Readout of non-irradiated and irradiated strip detectors with fast analogue electronics

Silicon microstrip detectors with 50 μm readout pitch were connected to fast LHC-type analogue readout electronics (DMILL SCT32A) and their performance evaluated before and after irradiation. The p-type strips with a length of 4 cm were fabricated on high-resistivity n-bulk wafers by CSEM. Fast neutrons from the TRIGA research reactor in Ljubljana were used to irradiate detectors to two different fluences: 4.5×1013 and 1.5×1014/cm2 1 MeV neutron equivalent non-ionizing energy loss. A 90Sr β source setup was used for detector performance measurements. Most of the observed signal/noise degradation after irradiation could be attributed to the signal loss. Around 82% charge collection efficiency was measured at higher fluence 100 V above full depletion voltage as determined with C–V measurements. Measurements were performed during annealing and reverse annealing of effective dopant concentration.