Heterostructured scintillators, a cooperative approach to radiation detection

Speaker: Dr Gregory Bizarri (Cranfield University)

https://www.cranfield.ac.uk/people/dr-gregory-bizarri-17086104

Title: Heterostructured scintillators, a cooperative approach to radiation detection: Application to Time-of-Flight Positron Emission Tomography 

Abstract: Core to advancing ToF-PET toward a less invasive, more flexible and high diagnostic power technology is the development of enhanced radiation detector materials. Currently the scintillators are not selected for their ability to fully answer the application's needs, but are chosen as a trade-off between requirements, cost and availability. The material of choice for ToF-PET, Lu₂SiO₅:Ce³⁺ (LSO) or its variant Lu_1.8Y_0.2SiO₅:Ce³⁺ (LYSO), underlines such technical compromise. LSO’s properties answer the needs for short attenuation length and decent light output, but fall short of approaching the sub-nanosecond response time, a strict requirement to advance substantially ToF-PET technology. This inability to match application needs to detector properties is deeply rooted in the historical approach of using a unique material, usually lanthanide doped, as the sole energy conversion medium. One of the promising avenues to bypass the current performance limitations is the development of heterostructured scintillators where multiple materials work in synergy to exceed the performance of each individual component. The presentation will introduce the concepts of the heterostructured scintillators and the scientific and technical challenges associated with the approach. The relationship between heterostructure design and performance will be presented and formulated into simple detector guidance rules. The technical feasibility will also be illustrated through the evaluation of the various steps required for the manufacturing of the heterostructure. Finally, preliminary scintillation responses of heterostructured pixels will be presented supporting the validation of the concept. The work contributes to the development of a fundamental and technical frameworks that could eventually advance radiation detection across multiple sectors of activities (medical imaging but also for instance high energy physics, security).