Thermal Analysis of a D0 H-Disk Wedge

Each H-Disk ring assembly is comprised of 24 wedge assemblies. Figures 1-1 and 1-2 show the wedge mechanical layout. Each wedge consists of sets of two single-sided silicon detectors (referred to as inner and outer detectors, corresponding to their radial positioning) as provided by Moscow State University. Since these detectors are single sided, two mated inner/outer sets are arranged back-to-back such that they effectively become a double-sided detector with a 15{sup o} angle between the strips on either side. Six SVX II chips are mounted near the outboard edge of each outer detector since this location provides access to bond pads spanning the entire detector surface. Since the detector and chip bond pads are on significantly different pitches (approximately 80 vs. 48 microns), a pitch adapter is used to transition this jump, thus simplifying wirebonding. With the accompanying electronics required to support detector operation placed adjacent to the chips, the mountirig ring, which also acts as a means of cooling for the wedge, is by necessity located some distance from the chips, which are the primary heat source. The purpose of this report is to document the results of a thermal performance study of a wedge assembly. The methods, assumptions, and results for this investigation are discussed