SCINTILLATION PROPERTIES OF GSO

The timing properties of Gd2SiO5:Ce (GSO) single crystal scintillators have previously been evaluated for positron emission tomography applications. The measured time resolution, however, was worse than expected from calculations based on photoelectron yield and a 60 nanosecond exponential decay constant, leading us to further investigate GSO's basic properties. With a time-correlated-single-photon technique, we found two decay components, one of 56 ns and one of 600 ns, the latter containing 10–15% of the total scintillation output. This may explain the difference between the experimental and theoretical time resolutions and confirms a previous hypothesis of a long decay component. In addition, we found that each component's decay constant strongly depends on the cerium concentration. The primary component varies from ∼20 ns to ∼190 ns and the secondary component varies from ∼70 ns to ∼1200 ns as the cerium concentration is varied from 5.0 mol% to 0.1 mol%. Copyright © 1990 by The Institute of Electrical and Electronics Engineers, Inc.