An Analysis of the Radiation Damage to the ATLAS Semiconductor Tracker End-Caps

The motivation, theoretical principles and analytical procedure for an assessment of the radiation damage to the ATLAS SCT end-caps is presented. An analysis of the leakage current across end-cap modules is performed for 2011 and 2012 data. A comparison between the observed and expected leakage current is made, with measurements favouring the shape of the theoretical evolution. Measured data is found to be systematically lower than predicted for a large subset of end-cap modules, while the remainder show surface current effects which interfere with bulk current observation. Uniform differences for modules at different radial distances suggest a radial temperature distribution in the end-caps, with absolute silicon sensor temperature to be established in further analysis.