Inelastic α-scattering to the continuum

The statistical multistep direc theory is applied to the 90Zr(α, α') reaction at 140 MeV. Using the averaging procedure already tested in (p, n) and (p vector, p') reactions, DWBA matrix elements are employed to construct both the single-step and multistep cross sections in the continuum. It is shown that good fits for angular distributions in the 10-60 MeV excitation range can be achieved only by taking into account the interaction of the incoming α-particles with performed α-particles in the target nucleus. By comparing both the shape and absolute value of cross sections with data, an α-clustering probability is extracted which is shown to be in agreement with independent analysis in the same mass region. Due to its surface localization, the possible role of inelastic α-scattering in the 100 MeV region to investigate α-clustering in nuclei is suggested. (orig.)