Ceramic scintillators are a type of Transparent Optical Ceramics (TOC), polycrystalline bodies composed of inorganic compounds such as metal oxides or halides. Ceramics are constructed by bonding fine powders of material at high temperature and pressure. Ceramic scintillators convert the energy in ionizing radiation (X-rays, gamma-rays, particles, and neutrons) into light. The light is measured by coupling the scintillator to an optical detector such as a photomultiplier tube, an Avalanche Photodiode (APD) or a Solid State Photodiode (SSPD).
Important requirements for ceramic scintillators include high light output, high stopping efficiency for the incident radiation, and fast response. Minimal afterglow, stable performance, low cost, and good linearity are also important.
Ceramics offer a number of advantages over single crystal scintillators including increased flexibility in scintillator composition, higher purity, lower processing temperatures, faster processing cycles, and lower cost. The technology also permits near net shape fabrication, thereby reducing machining costs and providing the ability to produce complex shapes if required.
Applications range from X-ray diagnostic imaging to X-ray CT scanning and nuclear medicine systems such as PET and SPECT. Similar devices are also used by homeland security for the detection of radioactive materials to counter external threats. In addition to scintillators, TOCS are used in lighting, IR ray domes for missile guidance systems, laser hosts, and transparent armor windows for military vehicles.