A multiplicity-vertex detector for the PHENIX experiment at RHIC

A Multiplicity-Vertex Detector (MVD) has been designed, and is in construction for the PHENIX Experiment at the Relativistic Heavy Ion Collider (RHIC). The 35 000 channel silicon detector is a two-layer barrel comprised of 112 strip detectors, and two disk-shaped endcaps comprised of 24 wedge-shaped pad detectors. The support structure of the MVD is very low mass, only 0.4% of a radiation length in the central barrel. The detector front-end electronics are a custom CMOS chip set containing preamplifier, discriminator, analog memory unit, and analog-to-digital converter. The system has pipelined acquisition, performs in simultaneous read/write mode, and is clocked by the 10 MHz beam crossing rate at RHIC. These die, together with a pair of commercial FPGAs that are used for control logic, are packaged in a mutlichip-module (MCM). The MCM will be fabricated in the High-Density-Interconnect (HDI) process. The prototype MCM design layout is described.