CE\u3cem\u3eν\u3c/em\u3eNS N\u3csup\u3e2\u3c/sup\u3e Scaling Test Preparation: Characterization of NaI[Tl] Scintillating Crystal

Background: The COHERENT collaboration is dedicated to measuring Coherent Elastic Neutrino-Nucleus Scattering (CEνNS), an interaction predicted by the standard model. In the pursuit of observing the N2 scaling predicted, COHERENT is deploying nine tons of NaI[Tl] detector to observe CEνNS recoils of sodium nuclei. Before the nine tons of this NaI[Tl] scintillator are deployed, however, each crystal and PMT must be characterized to understand the individual properties vital to precision in the measurement of CEνNS. This detector is also expected to allow COHERENT to observe charged current and CEνNS interactions with 127I. Methods: A standard operating procedure is developed to characterize each detector based on seven properties relevant to precision in the measurement of CEνNS: energy scale, energy resolution, low-energy light yield non-linearity, decay time energy dependence, position variance, time variance, and background levels. Results: Crystals and PMTs will be tested and characterized for these properties in the context of a ton-scale NaI[Tl] detector. Preliminary development of the standard operating procedure (SOP) has allowed for greater understanding of optimization methods needed for characterization for the ton scale detector. Conclusions: The SOP for characterizing these detectors is in its final stages. Finalization of the SOP will allow for characterizing these detectors on the mass scale needed given the unusually large volume of scintillator to be deployed for the collaboration