BERLIN — The world’s biggest particle accelerator has restarted after a break of more than three years for upgrading and maintenance work.
The 17-mile Large Hadron Collider is located under a Swiss-French border area near Geneva.
It's perhaps best known for helping confirm the subatomic Higgs boson in 2012.
The European Organization for Nuclear Research said two beams of protons circulated in opposite directions around the accelerator on Friday, but high-intensity, high-energy collisions are still a couple of months away.
It's the collider's third run.
A first round of experiments took place from 2010 to 2012, and a second from 2015 to 2018.
This round is expected to last until 2026.