Performance of the Mu2e Cosmic Ray Veto Modules

The Muon-to-Electron Conversion (Mu2e) experiment at Fermilab will search for charged-lepton flavor violation through the neutrino-less conversion of a muon to an electron in the presence of a nucleus. Mu2e aims for a single-event sensitivity of 3×10^-17, which would improve upon current experimental limits by four orders of magnitude. This sensitivity will require less than one expected background event over the lifetime of the experiment. The largest background comes from cosmic rays entering the experimental hall, which can produce electrons indistinguishable from a signal signature. To mitigate this, Mu2e will use a cosmic ray veto (CRV), which must exceed a veto efficiency of 99.99% to meet Mu2e's sensitivity goals. This talk reports on performance studies of CRV detector components.