Effects of alkali ions on luminescence and scintillation performance of Ce³⁺ doped phosphate glasses for radiation detection

The luminescence and scintillation properties of Ce³⁺ doped alkali phosphate glasses 56P₂O₅:8Gd₂O₃:5Al₂O₃:1CeBr₃:30XCl (PGAC:X, X = Li/Na/K/Rb/Cs) were studied for their potential applications in gamma and alpha detection. In the Fourier Transform Infrared Spectroscopy (FTIR), X-ray Luminescence (XRL), Photoluminescence (PL), and transmittance spectra, the red shift was found and explained by the concept of optical basicity. Broad Ce³⁺ emission and energy transfer from Gd³⁺ to Ce³⁺ were observed in XRL and PL measurements. Scintillation performance was studied by irradiating the samples under ¹³⁷Cs gamma and ²⁴¹Am alpha sources. The fast, intermediate, and slow decay components under gamma and alpha excitation were found around 30, 200 and 3000 ns, respectively. The decay time increased slightly from PGAC:Li to PGAC:Cs, indicating the less effective transition from Gd³⁺ to Ce³⁺. The alpha decay time was longer than the gamma decay time, revealing the Pulse Shape Discrimination (PSD) capability of the glasses for particle identification. The XRL intensity reduced significantly from PGAC:Li to PGAC:Cs samples did not reflect the scintillation tendency. By successfully detecting gamma and alpha scintillation signals, the scintillation performance of all samples was found to be similar. In general, all samples can be used for gamma and alpha detection. Using Rb⁺ or Cs⁺ ions is favorable in terms of high density and light yield, while Li⁺ ions enhance the transmittance and homogeneity. Furthermore, a correlation between P–O–H groups within the glass matrix and scintillation performance was also observed.