Precision Magnetic Measurements by the Floating Wire Analog Technique

Two SuperHILAC magnetic spectrometers were calibrated by means of current-carrying, floating wires. An "effective" radius-of-curvature as a function of single position measurements of magnetic-induction was determined with a probable error of ±0.02% over the range of rigidity: 0.3 ≤ Bp ≤ 2.4 (Tesla-meters). Employed in the calibrations were: optical detectors for determining wire position, an eddy-current "jiggler" for reducing pulley "stiction," a vacuum re-entrant tube for allowing calibration under spectrometer operating conditions, two-axis gradient correction coils for operating an NMR magnetometer in gradients of 70 Gauss/cm, a calculator program for facilitating data collection, and a computer program for data reduction and presentation.