ANZIVINO, G (reprint author), CERN,CH-1211 GENEVA,SWITZERLAND.
In the framework of the LAA project at CERN, the RD25 R&D group has built a fully projective, integrated electromagnetic and hadronic, lead/scintillating fibres compensating calorimeter prototype. The prototype consists of 41 modules, each made of a straight (or electromagnetic) and two wedged (or hadronic) sections, with a lead to fibres ratio of 4 to 1 in volume. We describe in this paper the performances of the calorimeter exposed to high energy electron and pion beams: results are presented on electromagnetic and hadronic energy resolution, position resolution and particle/particle separation in space. Prototype construction required the development of a technology, also described in this paper, which is directly scalable to the construction of a 4 sr detector, intended to measure, localize and identify particles in a multi-TeV hadron collider experiment.