Boron coated YAP:Ce scintillator as a UCN detector

The upcoming UCNProBe experiment at Los Alamos National Laboratory will measure the decay time of free neutrons with different systematic uncertainties than previous beam experiments. We have developed a new boron coated YAP:Ce scintillator whose properties are presented. The scintillator was tested for various scintillation properties, such as decay time, light yield, and quenching fraction. The advantage of the YAP scintillator is its high Fermi potential value, which reduces the probability for upscattering of ultracold neutrons, and thus the neutron detection efficiency can be directly measured by coincidence measurement of the 480 keV gamma radiation from neutron capture on boron. We report the scintillation studies on YAP and a preliminary UCN capture study on this boron coated scintillation and discuss the implications for the UCNProBe experiment.