A fluorescent material has a composition represented by (Gd.sub.1−α−β−γR.sub.αCe.sub.βTb.sub.γ).sub.3+a(Al.sub.1−u−vGa.sub.uSc.sub.v).sub.5−bO.sub.12, wherein: R is at least one of Y and Lu; a, b, α, β, γ, u and v satisfy ranges below: 0≦a≦0.1, 0≦b≦0.1, 0≦α≦0.8, 0.0003≦β≦0.005, 0.02≦γ≦0.2, 0.27≦u≦0.75, and 0≦v≦0.02; a relative density is 99% or more; and an effective atomic number is 35 or more and 60 or less.

Mixed halide scintillation materials of a first general formula A.sub.4B.sub.(1-y)M.sub.yX′.sub.6(1-z)X″.sub.6z and a second general formula A.sub.(4-y)BM.sub.yX′.sub.6(1-z)X″.sub.6z are disclosed. In the general formulas, A is an alkali metal, B is an alkali earth metal, and X′ and X″ are two different halogen atoms. Scintillation materials of the first general formula include a divalent external activator M such as Eu.sup.2+ or Yb.sup.2+ or a trivalent external activator M such as Ce.sup.3+. Scintillation materials of the second general formula include a monovalent external activator M such as In.sup.+, Na.sup.+, or Tl.sup.+ or a trivalent external activator such as Ce.sup.3+.

A flat-panel detector includes: a ray-conversion layer configured to convert rays into a light having a first wavelength; and a plurality of imaging units. At least one of the plurality of imaging units includes: a photo sensor configured for receiving the light and converting the light to an electrical signal; and a light guider located a side of the photo sensor adjacent to the ray-conversion layer, the light guider having a light entry surface adjacent to the ray-conversion layer and a light exit surface adjacent to the photo sensor, the light entry surface being configured to receive the light from the ray-conversion layer and having an area greater than an area of the light exit surface, and an orthogonal projection of the light exit surface in a direction perpendicular to the ray-conversion layer at least partially overlapping that of the photo sensor.

According to an embodiment, a radiation detector comprises a photoelectric conversion substrate and a scintillator layer. The photoelectric conversion substrate converts light into an electrical signal. The scintillator layer contacts the photoelectric conversion substrate and converts radiation incident from the outside into light. The scintillator layer is a fluorescer of CsI containing Tl as an activator. The CsI is a halide. The concentration of the activator inside the fluorescer is 1.6 mass %±0.4 mass %. The concentration of the activator inside the fluorescer in an in-plane direction of the scintillator layer has the relationship of central portion>peripheral portion. The central portion is a central region of a formation region of the scintillator layer. The peripheral portion is an outer circumferential region of the formation region of the scintillator layer.

Embodiments relate to an advanced fast and thermal neutron detector material composition with the properties useful for Special Nuclear Material (SNM) detection. Specific embodiments of the material composition result in two excimer scintillation light production mechanisms that provide two corresponding independent techniques for gamma discrimination; namely Pulse Shape Discrimination and Pulse Height Discrimination. A dual discrimination method, Pulse Shape and Pulse Height Discrimination (PSHD), can be implemented relying on both pulse height discrimination and pulse shape discrimination, and can allow the operation of large area, fast and thermal neutron detectors.

The present disclosure relates to a detection layer on a substrate. For example, a detection layer may include perovskite crystals of the type ABX.sub.3 and/or AB.sub.2X.sub.4. A may include at least one monovalent, divalent or trivalent element from the fourth or a higher period in the periodic table and/or mixtures thereof. B may include a monovalent cation, the volumetric parameter of which is sufficient, with the respective element A, for perovskite lattice formation. X may be selected from the group consisting of anions of halides and pseudohalides. The layer may have a thickness of at least 10 μm.

A crystal material represented by a general formula (1):
(Gd.sub.1-x-y-zLa.sub.xME.sub.yRE.sub.z).sub.2MM.sub.2O.sub.7   (1),
where ME is at least one selected from Y, Yb, Sc, and Lu; RE is Ce or Pr; MM is at least one selected from Si and Ge; and ranges of x, y, and z are represented by the following (i): (i) 0.0≦x+y+z<1.0, 0.05≦x+z<1.0, 0.0≦y<1.0, and 0.0001≦z<0.05 (where, when RE is Ce, y=0 is an exception).

A crystal material represented by a general formula (1):
(Gd.sub.1-x-y-zLa.sub.xME.sub.yRE.sub.z).sub.2MM.sub.2O.sub.7   (1),
where ME is at least one selected from Y, Yb, Sc, and Lu; RE is Ce or Pr; MM is at least one selected from Si and Ge; and ranges of x, y, and z are represented by the following (i): (i) 0.0≦x+y+z<1.0, 0.05≦x+z<1.0, 0.0≦y<1.0, and 0.0001≦z<0.05 (where, when RE is Ce, y=0 is an exception).

A scintillation crystal can include a cesium halide that is co-doped with thallium and another element. In an embodiment, the scintillation crystal can include CsX:Tl, Me, where X represents a halogen, and Me represents a dopant selected from the group consisting of chromium (Cr), zirconium (Zr), cobalt (Co), manganese (Mn), cadmium (Cd), dysprosium (Dy), thulium (Tm), tantalum (Ta), and erbium (Er), the dopant concentration of the element selected from the group consisting of chromium (Cr), zirconium (Zr), cobalt (Co), manganese (Mn), cadmium (Cd), dysprosium (Dy), thulium (Tm), tantalum (Ta), and erbium (Er) in the scintillation crystal is in a range of 1×10.sup.−7 mol % to 0.5 mol %. In a particular embodiment, the scintillation crystal may have a cesium iodide host material, a first dopant including a thallium cation, and a second dopant including a cation.

New composition of polymeric scintillator was revealed, which can be used particularly in medical diagnostics especially in productions of CT scanners, PET scanners and SPECT scanners.