The design, construction and performance of the ALEPH silicon vertex detector

The ALEPH Silicon Vertex Detector is the first detector operating in a colliding beam environment that uses silicon strip detectors which provide readout on both sides and hence a three-- dimensional point measurement for the trajectory of charged particles. \par The detector system was commissioned successfully at the $e^+e^-$ collider LEP at the research centre CERN, Switzerland, during the year 1991 while taking data at the $Z^0$ resonance. The achieved spatial resolution of the complete 73~728 channel device (intrinsic plus alignment) is $12 \; \mu m$ in the $r \cdot \phi$ view and $ 12 \; \mu m$ in the $z$ view. \par The design and construction of the entire detector system are discussed in detail and the experience gained in running the detector will be described with special emphasis on the uses of this novel tracking device for the physics of short-lived heavy particles produced in the decays of the $Z^0$ resonance.