Planar edgeless silicon detectors for the TOTEM experiment

Roman pot silicon detectors for the LHC TOTEM experiment require a highly reduced insensitive area at the edge where, for electrical stability, a terminating structure is required. This work provides an innovative approach based on standard planar fabrication technology which reduces the conventional width of the terminating structure to less than 100 micrometers. The approach decouples the electric behaviour of the surface and the sensitive volume. Beam test measurements demonstrate that detectors with this new structure are fully operational and fully efficient in less than 60 micrometers from the die cut. Detailed results are provided in the paper.