TEST-RESULTS OF A FULLY PROJECTIVE LEAD SCINTILLATING-FIBER CALORIMETER/

We report on an experimental study of the properties of a modular lead /scintillating-fiber calorimeter with a fully projective tower geometr y. Although the calorimeter structure is monolythic, an effective segm entation into an electromagnetic and an hadronic section is achieved b y separating the readout of the fibers running throughout the calorime ter from those starting beyond a depth of similar to 25 radiation leng ths. This feature is used for e/pi separation. Discontinuities in the sampling fraction near the boundaries of the modules cause a signal no nuniformity for electrons, which can be corrected. Similar effects obs erved for high energy hadrons are discussed. Results are given on the energy and position resolution for electrons, on the signal linearity and on the absolute light yield. Pion showers were only partially cont ained in this detector. The information from a backing calorimeter, co nsisting of fast thin-gap wire chambers interleaved by iron slabs, sig nificantly improves the energy resolution of the incompletely containe d pion showers.