ABSENCE OF ISOTOPIC DEPENDENCE IN THE SUBBARRIER FUSION OF TI-48-58,NI-60,NI-64 SYSTEMS( NI)

Fusion process in the near and sub-barrier region has been investigate d for the systems Ti-48+Ni-58,Ni-60,Ni-64 using the heavy-ion reaction analyzer (HIRA). Fusion excitation functions and the mean angular mom enta are obtained from the measured evaporation residue cross sections . Significant enhancements both in the cross section and mean angular momentum data are seen with respect to the predictions of the one-dime nsional barrier penetration model. Simplified coupled channel calculat ions incorporating linear coupling to the inelastic channels (lowest 2 (+) and 3(-) states of both the projectile and the target) are not abl e to explain the observed enhancements. A systematic analysis of the d ata indicates lack of isotopic dependence in the sub-barrier fusion fo r these three systems.