Abstract
| In the search for new materials and technologies to
push the timing performances of time-of-flight positron emission
tomography (TOF-PET) detectors, it is important to have a model
capable of predicting the coincidence time resolution (CTR) of the
system to be implemented. While for bulk standard scintillators,
a model that takes into account the intrinsic properties of the
material (and the characteristics of the photodetector) is already
well established, it has never been experimentally validated for
composite structures. As heterostructured scintillators–i.e., the
combination of two or more materials with complementary
properties–are emerging as a possible solution to the conflict
between fast timing and high detection efficiency for TOF-PET
detectors, such validation becomes necessary. In this work,
by using a time-correlated single photon counting (TCSPC) setup
capable of simultaneously recording the TCSPC signal and the
scintillation pulse on an event-by-event basis, we experimentally
demonstrate that the scintillation kinetics of heterostructures can
be modeled as a linear combination of the scintillation kinetics
of the materials that constitute the heterostructure itself. Based
on these results, we develop an extension of well-established
CTR analytical model which can be applied to heterostructured
scintillators. |