X- and γ -ray response of Sm-doped SrBr ₂ crystalline scintillators emitting red-NIR photons

Sm:SrBr 2 crystals with various Sm concentrations were prepared by the vertical Bridgman method, and the detector properties including emission spectra, decay time, and pulse height were investigated. The samples exhibit a broad emission band peaking at 690 nm and decay time of about 10 μ s, and the emission is attributable to the allowed 5d-4f luminescence of Sm 2+ . The pulse height analyses under 137 Cs γ -rays (662 keV) demonstrate that the light yields of the 0.03, 0.1, 0.3, and 1% Sm:SrBr 2 are 31000, 32000, 23000 and 13000 photons/MeV, respectively.