THE QUARTZ-FIBER ZERO-DEGREE CALORIMETER FOR THE NA50 EXPERIMENT AT CERN SPS

Quartz-fiber calorimeters have been the object of an intense and fruit ful work of research and development in the last few years. In this pa per we report about the first application of this technique in an expe riment. Namely, we describe the design and performance of the Zero-Deg ree Calorimeter (ZDC) used in NA50, a heavy-ion experiment at CERN SPS aiming to detect the formation of quark-gluon plasma in Pb-Pb collisi ons at 158 AGeV by studying the production of the charmonia states J/p si and psi'. The unique properties of the quartz-fiber calorimeters tu rn out to be well suited to match the specific requirements of this ex periment that operates at beam intensity of about 10(7) Pb-ion/s: radi ation hardness (up to a few Grads), short duration of the signal (simi lar to 10 ns), spatial resolution of a few hundreds of mu m, small siz e of the detector (5 x 5 x 65 cm(3)) and energy resolution adequate fo r providing a precise measurement of the collision centrality. (C) 199 8 Elsevier Science B.V. All rights reserved.