We have measured two-fragment reduced-velocity correlation functions of the intermediate mass fragments (IMF: 3≤Z≤7) produced in multifragment final states for the Kr+Nb system (E/A=35, 45, 55, 65, and 75 MeV). From the measured correlation functions we extract mean IMF emission lifetimes (τ) which are observed to decrease from τ≊400 fm/c at E/A=35 MeV to τ≊125 fm/c at E/A=55 MeV. For beam energies in excess of E/A=55 MeV, no further decrease in τ is observed, indicating a possible saturation of the mean emission lifetime for IMF produced in multifragment exit channels.

• Received 4 January 1993

DOI:https://doi.org/10.1103/PhysRevLett.70.3705