Abstract
Coincidence measurements of breakup fragments were carried out for the Li-7 + Sm-144 and Li-6,Li-7 + Pb-207,Pb-208, Bi-209 reactions at sub-barrier energies. Breakup modes in reactions of Li-6,Li-7 were identified through the reaction Q values, and the time-scales of each process inferred through the relative energy of the breakup fragments. Breakup was found to be predominantly triggered by nucleon transfer, with p pickup leading to alpha + alpha coincidences being the preferred breakup mode for Li-7, and n stripping leading to alpha + p for Li-6. Breakup triggered by 2n stripping was also found to be prominent in the Li-7 + Sm-144 reaction. The breakup yields were separated into prompt and delayed components based on the relative energies of the breakup fragments. This enables the identification of breakup process important in the suppression of complete fusion of Li-6,Li-7 at above-barrier energies.