Helium (used to cool superconducting magnets in hospital MRI scanners) and phosphorus (in agricultural fertilizers) are also under threat.

FORBES: Endangered Elements Pose Threat To Green Energy

If proven, the technology could rival the current favoured technique for initiating fusion which uses superconducting magnets to contain and fuse the hydrogen nuclei.

BBC: Laser heats up the fusion future

Another niche where powerful superconducting magnets are indispensable is high-energy physics.

ECONOMIST: Inside story

They are toughened with diamond-like carbon from the semiconductor industry and this is bonded on to the steel with niobium, a rare tin alloy normally used in superconducting magnets.

ECONOMIST: Skinned alive

The US Department of Energy has underwritten more than a dozen demonstration projects using superconducting magnets, cables and wires, all directed towards more efficient and compact generation and use of electricity.

BBC: Last Updated: Monday, 5 March 2007, 08:38 GMT