A Ton-Scale Detector for Observing CEvNS Recoils on Sodium Nuclei

This chapter discusses the motivation, design, and development work for COHERENT’s ton-scale NaI[Tl] array. It shows results of a measurement of the intrinsic backgrounds of the NaI[Tl] crystals that form the detector taken inside lead-shielding, and an in-situ measurement of backgrounds originating from these crystals at the SNS. It describes the development of a base for reading out low-energy CEvNS signals and higher-energy charged-current signals. A preliminary design for the COHERENT tonne-scale NaI[Tl] detector is presented, along with an estimate of its sensitivity for a three-year exposure.