Measurements of magnetic field alignment

The procedure for installing Superconducting Super Collider dipoles in their respective cryostats involves aligning the average direction of their field with the vertical to an accuracy of 0.5 mrad. The equipment developed for carrying out these measurements is described and the measurements performed on the first few prototype magnets are presented. The field angle as a function of position in these 16.6-m long magnets is a characteristic of the individual magnet with possible feedback information to its manufacturing procedure. A comparison of this vertical alignment characteristic with a magnetic-field intensity (using magnetic resonance imaging) characteristic for one of the prototypes is also presented.