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

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.