Harmonics suppression of fields arising from vacuum chamber eddy currents with application to SSC Low-Energy-Booster magnets

An expression for eddy currents induced in a thin-walled conductor due to a time-dependent electromagnet field excitation is formulated, allowing subsequent analytical development of a closed form expression predicting field harmonics in ac iron-core multipole electromagnets arising from eddy currents in the vacuum chamber. A passive technique for harmonics suppression is presented with specific application to the design of the Superconducting Super Collider (SSC) Low-Energy-Booster (LEB) Magnets