UHM Physics Department Colloquia
Designer Molecules for Radiation Detection in Physics and Nuclear Nonproliferation
by Dr. Patrick Feng (Sandia National Laboratories)
Thursday, 24 August 2017 from to (Pacific/Honolulu)
Luminescent organic materials are indispensable materials for diverse sensing and light-production applications, owing to their widely tunable chemical and photophysical properties. Organic fluorophores in particular are uniquely suited for radiation detection due to the efficient conversion of ionizing radiation into visible photons. Indeed, organic scintillators are among the few materials capable of directly detecting fast neutrons due to elastic recoils on hydrogen atoms that provide a unique signature for radiation sources of interest, i.e. illicit nuclear materials such as plutonium. In this presentation, I will give a brief overview of the advantages and drawbacks of existing organic-based scintillators, followed by a description of our ongoing efforts to address these limitations. These efforts are based upon the rational design of molecular properties, as required for high-performance, low-cost, and multi-functional radiation detection materials. Two specific examples that will be discussed include melt-cast organic glasses for neutron/gamma discrimination and metal-loaded polymers for gamma-ray spectroscopy. These case studies will highlight new capabilities afforded by these materials in comparison to traditional classes of organic scintillators.