Physics aspects of the DELPHI vertex detector

The contribution of the microstrip silicon vertex detector to the physics from the DELPHI experiment at LEP is presented. The tagging of quark flavour for Z0 decays to (dd, uu, ss), cc, bb, tt, and the spectroscopy of short-lived particles are the most natural initial physics goals for a vertex detector and provide a good introduction to more exotic physics investigations. Results of the Monte Carlo studies show the considerable improvement given by the vertex detector to these fields. The features important for the physics performance, such as detector geometry, measurement precision, alignment and pattern recognition, are discussed. Finally, some preliminary remarks concerning simple but efficient improvements of the detector geometry for the future are made.