The Energy Dependence of Flow in Ni Induced Collisions from400Ato1970AMeV

We study the energy dependence of collective (hydrodynamic-like) nuclear matter flow in (400–1970)A MeV $\mathrm{Ni}+\mathrm{Au}$ and (1000–1970)A MeV $\mathrm{Ni}+\mathrm{Cu}$ reactions. The flow increases with energy, appears to reach a maximum, and then to decrease at higher energies. A way of comparing the energy dependence of flow values for different projectile-target mass combinations is introduced, which demonstrates a more-or-less common scaling behavior among flow values from different systems.