The Effect of Self-Absorption on the Scintillation Properties of ${\rm Ce}^{3+}$ Activated ${\rm LaBr}_{3}$

Experimental studies of LaBr₃ doped with 5%, 10%, 20% and 30% Ce³⁺ and CeBr₃ are performed for application in TOF-PET. X-ray excited emission spectra, decay time constants, photoelectron yields and energy resolutions are measured from 100 K to 600 K. The results show a strong temperature and Ce³⁺ concentration dependence, which is mostly explained by Ce³⁺ self-absorption. We modeled how self-absorption affects the scintillation pulse shape and what the consequences are for the detector timing resolution. It shows that self-absorption elongates the decay time constant, whilst it does not affect the scintillation rise time.