Metal-loaded plastic scintillators for nuclear non-proliferation

Nuclear non-proliferation applications and monitoring of special nuclear materials (SNMs) prefer low-cost detector solutions that provide efficient gamma-ray and neutron detection in combination with neutron/gamma pulse shape discrimination (PSD). Among the inorganic and organic detector choices, recently developed plastic scintillators can be fabricated in large sizes at low cost and show good neutron detection efficiency in combination with excellent neutron/gamma PSD. Unfortunately, these plastic scintillator have low density and effective Z limiting gamma-ray detection to gross counting. In this paper we report on the characterization of metal-loaded plastic scintillators that provide gamma-ray spectroscopy as well as fast neutron detection, whereby discrimination between gamma-rays and neutrons is accomplished using pulse shape analysis. In particular, we report on the investigations of tin-, bismuth-, and lead-loaded plastic scintillators for nuclear non-proliferation.