THE E864 LEAD-SCINTILLATING FIBER HADRONIC CALORIMETER

A large hadronic lead scintillating fiber calorimeter has been built a nd integrated into the AGS experiment E864 [C. Pruneau et al., E864 Co llaboration, Proc. 6th Internat. Conf, on Calorimetry in High Energy P hysics, 1996, Frascati, Italy; F. Rotondo et al, E864 Collaboration, P roc. Quark Matter 96, Heidelberg, Germany, 20 May 1996] spectrometer t o provide an independent measurement of the mass of particles produced in heavy ion collisions. The ''spaghetti-type'' calorimeter design an d construction techniques are described in detail. Results from a prot otype and the full implementation of the calorimeter are reported. The hadronic energy resolution of the calorimeter is found to be delta E/ E = 0.035(+/-0.005) + 0.344(+/-0.008)/root E/GeV, in very good agreeme nt with a FLUKA calculation. The hadronic time resolution is measured to be better than 400 ps. The combined calorimeter energy and time sig nals provide for a mass determination with good resolution. The mass r esolution scales as delta m/m = 0.026 + 0.347/root E(GeV) for velociti es v/c < 0.98. (C) 1998 Published by Elsevier Science B.V. All rights reserved.