mass, charge, and energy and two particle coincidence measurements at $E_{{14}_{\mathrm{N}}}=13\mathrm{}$ MeV/nucleon support the identification of evaporation residues based on inclusive measurements of $Z$ and $E$ alone. The gross characteristics of the residues are consistent with the main process being complete fusion followed by equilibrium decay. The excitation functions of the ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}$ + ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ and ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ + ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ systems show significant differences which cannot be explained in terms of simple macroscopic models. At the highest bombarding energies the fusion cross sections decrease as $\frac{1}{E_{\mathrm{c}.\mathrm{m}.\mathrm{}}}$ for both systems and are consistent with a maximum angular momentum limit of $\sim 27\hslash$.