Reconstructing breakup at sub-barrier energies

Using a position sensitive detector array, back-angle coincidence measurements of breakup fragments at sub-barrier energies has enabled the complete characterisation of the breakup processes in the reactions of ^6,7Li with ²⁰⁸Pb. Breakup processes and their time-scales are identified through the reaction Q-values and the relative energy of the captured breakup fragments. The majority of breakup processes fast enough (∼10^-22s) to affect fusion are triggered by transfer of a neutron from ⁶Li, and of a proton to ⁷Li. These breakup mechanisms should therefore have a major contribution to the ∼30% suppression of complete fusion observed at above-barrier energies.