The quartz-fiber zero-degree calorimeter for the NA50 experiment at CERN SPS

Quartz-fiber calorimeters have been the object of an intense and fruitful work of research and development in the last few years. In this paper we report about the first application of this technique in an experiment. Namely, we describe the design and performance of the Zero-Degree Calorimeter (ZDC) used in NA50, a heavy-ion experiment at CERN SPS aiming to detect the formation of quark-gluon plasma in Pb–Pb collisions at 158 AGeV by studying the production of the charmonia states J/ψ and ψ′. The unique properties of the quartz-fiber calorimeters turn out to be well suited to match the specific requirements of this experiment that operates at beam intensity of about 107 Pb-ion/s: radiation hardness (up to a few Grads), short duration of the signal (∼10 ns), spatial resolution of a few hundreds of μm, small size of the detector (5×5×65 cm3) and energy resolution adequate for providing a precise measurement of the collision centrality.