Synchrotron is a type of Radiation. The SPS, or Super Proton Synchrotron, is a smaller circular collider which will inject the particle beams into the LHC.The particles actually go through a few colliders before entering the main 25km ring. I believe they're initially accelerated by a linear collider.
(
Ttssattsr,
Thu 7 Aug 2008, 16:17,
archived)