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

Camille Frangville (1) , Amélie Grabowski (1) , Jonathan Dumazert (1) , Eva Montbarbon (1) , Clément Lynde (1) , Romain Coulon (1) , Amélie Venerosy (2) , Guillaume Bertrand (1) , Matthieu Hamel (1)

1 LCAE (CEA, LIST) - Laboratoire Capteurs et Architectures Electroniques (CEA, LIST)
2 LCD (CEA, LIST) - Laboratoire Capteurs Diamant (CEA, LIST)

We report herein the application of a new series of plastic scintillators loaded with lithium tetraborate nanoparticles (Li2B4O7) designed for the simultaneous detection of fast neutrons, thermal neutrons and gamma-rays. First, MCNP simulations are performed to highlight the potential benefit of Li2B4O7 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 6Li(n, α) and 10B(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.

Mots clés: Plastic scintillator; nanoparticles; Ionizing radiation; lithium tetraborate; thermal neutrons; fast neutrons; Neutron-gamma discrimination; intrumentation; nuclear instrumentation; MCNP; simulation; nanoparticle-loaded scintillator; detection chamber; radioactivity

Domaines: Instrumentations et Détecteurs [physics.ins-det]; Physique Nucléaire Expérimentale [nucl-ex]

Camille Frangville, Amélie Grabowski, Jonathan Dumazert, Eva Montbarbon, Clément Lynde, et al.. Nanoparticles-loaded plastic scintillators for fast/thermal neutrons/gamma discrimination: Simulation and results. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2019, 942, pp.162370. ⟨10.1016/j.nima.2019.162370⟩. ⟨hal-03487337⟩