ALICE - A LARGE ION COLLIDER EXPERIMENT AT LHC

ALICE (a large ion collider experiment) is a dedicated detector design ed to exploit the unique physics opportunities which will be offered b y nucleus-nucleus collisions at the LHC. At the LHC, it will be possib le to explore a radically new regime of matter, stepping up by a large factor in both volume and energy density from the nuclear interaction s foreseeable at the SpS. In addition, thanks to the huge number of se condaries produced, it will be possible for the first time to treat a strongly interacting system as a thermodynamical one, measuring most o f the relevant variables on an event-by-event basis. ALICE has been co nceived as a general-purpose detector, in which most of the hadrons, l eptons and photons produced in the interaction can be measured and ide ntified. The baseline design consists of a central (\eta\ less than or equal to 0.9) detector covering the full azimuth and a forward (2.4 l ess than or equal to eta less than or equal to 4) muon arm, complement ed by a multiplicity detector covering the forward rapidity region (up to \eta\ = 4.5) and a zero degree calorimeter. The central detector w ill be embedded in a large magnet with a weak field of 0.2 T, and will consist of a high-resolution inner tracking system, a cylindrical tim e projection chamber, particle identification arrays (time of flight a nd ring imaging cerenkov detectors) and a single-arm electromagnetic c alorimeter. A forward magnetic spectrometer to study vector meson prod uction completes the apparatus.