IIRC, the beams intersect a few times in the 26km diameter tunnel, where the bunches go around at the speed of light. Depending on how many bunches there are, t

IIRC, the beams intersect a few times in the 26km diameter tunnel, where the bunches go around at the speed of light. Depending on how many bunches there are, that's ~ thousands of beam intersections per second. How many particle collisions there are per intersection depends on how densely packed the particles are and how many of them there are, known as the "luminosity" of the beam. And yes, in a "run", this is sustained indefinitely.