A team of Korean scientists say it might be possible to detect radiation up to a kilometer (0.6 miles) away thanks to a novel technique. The research was published in Nature Communications.
Detecting radiation is not easy. At Fukushima, for example, it’s taken years just to locate some of the fuel from the meltdown there in 2011, and the actual clean-up operation is still years away.
The main issue is the range limit of Geiger-Muller counters, used to detect radiation. They measure amongst other things Cobalt-60, which with a half-life of about 2,000 days is a clear indicator of man-made radiation. However, they can only make a reasonable detection at up to 3.5 meters (11.5 feet).
Instead, this team of scientists from the Ulsan National Institute of Science and Technology (UNIST) in Ulsan, South Korea propose using pulsed electromagnetic waves to detect radiation, and say the range can be greatly increased. The idea was first proposed by scientists at the University of Maryland in 2010.
"The proposed technique suggests that detecting the existence of radioactive material at a long distance can be possible," lead author Dr EunMi Choi from UNIST told IFLScience. "[For example], in a high radiation field that human beings and robots cannot access, dirty bomb detection, and any nuclear related activity."
How it works is two-fold. First, a high-powered electromagnetic wave source known as a gyrotron is fired into an antenna, which reflects the waves towards a source. If there is radioactive material present, this creates a plasma that is then broken down by the radiation, producing detectable free electrons, those not attached to an atom.
A diagram of how the technique works. Kim et al/Nature Communications