High-Temperature Performance of 9,10-Diphenylanthracene Single Crystals for Fast Neutron Detection

Exploring organic single crystals that can reliably operate in high-temperature environments is crucial for advancing fast neutron detection in extreme conditions. In this study, large-sized (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$34\times 20\times 8$ </tex-math></inline-formula> mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>) and high-quality 9,10-diphenylanthracene (DPA) single crystals were grown using a seed-assisted temperature-reduced crystallization method. The crystals showed strong thermal stability with a melting point of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$252.4~^{\circ }$ </tex-math></inline-formula>C. Under <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\gamma $ </tex-math></inline-formula>-ray excitation, the crystals demonstrated a high light yield of 25 776 photons/MeV with excellent linearity over a broad energy spectrum. Their radiation detection performance was systematically investigated under variable temperature conditions. Temperature-dependent pulse height spectrum (PHS) revealed a steady increase in light output from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$- 20~^{\circ }$ </tex-math></inline-formula>C to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10~^{\circ }$ </tex-math></inline-formula>C, followed by a significant decrease beyond <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$50~^{\circ }$ </tex-math></inline-formula>C. However, the DPA detector retains 72.1% of its light output at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$150~^{\circ }$ </tex-math></inline-formula>C compared to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$20~^{\circ }$ </tex-math></inline-formula>C, demonstrating its excellent performance at high temperatures. Neutron/gamma pulse shape discrimination (PSD) was tested from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$- 25~^{\circ }$ </tex-math></inline-formula>C to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$45~^{\circ }$ </tex-math></inline-formula>C. At room temperature, the detector achieved a maximum figure of merit (FOM) of 3.82 at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2900~\pm ~100$ </tex-math></inline-formula> keVee. Importantly, across the entire <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$- 25~^{\circ }$ </tex-math></inline-formula>C to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$45~^{\circ }$ </tex-math></inline-formula>C range, the FOM remained above 1.5 for energies above 200 keVee, demonstrating stable PSD performance. These results collectively demonstrate the strong overall performance of DPA single crystals in both light yield and neutron/gamma discrimination. These findings underscore the great potential of DPA single crystals for fast neutron detection in high-temperature environments, establishing them as a valuable material for future applications in extreme conditions.