Emission of energetic protons at backward angles in central collisions

Abstract Backward-angle protons produced in collisions between intermediate-energy complex projectiles and 238 U are shown to originate from reactions which involve large linear momentum transfers to the target. Spectral slopes yield apparent temperatures that are 2–3 times larger than for a fully equilibrated, complete-fusion source. Comparisons with intranuclear cascade and precompound decay calculations suggest a multiple-collision mechanism that is intermediate between quasi-free scattering and complete thermalization.