Measurements of muon flux in the Pyh\"asalmi underground laboratory

TL;DR

This study measures muon flux at various depths in the Pyh"asalmi mine, providing data that aligns with existing underground flux models and enhances understanding of cosmic-ray muons underground.

Contribution

The paper presents new muon flux measurements at multiple depths in the Pyh"asalmi mine, expanding data for underground cosmic-ray studies.

Findings

Muon flux decreases with depth as expected.

Measured fluxes are consistent with other underground laboratories.

A relation between muon flux and depth was established.

Abstract

The cosmic-ray induced muon flux was measured at several depths in the Pyh\"asalmi mine (Finland) using a plastic scintillator telescope mounted on a trailer. The flux was determined at four different depths underground at 400 m (980 m.w.e), at 660 m (1900 m.w.e), at 990 m (2810 m.w.e) and at 1390 m (3960 m.w.e) with the trailer, and also at the ground surface. In addition, previously measured fluxes from depths of 90 m (210 m.w.e) and 210 m (420 m.w.e) are shown. A relation was obtained for the underground muon flux as a function of the depth. The measured flux follows well the general behaviour and is consistent with results determined in other underground laboratories.