Speaker
Description
BUTTON-30 is a 30-tonne gadolinium-doped water-based liquid scintillator (Gd-WbLS) antineutrino detector at the Boulby Underground Laboratory (2850 m w.e.), the first underground deployment of Gd-WbLS and the first antineutrino detector sited directly in rock salt. We present a complete neutron-background model for the detector, developed in Geant4/RAT-PAC, for a sodium- and chlorine-dominated halite environment.
The study gives an end-to-end account of the inverse-beta-decay (IBD) background budget. Radiogenic (alpha,n) and spontaneous-fission production, cosmogenic neutron transport, and the cosmogenic radionuclide inventory are propagated through detector response and the coincidence analysis toward an IBD-like background estimate with a systematic budget, in which host-rock composition emerges as the leading uncertainty and motivates in-situ assay at the deployment station rather than an assumed composition.
Two themes carry beyond BUTTON-30. First, the cosmogenic radionuclide channels relevant to IBD in a water-based target are mapped and quantified, providing a characterisation of the prompt-single and beta-delayed-neutron backgrounds. Second, hadronic neutron production in this composition is compared with established reference calculations, framing BUTTON-30 as a potential in-situ constraint in salt and a testbed for the kiloton-scale and dark-matter detectors that the Boulby evaporites may host.