Click for live LHC beam status.
We don’t let people go down underground to certain areas to check or fix things while the beam is on. There’s always a tiny chance of losing control of a beam, or protons in the beam interacting with the beam pipe and creating other high-energy particles that could go through people.
Even when the beam is off, other hazards include the fact that the beam pipe magnets are cooled with a lot of liquid helium. The beam pipe is about 300 feet underground, so should enough of that liquid be warmed enough to turn into gas quickly it would make it hard have enough oxygen down there to breathe.
Anyway, when you see “Access” on the LHC beam status page it means people are down underground somewhere trying to check or fix something and so the beam will remain off until they’re out of harm’s way.
—Mike
Tags: LHC
