• B.J. Holzer, S. Bettoni, O.S. Brüning, S. Russenschuck
  CERN, Geneva
• R. Appleby
  UMAN, Manchester
• J.B. Dainton, L.N.S. Thompson
  Cockcroft Institute, Warrington, Cheshire
• M. Klein
  The University of Liverpool, Liverpool
• A. Kling, B. Nagorny, U. Schneekloth
  DESY, Hamburg
• P. Kostka
  DESY Zeuthen, Zeuthen
• A. Polini
  INFN-Bologna, Bologna

The LHeC aims at colliding hadron-lepton beams with center of mass energies in the TeV scale. For this purpose the existing LHC storage ring is extended by a high energy electron accelerator in the energy range of 60 to 140 GeV. The electron beam will be accelerated and stored in a LEP like storage ring in the LHC tunnel. In this paper we present the layout of the interaction region which has to deliver at the same time well matched beam optics and an efficient separation of the electron and proton beams. In general the large momentum difference of the two colliding beams provides a very elegant way to solve this problem: A focusing scheme that leads to the required beam sizes of the electrons and protons is combined with an early but gentle beam separation to avoid parasitic beam encounters and still keep the synchrotron radiation level in the IR within reasonable limits. We present in this paper two versions of this concept: A high luminosity layout where the mini beta magnets are embedded into the detector design as well as an IR design that is optimised for maximum acceptance of the particle detector.

• A. Kling, K. Balewski
  DESY, Hamburg

PETRA III is a 3rd generation synchrotron radiation light source which started commissioning in April 2009. Recently, first frequency map measurements have been made using the turn-by-turn capabilities of the beam position monitors and horizontal as well as vertical kicker magnets. The results are in good agreement with expectations from tracking studies performed with SixTrack.

• A. Kling, K. Balewski
  DESY, Hamburg
• R. Bartolini
  JAI, Oxford

PETRA III is a 3rd generation synchrotron radiation light source which started commissioning in April 2009. Turn-by-turn capabilities are available for all 227 BPMs installed in the storage ring thus providing a powerful diagnostic tool for the characterization of the linear and nonlinear motion of the stored beam. We report on first results of beam dynamics studies using multiturn data acquired at PETRA III and first steps towards a calibration of the linear and nonlinear lattice model of the storage ring.