Enhanced Fusion-Evaporation Cross Sections in Neutron-Rich ${}^{132}$Sn on ${}^{64}$Ni

Abstract

Evaporation residue cross sections have been measured with neutron-rich radioactive ${}^{132}$Sn beams on ${}^{64}$Ni in the vicinity of the Coulomb barrier. The average beam intensity was $2\times 10^4$ particles per second and the smallest cross section measured was less than 5 mb. Large subbarrier fusion enhancement was observed. Coupled-channels calculations taking into account inelastic excitation and neutron transfer underpredict the measured cross sections below the barrier.

4 pages including 1 table and 3 figures