51 / 1241
Detection of 511 keV photons
Scintillation detectors
• Inorganic crystal that emits visible light photons
after interaction of photons with detector.
• Number of scintillation photons is proportional to
the energy deposited in the crystal.
– NaI(Tl):
sodium iodide doped with thallium
– BGO:
bismuth germanate (Bi4Ge3O12)
– LSO:
lutetium oxyorthosilicate doped
with cerium(Lu2SiO5:Ce)
Photomultiplyer tubes (PMTs)
• Incoming photons from scintillation blocks are
converted into electrical signal