Fusion cross sections in systems leading to Hf170 at near-barrier energies

GIL, S.; HASENBALG, F.; TESTONI, J.E.; ABRIOLA, D.; BERISSO, M.C.; DI TADA, M.; ETCHEGOYEN, A.; FERNÁNDEZ NIELLO, J.O.; PACHECO, A.J.; CHARLOP, A.; SONZOGNI, A.A.; VANDENBOSCH, R.

PHYS. REV. - C

AMER PHYSICAL SOC

Año: 1995 vol. 51 p. 1336 - 1344

0556-2813

In an effort to study the effect of the entrance channel mass asymmetry on the fusion process at near-barrier energies, we have measured the fusion cross section and its distribution according to the different evaporation residues for the Si28+142Ce, S32+138Ba, and Ti48+122Sn systems. All these systems lead to the same compound nucleus Hf170. The measurements were performed using a delayed x-ray technique. For the last two systems we have also measured the fission cross sections in the same bombarding energy range. This experimental information can be used to restrict the free parameters of the statistical model used to account for the relative yield. A constrained and realistic statistical decay model is useful in reducing the uncertainties in the determination of the spin distribution from measurements of gamma multiplicities for these systems. The excitation function for the fusion cross section can be described using a schematic coupled channels calculation with realistic coupling strengths. Our results show no umambiguous effect that can be associated with the entrance channel mass asymmetry. © 1995 The American Physical Society.