• Mantovani, Giorgia
• Polo, Matteo
• Quaranta, Alberto
• Fabris, Daniela
• Moretto, Sandra
• Pino, Felix
• Maggioni, Gianluigi
• Carturan, Sara Maria
• Delgado, Jessica Carolina

Abstract

<jats:title>Abstract</jats:title><jats:p>Thermal neutron detection is a key subject for nuclear physics research and also in a wide variety of applications from homeland security to nuclearmedicine. In this work, it is proposed a novel flexible and conformable composite thermal neutron scintillator based on a fully enriched Lithium Tetraborate preparation (<jats:inline-formula><jats:alternatives><jats:tex-math>^{6}</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mrow /><mml:mn>6</mml:mn></mml:msup></mml:math></jats:alternatives></jats:inline-formula>Li<jats:inline-formula><jats:alternatives><jats:tex-math>_2^{10}</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mrow /><mml:mn>2</mml:mn><mml:mn>10</mml:mn></mml:msubsup></mml:math></jats:alternatives></jats:inline-formula>B<jats:inline-formula><jats:alternatives><jats:tex-math>_4</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow /><mml:mn>4</mml:mn></mml:msub></mml:math></jats:alternatives></jats:inline-formula>O<jats:inline-formula><jats:alternatives><jats:tex-math>_7</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow /><mml:mn>7</mml:mn></mml:msub></mml:math></jats:alternatives></jats:inline-formula>) 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. <jats:inline-formula><jats:alternatives><jats:tex-math></jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mo>∼</mml:mo></mml:math></jats:alternatives></jats:inline-formula> 57% with respect to the commercial EJ-420), an average light output of <jats:inline-formula><jats:alternatives><jats:tex-math></jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mo>∼</mml:mo></mml:math></jats:alternatives></jats:inline-formula> 9000 ph/neutron-capture, a remarkable insensitivity to <jats:inline-formula><jats:alternatives><jats:tex-math></jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>γ</mml:mi></mml:math></jats:alternatives></jats:inline-formula>-rays (Gamma Rejection Ratio &lt;10<jats:inline-formula><jats:alternatives><jats:tex-math>^{-11}</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mrow /><mml:mrow><mml:mo>-</mml:mo><mml:mn>11</mml:mn></mml:mrow></mml:msup></mml:math></jats:alternatives></jats:inline-formula>), 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 <jats:inline-formula><jats:alternatives><jats:tex-math></jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>γ</mml:mi></mml:math></jats:alternatives></jats:inline-formula>-rays, fast and thermal neutrons resulting from data processing is demonstrated.</jats:p>

Topics

• impedance spectroscopy
• polymer
• composite
• Silicon
• Lithium