Dynamic aperture effects due to linear coupling

The studies described show that the stability limit, A/sub SL/, depends on the starting location around the ring. This variation in A/sub SL/ around the ring can be correlated with the variation in the betatron distortion for particles starting at different places around the ring. It is proposed that the average of the A/sub SL/ found by starting at each of the QF, the focusing quadrupoles in the arcs, can be taken as a measure of the dynamic aperture. It is found that the average A/sub SL/ is reduced by about 15% by the random skew quadrupole field error multipoles expected in the RHIC (Relativistic Heavy Ion Collider).<>