Simulations of the nEDM@SNS light collection system efficiency

Abstract A system for collecting the scintillation light produced by capture of ultra-cold neutrons (UCN) on polarized 3 He is discussed and results from simulations its performance are presented. This will be implemented in nEDM@SNS, experiment searching neutron electric dipole moment (nEDM) at Spallation Neutron Source (SNS) Oak Ridge National Laboratory. Simulation show that collection detects average 17 photoelectrons per UCN- event (sufficient to generate a robust signal), reconstructs location beam direction approximately cm accuracy, events with high spatially uniform efficiency (0.95 1% variation), rejects greater than 50% beta decay background events.