Nanoparticles-loaded plastic scintillators for fast/thermal neutrons/gamma discrimination: Simulation and results

Abstract We report herein the application of a new series of plastic scintillators loaded with lithium tetraborate nanoparticles (Li 2 B 4 O 7 ) designed for the simultaneous detection of fast neutrons, thermal neutrons and gamma. First, MCNP simulations are performed to highlight the potential benefit of Li 2 B 4 O 7 loading. Then, a nanoparticle-loaded scintillator is prepared and evaluated towards the detection of a partially thermalized neutron/gamma 252-californium source. Several scenarios of radiation/matter interactions are evaluated against the observed results. A detection chamber composed of boron-containing chipboard wood has been specifically designed and a subtraction method was set up to afford the best discrimination pattern. For the first time, a triple discrimination is presented with a nanoparticles-loaded plastic scintillator, where both 6 Li(n, α ) and 10 B(n, α ) signatures are observed. A Figure of Merit of 1.40 was calculated between fast neutrons and gamma rays around 480 keVee. The Figure of Merit between fast + thermal neutrons and gamma rays is slightly worse as it is 1.16 at 380 keVee.