Timing and Energy Calibrations for Systematic Studies in Nab

Neutron beta-decay provides crucial information towards testing the unitarity of the CKM matrix through the parameter Vud. Nab's overarching goal is to determine 'a'- the angular correlation between the electron and the antineutrinoand 'b' the electron energy spectrum. Timing and energy calibrations are essential for minimizing systematic effects in the Nab experiment. One strategy to accomplish this is by using radioactive sources with electron-gamma ray coincidences to calibrate a CeBr3 scintillator which will be used as a stopwatch for the Nab detectors. In this presentation we will show how we calibrate the CeBr3 detector to less than a nanosecond, the analyses performed, and outline future work at Oak Ridge National Lab.