AugerPrime: The second phase of the Pierre Auger Observatory*

The Pierre Auger Observatory has been significantly enhanced through the implementation of AugerPrime, a comprehensive upgrade primarily targeted at improving the precision of composition measurements made by the Surface Detector (SD). AugerPrime represents a crucial evolution from the Phase-I setup, incorporating key modifications to broaden the Observatory's capabilities. The main component of the upgrade is the addition of Surface Scintillator Detectors (SSDs) and radio antennas atop the existing Water-Cherenkov Detectors to enhance the reconstruction capabilities of the SD by analyzing the different responses to the electromagnetic and muonic components of extensive air showers. The upgrade also includes new electronics with improved timing resolution, the expansion of the Underground Muon Detector, and the extension of the duty cycle of the Fluorescence Detector.

Although the full scope of AugerPrime is still being implemented, the SSDs and electronics upgrades are now fully deployed, while radio has just reached the 50% mark. A recent major review has underscored the upgrade's potential for success, acknowledging its substantial improvements in precision and reliability. In light of this successful review, the Pierre Auger Observatory is now recommended to continue operations through 2035. This extended operational timeline ensures the collection of an extensive and invaluable dataset, allowing researchers to explore the complexities of cosmic-ray interactions and composition with unprecedented accuracy. This presentation will delve into the technical details of the AugerPrime upgrade, highlighting the key advancements in detector technology and discussing the implications of the extended operational period for the Pierre Auger Observatory.