BEXCO - Room F(201/202/203/204)
[CRI163] The dynamic range of the AugerPrime Surface Detector: technical solution and physics reach
Ground arrays for ultra-high energy cosmic ray detection based on water-Cherenkov stations or scintillator modules are unavoidably limited by the saturation suffered by the counters closest to the shower axis. Reducing to a negligible level the amount of events with saturated detectors is mandatory to unambiguously record the highest energy events and to decrease the systematic uncertainties affecting the measurements. The Surface Detector Array of the upgraded Pierre Auger Observatory includes 1660 water-Cherenkov stations (WCD) covered by a 4 m^2 plastic scintillator plane (SSD). The impact point of the extensive air shower, its arrival direction and the lateral distribution of particles at ground can be reconstructed exploiting the recorded signals and their timing. The stations will use new electronics that will process signals from both the tanks and the scintillators with increased quality. The implementation of an extra small photomultiplier in each WCD and suitable photomultipliers with very large linearity in the SSD will allow us to extend the dynamic range to more than 32 times the largest signals currently measured. We describe the chosen technical solution and discuss the expected performances of the detectors, which will be able to measure non-saturated traces as close as few hundred meters to the core.