Radial magnetic field measurements with a Hall probe device in the muon (g-2) storage ring magnet at BNL

Abstract

A Hall probe device has been built to measure the radial component of the magnetic field in the muon (g-2) storage ring at Brookhaven National Laboratory. The ultraprecise (g-2) magnet provides a dominantly vertical magnetic field of about 1.45 T. In order to limit the vertical shift of the muon orbit, the average radial field component should be no more than 5 x 10(-5) of, the vertical field. Our measurements with the Hall probe device achieved an accuracy of 1 x 10(-5). which is one of the most precise measurements with Hall probes. This provides adequate accuracy for shimming and control of the radial field. (C) 2001 Elsevier Science B.V. All rights reserved.