A silicon micro vertex detector for the ZEUS experiment

At the time of the HERA luminosity upgrade in the year 2000, the ZEUS experiment will be extended with a silicon micro-vertex detector. The barrel part of this vertex detector is a 60 cm long cylinder with silicon sensors arranged around the beam pipe. The forward part consists of four circular-shaped disks. In this paper the design criteria are explained. Since the front-end electronics are incorporated inside the active volume of the detector an important issue is the cooling. In addition, the alignment monitoring and geometrical survey scheme are presented.