Comprehensive characterization of a YAG:Ce scintillator: light yield, alpha quenching and pulse-shape discrimination

Abstract

Solid-state scintillators are widely used in particle and applied physics due to their versatility and resistance to diverse environments and operating conditions. This broad range of applications calls for thorough characterization of scintillating crystals. Among these materials, cerium-doped yttrium aluminum garnet (YAG:Ce) is a promising scintillator owing to its favorable timing characteristics, high light yield, good mechanical properties, and chemical stability. In this work, we report a comprehensive experimental characterization of a YAG:Ce crystal exposed to both $γ$ and $alpha$ radiation. We extract the scintillation decay time and light yield, and study their evolution from room temperature down to approximately $-50 ^\circ$ C. We perform a detailed investigation of the quenching factor for \al particles in the energy range from about $6$ MeV down to $1$ MeV, finding a value that decreases from approximately $0.17$ to $0.10$. We also explore the possibility of pulse-shape discrimination based on the different signal evolution depending on the interaction type, demonstrating strong classification capabilities. These results provide a detailed assessment of the performance of \YAG for radiation-detection applications and offer insight into its potential use in environments requiring reliable particle identification and stable response across a wide range of operating conditions.

Figures (4)

• Figure 1: Comparison between normalized experimental physics pulses and pulses constructed from single-cell templates. (Left) Average pulse from $\alpha$ events corresponding to the $5.49$-MeV peak of ^241Am. (Right) Average pulse from $\gamma$ events corresponding to the $511$-keV peak of ^22Na. The vertical dashed line marks the beginning of the data interval used for the minimization.
• Figure 2: Pressure (top) and QF of YAG:Ce (bottom) as a function of $\alpha$ energies. Different series were acquired at fixed source-detector distances of $49$ and $97$ mm and with different gases: air, argon, and helium. We considered a systematic uncertainty corresponding to a $\pm 1$ mm variation in the source-detector distance, which defines the error bars on the energy value, and propagated the uncertainty from the linear $\beta$/$\gamma$ calibration as the error on QF.
• Figure 3: Evolution of $\tau_\mathrm{long}$ of YAG:Ce as a function of temperature normalized to the value room temperature. Over the investigated range (approximately $225-295$ K), $\tau_\mathrm{long}$ increases by approximately a factor of two.
• Figure 4: Discrimination of $\alpha$ and $\gamma$ events from the $5.49$-MeV and $511$-keV peaks during a run with both ^241Am and ^22Na sources at a pressure aligning the $\alpha$ peak with the $\gamma$ region. (Top) Partial-charge parameter vs. area of the pulses, showing two populations identified by clustering. (Bottom) Energy spectrum with the isolated populations.