• Y.T. Yan, A. Chao
  SLAC, Menlo Park, California
• M. Bai
  BNL, Upton, Long Island, New York

Funding: US DOE

Unlike an electron storage ring with radiation damping, resonance excitation is unsuitable to a proton storage ring for turn-by-turn betatron orbit data. However, one may consider modified betatron motion driven by ac dipoles oscillating at frequencies near the betatron tunes. With a matrix formulation for adding ac-dipole effects on 2-D coupled one-turn map, we concatenate the ac-dipole effects and the one-turn map to obtain a modified linear map. The ac-dipole effects are equivalent to inserted symplectic linear maps at the ac-dipole locations. If the maps are normalized through decoupling similarity transformation, the decoupled maps for the ac-dipole effects are equivalent to 1-D thin quads inserted at the corresponding locations, the same conclusion for the 1-D driven oscillation*. For optics modeling with MIA technique**, one must make sure that there are, simultaneously, two transverse ac-dipole driven betatron oscillations along with one longitudinal synchrotron oscillation. Once the optics model for the modified betatron motion is obtained, one can then obtain the proton storage ring model by de-concatenating the inserted ac-dipole linear maps.

* R. Miyamoto, S.E. Kopp, A. Jansson, and M.J. Syphers, PRSTAB 11, 084002 (2008).
** Y.T. Yan, ICFA Beam Dynamics Newsletter, No. 42, pp. 71-87 ( 2007), Y. Cai, W. Chou, Eds.

• 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.

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