• M.K. Sullivan, K.J. Bertsche
  SLAC, Menlo Park, California
• S. Bettoni
  CERN, Geneva
• E. Paoloni
  University of Pisa and INFN, Pisa
• P. Raimondi
  INFN/LNF, Frascati (Roma)
• P. Vobly
  BINP SB RAS, Novosibirsk

A final focus magnet design that uses super-ferric magnets is introduced for the Super-B interaction region. The baseline design has air-core super-conducting quadrupoles. This idea instead uses super-conducting wire in an iron yoke. The iron is in the shape of a Panofsky quadrupole and this allows for two quadrupoles to be side-by-side with no intervening iron as long as the gradients of the two quads are equal. This feature allows us to move in as close as possible to the collision point and minimize the beta functions in the interaction region. The super-ferric design has advantages as well as drawbacks and we will discuss these in the paper.

• N. Vinokurov, E.N. Dementyev, B.A. Dovzhenko, Ya.V. Getmanov, E.I. Kolobanov, V.V. Kubarev, G.N. Kulipanov, L.E. Medvedev, S.V. Miginsky, L.A. Mironenko, V. Ovchar, K.V. Palagin, B.Z. Persov, V.M. Popik, T.V. Salikova, M.A. Scheglov, S.S. Serednyakov, O.A. Shevchenko, A.N. Skrinsky, V.G. Tcheskidov, Y.F. Tokarev, P. Vobly, N.S. Zaigraeva
  BINP SB RAS, Novosibirsk
• B.A. Knyazev, N. Vinokurov
  NSU, Novosibirsk

The Novosibirsk ERL has rather complicated magnetic system. One orbit (11-MeV) for terahertz FEL lies in the vertical plane. Other four orbits lie in the horizontal plane. The beam is directed to these orbits by switching on of two round magnets. In this case electrons pass through RF cavities four times, obtaining 40-MeV. At the 4th orbit the beam is used in FEL, and then is decelerated four times. At the 2nd orbit (20 MeV) we have a bypass with another FEL. When bypass magnets are switched on, the beam passes through this FEL. The length of bypass is chosen to provide the delay necessary to realize deceleration at the3rd pass through accelerating cavities. In 2008 two of four horizontal orbits were assembled and commissioned. The electron beam was accelerated twice and then decelerated down to low injection energy. First multi-orbit ERL operation was demonstrated successfully. In 2009 the first lasing at the second FEL, installed on the bypass of the second track, was achieved. The wavelength tunability range is 40 - 80 micron. Energy recovery of a high energy spread used electron beam was optimized. Third and fourth orbit assembly is in progress.

Slides

• Y. Papaphilippou, F. Antoniou, M.J. Barnes, S. Bettoni, S. Calatroni, P. Chiggiato, R. Corsini, A. Grudiev, R. Maccaferri, M. Modena, L. Rinolfi, G. Rumolo, D. Schoerling, D. Schulte, M. Taborelli, A. Vivoli
  CERN, Geneva
• E.B. Levichev, S.V. Sinyatkin, P. Vobly, K. Zolotarev
  BINP SB RAS, Novosibirsk

The CLIC damping rings should produce the ultra-low emittance necessary for the high luminosity performance of the collider. This combined to the high bunch charge present a number of beam dynamics and technical challenges for the rings. Lattice studies have been focused on low emittance cells with optics that reduce the effect Intra-beam scattering. The final beam emittance is reached with the help of super-conducting damping wigglers. Results from recent simulations and prototype measurements are presented, including a detailed absorption scheme design. Collective effects such as electron cloud and fast ion instability can severely limit the performance and mitigation techniques have been identified and tested. Tolerances for alignment and technical system design such as kickers, RF cavities, magnets and vacuum have been finally established.