The ZEUS microvertex detector

For the HERA luminosity upgrade in the year 2000, the ZEUS experiment is preparing a high-precision vertex detector using single-sided silicon microstrip detectors with capacitive charge division. The readout pitch of the detectors is 120 μm with five intermediate strips. The paper reviews the design of the microvertex detector consisting of a central part with three double layers and four wheels in the forward region. Results on electrical measurements before and after irradiation on the detectors and on the test structures designed for quality-control measurements are presented. For a number of prototype detectors mounted to the prototype readout electronics (HELIX-128) the pulse height distribution and the position resolution has been measured in a test beam using 6 GeV electrons. The expected position resolution of about 7.5 μm at normal incidence has been achieved.