Final characterization of the ATLAS IBL detector modules with 241Am during the construction phase

During the first LHC long shutdown (2013/14) a new innermost pixel layer will be added to the present ATLAS pixel system. The Insertable B-Layer (IBL) is a high-reliability, ultra light and radiation hard Pixel detector (3D n-in-p and planar n-in-n sensors) which will restore the full b tagging efficiency, will preserve tracking performance in face of increasing luminosity effects and will add tracking precision to the existing detector. The production of the modules has already started, as their special mechanical supports (staves), which will be arranged cylindrically around the beampipe. A systematic quality assurance (QA) concerning modules, staves and flex from the production to the final assembly on the beampipe has been already started. The QA is performed in several institutes. In particular the final validation before the installation in the ATLAS experiment will be done at CERN. A special set-up has been arranged in order to perform a full chain test from sensors through data acquisition. A CO2 cooling system (TRACI) is used to cool down the pixel detectors up to -40°C and an electronic chain similar to the final one has been developed. Furthermore a linear motion system carrying two 241Am sources with an activity of 41 MBq each is mounted over the stave in order to perform a final characterization of the sensor performance, in term of noisy pixel, efficiency and spectrum scan. The linear motion software allows programming a systematic and automatic data taking for each stave module giving the opportunity to test quickly more modules simultaneously. In this work a detailed review of the tests conducted on the staves received at CERN is presented.