Comprehensive study of pulse shape discrimination in a Ga-doped zinc oxide scintillating detector

Doping with Ga effectively enhances the crystal quality and optical detection efficiency of zinc oxide (ZnO) single crystals, which has attracted considerable research interest in radiation detection. The application of ZnO:Ga (GZO) in nuclear energy is particularly significant and fascinating at the fundamental level, enabling neutron/gamma discrimination while preserving the response time properties of the single crystal in sub-nanoseconds, maximizing the effective counting rate of the pulsed radiation field. In this study, the single-particle waveform discrimination characteristics of GZO were evaluated for five charged particles (alpha\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\alpha$$\end{document}, beta\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\beta$$\end{document}, H+\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {H}<^>+$$\end{document},Li+\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {Li}<^>+$$\end{document}, and O8+\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {O}<^>{8+}$$\end{document} and two prevalent uncharged particles (neutrons and gamma rays). Based on the time-correlation single-photon counting (TCSPC) method, the luminescence decay time constants of the charged particles in the GZO crystal were determined as follows: 1.21 ns for H+\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {H}<^>+$$\end{document}, 1.50 ns for Li+\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {Li}<^>+$$\end{document}, 1.70 ns for O8+\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {O}<^>{8+}$$\end{document}, 1.56 ns for alpha\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\alpha$$\end{document} particles, and 1. 09 ns for beta\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\beta$$\end{document} particles. Visible differences in the excitation time spectra curves were observed. Using the conventional time-domain or frequency-domain waveform discrimination techniques, waveform discrimination of 14.9 MeV neutrons and secondary gamma rays generated by the CPNG-6 device based on GZO scintillation was successfully implemented. The neutron signal constituted 77.93% of the total, indicating that GZO exhibited superior neutron/gamma discrimination sensitivity compared with that of a commercial stilbene crystal. Using the neutron/gamma screening outcomes, we reconstructed the voltage pulse height, charge height, and neutron multiplication time spectra of the pulsed neutron radiation field. The reconstructed neutron multiplication time spectrum exhibited a deviation of less than 3% relative to the result obtained using a commercial stilbene scintillator. This is the first report in the open literature on the neutron/gamma discrimination and reconstruction of ZnO pulsed radiation-field information.