Establishment of Precise Magnetic Fields in the Momentum Analyzing System at SLAC

Precise magnetic fields are necessary to achieve high-quality particle beam-transport in the SLAC beam switchyard. A discussion of the methods of magnetic measurements associated with testing and establishing these fields is presented. These measurements and some of the important results obtained are described. In order to satisfy the criteria placed on the transport systems each magnet was measured and the critical magnets of the transport system were selected for placement in the beam switchyard on the basis of several of their measured characteristics. A description of the selection procedure is presented, and the effects of the individual magnet differences are discussed. Details of measurement techniques and the resulting procedures which are used for setting up the beam switchyard for a particular momentum are given.