Tungsten gallium-phosphate glasses as promising intrinsic scintillators

Tungsten gallium-phosphate glasses with composition NaPO3-20Ga(2)O(3)-xNa(2)WO(4) (x = 0, 1, 3, 5 and 10% mol) were synthesized by the melt-quenching technique with high chemical stability and excellent optical properties, and evaluated as potential intrinsic glass scintillators. Fourier-transform infrared measurements showed a decrease in the amount of OH- groups for increasing Na2WO4 contents, while X-ray photoelectron spectroscopy revealed the presence of sole W6+ species. Optical transmission measurements showed a high level of transmittance (similar to 90%) over a broad spectral range (400 to 2500 nm). Luminescence was found to correspond to a broad emission characteristic of the WO42- complex that can be excited by ultraviolet and X-rays with average lifetimes ranging from 32 to 20 mu s. At cryogenic temperatures, the NaPGaW glasses showed a significant increase in the luminescence emission.