The Super Proton Synchrotron at CERN. Started up in 1981. The SPS was the accelerator that gave the physicists the confirmation of the electro-weak force theory in 1983. The SPS actually started in 1976 as an ordinary proton accelerator but was upgraded in 1981 to be used as a proton-antiproton collider. It is the 2nd largest accelerator at the CERN site.