Europium-doped barium halide scintillators for x-ray and γ-ray detections

Single crystals of undoped or europium-doped barium chloride, bromide, and iodide were investigated under x-ray and gamma-ray excitations. The Eu2+-related x-ray excited luminescence found in the Eu-doped barium halides occurs at 402, 404, and 425 nm for the chloride, bromide, and iodide, respectively. BaCl2:Eu2+ shows the best scintillation properties of the systems investigated. The light yield is about 20 000 +/- 2000 photons per MeV of absorbed gamma-ray energy, the energy resolution for the 662 keV photopeak is 8.8%+/- 0.9%, and the scintillation decay time is 390 +/- 40 ns. (c) 2007 American Institute of Physics.