4-PI STUDIES OF THE 1.8-4.8 GEV HE-3-NAT, AU-197 REACTIONS .1. ENERGYDEPOSITION( AG)

The Indiana Silicon Sphere 4 pi detector has been used to measure ligh t-charged particles and intermediate-mass fragments (IMFs) emitted in the 18-4.8 GeV He-3+ Ag-nat, Au-197 reactions. Ejectile multiplicity a nd total event kinetic energy distributions scale systematically with projectile energy and target mass, except for the Ag-nat target at 3.6 and 4.8 GeV. For this system, a saturation in deposition energy is in dicated by the data, suggesting the upper projectile energy for stoppi ng has been reached. Maximum deposition energies of similar to 950 MeV for the Ag-nat target and similar to 1600 MeV for the Au-197 target a re inferred from the data. The results also demonstrate the importance of accounting for fast cascade processes in defining the excitation e nergy of the targetlike residue. Correlations between various observab les and the average IMF multiplicity indicate that the total thermal e nergy and total observed charge provide useful gauges of the excitatio n energy of the fragmenting system. Comparison of the experimental dis tributions with intranuclear cascade predictions shows qualitative agr eement.