The firstever full-scale superconducting ‘double pancake’ prototype has been unveiled,and steel plates are at the core of the experimental structure.

It is partof the EU’s joint undertaking to develop fusion power on Earth – dubbed Fusionfor Energy, or F4E for short.

The EU isworking with its global counterparts, including China, Japan, India, Russia,the US and South Korea, to try to advance fusion power to a stage where it is areliable and viable form of energy.

In thislatest milestone, which took place in Italy, the first ‘double pancake’toroidal field coil was constructed.

Each doublepancake – of which there are seven – contains D-shaped steel plates, calledradial plates, to mechanically support the conductor.

A conductorlength is also attached, to carry the electrical current, and this consists ofaround 1,000 wires made of copper and superconducting materials, with astainless steel jacket of diameter 43.7mm and thickness 2mm.

Inparticular, the construction must be completed to an accuracy of 0.01%, meaningthe conductor must be wound very precisely; and the structural steel plateshelp to maintain that accurate position once it is completed.