Seeing the Unseen: Gamma Cameras for Radiation Detection
A firefighter with a thermal imager can see the source of a fire through smoke. But how do you see a radiation source that has no smell, no glow, and no heat? Gamma cameras solve this problem: they capture gamma rays emitted by radioactive materials and overlay their 'trace' onto a regular photograph. The result is an image showing that the source is, say, behind the far door.