>>11923293The LHC's main ring is bi-directional. It has 2 beam tunnels running side-by-side, one running clockwise, the other counterclockwise, and they flip over each other at the detectors. The combined energy of the head-on collisions is what gives the final ~14TeV value. Tapping off into a linear segment would cut the total energy in half released in a collision.
In addition to that, running it in rings instead of tapping off into a linear segment into the proposed chamber means you can rerun the same collisions essentially so long as the ring has particles in it. If you beamdump, you essentially give up all that energy and speed, and it takes I think close to a day to get it going again for another run. According to the Wikipedia article on it, the LHC at full speed has a collision frequency rate of something like 40 million a second.
Bending the beams further inwards to a central chamber would not only do what the current ring already does, but it would also rob the beams of power as making that turn costs energy. Its why ring accelerators run into limits: Synchotron radiation releases energy from the particles in the form of high energy x-rays. Eventually energy lost = energy in, and at that point you cannot accelerate any faster. Its also why all non-linear accelerators are underground; they need to contain the radiation output both from the ring and from the experiment chambers.
