US Lab Behind Fusion Breakthrough Reaches Ignition Again

The US government lab that last year reached a long-sought milestone in nuclear fusion — achieving a controlled reaction that yielded more energy than it took to produce — has repeated the achievement, after months of near-misses.

Being able to reproduce the Dec. 5 breakthrough may bring the world one step closer to using fusion, which powers the stars, as an abundant source of clean energy. But that future likely remains years off, if it happens at all.

Read More: After Fusion Milestone, New Hopes and Old Doubts: QuickTake

The Lawrence Livermore National Laboratory near San Francisco conducted a series ...