Uranium scintillator calorimeter at the CERN ISR

The design, Monte Carlo studies and test beam results of a uranium/scintillator calorimeter to be installed in the Intersecting Storage Ring (ISR) at CERN are described. In its final stage the calorimeter will cover the full azimuth over a polar region of 450 < theta < 1350. The full calorimeter is built in a modular way from 128 stacks, with each stack internally subdivided into six cells of 20 x 20 cm2 cross section. The readout is by wavelength shifting (WLS) plates with a separate readout of the front part of the calorimeter (first ten plates) to allow electromagnetic/hadronic separation. Since the readout plates are on both sides of the cells, position information is obtained from the left/right ratio