Study of Reconstructed 39Ar Beta Decays at the MicroBooNE Detector

UNSPECIFIED (2018) Study of Reconstructed 39Ar Beta Decays at the MicroBooNE Detector. Other. UNSPECIFIED.

Abstract

In atmospheric argon, 39Ar beta decays occur at a rate of roughly one Becquerel per kilogram; as a result, large liquid argon time projection chambers (LArTPCs) see plentiful amounts of these decays in each event readout window. These 39Ar beta decays can provide a variety of different uses in LArTPC experiments. They allow for the study of reconstructing point-like ionization charge deposition in the detector, which is relevant for the reconstruction of supernova neutrino interactions. The point-like topology and well-known energy spectrum of 39Ar beta decays also provides a unique handle for calibrations. Presented here is the first study of reconstructing 39Ar beta decays in the MicroBooNE LArTPC. The spectrum of reconstructed electron energies from 39Ar beta decays, measured using raw TPC waveforms, is found to have a similar end point as the predicted distribution. Additionally, the signal shapes of reconstructed 39Ar beta decay candidates are used to validate the collection plane wire field response.