Potassium-40 geoneutrinos detection and the Earth's large-scale structures imaging by directional geoneutrino detection

TL;DR

This paper explores a directional detection method for geoneutrinos, focusing on K-40, to image Earth's large-scale structures and determine its inner composition.

Contribution

It proposes a Cherenkov liquid scintillator technique for directional geoneutrino detection and evaluates its sensitivity and imaging potential.

Findings

3 sigma sensitivity to potassium neutrinos is 2.8 kiloton-years.

Exposure of 10.6 kiloton-years can reject uniform geoneutrino distribution at 3 sigma.

Directional detection can help image Earth's large-scale structures.

Abstract

Geoneutrinos, the electron (anti)neutrinos generated in decays or decay chains of the radioactive elements within the Earth, primarily K-40, U-238, and Th-232, serve as a unique probe for the inner chemical composition of the Earth. A directional geoneutrino detection method with a Cherenkov liquid scintillator is investigated in this work. The neutrino-electron elastic scattering in the scintillator is employed to detect geoneutrinos. The direction reconstruction resolution for neutrinos is studied based on previous measurements and simulations. The intrinsic neutrino background from the Sun is suppressed with an optimized solar angle cut. The 3 sigma sensitivity to discover the potassium neutrinos is 2.8 kiloton-years. The potential to reach a non-uniform geoneutrino image with the Earth's large-scale structures is also studied. The required exposure is 10.6 kiloton-years to reject a uniform geoneutrino distribution by 3 sigma.