Quality Control Setup and Characterization of Silicon Pixel Detector Loaded Modules for the Inner Tracker of the ATLAS Experiment for HL-LHC

Physicists and engineers at CERN use the world's largest and most complex scientific instruments to study the basic constituents of matter – fundamental particles. Subatomic particles are made to collide together at close to the speed of light. The process gives us clues about how the particles interact and provides insights into the fundamental laws of nature. The purpose is to advance the boundaries of human knowledge by delving into the smallest building blocks of our universe. The instruments used at CERN are purpose-built particle accelerators and detectors. Accelerators boost beams of particles to high energies before the beams are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions. Nowadays, The European Organization for Nuclear Research (CERN) is in the process of developing the technologies required to upgrade their state-of-the-art particle accelerator, the Large Hadron Collider (LHC). This upgraded machine, known as the High Luminosity Large Hadron Collider (HL-LHC) aims to increase the number of particle collisions (formally referred to as luminosity) by a factor of 10 to increase the number of observations of rare particle phenomena. While the actual installation is expected to commence in 2027, the various engineering sections at CERN are already diligently working towards this milestone. One aspect of this upgrade involves the upgrade of the ATLAS detector system. In fact, The ATLAS detector at the Large Hadron Collider is undergoing a major upgrade with the construction of a new silicon Inner Tracker (ITk) that will operate at High Luminosity. This silicon tracking detector plays a crucial role in reconstructing tracks of charged particles. The ITk's pixel detector, located closest to the collision point, will comprise of approximately 10,000 pixel modules loaded onto carbon cooling structures. These loaded quad modules consist of four front-end chips, the silicon sensor, wire-bond protection, and are assembled onto thermal conductive support structures. The EP-ADE-TK section at CERN is working on a replacement of the Inner Detector with the new Inner Tracker.  Keywords: LHC, HL-LHC, ATLAS, ITK.