Hadron Elektron Ring Anlage

HERA (Hadron-Elektron-Ringanlage, or Hadron-Electron Ring Accelerator) was a particle accelerator at DESY in Hamburg. Its operation started in 1992. At HERA, electrons or positrons were collided with protons at a center of mass energy of 318 GeV. It was the only lepton-proton collider in the world while operating. Also, it was on the energy frontier in certain regions of the kinematic range. HERA was closed down June 30th in 2007 .
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