Correction of magnetization sextupole and decapole in a 5 centimeter bore SSC dipole using passive superconductor

Higher multipoles due to magnetization of the superconductor in 4-cm- and 5-cm-bore Superconducting Super Collider (SSC) superconducting dipole magnets have been observed. The use of a passive superconductor to correct the magnetization sextupole has been demonstrated on two dipoles built by the Lawrence Berkeley Laboratory. In the present work, it is shown how passive correction can be applied to the 5-cm SSC dipoles to remove sextupole and decapole caused by magnetization of the dipole superconductor. Two passive superconductor corrector options are presented. Both methods of passive superconductor correction will reduce magnetization sextupole at injection at 1 TeV or above any order magnitude or more over a wide range of operating temperatures. Increasing the diameter of the filament in block 1 increases the magnetization decapole at injection while the separate passive superconductor method reduces magnetization decapole. Both methods of correction reduce the magnetization sextupole whether the field is rising or falling. The change in magnetization sextupole and decapole due to flux creep decay of the superconductor during injection can be partially compensated for by using the passive superconductor.<>