MAGNETIC MEASUREMENTS FOR TUNING AND OPERATING A HYBRID WIGGLER

Abstract
A hybrid, vanadium-permendur/rare-earth-cobalt (REC) wiggler has been designed, built, and measured at the Lawrence Berkeley Laboratory (LBL) as a joint project with the Stanford Synchrotron Radiation Laboratory (SSRL) and the Exxon Research and Engineering Company. This paper describes two magnetic measurement techniques used to characterize and tune the wiggler. We describe Hall effect gaussmeter measurements that : (1) confirmed and quantified the wiggler sinusoidal field distributions, and (2) calibrated variable-flux-shunt adjustments, which can provide "fine-tuning" for individual poles. We also describe measurements of integrals of magnetic induction with integral coils and electronic integrators. Coils and integrators were used to : (1) calibrate the end-pole currents required to zero the half-magnet integrals, (2) measure the horizontal-component integral, and (3) measure variations in single period integrals as functions of longitudinal position in the wiggler