Construction of Energy Doubler Correction Magnets

Discussed below are two types of correcting magnets currently being made at Fermilab. There are several reasons for including these correcting magnets in an accelerator: the higher order harmonics produced by large dipole and quadrupole magnets must be reduced; there is a need for vertical and horizontal steering for closed orbit correction, chromaticity correction, tune adjustment, extraction, colliding beam mode, etc. There are four types of coils necessary to perform the functions stated above: octupole, sextupole, quadrupole, and dipole. About 180 coils of each kind are needed for the whole ring.