Multimode Organic Scintillators for Neutron/Gamma Detection

There is significant interest in multi-functional materials enabling gamma-ray spectroscopy, neutron/gamma pulse shape discrimination (PSD), ultra-fast response, and time-of-flight (TOF) neutron detection. These materials would be used in a variety of mission scenarios for the localization and monitoring of special nuclear materials. Commercial inorganic scintillators offer some of these characteristics but are often expensive and not available in large sizes. Likewise, organic scintillators such as stilbene provide efficient fast-neutron detection and good PSD but lack gamma-ray spectroscopy. In this project we propose to develop multimode organic scintillators based upon the organic glass technology invented at Sandia National Laboratories (SNL). Our goal is to produce multimode organic scintillators that retain the excellent neutron detection and PSD characteristics of stilbene crystals, while adding increased gamma sensitivity and spectroscopic capability that is missing from stilbene. A related objective is to also provide faster decay characteristics for high count-rate environments and/or scenarios that require accurate timing resolution. The use of these materials will allow us to develop integrated detection system capable of 1) high count-rates, 2) gamma-ray and fast neutron detection with high sensitivity and PSD, 3) TOF techniques for neutron imaging and neutron energy information, and 4) good energy resolution.