Luminosity Upgrade of Hera

After six years of operation the electron proton collider HERA had reached a luminosity of 1:4 10 cm s , very close to the design value. We present an overview on the HERA upgrade project that pursues the goal to further increase the luminosity three-fold by the year 2000. The increase is achieved by reducing the beam cross sections at the IP to 120 30 m (RMS values). If furthermore design currents can be reached in both machines the improvement factor is up to 5. The upgrade involves a complete rebuild of the interaction regions as well as lattice modifications in the electron ring. Major issues of the project are superconducting magnets that will be installed inside the colliding beam detectors, unconventional normalconducting magnets, the handling of synchrotron radiation in the IR, and electron beam dynamics. 1 CONCEPT AND PARAMETERS HERA is a 6:3 km long electron/proton collider, presently running at 27:5GeV for the electrons and 920GeV for the protons. The proton machine uses superconducting magnets in the arcs. The machine is equipped with four interaction regions (IR’s), two of them for electron proton collisions with the detectors ZEUS and H1. The HERA luminosity can be written as follows: