Nuclear monitoring with air samples more reliable, say scientists

In a breakthrough, scientists have isolated an exotic radioactive gas which, they claim, would make it easier to detect underground nuclear tests from air samples.

A global network of monitoring stations constantly samples the air for signs of underground nuclear tests. One thing the stations look for is the radioactive gas xenon-133.

Nuclear explosions produce an excited form called xenon-133m, in which the atomic nucleus is boosted to a higher-energy state, but it is not known exactly how sensitive detectors are to this form as there has been no way to make pure samples of xenon-133m with which to test them.

Now, Kari Perrvi of the Radiation and Nuclear Safety Authority in Finland has solved the problem.

The team placed a cloud of xenon-133 atoms inside a magnetic trap and then jolted it with oscillating electric and magnetic fields; this pushed out the unexcited form, leaving only the excited form behind, the New Scientist has reported.

The work could make nuclear monitoring with air samples more reliable, according to findings published in the Applied Radiation and Isotopes journal.

But James Acton of the Carnegie Endowment for International Peace in Washington said the gas might stay trapped below ground if there were no cracks for it to seep through, making on-site visits a better approach.


Two more sources of radiation detected April 14, 2010

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