Specification of multipole tolerances for the APS quadrupole magnet

This note will address a proposed method for specifying the multipole tolerance for the design and production of APS quadrupole magnets. The tolerances for the multipole components for the quadrupole magnets will be set to that level which reduces the dynamic aperture by about 10--15% from the ideal machine dynamic aperture (as specified in CDR-87). This level may appear rather stringent, especially compared to the 50--60% reduction resulting from quad placement errors. However, when all tolerances are taken together, the residual dynamic aperture would be prohibitively small and commissioning would be difficult if these tolerances were at twice this level. The dynamic aperture was determined using the numerical tracking program RACETRACK