Provided is a scintillator material that is excited by radiation rays to emit visible light. The scintillator material has a cristobalite structure obtained by crystallizing a part of silica. A fluorescent material SrI.sub.2:Eu.sup.2+ is incorporated into the cristobalite structure to form a nanocomposite, and the cristobalite structure contains an alkali metal ion.

Scintillator materials, as well as related systems, and methods of detection using the same, are described herein. The scintillator material composition may comprise a Tl-based scintillator material. For example, the composition may comprise a thallium-based halide. Such materials have been shown to have particularly attractive scintillation properties and may be used in a variety of applications for detection radiation.

A scintillator screen for use in backscatter and transmission X-ray detectors is provided. The scintillator screen includes at least a phosphor layer comprising a plurality of phosphor particles preferably having a mean particle size ranging from 30 m to 70 m, and preferably from 30 m to 50 m. Alternatively, each of the plurality of phosphor particles has a particle size in a range of 30 m to 70 m, and preferably from 30 m to 50 m. A thickness of the scintillator layer ranges from 100 m to 4000 m while packing fraction of phosphor weight to total weight of phosphor and a binder ranges from 50% to 90%. The phosphor layer preferably includes europium-doped barium fluorochloride (BaFCl:Eu) for use in a backscatter X-ray detector and preferably includes Gadolinium Oxysulfide (Gd.sub.2O.sub.2S) for use in a transmission X-ray detector.