Plastic Scintillatos with Gamma-Neutron PSD

The proliferation of weapons of mass destruction such as nuclear missiles and dirty bombs is a serious threat in the world today. Fast-neutron detectors are an important tool in monitoring the proliferation of nuclear weapons. Discrimination between fast neutrons and gamma rays is typically achieved with liquid and organic crystalline scintillators. Traditional plastic scintillators do not offer good gamma- neutron PSD, though newer concepts being developed at LLNL, SNL, RMD and elsewhere are opening up pathways for plastics with good PSD. One new concept being explored for developing plastics with good gamma-neutron PSD is to incorporate heavy metal complexes in plastic scintillators to allow triplet harvesting and thereby achieve the desired gamma-neutron PSD. We believe that these novel plastic scintillators with heavy metal complexes are very promising materials to replace the current state-of-the-art fast-neutron detectors used in nuclear non-proliferation. The goal of the proposed effort is to undertake a systematic investigation of these novel plastic scintillators with heavy metal complexes in order to advance the fast-neutron detection technology with PSD capability. To achieve this goal, the first step will be to select the appropriate heavy metal complexes. Next, we will fabricate the novel plastic scintillators incorporating the heavy metal complexes using standard polymerization techniques. Subsequently, we will evaluate their scintillation properties such as light output and temporal response under gamma-ray and neutron irradiation. Emission spectra will also be measured. Fast-neutron spectroscopy will be performed. Neutron-gamma pulse shape discrimination studies will be carried out. 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, and non-destructive testing.