Stray Field Reduction of Als Eddy Current Septum Magnets**Supported by the U.S. Department of Energy under Contract No. DEAC03 76SF00098;

Stray field from an eddy current septum magnet adversely affects the circulating beam and can be reduced using several techniques. The stray field time history typically has a fast rise section followed by a long exponential decay section when pulsed with a half sine drive current. Changing the drive current pulse to a full sine has the effect of both reducing peak stray field magnitude by ∼ 3x and producing a quick decay from this peak to a lower field level which then has a similar long decay time constant as that from the half sine drive current pulse. A method for tuning the second half-sine (reverse) current pulse to eliminate the long exponential decay section is given. A method for halving the remaining brief peak is also given. © 2005 IEEE.