High-performance large diameter SrI2:Eu2+ crystals

- In this presentation, we will discuss crystal growth and scintillation properties of large diameter SrI
₂
:Eu
²⁺
single transparent crystals. The crystals were grown successfully using the vertical Bridgman technique. Crystals with different diameters from 1 inch to 2 inches are discussed. SrI
₂
:Eu
²⁺
, a scintillator discovered a half century ago by Hofstadter, was recently re-discovered as an outstanding material for gamma ray-spectroscopy. Its key properties include good non-proportionality, high light yield (from 85,000 to 120,000 photons/MeV) and excellent energy resolution (2.8 % at 662 keV). Due to its good properties our immediate focus has been on scaling up and development of this material for commercial use. Other properties of SrI
₂
:Eu include Z
_eff
of 50, a mono-exponential decay with a time constant of 1μs to 5 μs (depending on crystal size and dopant concentration), an emission band at 410-450 nm (2.7-3.0 eV). SrI
₂
also shows no intrinsic radioactivity unlike lanthanide compositions.