Design, performance and status of the CLEO III silicon detector

Abstract The CLEO III silicon detector is part of a general upgrade of the CLEO detector to allow for operation at a luminosity of 2×10 33 cm −2 s −1 , which will be provided by the Cornell Electron–Positron Storage Ring (CESR) beginning in 1999. The silicon detector is a four-layer barrel design covering radii from 2.5 to 10.2 cm with 93% solid angle coverage. The silicon sensors are DC-coupled and double-sided with double-metal readout on the p-side. The n-type strips measure φ , with 50 μ m pitch while the p-type strips measure z , the coordinate along the beam axis, with 100 μ m pitch. The readout electronics are mounted on BeO hybrids attached to the conical support structure and connected to the silicon sensors via a thin kapton flex cable. The electronics consist of an R / C chip with bias resistors and decoupling capacitors, a low-noise preamp/shaper chip and a digitizer/sparsifier chip. Readout is done using VME-based sequencer boards. Production of all detector components is nearing completion and installation of the detector will take place in early 1999.