Measurement of the muon flux in the bunker of Monte Soratte with the CRC detector

TL;DR

This study measures the muon flux inside the Monte Soratte bunker using the CRC detector to evaluate its suitability for low-background astroparticle physics experiments.

Contribution

It provides the first muon flux measurement inside the Monte Soratte bunker using a portable detector during COVID-19 lockdown.

Findings

Muon flux is over two orders of magnitude lower than surface levels.

The bunker environment is suitable for low-background physics experiments.

The CRC detector proved effective in remote, low-resource conditions.

Abstract

In the context of the PTOLEMY project, the need for a site with a rather low cosmogenic induced background led us to measure the differential muon flux inside the bunker of Monte Soratte, located about 50~km north of Rome (Italy). The measurement was performed with the Cosmic Ray Cube (CRC), a portable tracking device. The simple operation of the Cosmic Ray Cube was crucial to finalise the measurements, as they were carried out during the COVID-19 lockdown and in a site devoid of scientific equipment. The muon flux measured at the Soratte hypogeum is above two orders of magnitude lower than the flux observed on the surface, suggesting the possible use of the Mt. Soratte bunker for hosting astroparticle physics experiments requiring a low environmental background.