Answer
The Alternating Gradient Synchrotron (AGS) is a particle accelerator located at Brookhaven National Laboratory in Upton, New York. It is a circular accelerator that uses alternating magnetic fields to accelerate protons to energies of up to 30 billion electron volts (GeV). The AGS was built in the 1950s and was one of the first accelerators to use alternating gradient magnets.