Scintillation characteristics of the EJ-299-02H scintillator

A study of the dead layer thickness and quenching factor of a plastic scintillator for use in ultracold neutron (UCN) experiments is described. Alpha spectroscopy was used to determine the thickness of a thin surface dead layer to be 630 ± 110 nm. The relative light outputs from the decay of ²⁴¹Am and Compton scattering of electrons were used to extract Birks’ law coefficient, yielding a kB value of 0.087 ± 0.003 mm/MeV, consistent with some previous reports for other polystyrene-based scintillators. The results from these measurements are incorporated into the simulation to show that an energy threshold of (∼9 keV) can be achieved for the UCNProBe experiment. This low threshold enables high beta particle detection efficiency and the indirect measurement of UCN. The ability to make the scintillator deuterated, accompanied by its relatively thin dead layer, gives rise to unique applications in a wide range of UCN experiments, where it can be used to trap UCN and detect charged particles in situ.

This work was supported by the Los Alamos National Laboratory LDRD Program (Project No. 20190048 ER), the National Science Foundation (Grant No. PHY1914133), and the U.S. Department of Energy, Office of Nuclear Physics (Grant Nos. DE-FG02-97ER41042 and DE-FOA-0002821).

N. Floyd: Data curation (equal); Formal analysis (equal); Investigation (equal); Methodology (equal); Visualization (equal); Writing – original draft (equal). Md. T. Hassan: Data curation (supporting); Investigation (equal); Methodology (equal). Z. Tang (汤兆文): Conceptualization (lead); Funding acquisition (lead); Methodology (supporting); Project administration (lead); Resources (lead); Supervision (lead); Validation (lead); Writing – review & editing (lead). M. Krivoš: Supervision (supporting); Writing – review & editing (supporting). M. Blatnik: Resources (supporting); Writing – review & editing (supporting). C. Cude-Woods: Conceptualization (supporting); Writing – review & editing (supporting). S. M. Clayton: Conceptualization (supporting); Funding acquisition (supporting); Project administration (supporting); Resources (supporting); Writing – review & editing (equal). A. T. Holley: Conceptualization (supporting); Methodology (supporting); Writing – review & editing (supporting). T. M. Ito: Conceptualization (supporting); Funding acquisition (supporting); Writing – review & editing (supporting). B. A. Johnson: Conceptualization (supporting); Writing – review & editing (supporting). C.-Y. Liu: Conceptualization (supporting); Writing – review & editing (supporting). M. Makela: Conceptualization (supporting); Funding acquisition (supporting); Project administration (supporting); Resources (supporting); Supervision (supporting); Writing – review & editing (supporting). C. L. Morris: Conceptualization (supporting); Funding acquisition (supporting); Project administration (supporting); Resources (supporting); Supervision (supporting); Writing – review & editing (supporting). A. S. C. Navazo: Resources (supporting); Writing – review & editing (supporting). C. M. O’Shaughnessy: Conceptualization (supporting); Funding acquisition (supporting); Methodology (supporting); Project administration (supporting); Resources (supporting); Writing – review & editing (supporting). E. L. Renner: Conceptualization (supporting); Methodology (supporting); Resources (supporting); Writing – review & editing (supporting). R. W. Pattie: Writing – review & editing (supporting). A. R. Young: Conceptualization (supporting); Funding acquisition (supporting); Supervision (supporting); Writing – review & editing (supporting).

The data that support the findings of this study are available from the corresponding author upon reasonable request.

The authors have no conflicts to disclose.