Development of cosmic ray detection module with liquid scintillator and wavelength shifting fiber

Abstract

 For neutrino physics and rare event searches, backgrounds from cosmic muons pose a notable challenge
and must be identified and rejected. It is also a challenge to control the experimental cost with a better
detector performance for a large array of cosmic ray detection. We propose a cosmic ray detection module
with liquid scintillator and wavelength shifting fibers. Preliminary tests were conducted on the detector
module filled with air or water. The results indicate that the detector’s photoelectron response is weak
but consistent with expectation, with minimal variation across different water thicknesses. With 8cm thick
water filled, the photoelectron distribution follows a Landau distribution, with a peak at approximately 7.7
photoelectrons. In future research, liquid scintillator will be incorporated into the detector module to fur
ther test its detailed performance. The outcomes of this study hold significant potential for applications in
cosmic ray observation experiments and underground rare-event detection, providing a viable option for
future large-scale observatories. This work highlights the feasibility of liquid scintillator-based detectors
in addressing current and emerging challenges in particle physics and astrophysics.