Temperatures and excitation energies of hot nuclei in the reactions of /sup 32/S+Ag and /sup 16/O+Ag at 30 MeV/nucleon

For the reactions of 30 MeV/nucleon /sup 16/O and /sup 32/S with Ag, singles and coincidence measurements have been made for heavy residues, fragments (3less than or equal tozless than or equal to14), and light charged particles (zless than or equal to2). Mass-velocity correlations for the residues and fragment-residue coincidences indicate that increasing residue velocities do correspond to increasing excitation energy. Excitation energies as high as 90% of those which would result from complete fusion are reached. The spectra of light particles detected in coincidence with residue groups having different average velocities are analyzed with a moving source fit. When recoil effects are properly taken into account, excellent fits to the data are obtained. From the energy spectra and multiplicities of particles emitted from a fusion-like source the initial temperatures of the primary composite nuclei are determined. The results suggest that a plateau temperature near 6.5 MeV is reached above excitation energies of 3 MeV/nucleon. The temperatures are compared to those resulting from various model calculations.