Clustering In N Not Equal Z Nuclei.

The structure of the O-18 nucleus at excitation energies above the a decay threshold was studied using C-14+alpha resonance elastic scattering and (Li-7,t) alpha-transfer reactions. A number of states with large alpha reduced widths have been observed, indicating that the alpha-cluster degree of freedom plays an important role in this N not equal Z nucleus. A 0(+) state with an a reduced width exceeding the single particle limit was identified at an excitation energy of 9.9 +/- 0.3 MeV. We discuss evidence that states of this kind are common in light nuclei and give possible explanations of this feature. Also, the astrophysical implications of the cluster structure of O-18 is discussed.