PARTICLE AND FRAGMENT EMISSION IN VIOLENT RELATIVISTIC HEAVY-ION COLLISIONS: THE 4π-DETECTOR AT GSI, A NEW FACILITY FOR THIS INVESTIGATION

By the end of 1989 a new accelerator complex, SIS/ESR, comprising a synchrotron and a storage ring for heavy-ions, came into operation at GSI (Darmstadt). To serve this facility, the construction of a detection ensemble devoted to the measurement of π, K, p, complex particles (Z ≤ 2) and fragments (Z > 2) operating in a near 4π geometry has been undertaken. Charged particles and fragments only are dealt with in this contribution. The main motivations of Physics which justify such an enterprise are exposed, then the part (Phase I) of the detector designed for particle and fragment detection, is described in some detail while the Phase II, not yet operational, is only touched upon. Some first results obtained from measurements relative to Au (150 A MeV ) + Au central collisions are presented and discussed.