 From the Booster the particles were fed into the Main Injector, which had been completed in 1999 to perform a number of tasks.It could accelerate protons up to 150 GeV; produce 120 GeV protons for antiproton creation; increase antiproton energy to 150 GeV; and inject protons or antiprotons into the Tevatron.The antiprotons were created by the "Antiproton Source".