Investigation on the Fast Component Light Yield of BaF2:Y Crystal

Due to its ultrafast cross-luminescence, the BaF 2 crystals with a subnanosecond decay time are promising for high-reputation radiation detection. However, there is a slow scintillation component with a decay time of about 600 ns in the crystal, which induces a pile-up effect. The Y doping in the crystal was confirmed to be effective in slow component suppression. In this investigation, the fast/total (F/T) light yield (LY) ratios and fast component LY of BaF 2 :Y crystals with various Y concentrations were investigated by the fast sampling technique. It was demonstrated that Y doping not only suppresses the slow component but also weakens the fast component. A good negative correlation was observed between the F/T LY ratios and fast component LY of BaF 2 :Y crystals, indicating that it was impossible to obtain the BaF 2 :Y crystal with a high F/T LY ratio and a high fast component LY at the same time. The influence of wrapping materials on the F/T LY ratio was also investigated. The result illustrates that both the undoped and Y-doped BaF 2 crystals without wrapping materials show the best F/T LY ratio, indicating that the tradeoff between LY and F/T LY ratio is needed in the applications.