Alignment System of the ATLAS Muon End-Cap New Small Wheels

The muon spectrometer of the ATLAS detector at the LHC consists of thousands of muon precision chambers. Precise muon track reconstruction is crucial in order to achieve the physics goals of the ATLAS experiment, but attaining the required level of precision is not trivial due to the size and nature of the muon detectors. To reach the 80 microns precision needed to obtain a 10% precision on 1 TeV-momentum muon, an optical-based alignment system has been designed and installed on the muon spectrometer. In this talk I will discuss the recent upgrades of the alignment system, which consists of thousands of coupled light sources and optical sensors, focusing on the construction and commissioning of the system for the New Small Wheels, a brand-new addition to the muon end-cap spectrometer.