Decoupling Schemes for the Tevatron in the Presence of Skew Quadrupole Fields

Increasing demands for luminosity in existing and future colliders have made both lattice design and error tolerance and correction critical to achieving performance goals. The current state of the Tevatron collider is an example, with a strong skew quadrupole error present in the operational lattice. This work studies the high order performance of the Tevatron and the strong nonlinear behavior introduced when a significant skew quadrupole error is combined with conventional sextupole correction, a behavior still clearly evident after optimal tuning of available skew quadrupole circuits. An optimization study is performed using different skew quadrupole families, and, importantly, local and global correction of the linear skew terms in maps generated by the code COSY. This correction scheme is compared with the present Tevatron operational lattice and corrector configuration.