Measurement of the cosmic muon flux at the Stawell Underground Physics Laboratory

TL;DR

This paper presents the first measurement of the underground cosmic muon flux at the Stawell Underground Physics Laboratory, using scintillator panels, providing precise data that aligns well with simulations.

Contribution

It provides the first measurement of muon flux at this site, validating simulation models with high precision and supporting future underground physics experiments.

Findings

Measured muon flux: (6.33 +/- 0.04_stat +/- 0.35_sys) x 10^{-8} s^{-1} cm^{-2}

Measurement agrees with simulations within a small uncertainty margin

Demonstrates the effectiveness of the muon veto system for SABRE South

Abstract

We report the first measurement of the underground cosmic muon flux at the Stawell Underground Physics Laboratory. The measurement uses eight EJ200 plastic scintillator panels, equipped with Hamamatsu R13089 PMT pairs at the ends, which are the primary components of the muon veto system for the upcoming SABRE South experiment. The measured muon flux is f = (6.33 +/- 0.04_stat +/- 0.35_sys) x 10^{-8} [s^{-1} cm^{-2}]. This measurement is in excellent agreement with simulations, with a relative uncertainty an order of magnitude smaller than the modelling uncertainty.