Nobody said it was going to be easy. After years of delays, work has finally begun on key components of ITER, the ambitious international project to build a revolutionary nuclear fusion reactor. ITER remains dogged by its own complexity, however, and its director-general says that it may not now fire up until 2023 – three years later than the most recent official deadline.
ITER's ultimate aim is to generate energy in the same way that the sun does, by fusing hydrogen nuclei to form helium. It will do this by using a magnetic field to confine a superheated hydrogen plasma inside a doughnut-shaped reactor called a tokamak.
A collaboration between China, Russia, India, Japan Korea, the US and the EU, ITER's reactor will be larger and far more intricate than any previous tokamak. It will have as many as 10 million parts – its builders call it the puzzle with 10 million pieces – and will sit at the centre of a vast support system. The result will rival the Large Hadron Collider for the title of most complex machine on earth.To read more, click here.