Operational history of the SPS collider 1981-1990

In June 1978 approval was given for the construction of an antiproton production and storage facility, the AA complex, and for the modification of the SPS to be able to inject, accelerate, and store bunches of 270-GeV protons and antiprotons with collisions in the center of two large experimental detectors. Two years later, after the construction of the necessary equipment and preparatory excavation of the two underground zones, the SPS fixed target operation was interrupted for nearly 12 months to complete the installations. First collisions of two bunches of protons against one bunch of antiprotons were observed on July 10, 1981. Along with the increase in the number of antiprotons produced and stored in the antiproton accumulator and the smaller and smaller beam sizes in the region of the experimental detectors, the understanding and control of the collider as a complicated machine physics experiment has gradually increased.<>