AGS-Booster orbit and resonance correction

A large tune-spread due to space charge and strong random eddy current sextupoles exists at injection in the Alternating Gradient Synchrotron (AGS) Booster. As a result, particles in the beam may cross several imperfection resonances that can be caused by random magnet errors. The correction scheme proposed deals with four half-integer stopband resonances, four third-order sextupole induced resonances, and both the sum and difference linear coupling resonances. All of these resonances can have a chance to be swept through by the beam during injection, bunching, and the early stage of acceleration. A system of correctors involving skew quadrupoles, trim quadrupoles, and sextupoles is described with the capability of simultaneously correcting all the major resonances involved. Also, a closed-orbit correction scheme is described which requires, to be effective, a cascade of local three-magnet bumps. Several magnet imperfections and survey misalignment errors are investigated. Preliminary simulations show that the corrector strengths required for the quadrupole and skew quadrupole correctors are less than 1% of the main quadrupole strengths, and the strengths of the sextupole correctors are less than 2% of the main sextupole strengths.<>