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After providing collisions of polarized protons at a beam energy of 100 GeV since 2001, the Relativistic Heavy Ion Collider (RHIC) at BNL had its first opportunity to collide polarized protons at its maximum beam energy of 250 GeV in the 2009 polarized proton operations. Equipped with two full Siberian snakes [1] in each ring, RHIC preserves polarization during acceleration from injection to 100 GeV with precise control of the betatron tunes and vertical orbit distortions. However, the strong intrinsic spin resonances beyond 100 GeV are more than two times stronger than those below 100 GeV, requiring much tighter tolerances on vertical orbit distortions and betatron tunes. With the currently achieved orbit correction and tune control, average polarizations of {approx_equal} 42% at top energy and average polarizations of {approx_equal} 55% at injection energy were achieved. Polarization measurements as a function of beam energy also indicated aU polarization losses occurred around three strong intrinsic resonances at 136 GeV, 199.3 GeV and 220.8 GeV Peak luminosity of 122 x 10{sup 30} cm{sup -2} s{sup -1} was also demonstrated. This paper presents the performance of the first RHIC 250 GeV operation and discusses the depolarization issues encountered during the run.

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 Alternating Gradient Synchrotron (AGS) during the energy ramp. An adiabatic change of the AGS lattice is needed to avoid the emittance growth in both horizontal and vertical planes, 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. Results with different optics are presented in this paper.