New Operation Scenarios for Severely Irradiated Silicon Detectors

Abstract

Recent charge collection measurements after severe hadron irradiation have proved that n-side readout segmented planar silicon detectors can successfully operate up to the doses anticipated for the innermost layers of the upgraded experiments in the future super LHC (sLHC) at CERN. The charge collected by the irradiated sensors is sufficient to guarantee a signal over noise (S/N) ratio above 10 even for the pixel layers located at the smallest radial distance from the beam line (less than 4 cm away). The signal depends on the applied bias and voltages as high as 1000V could be required to satisfy the minimum signal height for the most exposed detectors. The radiation at the doses of the pixel layers in the sLHC also cause an important increase of the reverse current The high bias voltages and reverse currents cause significant power dissipation and adequate cooling needs to be applied to limit the current well below the thermal-runaway level.