passive detector
Quick Summary
Passive detectors indicate the presence of ionizing radiation after exposure has occurred, by measuring a physical or chemical change induced by the radiation. These detectors are widely used for monitoring occupational radiation exposure.1
One type is the bubble detector, which uses superheated liquid droplets. When a neutron interacts with a droplet, it vaporizes, creating a bubble. The number of bubbles is proportional to the neutron intensity. Bubble detectors are insensitive to gamma rays and can be recycled.2
Another passive detector type is the thermoluminescent dosimeter (TLD). These use crystalline materials where ionizing radiation creates electron-hole pairs that become trapped. When heated, these trapped charges are released, emitting light. The intensity of the emitted light is proportional to the accumulated radiation dose.3
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