Novel flexible and conformable composite neutron scintillator based on fully enriched lithium tetraborate

Thermal neutron detection is a key subject for nuclear physics research and also in a wide variety of applications from homeland security to nuclear medicine. In this work, it is proposed a novel flexible and conformable composite thermal neutron scintillator based on a fully enriched Lithium Tetraborate preparation ((Li2B4O7)-Li-6-B-10) combined with a phosphorescent inorganic scintillator powder (ZnS:Ag), and is then distributed into a polydimethylsiloxane matrix. The proposed scintillator shows a good neutron detection efficiency (max. similar to 57% with respect to the commercial EJ-420), an average light output of similar to 9000 ph/neutron-capture, a remarkable insensitivity to gamma-rays (Gamma Rejection Ratio <10(-11)), and an extraordinary flexibility, so as to reach extremely small curvature radii, down to 1.5 mm, with no signs of cracking or tearing. Its characteristics make it suitable to be employed in scenarios where non-standard geometries are needed, for example, to optimize the detector performance and/or maximize the detection efficiency. Finally, the response of a hybrid detector made of a plastic scintillator, wrapped with the proposed scintillator, coupled to a silicon photomultiplier array is described, and the excellent discrimination between gamma-rays, fast and thermal neutrons resulting from data processing is demonstrated.

Automated summary

Thermal neutron detection is important in nuclear physics research and various applications. This study proposes a flexible and conformable composite scintillator for thermal neutron detection, using fully enriched Lithium Tetraborate combined with a phosphorescent inorganic scintillator powder, distributed in a polydimethylsiloxane matrix. The scintillator shows high detection efficiency, insensitivity to gamma-rays, and extraordinary flexibility, suitable for non-standard geometries. Additionally, a hybrid detector coupled with a silicon photomultiplier array shows excellent discrimination between gamma-rays, fast and thermal neutrons.