2-DIMENSIONAL ALPHA-CLUSTER STRUCTURES IN SI-28

A study has been made of the C-12(O-16,(CC)-C-12-C-12)alpha reaction b etween the centre of mass energies of 28.3 to 36.8 MeV. A number of re sonances in Si-28 have been observed for final channels leading to the unbound 10.35, 11.09 and 14.82 MeV states in O-16. At two energies as sociated with previously observed resonances, the angular correlations of the exit channel particles have been analysed to measure the domin ant angular momentum of the Si-28 compound nucleus. Additional data we re acquired at two off-resonance energies for comparison. Using an ess entially model independent analysis, the values obtained were all in t he region of 19-21 (h) over bar, and are comparable with the grazing a ngular momentum in the entrance channel. The results are relevant to r ecent theoretical predictions of planar ct-cluster structures in Si-28 and are discussed in the context of the model predictions. (C) 1997 E lsevier Science B.V.