New promising scintillators for gamma-ray spectroscopy: Cs(Ba,Sr)(Br,I)<inf>3</inf>

Abstract

New scintillators belonging to Cs(Ba,Sr)(Br,I) <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> crystal family have been grown and investigated at RMD. The crystals were grown using the melt-based vertical Bridgman method. The iodide compositions were brighter compared to the bromides. Scintillation properties of these crystals have been studied under gamma irradiation, particularly CsBaI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> :Eu in more details. CsBaI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> :Eu has a tetragonal structure, and a density of 4.8 g/cc. The primary investigations of CsBaI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> :Eu show an excellent energy resolution of 3.8% at 662 keV, high light yield of ~55,000 photons/MeV, and a primary decay time of 760 ns. For CsBaI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> :Eu, the emission occurs over a single band (400-500 nm), which is due to d → f transition of Eu <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> , with the emission wavelength peaking at 429 nm. The crystal shows high proportionality over a wide range of energies from 14 keV to up to 1.2 MeV.