Upgrade of pixel sensor telescope for the characterization of ALPIDE sensor

Abstract

A Large Ion Collider Experiment (ALICE) is an experiment station at CERN that detects quark-gluon plasma, a state of matter thought to have formed immediately after the big bang. A plan was proposed to upgrade the particle detector in the Inner Tracking System (ITS) of ALICE by 2020. In the upgrade, new silicon sensor technology, the Monolithic Active Pixel Sensor (MAPS), will be used to replace the ITS. The new sensor is called ALICE PIxel DEtector (ALPIDE). This project focused on the characterization of ALPIDE sensors with a new version of a pixel sensor telescope using the 1.2 GeV electron beam at the Synchrotron Light Research Institute Beam Test Facility (SLRI-BTF). Seven ALPIDE sensors were lined up as a stacked sensor to perform a test using the electron beam at SLRI-BTF. The previous version of the telescope could only characterize the middle area of the sensor; however, the new sensor telescope can be used to characterize edges and corners of the sensor. This advantage provides us with a complete view of the detection efficiency in all sections of the ALPIDE sensor. The detection efficiency of the sensor will be investigated and analyzed by EUTelescope software.