Neutrino-Nucleus Scattering Studies with the COHERENT Multi-ton NaI Array

A modular NaI[Tl] scintillation crystal detector array is designed to measure coherent elastic neutrino-nucleus scattering (CEvNS) and charged current interactions as part of the suite of COHERENT collaboration detectors deployed at the Spallation Neutron Source at the Oak Ridge National Laboratory. A CEvNS measurement on ²³Na will provide the smallest neutron number (N) result and when combined with cesium and argon measurements and a future germanium value, will test the expected standard model dependence of the cross section on N². The measured functional dependence of the cross section on N² will provide information on the form factor deviations from unity used in the calculations. Simulation studies on 7 modules with ~3.4 tons of NaI indicates a significance of about 3σ per year for a counting experiment on ²³Na. The detector design allows for a simultaneous measurement of the charged current, electron neutrino, inelastic scattering cross section on ¹²⁷I that is sensitive to quenching of the g_A coupling strength in weak processes with momentum transfer ~ 30 MeV and relevant to neutrinoless double beta decay calculations. The physics program, design, deployment status and tests of the initial 5-module array will be presented.