Angular distributions and energy spectra of fragments formed in the interaction of uranium-238 with 400 GeV protons

Angular distributions and differential ranges at five angles to the beam have been measured for 23 fragments, ranging from ;The energetic component was fit with a thermal fragment emission model and was found to be consistent with binary fission and, for the lightest products, with fragmentation. The model fits provided a means of quantitatively separating the components. The low-energy component was found to be consistent with a deep spallation mechanism. Physical parameters calculated for both components were within the expected ranges.;The formation of most products was determined to be inconsistent with the two-step model. An invariant cross section analysis of the high-energy component suggests that peaks at sideward angles reflect the intrinsic angular distributions. No significant correlation between source and fragment velocities was found. The deep spallation component was found to be emitted from a source moving at large angles to the beam. Physical parameters calculated from the data with the fast breakup model were within expected ranges, with the exceptions of the width of the spray particle momentum distribution and the Coulomb angle.