High quantum yield Tb3+doped glass scintillator based on Ta2O5 and La2O3 in mixed glass former for synchrotron and medical x-rays imaging applications

초록

In this work, high quantum yield glass scintillator based on Ta2O5 and La2O3 in mixed glass former (SiO2+B2O3) for synchrotron and medical x-rays imaging applications were developed. Glasses were fabricated by conventional melt quenching method in the ratio of xTb2O3 - 10Ta2O5- 20La2O3 - 10SrO - 10SiO2 - (50-x)B2O3 (x = 0, 1, 3, 5, 7, 9, 11, 13, 15). The results indicated that an increase in Tb2O3 content enhanced the density, refractive index, molar volume, ion concentration, and effective atomic number of the glass, thereby making it heavier and more interaction with x-rays. Additionally, the reduced inter-ionic distance implies that the Tb3+ ions are closer together. The closer ion concentration leads to quenching of photoluminescent light at 7.0 % mol of Tb2O3 and a decrease in decay time value. The quantum yield achieved a maximum value of 77.5 % at the same concentration of Tb2O3. Absorption spectra clearly showed peaks at 486, 1903, and 2201 nm, indicating Tb3+ ion in the glass matrix. The seven emission peaks were observed correspond to electron transitions from the 5D4 level to the 7Fj (j=0,1,2,3,4,5,6) states, respectively. Scintillation light was studied through radioluminescence spectra, and similar patterns were observed in photoluminescence. Scintillation decay times were measured using pulse x-ray excitation and results comparable to photoluminescence decay times in the millisecond range were obtained. Highquality images with maximum spatial resolution of 10 lp/mm were demonstrated using synchrotron and medical x-rays with the developed glass scintillator. The glass developed with 7.0 % mol of Tb2O3 has properties that make it suitable for use as a scintillator in high-resolution X-ray imaging devices.

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