colliding

n. (Physics) a particle accelerator in which two separate beams of particles (usually of opposite charge) are circulated in opposite directions and directed so as to collide head on; -- called also colliding-beam accelerator and collider. This technique allows the production of collisions of higher energy than would be possible with a single beam produced by the same device.
Syn. -- particle collider; colliding-beam accelerator; collider. [ WordNet 1.5 +PJC ]