A Fast-Sampling, Fixed Coil Array for Measuring the AC Field of Fermilab Booster Corrector Magnets

A system employing an array of inductive pick-up coils around the perimeter of a cylinder has been developed for measurements of the rapidly changing field in the new corrector magnets for the Fermilab Booster. The coils are fabricated on printed circuit boards and feature windings which buck dipole, quadrupole, and sextupole fields, allowing sensitive measurements of both strength and higher-order harmonics. The array of coils is simultaneously sampled at data rates of up to 100 kHz with 10 kHz bandwidth using 24-bit ADC's.