The ADA Storage Ring is being celebrated today at the Frascati National Laboratory of the INFN. Built in 1961, it revolutionised particle physics. Now, half a century later, some 30,000 accelerators are in operation, including the massive LHC in Geneva.

The ADA, the first accelerator to produce collisions between particle beams, today received an important recognition by the European Physical Society (EPS), which declared it a historic site. The storage ring (ADA - Anello di Accumulazione) was built at Frascati in 1961 by a team of young scientists led by Austrian physicist Bruno Touschek. His groundbreaking idea was to construct a ring for two beams of particles (electrons and positrons) circulating in opposite directions and which were accelerated to make them collide and produce new particles. Its colossal descendant, the LHC, is based on the same principle, with the difference that it is used for proton beam collisions. The following year the ADA was moved to the LAL (Laboratoire de l'Accélérateur Linéaire) in Orsay, France, where experiments could be performed at higher intensities; this move marked the start of experiments in the physics of collisions between electrons and their antiparticles, positrons. Later on, the Adone (1969) and Dafne (1999) accelerators, which made fundamental contributions to progress in elementary particle physics, were also built at the INFN’s national laboratory.

Although the ADA had a short scientific life, it remains a milestone in the history of science as the progenitor of generations of accelerators, of which there are currently some 30,000 worldwide. Besides opening up new frontiers in our understanding of the infinitely small, accelerators are now also an important tool for industry and medicine. More than half a century later, in the year when the Nobel Prize for Physics was awarded to Englert and Higgs for the discoveries using the LHC, the European Physical Society (EPS) has declared the ADA a historic site. The prominent organisation presents the award to sites, and in this case to machines, that have played a particularly important role in the history of physics in Europe.

Source: INFN website