Geoneutrinos and reactor antineutrinos at SNO+

TL;DR

This paper discusses the potential of the SNO+ detector to measure geoneutrinos and reactor antineutrinos, highlighting its unique capability to distinguish signals from natural Earth sources and nuclear reactors, especially CANDU cores.

Contribution

It introduces the SNO+ experiment's potential to measure geoneutrinos and reactor antineutrinos with unprecedented detail, including the first long baseline measurement dominated by CANDU reactors.

Findings

SNO+ can distinguish between geoneutrino and reactor antineutrino signals.

Approximately 18% of the geoneutrino signal originates from local rocks.

Uncertainty in local lithology affects mantle signal discrimination and spectral analysis.

Abstract

In the heart of the Creighton Mine near Sudbury (Canada), the SNO+ detector is foreseen to observe almost in equal proportion electron antineutrinos produced by U and Th in the Earth and by nuclear reactors. SNO+ will be the first long baseline experiment to measure a reactor signal dominated by CANDU cores ($\sim$55\% of the total reactor signal), which generally burn natural uranium. Approximately 18\% of the total geoneutrino signal is generated by the U and Th present in the rocks of the Huronian Supergroup-Sudbury Basin: the 60\% uncertainty on the signal produced by this lithologic unit plays a crucial role on the discrimination power on the mantle signal as well as on the geoneutrino spectral shape reconstruction, which can in principle provide a direct measurement of the Th/U ratio in the Earth.