Searching for Cosmic Rays with the BEACON Prototype

A cosmic ray search with the prototype for the Beamforming Elevated Array for COsmic Neutrinos (BEACON) helps characterize the BEACON instrument, including the RF trigger that is ultimately crucial for detecting tau-neutrino induced geomagnetic emission with this mountaintop array. The well-studied cosmic ray flux allows us to quantify the detector’s performance and discrimination against backgrounds. Detection and characterization of a well-understood population of cosmic- ray events seen by the detector can be used to optimize the RF trigger on a full-scale BEACON experiment. Presented here are the preliminary results of a cosmic ray search using the 2021 detector, and the motivation for a detector upgrade in October 2023. These detector upgrades introduced a new antenna design, new modular data acquisition hardware, and an independent scintillator array detector. The scintillator array provides an independent detection of cosmic rays, yielding a sample of cosmic ray events with coincident RF triggers to characterize the RF trigger. The progress for a cosmic ray search with the 2023 detector using coincident scintillator and RF signals is presented.