The US government’s nuclear physicists say they are closing in on fusion ignition – the point at which a fusion reaction becomes self-sustaining – in the lab by compressing matter with lasers.
We’re told they were able to produce more than 1.3 megajoules of energy in 89 picoseconds – that’s 89 trillionths of a second – at Lawrence Livermore National Laboratory’s National Ignition Facility (NIF) earlier this month. That energy release works out to 15 petawatts, 311 grams of TNT exploding, or the chemical energy equivalent of a big pile of batteries.
“A nine-volt battery stores about 15 kilojoules of energy, so the energy content is roughly equivalent to 80 nine-volt batteries of chemical energy,” Omar Hurricane, chief scientist for the Inertial Confinement Fusion Program at LLNL, told The Register, putting the 1.3MJ into perspective.
Crucially, that figure is about 70 per cent of the energy fired into the experiment, which involved crushing a tiny amount of fusion fuel until its atoms fused, releasing energy. This is a notable milestone, the scientists said, because it puts them at the threshold of fusion ignition, which is the point where a fusion reaction becomes self-sustaining: the energy released keeps the reaction going, continually producing energy until the fuel runs out, as seen inside stars over the eons. Humans can potentially harness this energy for various purposes.
“Ignition is a tipping-point in the fusion process where the fusion heats itself and overwhelms all the cooling losses that can occur,” Hurricane said. “Once this happens a feedback process is generated where heating creates more fusion, which creates more heating, which creates more fusion, and so on.” read more…