ULTRA-pure samples of a radioactive gas could soon make it harder for nations to carry out nuclear tests in secret.
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 because there has been no way to make pure samples of xenon-133m with which to test them.
“Creating pure samples of the gas produced by nuclear…
