Question: what sort of things do you collide

Claire Lee answered on 17 Jun 2013:

Mainly protons.

So you know how everything is made up of atoms? Well, atoms themselves are made up of even smaller particles. There is a nucleus, which had protons and neutrons, and then there are electrons orbiting the nucleus.

Hydrogen just has 1 proton and 1 electron though – and what the LHC beam guys do is take some hydrogen gas, send it through an electric field so that the electrons go one way and the protons go the other way. They let the electrons go, but they keep the protons and send them down a series of beampipes and accelerators until they eventually get into the LHC.

In the LHC they circle them round and round (two beams, going in different directions) until they have enough energy, and then they point the beams at each other and the protons collide! These types of collisions give us the types of events where we can make a Higgs, for example.

Also, they sometimes use lead ions, either smashing lead on lead, or a proton onto lead. This gives a different type of result, and the stuff that comes out of these collisions looks more like what the universe looked like a few seconds after the Big Bang.