The CMS Muon Endcap (ME0) GEM Detector

The CMS Muon system is undergoing substantial upgrades in preparation for High-Luminosity LHC operations, including the installation of the Muon Endcap 0 (ME0) detector. The ME0, a 6-layer station slated for production beginning in 2024, will extend the geometrical acceptance for muons in the pseudorapidity range of 2.03 < |$\eta$| < 2.8. Each of the 18 chambers per endcap houses six triple-Gas Electron Multiplier (GEM) detectors, which will enhance muon tracking by providing six hits per track, providing a reliable track reconstruction at the first trigger level. Production and quality control are distributed across multiple sites to streamline the process. Design improvements for ME0 have been informed by lessons learned from previous upgrades, aligning with the broader goals of strengthening muon triggering and reconstruction capabilities. This report presents an overview of the ME0 upgrade and its current status.