A NEW CLOSED FORM EXPRESSION FOR THE TOTAL REACTION CROSS-SECTION OF HEAVY IONS

A new analytical expression for the HI total reaction cross-section which exhibits the macroscopic features of the transparency factor is derived. Comparison with optical model calculation are made for the 12 C +208 Pb and 16 O +208 Pb at several energies.

Optical-model calculation of the 9Be(3He, 3He)9Be elastic scattering

Optical-model analysis of the elastic scattering of 6.0- and 8.0-MeV 3He particles on 9Be is performed with and without spin–orbit coupling. Good agreements with data are obtained, indicating the applicability of the optical model in describing the elastic scattering of 3He particles from such light nuclei as 9Be. Inclusion of spin–orbit interaction is found to improve fits, especially at backward angles. Almost equally good results are obtained by volume or surface absorption, although surface absorption gives slightly better fits at 8.0 MeV. Parameters giving the optimum fits to the data are presented and several ambiguities in the potential are discussed.