@jfrazierjr - This won't give us any energy. Rather we pump energy in to get the particles up to speed and then study the results after they collide. It's like pumping a load of petrol into two trucks, watching the fireball when they collide and then measuring how far the bumper went.
@RP - the protons will collide in a vacuum - the center of the pipe is as empty as the engineers can get it to reduce the chance of them accidentally hitting something other than the proton that is coming the other way. Therefore the collision itself is almost identical to a collision in outer space. In fact, at the atomic scale, even gas is mostly empty, so it's functionally the same as collisions in the atmosphere too, which is where the cosmic ray interactions happen. What happens to the debris afterwards - when it flies off and hits the solid bit, the detectors, is essentially just garbage collection. We pick up the bits and see what happened. So the detector doesn't influence the collision itself. In this way, the collision should be as identical to a collision that occurs outside a detector as possible. Otherwise all we'd be studying was how physics works inside a detector - which wouldn't really help us to understand the wider world :)