Evidence for α -cluster structure in Ne21 in the first measurement of resonant O17+α elastic scattering

The first study of resonances in O17+α elastic scattering was carried out using the thick target inverse kinematics method. The data were analyzed in the framework of an R-matrix approach. Many α-cluster states were found in the Ne21 excitation region of the 9–13 MeV excitation energy including the first observation of a broad l=0 state in an odd-even nucleus, which is likely the analog of the broad 0+ at 8 MeV in Ne20. The observed structure in Ne21 appeared to be strikingly similar to that populated in the resonant O16+α scattering in Ne20. The results are also useful for refinement of data on an O17(α,n) reaction important for astrophysics.