Prototype testing for the UCNProBe experiment

Recent measurements of the free neutron lifetime using ultracold neutrons (UCNs) continue to disagree with results from cold neutron beam experiments by four to five standard deviations. The UCNProBe experiment will measure the neutron decay lifetime using UCNs and address this discrepancy. To measure the beta decay lifetime, we will count the number of UCNs in the trap as well as the number of beta decay electrons to 0.1 percent precision. The apparatus consists of a layer of deuterated scintillator for confining UCNs and an outer veto plastic scintillator layer. In this talk, we will present the new detection method for collecting light from the scintillating layers using PMTs, as well as expected backgrounds from neutron capture and mitigation, and ongoing prototype testing.