Characterization of Two Ton NaI Scintillator

The COHERENT collaboration is dedicated to measuring Coherent Elastic Neutrino-Nucleus Scattering (CE$\nu$NS), an interaction predicted by the standard model that ultimately serves as a background floor for dark matter detection. In the pursuit of observing the $N^2$ scaling predicted, COHERENT is deploying two tons of NaI[Tl] detector to observe CE$\nu$NS recoils of sodium nuclei. Before the two tons of this NaI[Tl] scintillator are deployed, however, all crystals and PMTs must be characterized to understand the individual properties vital to precision in the measurement of CE$\nu$NS. This detector is also expected to allow COHERENT to observe charged current and CE$\nu$NS interactions with $^{127}$I. A standard operating procedure is developed to characterize each detector based on seven properties relevant to precision in the measurement of CE$\nu$NS: energy scale, energy resolution, low-energy light yield non-linearity, decay time energy dependence, position variance, time variance, and background levels. Crystals will be tested and characterized for these properties in the context of a ton-scale NaI[Tl] detector. Preliminary development of the SOP has allowed for greater understanding of optimization methods needed for characterization for the ton scale detector.