Comparison of Fast Scintillators With TOF PET Potential

The renewed interest in time-of-flight (TOF) positron emission tomography (PET) has been accompanied by new research in the development of fast scintillators, mainly halides and/or lutetium-based compounds doped with Ce or Pr. In this work we measure some intrinsic properties of these materials, such as decay time and light output, which have a direct effect on time resolution, the key performance parameter for a TOF-grade detector. In particular, we report on measurements on LSO:Ce, LuAG:Pr, LuYAP:Ce, LaBr₃:Ce and LaCl₃:Ce. The scintillators are characterized in terms of absolute light yield, decay time, energy resolution, emission and excitation spectra, and time resolution. A new figure of merit to compare scintillators based on their performance in a TOF PET scanner is introduced. This figure of merit, the TOF effective sensitivity eta , includes both interaction probability and timing characteristics.