Detector Systematics for the Nab Experiment

The Nab experiment at the Spallation Neutron Source (SNS) will make precision measurements of the electron-neutrino correlation coefficient and the Fierz interference term for neutron beta decay. The experiment will use a novel field expansion spectrometer to measure electron energy and proton momentum. Two important systematics are detector energy calibration and time of flight shift. Energy calibration is specified as \delta E < 200eV and time of flight shift is specified as \delta t < 0.3 ns. In situ radioactive sources will be heavily used in efforts to characterize both of these systematics. Characterizing the detectors’ energy response linearity will be done using a pulser. This talk will present these systematics, their importance to Nab, plans for measurement, as well as Geant4 simulation to show the plausibility of our plans.