POSSIBLE MULTIPHONON EFFECTS ON THE SUBBARRIER FUSION OF CL-37-64(NI)

The barrier distribution extracted from previous fusion data for Cl-37 + Ni-64 shows unexpected structure which can not be explained within the oblate-spherical model proposed earlier for projectile-target, A t wo-or three-barrier fit with appropriate barrier positions and strengt hs is necessary in order to describe the data. Simple coupled-channel calculations are made which indicate that the inclusion of double-phon on channels for the target could probably provide the mechanism needed to reproduce the experimental barrier distribution giving still a goo d description of the excitation function.