New Small Wheel Upgrade – Small Thin Gap Chamber Assembly, Testing, and Integration

The small wheel is the innermost component of the muon endcap of the ATLAS experiment at CERN. It is currently being upgraded and replaced by a newer and more efficient model for the higher luminosity runs of the Large Hadron Collider (LHC). New wire chambers for triggering, nicknamed small-strip Thin Gap Chambers (sTGCs), are among the most important elements being enhanced in the New Small Wheel (NSW). The chambers are produced in various institutions worldwide, and then delivered to CERN for wedge assembly and testing. This paper gives a summary of the production chain used for the integration of sTGCs at CERN, with an emphasis on the testing carried out at the Gamma Irradiated Facility (GIF++) and long-term high voltage (HV) testing post-assembly.