HERA-electron-proton colliding beam project at DESY

The HERA storage ring project designed for studying colliding electron-proton beams is described. Experiments planned at the HERA facility are considered. Problems of the facility construction cost and its completion date are discussed. The scheme of the HERA facility and its position relative to the PETRA operating storage ring, section of the HERA tunnel and sections of magnets for electron and proton rings are given. The HERA facility ring has four rf-resonator straight gaps each 360 m in length. Electron energy can be varied from 10 to 30 GeV, for protons this range is from 100 to 820 GeV. For maximum energy beam luminosity will amount to 0.35x1032 cm2xs-1 at 224 bunches, and 3x1011 electrons and 0.35x1011 protons per a bunch. Operation frequency of the electron ring HF system is 500 MHz, for the proton one - 200 MHz. 14 GeV particles will be injected into the HERA ring from the linear accelerator, the DESY synchrotron and the PETRA storage ring. Total time of storage of the estimated number of particles is 10 min. It is concluded that the HERA storage ring will permit to investigate substance structure up to approximately 10-16 cm and energy range obtained by this facility will permit to prove the complex structure of quarks