Does it involve the use of magnits?
Yes, it’s like a giant japanese bullet train with a huge circular track – makes the train go faster and faster then at the last minute they switch the points, divert the train and slam it into something.
Stuff is made of atoms, right? Well atoms are made of smaller particles, and those particles are made of still smaller particles. Theoretical Physicists make up theories to try and figure out how things work – why we have particles and stuff, and what they are – and the theories predict certain things will exist and how to find them. The machine tests the theories by smashing particles into each other.