Antiproton Accumulator

The Antiproton Accumulator (AA) was an infrastructure connected to the Proton–Antiproton Collider (SppS) – a modification of the Super Proton Synchrotron (SPS) – at CERN. The AA was built in 1979 and 1980, for the production and accumulation of antiprotons. In the SppS the antiprotons were made to collide with protons, achieving collisions at a center of mass energy of app. 540 GeV (later raised to 630 GeV and finally, in a pulsed mode, to 900 GeV). Several experiments recorded data from the collisions, most notably the UA1 and UA2 experiment, where the W and Z bosons were discovered in 1983.

The concept of the project was developed and promoted by C. Rubbia, for which he received the Nobel prize in 1984. He shared the prize with Simon van der Meer, whose invention of the method of stochastic cooling made large scale production of antiprotons possible for the first time.