Strontium and barium iodide high light yield scintillators

Abstract

Europium-doped strontium and barium iodide are found to be readily growable by the Bridgman method and to produce high scintillation light yields. SrI2Eu emits into the Eu2+ band, centered at 435 nm, with a decay time of 1.2 s and a light yield of 90 000 photons/MeV. It offers energy resolution better than 4% full width at half maximum at 662 keV, and exhibits excellent light yield proportionality. BaI2Eu produces 30 000 photons/MeV into the Eu2+ band at 420 nm 1 s decay. An additional broad impurity-mediated recombination band is present at 550 nm 3 s decay, unless high-purity feedstock is used.