Year
2023
File Attachment
Abstract
Inorganic scintillators are commonly used for various gamma-spectroscopy applications due to their relatively high
light yield and good energy resolution. Because of their high refractive indices, inorganic scintillators often suffer
from significant light losses due to total internal reflection. If the light collection at the scintillator-photosensor optical
interface is improved, the energy resolution would also be improved, allowing for new applications for these scintillators.
This project utilizes 2-D repetitive nanostructures, called photonic crystals, engineered onto the scintillator surface.
Photonic crystals can enhance light collection from the scintillator through constructive light interference. The
optimization simulations use Monte Carlo and deterministic models to simulate accurate light transport at microand nano-meter scales. Current simulations do not account for reflections at the scintillator-photosensor boundary
and only represent the transmission for a single light pass. Future simulations will include multiple reflections. The
latest simulations and experiments were performed using BGO inorganic scintillators. An optimized combination of
a BGO scintillator coupled to 2-D Si3N4 photonic crystals improves the light transmission by more than 90% for a
single light pass. Moreover, the optimized optical coupling is also being manufactured and will be analyzed using
several gamma sources. The collected experimental data will validate and improve the existing simulation models.
It is anticipated that the optimized, optically coupled nanostructures will lead to substantial enhancements in light
collection and energy resolution.