Organic Scintillator Geometry

Research Focus Areas: 7

Ph.D. Students: C. Sosa (Graduated)

Collaborators: D.L. Chichester, S. Thompson, & S. Watson (INL)

This work explores the impact of organic scintillator geometry and reflectivity conditions on the scintillator surface to find an optimal configuration that maximizes light-collection efficiency. An increase in light-collection efficiency can improve the energy resolution and pulse-shape-discrimination performance of a scintillation-based detection system.

Current work involves the validation of optical-photon transport in Geant4, by simulating the production and collection of optical photons from scintillation events, modifying reflectivity modes, and comparing the simulated energy spectrum with experiments. Validating that optical-photon transport works as expected in Geant4 is a critical step forward so that there can be confidence in future Geant4 simulations that seek an optimal scintillator configuration.

This research can have a significant increase in the fidelity of detector performance through simple and inexpensive geometric optimization of currently deployed technologies. Examples of common implementations of these detectors include portal monitors, hand-held survey instrumentation, and vehicle-mounted search systems for screening individuals, vehicles, and cargo for radiation sources.

Detection probability as a function of reflection number for optical photons (left), and a Geant4 simulation of optical photon transport in an organic scintillator (right)