Characterization of nuclear sources from neutron-neutron, proton-proton and neutron-proton correlation functions

Two-neutron, two-proton and neutron-proton correlation functions have been measured simultaneously for the E/A = 45 MeV Ni-58 + Al-27 reaction. Calcul ations from a statistical model have been compared to singles energy spectr a as well as to total and gated correlation functions. This imposes very st rong constraints on the model parameters. The use of directionally gated co rrelation functions helps to disentangle space and time information. Values of Gaussian radii, emission lifetimes, initial temperatures, source veloci ties and flow velocities are extracted. Correlation functions gated on tota l momentum of the nucleon pairs suggest that more energetic particles are e mitted on a fast time scale (< 100 fm/c) and that the fraction of pre-equil ibrium to equilibrium emission is larger for protons than for neutrons. (C) 2000 Elsevier Science B.V. All rights reserved.