Pixelated Scintillation Arrays and Modules
Cadmium tungstate (CdWO4) is a high density, high atomic number scintillator with relatively high light yield, and extreme low after glow. The after glow at 3ms is less than 0.1%. The emission maximum is at 475nm and the total light output is 12 to 15 photons/keV. The light yield relative to NaI(Tl) on a bialkali PMT is 30 to 50%. The high density and stopping power of CdWO4 make it an efficient absorber, particularly for high energy X-ray. It takes only 3mm to stop up to 150keV photons.