Quadrupole magnet for the APS storage ring

An asymmetric core geometry has been selected for the quadrupole magnets in the storage ring of the Advanced Photon Source (APS) in order to accommodate the vacuum chamber and photon beam pipes. The requirements of the positron beam make it necessary that the magnet be able to produce a field gradient of 20-T/m with high accuracy. The design for this magnet has been fully developed in preparation for the construction of a prototype. Some unique features included in the design are described. Design choices are being validated by extensive magnetic-field calculations in both two and three dimensions. The results of these calculations are presented.<
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