Final size planar edgeless silicon detectors for the TOTEM experiment

The TOTEM experiment will detect leading protons scattered in angles of microradians from the interaction point at the large hadron collider. This will be achieved using detectors with a minimized dead area at the edge. The collaboration has developed an innovative structure at the detector edge reducing the conventional dead width to less than 100 μm, still using standard planar fabrication technology. In this new development, the current of the surface is decoupled from the sensitive volume current within a few tens of micrometers. The basic working principle is explained in this paper. Final size detectors have been produced using this approach. The current–voltage and current–temperature characteristics of the detectors were studied and the detectors were successfully tested in a coasting beam experiment.