Scintillator-based Timepix3 detector for neutron spin-echo techniques using intensity modulation

Fumiaki Funama; Su-Ann Chong; Matthew Loyd; Kazimierz J Gofron; Yuxuan Zhang; Stephen J Kuhn; Chen Zhang; Michael R Fitzsimmons; Anton Khaplanov; Bogdan Vacaliuc; Lowell Crow; Fankang Li

doi:10.1063/5.0189920

Scintillator-based Timepix3 detector for neutron spin-echo techniques using intensity modulation

Rev Sci Instrum. 2024 Mar 1;95(3):033304. doi: 10.1063/5.0189920.

Authors

Affiliations

¹ Neutron Technologies Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA.
² Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA.
³ Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA.
⁴ Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA.
⁵ Second Target Station, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA.

PMID: 38501936
DOI: 10.1063/5.0189920

Abstract

A scintillator-based Timepix3 (TPX3) detector was developed to resolve the high-frequency modulation of a neutron beam in both spatial and temporal domains, as required for neutron spin-echo experiments. In this system, light from a scintillator is manipulated with an optical lens and is intensified using an image intensifier, making it detectable with the TPX3 chip. Two different scintillators, namely, 6LiF:ZnS(Ag) and 6LiI:Eu, were investigated to achieve the high resolution needed for spin-echo modulated small-angle neutron scattering (SEMSANS) and modulation of intensity with zero effort (MIEZE). The methodology for conducting event-mode analysis is described, including the optimization of clustering parameters for both scintillators. The detector with both scintillators was characterized with respect to detection efficiency, spatial resolution, count rate, uniformity, and γ-sensitivity. The 6LiF:ZnS(Ag) scintillator-based detector achieved a spatial resolution of 200 μm and a count rate capability of 1.1 × 105 cps, while the 6LiI:Eu scintillator-based detector demonstrated a spatial resolution of 250 μm and a count rate capability exceeding 2.9 × 105 cps. Furthermore, high-frequency intensity modulations in both spatial and temporal domains were successfully observed, confirming the suitability of this detector for SEMSANS and MIEZE techniques, respectively.