Hotter than the Sun: JET – Earth’s biggest fusion reactor, in Culham

A star performer producing fission-free plasma power

Geek's Guide to Britain I'm in a room that, in normal circumstances, is not fit for human habitation. It features a number of big red buttons surrounded by illuminated yellow rings - just in case. "Push button to switch off Jet. Press only in case of extreme emergency," the signs read, informatively."