Measurement of fusion excitation function for ⁷Li+⁶⁴Ni near the barrier

¹ Saha Institute of Nuclear Physics, 1/AF, Bidhan Nagar, Kolkata - 700 064, India
² Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai - 400 005, India
³ Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai - 400 085, India

Published online: 11 May 2016

Abstract

Total fusion (TF) excitation function has been measured for the system ⁷Li + ⁶⁴Ni at the energies near the Coulomb barrier of the system. The evaporation residue (ER) cross sections have been estimated through the online detection of characteristic γ-rays of the ERs. The summed ER cross sections yielding the experimental TF cross section have been compared with the theoretical one dimensional barrier penetration model (1DBPM) prediction. The measured and the model cross sections are very close to each other at above barrier energies. However, an enhancement of the experimental TF cross section with respect to the 1DBPM prediction is observed at below barrier energies. Coupled channels (CC) calculation with inelastic excitations alone could not explain the enhancement. The origin of the enhancement is identified as due to the enhanced population of the αxn channels.