US physicists developed a new method to detect radioactive materials using carbon-dioxide lasers.
This technique allows for remote detection, useful for national defense and emergency response.
It works through a process called avalanche breakdown, where radioactive decay releases charged particles that ionize the air, creating plasma.
The laser accelerates electrons in the plasma, causing them to produce detectable optical backscatter.
This method improved detection range to 10 meters, ten times better than previous techniques.
Long wavelengths of the laser help detect low concentrations of radioactive particles and reduce interference.
Researchers used fluorescence imaging to study plasma and confirmed their findings with a mathematical model.
This breakthrough could allow detection of gamma-ray sources from up to 100 meters away, with challenges beyond that due to signal issues.
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