Night-Vision Goggles Spot Radiation
WARRINGTON, UK -- Tinkering with an old phenomenon in physics, designers are tackling a modern danger. They have retooled military night-vision goggles to see alpha radiation through scintillation, the effect discovered by Ernest Rutherford wherein alpha particles emit tiny flashes of light when they bounce off zinc sulfide.
The difficulty with detecting alpha particles is that they travel only a centimeter or two from the radiation source, said Mike Scott, a spokesman for British Instrument Consultants, which is developing the goggles. With today's probes, it is easy to miss alpha radiation, which is emitted from radionuclides such as plutonium -- especially from a spill on an uneven surface. "I've seen monitors in the industry that are fairly haphazard about the way the probe is applied and waved around to find alpha contamination," he said.
The company calibrated the night-vision goggles to make them ultrasensitive to scintillation from irradiated zinc sulfide. Called LumineX, the adapted goggles pick up flashes from five or six feet away and will soon be able to detect alpha radiation at lower levels than the standard probes can. The latter have trouble detecting 4 or 5 Bq/cm2, Scott said, but his company is fine-tuning its device to catch a single becquerel per square centimeter. "In early June, I should have a goggle that's pretty damned good."
On the downside, the device requires that the user spray the test area with zinc sulfide, and currently it works only in the dark. In the case of a nuclear spill outdoors, daylight would blind the goggles' sensors. Nevertheless, the nuclear industry has shown interest in the technology, in particular a decommissioned nuclear power plant in Dounreay in northern Scotland.
Peace of mind
A key factor for people who spend their lives chasing radiation particles is peace of mind, Scott said. "The big spooky thing, or one of the things, that scares people about radiation is that you can't see it, you can't smell it and all the rest of it." Being able to visualize contamination with LumineX changes that. "It's a little bit more reassuring, I think."
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