The CLEO-II detector

Abstract The new detector for data recording by the CLEO collaboration at the Cornell Electron Storage Ring is described. This detector has been designed to optimize studying e + e − annihilation into hadronic matter at a total energy of 10 GeV. It consists of high precesion charged particle tracking chambers and an electromagnetic calorimeter together with systems for particle identification. The design of the detector and its performance over the first year and a half of operation are presented.