R&D Efforts at UMass to Progress the Understanding of Charge and Light Calibration for nEXO.

The 5-ton liquid xenon TPC of the nEXO experiment will search for the elusive neutrinoless double beta decay of ¹³⁶Xe with a half-life sensitivity goal of >10²⁸ years. This presentation will describe the status of the R&D at UMass Amherst on novel calibration strategies for ionization charge clusters and photon detection calibration to help reach that sensitivity goal. We explore photo-electricity of gold to produce ionization clusters, and measure their properties as they drift through liquid xenon. We use a dual grid ionization chamber as one way to measure the properties of these electron clusters, also discussed in this presentation.