The world's greatest particle-smasher gears up for a second try. Physicist John Ellis previews what will happen when the fireworks resume

摘要

The biggest particle accelerator ever made-the Large Hadron Collider in Geneva-spectacularly fizzled shortly after scientists turned it on in September 2008. What felled the gargantuan machine was a single badly soldered connection. When the powerful electrica} currents running through the LHC came to bear on that tiny piece of solder, the resulting heat set off a cascade of events, ending in a sudden release of helium that blew aside several of the collider's massive superconducting magnets. The staff at the European Organization for Nuclear Research, or CERN, spent the past year repairing the damage, inspecting tens of thousands of connections, and bolting down the magnets in case of another accident. By the end of 2009, CERN scientists were ready to start again, using the LHC to investigate the deepest mysteries in physics-including why matter has mass. John Ellis, a theoretical physicist at CERN who has been involved in the project for 25 years, talked with DISCOVER about the repairs and the prospects for the LHC.