Transient Phenomena in Scintillation Materials

Time resolution becomes an increasingly important property of the scintillators to be exploited in radiation detectors for coming high-luminosity high-energy physics experiments and medical imaging applications. Multicomponent scintillators enable purposeful design of scintillation properties and, consequently, are attractive for fast radiation detection but suffer for the emission delay due to trapping of nonequilibrium carriers. Therefore, novel measurement techniques are required to characterize the timing properties for purposeful improvement of the scintillators. Here, the capabilities of the differential optical absorption technique, exploited in subpicosecond domain in pump and probe configuration, are introduced and the results obtained by application of this technique for studying the carrier dynamics in two prospective scintillators, garnet-type Gd$_{3}$Al$_{2}$Ga$_{3}$O$_{12}$ (GAGG) doped by cerium and codoped by magnesium and Ce-doped oxyorthosilicates LSO and LYSO, are presented. The importance of electron trapping for the timing properties of these scintillators is revealed.