Modified floating-zone crystal growth of Mg4Ta2O9 and its scintillation performance

Abstract

Aiming to explore scintillator candidates for high-energy radiography, the environmentally friendly compound Mg₄Ta₂O₉ was selected. Bulk crystals of good optical quality are needed to evaluate its scintillation performance against other commercial scintillators currently used such as CdWO₄ and CsI:Tl. In this work, bulk single crystal rods of 3.5 mm in diameter with length up to 50 mm were obtained through optimization of the growth process. Particularly, the thermal gradients that impact the cooling of the crystal in the floating-zone furnace were modified. The scintillation properties of the produced Mg₄Ta₂O₉ crystals, are reported. The scintillation decay and afterglow not reported previously have been measured. The afterglow results are compared to those of CdWO₄, CsI:Tl and Y₃Al₅O₁₂:Ce. We confirmed a luminosity similar to that of CdWO₄.