Zinc sulfide (ZnS:Ag) scintillators coated with a thin 10B layer are widely used for ultracold neutron (UCN) detection, but their application is limited by long decay times and significant phosphorescence. We investigated two possible replacement scintillators: yttrium aluminum perovskite (YAP:Ce) and lutetium ttrium orthosilicate (LYSO:Ce). Both exhibit decay times on the order of 30-40 ns, which can help reduce dead time in high-count-rate experiments. YAP:Ce showed approximately 60% lower phosphorescence than ZnS:Ag after 2 days and detected about 20% more UCN. In contrast, LYSO:Ce exhibited higher phosphorescence and produced fewer UCN counts compared to both ZnS:Ag and YAP:Ce. While both tested scintillators are capable UCN detectors, YAP:Ce consistently outperformed LYSO:Ce across all measured performance metrics.
@article{arxiv.2509.04332,
title = {Detection of ultracold neutrons with powdered scintillator screens},
author = {M. Krivos and N. C. Floyd and C. L. Morris and Z. Tang and M. Blatnik and S. M. Clayton and C. B. Cude-Woods and A. Fratangelo and A. T. Holley and D. E. Hooks and T. M. Ito and C. -Y. Liu and M. Makela and M. R. Martinez and A. S. C. Navazo and C. and M. O'Shaughnessy and R. W. Pattie and E. L. Renner and T. A. Sandborn and T. J. Schaub and M. Singh and I. L. Smythe and F. W. Uhrich and N. K. Washecheck and Z. Wang and A. R. Young},
journal= {arXiv preprint arXiv:2509.04332},
year = {2026}
}