Design of end magnetic structures for the Advanced Light Source wigglers

The vertical magnetic structures for the Advanced Light Source 15 cm planar wiggler and 20 cm period elliptical wiggler are of hybrid permanent magnet design. The ends of these structures are characterized by diminishing scalar potential distributions of the poles which control beam trajectories. They incorporate electromagnetic correction coils to dynamically correct for variations in the first integral of the field as a function of gap. A permanent magnet trim mechanism is incorporated to minimize the transverse integrated error field distribution. The ends were designed using analytic and computer modeling techniques. The design and modeling results are presented.