Concept and Performance of the ALICE Experiment at the LHC

An important part of the experimental program at the LHC to be built at CERN will be devoted to the study of the phase transition to quark-gluon plasma in heavy-ion collisions. ALICE is the only LHC experiment fully dedicated to analyse heavy-ion collisions at a center-of-mass energy of 5.5TeV per nucleon. The prime aim of the detector is to study in detail the behaviour of matter at high energy densities in order to establish the existence of QCD bulk matter and to bring into evidence the characteristics of the phase transition from the hadronic phase to the quark-gluon plasma. ALICE will cover the hadronic observables and decays of charmed and strange particles in a multilayered central barrel part where momentum determination as well as particle identification will be performed with a coverage of +- 0.9 rapidity units around midrapidity. On the other hand, the search for the suppression of quarkonia states is envisaged with a dedicated dimuon spectrometer positioned at forward rapidities. In this presentation we will give a short presentation of the layout of ALICE. The design and performance of the main detectors are presented as well as some R&D results.