Initial Performance of Beam Pipe PWC Installed in CLEO at CESR

Abstract

We have constructed a triplet of cylindrical proportional chambers with anode and cathode strip read out that now forms the innermost element of the CLEO detector. The double read out allows tracking in both the axial and longitudinal views. Center of charge calculation on the cathode strips provides an accuracy of about 0.3 mm on the longitudinal coordinate. We describe the construction and the initial performance of the chambers and discuss their use in the trigger system, in rejecting cosmic rays and beam-gas and beam-wall interaction and in selecting specific final states.