DEVELOPMENT OF CENTRAL COLLECTIVE FLOW IN 100 MEV U AU+AU CENTRAL COLLISIONS/

Using the QMD model, the time evolution of the Au+Au system at 100 MeV /u has been studied. For very central collisions, the conditions for f reeze-out and how the different physical quantities approach equilibri um are investigated. The calculation results show that for 100 MeV/u A u+Au at b = 0 fm, the maximum density can reach 1.6 rho(0), after whic h the system expands to a low density region. A position correlated ce ntral dow develops during the expansion stage. Through study of the tw o-particle relative momentum spectrum, it is possible to separate the central dow from random thermal motion. The dependence of this central flow on the equation of state (EOS) is also discussed.