Characterization of irradiated P-type silicon detectors by the ALIBAVA system

Abstract

The ATLAS Tracker System has been designed to withstand the radiation doses accumulated with 10 years of running at a LHC luminosity of 10 34 cm - 2 s - 1 . The operation under an upgraded luminosity of 10 35 cm - 2 s - 1 (superluminous LHC) implies to upgrade the semiconductor tracking systems of the LHC experiments. The expected dose for the inner detector trackers at the superluminous LHC experiments is up to 10 16 1 MeV equivalent neutron cm - 2 after the envisaged five years of operation. Investigations have showed arguments in favour of implementing the n-type strip readout on a p-type substrate (currently the Semiconductor Tracker, SCT, uses p-type strip readout on a n-type substrate). In order to evaluate the radiation damage p-type microstrip sensors have been irradiated with neutrons and protons at several fluxes up to 10 16 cm - 2 . Electrical and charge collection efficiency measurements have been carried out by means of a radioactive source setup as well as by an infrared laser illumination and the measurements compared with a non-irradiated sensor as a reference. The ALIBAVA acquisition system has been used. It is a compact and portable system which contains two front-end readout chips (Beetle chip) to acquire the detector signals. One of the advantages of the ALIBAVA system is that it uses LHC speed electronics. Another one is that it performs a pulse by pulse and strip by strip analysis.