The Indiana Silicon Sphere 4 detector has been used to measure light-charged particles and intermediatemass fragments ͑IMFs͒ emitted in the 18-4.8 GeV 3 Heϩ nat Ag, 197 Au reactions. Ejectile multiplicity and total event kinetic energy distributions scale systematically with projectile energy and target mass, except for the nat Ag target at 3.6 and 4.8 GeV. For this system, a saturation in deposition energy is indicated by the data, suggesting the upper projectile energy for stopping has been reached. Maximum deposition energies of ϳ950 MeV for the nat Ag target and ϳ1600 MeV for the 197 Au target are inferred from the data. The results also demonstrate the importance of accounting for fast cascade processes in defining the excitation energy of the targetlike residue. Correlations between various observables and the average IMF multiplicity indicate that the total thermal energy and total observed charge provide useful gauges of the excitation energy of the fragmenting system. Comparison of the experimental distributions with intranuclear cascade predictions shows qualitative agreement.

Spectra, angular distributions, and cross sections have been measured for Z =3-12 fragments produced in the reaction of 161-MeV protons with a silver target. Nonequilibrium mechanisms dominate the fragment yields at forward angles and for low-Z ejectiles. Equilibrated emission is primarily responsible for fragments observed at backward angles, an effect which grows in importance with increasing fragment Z value. A power-law fit to the elemental cross section distributions yields an exponent~=4.7, significantly larger than observed for higher-energy protons. These data are compared with the predictions of statistical decay, accreting source, and preequilibrium calculations.

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Angular correlations between coincident fission fragments have been measured for 40-, 90-, and 150-MeV proton-induced reactions on a U target. From these data linear momentum transfer distributions have been derived, which are then compared with other results for protons and more complex projectiles. On a per nucleon basis, protons exhibit the largest average linear momentum transfer values of any projectile over the energy range from E/2 =40 to 1000 MeV. This can be understood in terms of fundamental scattering cross sections, and is qualitatively demonstrated by intranuclear cascade calculations. Both cascade and precompound decay calculations reproduce the linear momentum transfer distributions with moderate success.

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