PERFORMANCE OF THE CHORUS LEAD-SCINTILLATING FIBER CALORIMETER

We report on the design and performance of the lead-scintillating fibe r calorimeter of the CHORUS experiment, which searches for nu(mu)-nu(t au) oscillations in the CERN Wide Band Neutrino beam. Two of the three sectors in which the calorimeter is divided are made of lead and plas tic scintillating fibers, and they represent the first large scale app lication of this technique for combined electromagnetic and hadronic c alorimetry. The third sector is built using the sandwich technique wit h lead plates and scintillator strips and acts as a tail catcher for h adronic energy flow. From tests performed at the CERN SPS and PS an en ergy resolution of sigma(E)/E=(32.3+/-2.4)%/root E(GeV)+(1.4+/-0.7)% w as measured for pions, and sigma(E)/E=(13.8+/-0.9)%/root E(GeV)+(-0.2/-0.4)% for electrons.