Optical-model analysis of the scattering of 24.7 MeV alpha particles

Abstract

The measured elastic scattering of 24.7 MeV alpha particles from the nuclei O, Mg, Al, Si, Ca, Ma, Ni, Co, Cu, Ge, Zr, Ag, In, Sn, Hf, W, Au, Bi and U has been analysed using the optical model. Fits were obtained using a four-parameter Woods-Saxon potential. No marked improvement was found by using a more general potential. The fits for medium and heavy nuclei are good, but those for the lighter nuclei are noticeably poorer. Potential ambiguities were studied in some detail for Ni and Mg, and potentials with depths of about 150 MeV and 200 MeV were obtained for all the nuclei in addition to a more shallow potential. The medium-weight nuclei show a preference for the deep potentials, the light nuclei for the shallow ones. The behaviour of the predicted scattering matrix elements is discussed also.