Analysis and test of overhanging-metal microstrip detectors

The adoption of overhanging-metal contacts have been suggested as an effective mean to limit breakdown risks in heavy-damaged, high-voltage biased microstrip detectors. In this summary, the influence of such overhangs on device noise parameters is analyzed, with particular reference to the interstrip capacitance. Data have been collected on a set of detectors featuring variable overhang extensions and different width/pitch ratios, and numerical simulation has been exploited to provide physical interpretation of the experimental findings. In particular, the non-trivial dependence of interstrip capacitance over geometrical parameters is discussed. By looking at leakage currents and charge-collection as well, it is shown that limited-extension overhangs still have highly beneficial effects on the breakdown properties, while having no practical drawbacks on the detector performance