The Alternating Gradient Synchrotron was built on the innovative concept of the alternating gradient, or strong-focusing principle, developed by Brookhaven physicists. This breakthrough concept in accelerator design allowed scientists to accelerate protons to energies that would have been otherwise unachievable. The AGS became the world's premiere accelerator when it reached its design energy of 33 billion electron volts (GeV) on July 29, 1960.
Until 1968, the AGS was the highest energy accelerator in the world, slightly higher than its 28 GeV sister machine, the Proton Synchroton at CERN, the European laboratory for high-energy physics. While today's newest accelerators can reach energies in the trillion electron volt region, the AGS has earned researchers three Nobel Prizes and today serves as the injector for Brookhaven's Relativistic Heavy Ion Collider; it remains the world's highest intensity high-energy proton accelerator.
The AGS receives protons from Brookhaven's 200 million electron-volt linear accelerator (LINAC). The AGS Booster, constructed in 1991, further augmented the capabilities of the AGS, enabling it to accelerate protons and heavy ions to much higher energies than before. Applications for the AGS continue to be expanded with the construction of the NASA Space Radiation Laboratory
The work performed at the accelerator led to three Nobel Prizes:
Currently the primary function of AGS is to pre-accelerate ions for the Relativistic Heavy Ion Collider, also operated by BNL.