• F. Lin, H. Huang, A.U. Luccio, T. Roser
  BNL, Upton, Long Island, New York

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.

A new horizontal tune jump mechanism has been proposed to overcome the horizontal intrinsic resonances and preserve the polarization of the proton beam in the AGS during the energy ramp. An adiabatic change of the AGS lattice is needed to avoid the emittance growth in both horizontal and vertical motion, as the emittance growth can deteriorate the polarization of the proton beam. Two critical questions are necessary to be answered: how fast can the lattice be changed and how much emittance growth can be tolerated from both optics and polarization points of view? Preliminary simulations, using a realistic AGS lattice and acceleration rate, have been carried out to give a first glance of this mechanism. Several different conditions are presented in this paper.

• H. Huang, L. A. Ahrens, M. Bai, K.A. Brown, C.J. Gardner, J.W. Glenn, F. Lin, A.U. Luccio, W.W. MacKay, T. Roser, V. Schoefer, S. Tepikian, N. Tsoupas, K. Yip, A. Zelenski, K. Zeno
  BNL, Upton, Long Island, New York
• H.M. Spinka, D.G. Underwood
  ANL, Argonne

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.

After installation of two partial snakes in the Brookhaven Alternating Gradient Synchrotron (AGS), a polarized proton beam with 1.5*10¹¹ intensity and 65% polarization has been achieved. There are residual polarization losses due to horizontal resonances over the whole energy ramp and some polarization loss due to vertical intrinsic resonances. Many efforts have been put in to reduce the emittances coming into the AGS and to consequently reduce polarization loss. This paper presents the accelerator setup and preliminary results from run-9 operations.

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