Harmonic analysis of Fermilab Main Ring quadrupoles

Utilizing a rotating coil harmonic measurement system, a sample of more than 35 Fermilab Main Ring quadrupoles has been measured. The asymmetric design of these magnets provides many easily measured harmonic coefficients. Results for harmonic coefficients at various excitation levels are presented. Since the magnets were designed with an elliptical aperture, the only symmetries which are preserved by design are the top/bottom and left/right symmetries. This permits a much richer spectrum of harmonic components than a symmetric quadrupole. Overall the harmonic measurement system makes it possible to characterize the gradient errors for Main Ring quadrupoles throughout the range of interest for current operation or main injector use.<
>