Development of SrI2 scintillators for spectroscopy and x-ray imaging applications

Currently, there is a great interest in the research and development of SrI₂:Eu²⁺ scintillating crystals. The high light yield, high density (4.6 g/cm³) and high effective atomic number (49.4) make the Eu²⁺-activated SrI₂ suitable for use as x-ray and gamma ray detector. SrI₂:Eu²⁺-single crystals were grown with the vertical Bridgman technique in silica ampoules to prevent melt hydration and oxygen contamination during the crystal growth. For measurements, crystals were hermetically encapsulated in aluminum containers with quartz glass optical windows. The radioluminescence spectra of the SrI₂:Eu²⁺-samples show maximum at 431 nm and 432 nm for the 5% and 6% dopant concentrations respectively. The light yield of the bulk samples was up to 80 000 photons/MeV and up to 119 000 photons/MeV for a 360 μm sample integrated in an x-ray imaging setup.