How It Works CERN particle accelerator restarted The world’s biggest and most powerful atom smasher is once again circulating beams of protons after a shutdown of more than three years for upgrades. By Arete News - April 22, 2022 Inside CERN's Large Hadron Collider (AN/J. Heilprin) You need to login to view this content. Please Login. Not a Member? Join Us