The Production of Very-High Light Particles in Heavy Ion Reactions, E/a Less than or Equal to 40 Mev/u.

It has been observed experimentally in medium energy heavy ion reactions that it is possible to produce light particles with energies approaching the beam energy. Several experiments were done to examine this phenomenon at higher beam energies and the results were remarkable. Beams of heavy ions (A >=q 16) with energy in the range of 0.3-1.3 GeV were stopped in thick targets. Light particles (protons, deuterons, tritons and alphas) emitted in forward angles with very high energy were stopped in large scintillators including one detector (4.2 x 15 cm Bismuth Germanate Oxide) capable of stopping 0.3 GeV protons and 1.3 GeV alphas. Remarkably, alpha-particles are emitted near 0^circ with nearly the full beam energy for ^{16}O and ^{32}S beams. The results were interpreted by a break-up plus Fermi motion mechanism known as the moving-source model and source velocities and temperatures deduced. Source velocities near the beam velocity are needed to fit the foreward-angle data. This and the particle multiplicites are consistent with projectile fragmentation.