Relatore
Descrizione
Rare event searches, such as those targeting dark matter interactions and neutrinoless double beta decay (0νββ), face challenges from gamma-rays originating in rock, contributing to electron recoil background. This report presents a dual investigation: measurements of natural radioactivity in rock samples from Boulby Mine and a simulation assessing shielding thickness for a future detector. The measurements provide data for normalising conditions in prospective experiments at Boulby. The simulation studies the effectiveness of water shielding around a detector, focusing on the Weakly Interacting Massive Particle (WIMP) energy range (0 – 20 keV) and the energy range near the 0νββ Q-value (2.458 MeV).
The study design features a simplified xenon-based detector with a 70-tonne active volume, encompassed by veto systems and water shielding. Our findings indicate that gamma-ray background is unlikely to persist through analysis cuts in the WIMP energy range. However, for 0νββ decay signal searches, adjustments will be required; the sensitivity of a next-generation detector demands a background of < 1 event per 10 years, necessitating a reduction in the fiducial volume of the detector.
