Plutonium-239 is used in nuclear weapons, but it has been difficult to detect in the lab. Researchers in New Mexico have now succeeded in measuring the isotope's nuclear magnetic resonance (NMR) signal.

Interactions within plutonium atoms have frustrated attempts over the past 50 years to find the NMR signal of pure plutonium. To reduce the impact of these interactions, Georgios Koutroulakis and his colleagues at the Los Alamos National Laboratory analysed plutonium dioxide, PuO2 — which has a more stable NMR signal than other plutonium compounds — at a very low temperature.

Teasing out the atom's signature in other compounds could be difficult, but at least now researchers know where to look, the authors say.

Science 336, 901–904 (2012)