Experience with the ZEUS micro-vertex detector

The HERA accelerator underwent a major upgrade in the year 2000. The upgrade was partly motivated by the desire to determine the contribution of heavy quarks and gluons to the proton structure more accurately. To benefit from the expected increase in luminosity, the ZEUS experiment was equipped with a silicon micro-strip detector. This vertex detector was designed to recognize short lived c- and b-hadrons, produced in deep inelastic scattering. After the restart, the HERA collider suffered from severe background problems and therefore the ZEUS experiment collected significant luminosity only since the end of 2004. Until the end of 2006 the integrated luminosity collected by the ZEUS experiment is 350pb-1, most of it with good vertex detector data (99%).