Beam Based Alignment of Combined Function Magnets in the Upgraded Hera Interaction Regions

In order to maximize the achievable luminosity of HERA the final focusing triplets of the lepton beam are installed close to the interaction point (IP). The dipole component of the magnets produces the necessary separation angle between the lepton and the proton beam. The synchrotron radiation generated in the magnets has to be passed through the detector beam pipe with extremely small losses for background reasons. Shape and power of the synchrotron radiation fan depend critically on the precise alignment of those magnets. We present measurements aimed at the determination of the beam vs. magnet offsets, as well as the identification of magnet position errors. We discuss systematic and random errors and difficulties that arise from the non-zero design offsets of the magnets. In order to increase the reliability and the speed of the measurements, automated procedures were developed and incorporated into the HERA control system.