Abstract :
Proton and electron optics for the HERA straight sections are presented. The layout is based on a symmetric head on interaction geometry. Layout and optics have been optimized with respect to electron-proton luminosity, and by taking into account partly conflicting requirements such as: space for installation of components (detectors, injection, cavities, beam dump, ...), minimum refrigeration demand, cost minimization, background, apertures, spin rotator, spin matching, satellite resonances, and flexibility of operation. The choice of interaction parameters results in a luminosity of 0.25 · 1032cm-2S-1 (30×820 GeV, limited by beam-beam tune shifts). Aperture requirements for the proton magnets are discussed for both luminosity and injection conditions. For initial electron ring operation a simple spin rotator by-pass option is sketched. With the assumption that in the first stage of HERA there will be no e-p interaction in the west, the Straight Section West is modified in favour of injection and beam dump demands.
