ADA collider

ADA (short for Anello Di Accumulazione, also stylized as AdA) was one of the first Italian particle accelerator and the first-ever electron–positron particle collider measuring around in diameter which was designed to store beams of 250 MeV.
History.
The AdA collider was built at the LNF (Frascati National Laboratory) in Frascati in the year of 1961 with the help of a group of Italian physicists guided by the Austrian physicist Bruno Touschek (the individual to propose the idea of its development)"." During the time of ADA's proposal, many American physicists were distancing themselves from using accelerators that sent a beam of particles into a fixed target to experiment with colliding two beams of particles instead"." ADA was a great extension of this idea as it replaced one of the beams of particles (electrons) with a beam of antiparticles (positrons), a modification that was new and never before tested by physicists.
After the machines construction, it was operated from 1961 to 1964, by the National Institute of Nuclear Physics, in Frascati, Italy. 
However, in 1962, the machine was relocated to the Laboratoire de l’Accelerateur Lineaire in Orsay, France, where it was used for an additional four years alongside the laboratory's powerful particle injector.
Towards the end of 1963, AdA's first electron-positron collisions were recorded. Then, the machine was operated a few more years for further successful and decisive tests before dismantling. AdA was never used to collect physics data. Instead, it was a testing ground for a breed of machines that was to change the course of particle physics in the following decades.
The collider is no longer operational but the legacy of the machine still lives on today. On 5 December 2013, the Italian National Institute of Nuclear Physics (INFN) Frascati National Laboratory (LNF) was given the great honour of becoming an EPS Historic Site for the realization of the Storage Ring AdA, the first official particle-antiparticle collider. Today, the European Physical Society recognized machines grand importance to particle physics, marking it as a historic site in its original home of the Frascati National Laboratory, that is part of Italy's National Institute of Nuclear Physics.
Impact of the ADA collider.
The ADA collider had a large impact on accelerator physics. The machine was the first particle-antiparticle collider and the first electron-positron storage ring. It also proved the possibility of accelerating and colliding a beam of particles and antiparticles in the same machine. The ADA collider opened the possibility for a long line of particle and antiparticle colliders and storage rings long after its lifespan. These include the Frascati National Laboratory's ADONE (big AdA or Higher energy collider) and CERN’s Large Electron-Positron collider. ADA's success was also instrumental to discovering the Touschek effect in the year of 1963 that explains how the length of time a beam lasts is effected by the scattering of particles inside a beam. It also allowed scientists to witness the interaction and annihilation of particles and antiparticles during energetic collisions alongside allowing physicists to understand better several aspects of accelerator physics that would not have been possible if not for the machines existence.