Performance of irradiated n+n+-on-pp silicon microstrip sensors

The silicon microstrip detector type with n+n+ readout fabricated on p bulk, n+n+-on-pp, is a candidate to be operational in radiation environments much severer than in LHC. We characterized n+n+-on-pp detectors which were irradiated up to 1.1×1014protons/cm2 10 years ago. The noise level and charge collection were evaluated using the ATLAS SCT readout electronics system. Radiation-induced increase in the noise and loss in the charge collection are not significant. The charge collection is not degraded in any particular point in the inter-strip region when the detector is operated under partial depletion.