• F. Zimmermann, O.S. Brüning, E. Ciapala, F. Haug, J.A. Osborne, D. Schulte, Y. Sun, R. Tomás
  CERN, Geneva
• C. Adolphsen
  SLAC, Menlo Park, California
• R. Calaga, V. Litvinenko
  BNL, Upton, Long Island, New York
• S. Chattopadhyay
  Cockcroft Institute, Warrington, Cheshire
• J.B. Dainton, M. Klein
  The University of Liverpool, Liverpool
• A.L. Eide
  LPNHE, Paris

We consider three different scenarios for the recirculating electron linear accelerator (RLA) of a linac-ring type electron-proton collider based on the LHC (LHeC): i) a basic version consisting of a 60 GeV pulsed, 1.5 km long linac, ii) a higher luminosity configuration with a 60 GeV 4 km long cw energy-recovery linac (ERL), and iii) a high energy option using a 140 GeV pulsed linac of 4 km active length. This paper describes the footprint, optics of linac and return arcs, emittance growth from chromaticity and synchrotron radiation, a set of parameters, and the performance reach for the three scenarios.