Journal of Crystal Growth, Vol.318, No.1, 820-822, 2011
NaI(Tl) and CsI(Tl) scintillation crystal growth by skull method
The goal of this work is to advance the skull method for NaI(Tl) and CsI(Tl) scintillator crystal growth. The experiments with 250 x 180 x 45 mm(3) ingots demonstrate their capability to come out with a successful growth of relatively large uniform scintillation crystals. The Tl(+) distribution along the ingots was tested for various temperature fields and activator contents. It was shown that even a minimal thermal convection allowed to smooth the activator distribution and led to the minimal spread of the scintillation characteristics from the bottom of the ingot upwards and across it. The spectroscopic level of the reference detectors 25 mm in diameter and 25 mm high was as high as 6.5% for (137)Cs test, i.e. it corresponded to the "conventional" Bridgman or Czochralski growth techniques. (C) 2010 Elsevier B.V. All rights reserved.