Adiabatic heavy-ion fusion potentials for fusion at deep sub-barrier energies
The recently reported unusual behaviour of fusion cross-sections at extreme sub-barrier energies has been examined. The adiabatic limit of fusion barriers has been determined from experimental data using the barrier penetration model. These adiabatic barriers are consistent with the adiabatic fusion barriers derived from the modified Wilzynska-Wilzynski prescription. The fusion barrier systematics has been obtained for a wide range of heavy-ion systems.