Advanced Plastic Scintillators for Nuclear Non-Proliferation Monitoring

The proliferation of weapons of mass destruction such as nuclear missiles and dirty bombs are a serious threat in the world today. Preventing the spread of these nuclear weapons has reached a state of heightened urgency in recent years. Neutron detection is an important component of the overall detection techniques used in identifying SNMs. At present, there is a real need for a compact, efficient detection system that would allow neutron detection with an ability to discriminate gamma events from neutron events. Gamma discrimination is critical because gamma rays are common background in neutron detection environment during SNM monitoring. Also, the ability to provide neutron spectroscopy whereby information on the energy of neutrons is obtained is of importance for next generation detectors as well. Unfortunately, none of the available neutron detection technologies satisfy all of these requirements. Recent research at RMD has focused on investigation of novel plastic scintillators that can provide neutron/gamma pulse shape discrimination capability. Our results show that these novel plastic scintillators have a relatively high light output (higher than BGO), a fast scintillation decay and exhibit good neutron/gamma pulse shape discrimination. The goal of the proposed effort is to undertake a systematic investigation of these novel plastic scintillators in order to optimize and advance the fast-neutron detection technology. To achieve this goal, the first step will be to tune the compositions including the monomers and additives (also referred to as primary and secondary solvents) as well as the optical emitters. Polymerization conditions will be examined as well to produce high quality plastic scintillators. Subsequently, we will evaluate their scintillation properties. Fast-neutron spectroscopy and gamma-neutron PSD will be performed. Commercial Applications and Other Benefits: The proposed detector technology will be very promising for nuclear non-proliferation. It will also be applicable to neutron imaging systems, astronomy, non-destructive testing and medical imaging