Design, performance and status of the CLEO III silicon detector

The CLEO III silicon detector is part of a general upgrade of the CLEO dete ctor to allow for operation at a luminosity of 2 x 10(33) cm(-2) s(-1), whi ch will be provided by the Cornell Electron-Positron Storage Ring (CESR) be ginning in 1999. The silicon detector is a four-layer barrel design coverin g radii from 2.5 to 10.2 cm with 93% solid angle coverage. The silicon sens ors are DC-coupled and double-sided with double-metal readout on the p-side . The n-type strips measure phi, with 50 mu m pitch while the p-type strips measure z, the coordinate along the beam axis, with 100 mu m pitch. The re adout electronics are mounted on BeO hybrids attached to the conical suppor t structure and connected to the silicon sensors via a thin kapton flex cab le. The electronics consist of an R/C chip with bias resistors and decoupli ng capacitors, a low-noise preamp/shaper chip and a digitizer/sparsifier ch ip. Readout is done using VME-based sequencer boards. Production of all det ector components is nearing completion and installation of the detector wil l take place in early 1999. (C) 1999 Elsevier Science B.V. All rights reser ved.