Multifragment decays of central collisions in Kr-84 + (197)AU at E/A =
35, 55, and 70 MeV are studied. The dependence of the extracted emiss
ion time on the velocity of the fragment pair is investigated. More en
ergetic pairs manifest a stronger Coulomb interaction, indicating emis
sion from a source of smaller spatial-temporal extent than less energe
tic pairs. This trend can be understood in the context of a statistica
l model that allows the source characteristics to evolve as the fragme
nts are emitted.