Radiation safety

Improving remote detection of radioactivity

After a nuclear power plant accident, for safety reasons it can be difficult for humans or even robots to get close enough to the facility to assess the situation. To get accurate information without putting people or equipment at risk, responders would benefit from better technology to sense radioactive material from afar. That could come from high-power pulsed electromagnetic waves, reports a team from Ulsan National Institute of Science & Technology (UNIST).

First proposed in 2010 by the University of Maryland’s Gregory S. Nusinovich and colleagues, the approach involves using an antenna to direct high-intensity millimeter or terahertz waves at a target area. If material there is radioactive, γ radiation or α particles ionize the surrounding air, releasing free electrons. The interaction of the antenna-directed electromagnetic waves and ionized air induces plasma formation, and the plasma in turn reflects the electromagnetic waves back to the source site for detection.