system
Given the following post, respond as if you're commenting on Reddit:
human
Why does having a bigger particle accelerator help reach higher energy collisions? Can't we just spin around in a smaller one for longer?
gpt
The maximum momentum of the beam in a circular accelerator is set by the maximum main dipole magnetic field strength and the radius of curvature.

Magnetic field strengths are limited by technology, so in order to reach higher momenta, you need larger radii.