The Alternating Gradient Synchrotron (AGS) is a particle accelerator located at the Brookhaven National Laboratory in Long Island, New York, United States.
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 Synchrotron 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 Booster, constructed in 1991, further augments the capabilities of the AGS, enabling it to accelerate more intense proton beams and heavy ions such as Gold. Brookhaven's linear accelerator (LINAC) provides 200 million electron volt (MeV) protons to the AGS Booster, and the Electron Beam Ion Source (EBIS) and Tandem Van de Graaff accelerators provide other ions to the AGS Booster. The AGS Booster then accelerates these particles for injection into the AGS. The AGS Booster also provides particle beams to the NASA Space Radiation Laboratory.
The work performed at the accelerator led to three Nobel Prizes in Physics: