The elastic scattering of ²⁸Si by ²⁸Si

The elastic scattering of ¹²c by ¹²c ¹ and ¹⁶O by ¹⁶O² has shown among other interesting results, gross resonance struc- ture that has led to the postulation of the existence of quasi- molecular states in the case of ¹²C + ¹²C. Subsequent work with C other nuclei have failed to show similar resonance structure and it seems probable that this structure is associated with the rel- atively tight binding of ¹²C and ¹⁶O, resulting in low excitation o energies of the compound system and consequently few competing inelastic processes. The availability of beams of ²⁸Si ions from the Chalk River MP Tandem prompted a study of the ²⁸Si + ²⁸Si elastic scattering. Fig. 1 shows a comparison between various nuclear para- meters associated with the Si + Si system and those for the C + c and 0 + 0 systems. The BE2's from coulomb excitation are presented here simply to illustrate the presence of deformation in ¹²C and ²⁸Si si and its absence in ¹⁶O. The form of the de formation is noted in the row below. While nuclear deformation may not have a strong influence on the nucleus-nucleus interaction, it might be expected that a well with a more fuzzy edge would result from the deformation. The value of a_o is that given by Bromley et al.¹ and leads to the interaction radii, R_int', and coulomb barriers. E_barrier, as shown. E_exc is the excitation energy of the compound nucleus for incident energies corresponding to the barrier, and E_α, E_p and E_n are the energies available for α particle, proton and neutron emission.