THE CORRELATION-FUNCTIONS AND EMISSION TIME SCALES FOR LIGHT PARTICLES AND LIGHT FRAGMENTS IN AR-40-197 REACTIONS 25 MEV(AU)NUCLEON/

Two-particle correlation functions were measured for the emission of p rotons, deuterons, tritons, alpha, and lithium fragment at small relat ive momenta in Ar-40-induced reactions on Au-197 at 25 MeV/nucleon. Ba sed on three-body trajectory calculations the emission time scales for the particles were extracted from p-d, d-d, t-t, and lithium-lithium correlation functions. The mean emission time was found to decrease wi th increasing sum of the kinetic energies of the particle in a correla ted pairs, indicating the emission of more energetic particles at earl ier stages of the reaction than at later stages. The time scale for th e emission of lithium fragments emission suggests that sequential bina ry disassembly occurs in Ar-40+Au-197 reaction at MeV/nucleon. Mean em ission temperature of 3.5(-0.8)(+1.3) and 3.6 +/- 0.4 MeV were also ex tracted from the relative populations of the excited and ground states of the respective emitted nuclides Be-8 and He-4. (C) 1997 Elsevier S cience B.V.