Layered water Cherenkov detector for the study of ultra high energy cosmic rays

TL;DR

This paper introduces a new layered water Cherenkov detector design that enhances the measurement of muonic and electromagnetic components in cosmic ray air showers, enabling better primary cosmic ray mass classification at ultra high energies.

Contribution

The novel layered detector design improves component separation and primary particle classification compared to existing detectors in cosmic ray observatories.

Findings

Significant improvement in muonic and electromagnetic component measurement.

Fisher discrimination values of ~2 for iron vs. hydrogen primaries at >10^19 eV.

Potential for event-by-event cosmic ray mass classification.

Abstract

We present a new design for the water Cherenkov detectors that are in use in various cosmic ray observatories. This novel design can provide a significant improvement in the independent measurement of the muonic and electromagnetic component of extensive air showers. From such multi-component data an event by event classification of the primary cosmic ray mass becomes possible. According to popular hadronic interaction models, such as EPOS-LHC or QGSJetII-04, the discriminating power between iron and hydrogen primaries reaches Fisher values of $\sim$ 2 or above for energies in excess of $10^{19}$ eV with a detector array layout similar to that of the Pierre Auger Observatory.