Compositional regulation of multi-component GYGAG:Ce scintillation ceramics: Self-sintering-aid effect and afterglow suppression

Abstract

Y,Ce) 3 (Y x Ga 1−x ) 2 GaAl 2 O 12 (GYGAG:Ce) scintillation ceramics with different Y excess, where x = 0.005−0.08, were fabricated by the solid-state reaction method. The effects of stoichiometry on the phase composition, optical quality, and microstructure of GYGAG:Ce ceramics were analyzed. GYGAG:Ce ceramics have a pure garnet phase and obtain good in-line transmittance when x < 0.04, while more Y excess leads to the creation of the secondary phase. The change of x value influences the sintering behavior of the GYGAG:Ce ceramics: The excess of Y works as the self-sintering aid and significantly reduces the sintering temperature of ceramics. When x = 0.01-0.04, the X-ray excited luminescence (XEL) spectra and light yields of GYGAG:Ce ceramics are similar. The fast scintillation decay time and afterglow intensity of GYGAG:Ce ceramics show a slight decrease with increasing x value. Finally, additional 50-500 ppm MgO and 100-500 ppm CaO were introduced to the GYGAG:Ce ceramic with x = 0.04, and both were found to significantly increase the fast scintillation component and reduce the afterglow intensity by two orders of magnitude to 0.01% after X-ray cut-off.

Stoichiometric modulation and scintillation property characterization of Ce,Ca:LuAG ceramics

“…A slow component in the scintillation response of scintillating materials is very unfavorable for HEP experiments as it can cause the pile‐up effect. Co‐doping of Mg 2+ and Ca 2+ proved to be an effective strategy for accelerating scintillation decay and suppressing slow components, but these two similar divalent ions produce different practical effects 11–15 . Mg 2+ co‐doping may show an advantage in boosting light yield (LY), while Ca 2+ co‐doping is indisputable in a significant increase of the fast‐to‐total (F/T) ratio 16–18 .…”

“…Co-doping of Mg 2+ and Ca 2+ proved to be an effective strategy for accelerating scintillation decay and suppressing slow components, but these two similar divalent ions produce different practical effects. [11][12][13][14][15] Mg 2+ co-doping may show an advantage in boosting light yield (LY), while Ca 2+ co-doping is indisputable in a significant increase of the fast-to-total (F/T) ratio. [16][17][18] In 2020, in the results reported by Hu et al , 5 the F/T ratio (LY 0.2 µs /LY 3 µs ) of Ce,Mg:LuAG ceramics tops out at about 80%, while that of Ce,Ca:LuAG ceramics approaches 90%.…”