A Single arm spectrometer detector system for high-energy heavy ion experiments

Abstract The recent availability of 14.6 GeV/ c per nucleon 16 O and 28 Si ions from the Brookhaven National Laboratory Tandem-AGS accelerator facility has prompted the design, construction and operation of a large-solid-angle (25 msr) magnetic spectrometer with particle identification from ∼0.5 to ∼4.7 GeV/ c . A small-solid-angle Cherenkov counter complex views the target through the magnet and extends the particle identification up to ∼15 GeV/ c . This experiment (E-802) employs event characterization detectors, a charged-particle multiplicity array, a highly segmented lead-glass detector, and a zero degree calorimeter. The facility measures momentum spectra of identified heavy-ion-produced hadrons with high resolution ( Δp / p ≤0.005) as a function of collision centrality given by triggers from the event characterization detectors. Construction and performance details of the spectrometer components and auxiliary detectors are described.