Correction of horizontal-vertical coupling in the SSC

Coupling between the horizontal and vertical betatron motion in the SSC (Superconducting Super Collider) is produced by skew quadrupole errors in the dipole magnets, angular alignment errors in the quadrupoles, and vertical closed-orbit errors in the sextupoles. The anticipated random errors in the arcs alone will produce a coupling coefficient of about 0.017 in the current lattice. The largest source of coupling for collision optics is expected to be the quadrupole triplets adjacent to the low-beta interaction points, each pair of which, if uncorrected, can contribute about 0.05 to the coupling efficient. A correction scheme using skew quadrupoles at favorable positions in the interaction straight sections has been devised and tested. An interactive, graphical simulation was performed using this corrector configuration. In the simulation each skew quadrupole family was set to the value which minimized the separation between the two tunes, cycling between families until the machine was sufficiently decoupled (|C |<0.001)