Test beam results of Current Injected Detectors (CID) irradiated up to 5×1015 1 MeV neq/cm2

Two full size strip detectors were investigated in this study: one with p+ strips (p+/n-/n+) and another with n+ strips (n+/p-/p+). Both detectors, are made of magnetic Czochralski silicon (MCz-Si) and irradiated to S-LHC fluencies, were tested with 225 GeV muon beam in the CERN H2 area. The Current Injected Detector (CID) sensors were operated in a cooling box capable of providing a -53 °C temperature. Results indicate a relative charge collection efficiency (CCE) at 5×1015 neq/cm2 above 30% in irradiated p+/n-/n+ CID detector at 600 V bias voltage. The signal to noise ratio of this CID module was about eight and a forward current of 30 μA was needed for detector biasing. In standard reverse bias, the same detector could not provide a sufficiently large signal for particle tracking purposes. A p-type (n+/p-/p+) sensor was irradiated to a fluence of 2×1015 neq/cm2 and measured under the same test beam conditions. According to the theory of CIDs developed by the CERN RD39 Collaboration, this detector module could be biased up to only 230 V due to the low irradiation fluence. The CCE at 230 V was 35% in CID operation and 20% when reverse biased.