Relationship between microstructure and efficiency of lithium silicate scintillating glasses: The effect of alkaline earths

Lithium silicate glasses containing Ce{sup 3+} are known to be scintillators. Glasses in this family in which the Li is enriched ({sup 6}Li) are used as neutron detectors. The addition of Mg to this glass is known to increase the scintillation efficiency. We have found that substituting other alkaline earths results in a monotonic decrease of the scintillation efficiency with increasing atomic number. The total variation in scintillation efficiency from Mg to Ba is nearly a factor of 3. Prior experiments with this glass family show small differences in Raman and fluorescence spectra; evidence from thermoluminescence experiments indicates that the scintillation efficiency is most strongly correlated with structural effects in the neighborhood of the Ce{sup 3+} activator ion. The results of low-temperature studies of fluorescence and thermoluminescence of these glasses will be reported.