• R. Tomás, H.-H. Braun, J.-P. Delahaye, A. Marin, D. Schulte, F. Zimmermann
  CERN, Geneva
• D. Angal-Kalinin, J.K. Jones
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• S. Bai, J. Gao, X.W. Zhu
  IHEP Beijing, Beijing
• P. Bambade, M. Renier
  LAL, Orsay
• Y. Honda, S. Kuroda, T. Okugi, T. Tauchi, N. Terunuma, J. Urakawa
  KEK, Ibaraki
• A. Scarfe
  UMAN, Manchester
• A. Seryi, G.R. White, M. Woodley
  SLAC, Menlo Park, California

The CLIC Final Focus System has considerably larger chromaticity than those of ILC and its scaled test machine ATF2. We propose to reduce the IP betas of ATF2 to reach a CLIC-like chromaticity. This would also allow to study the FFS tuning difficulty as function of the IP beam spot size. Both the ILC and CLIC projects will largely benefit from the ATF2 experience at these ultra-low IP betas.

• S. Bai, J. Gao, X.W. Zhu
  IHEP Beijing, Beijing
• A.S. Aryshev
  JAI, Egham, Surrey
• P. Bambade, T. Okugi
  KEK, Ibaraki
• Y. Kamiya
  ICEPP, Tokyo
• D.J. McCormick, M. Woodley
  SLAC, Menlo Park, California
• M. Oroku, T. Yamanaka
  University of Tokyo, Tokyo

Funding: NSFC 10525525 and 10775154. CNRS-IN2P3 and ANR.

The ATF2 project is the final focus system prototype for ILC and CLIC linear collider projects, with a purpose to reach a 37nm vertical beam size at the interaction point. We report on techniques developed based on simulation studies to adjust the horizontal and vertical beam waists independently in the presence of errors, at two different IP locations where the beam size can be measured with different accuracies. During initial commissioning, we will start with larger than nominal β-functions at the IP, to reduce the effects from higher-order optical aberrations and thereby simplify the optical corrections needed. The first measurements in such intermediate β-configurations are reported.

• A. Seryi, J.W. Amann, P. Bellomo, B. Lam, D.J. McCormick, J. Nelson, J.M. Paterson, M.T.F. Pivi, T.O. Raubenheimer, C.M. Spencer, M.-H. Wang, G.R. White, W. Wittmer, M. Woodley, Y.T. Yan, F. Zhou
  SLAC, Menlo Park, California
• D. Angal-Kalinin, J.K. Jones
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• R. Apsimon, B. Constance, C. Perry, J. Resta-López, C. Swinson
  JAI, Oxford
• S. Araki, A.S. Aryshev, H. Hayano, Y. Honda, K. Kubo, T. Kume, S. Kuroda, M. Masuzawa, T. Naito, T. Okugi, R. Sugahara, T. Tauchi, N. Terunuma, J. Urakawa, K. Yokoya
  KEK, Ibaraki
• S. Bai, J. Gao
  IHEP Beijing, Beijing
• P. Bambade, Y. Renier, C. Rimbault
  LAL, Orsay
• G.A. Blair, S.T. Boogert, V. Karataev, S. Molloy
  Royal Holloway, University of London, Surrey
• B. Bolzon, N. Geffroy, A. Jeremie
  IN2P3-LAPP, Annecy-le-Vieux
• P. Burrows
  OXFORDphysics, Oxford, Oxon
• G.B. Christian
  ATOMKI, Debrecen
• J.-P. Delahaye, D. Schulte, R. Tomás, F. Zimmermann
  CERN, Geneva
• E. Elsen
  DESY, Hamburg
• E. Gianfelice-Wendt, M.C. Ross, M. Wendt
  Fermilab, Batavia
• A. Heo, E.-S. Kim, H.-S. Kim
  Kyungpook National University, Daegu
• J.Y. Huang, W.H. Hwang, S.H. Kim, Y.J. Park
  PAL, Pohang, Kyungbuk
• Y. Iwashita, T. Sugimoto
  Kyoto ICR, Uji, Kyoto
• Y. Kamiya
  ICEPP, Tokyo
• S. Komamiya, M. Oroku, T.S. Suehara, T. Yamanaka
  University of Tokyo, Tokyo
• A. Lyapin
  UCL, London
• B. Parker
  BNL, Upton, Long Island, New York
• T. Sanuki
  Tohoku University, Graduate School of Science, Sendai
• A. Scarfe
  UMAN, Manchester
• T. Takahashi
  Hiroshima University, Graduate School of Science, Higashi-Hiroshima
• A. Wolski
  Cockcroft Institute, Warrington, Cheshire

ATF2 is a final-focus test beam line that attempts to focus the low-emittance beam from the ATF damping ring to a beam size of about 37 nm, and at the same time to demonstrate nm beam stability, using numerous advanced beam diagnostics and feedback tools. The construction is well advanced and beam commissioning of ATF2 has started in the second half of 2008. ATF2 is constructed and commissioned by ATF international collaborations with strong US, Asian and European participation.

Slides