The upgraded electronics of the Pierre Auger surface detector

The surface detectors of the Pierre Auger Observatory are being upgraded by adding new detectors and replacing electronics.
The upgrade project, called "AugerPrime," includes the addition of a small PMT to increase the dynamic range of particle counting, a plastic scintillator above each water-Cherenkov detector to improve the discrimination between the electromagnetic and muonic shower components, a radio detector to measure radio emission from inclined air showers, and a set of underground muon counters to provide additional information on muon content in atmospheric showers.
The new electronics, dubbed Upgraded Unified Board (UUB), is designed to acquire all of these additional detectors and includes improved GPS receiver, higher sampling rate, increased dynamic range, greater processing capacity, and improved calibration and monitoring systems. In the following, we will describe the UUB design and discuss its performance as observed in the first data from the upgraded array.