A new way of utilizing pole face windings and magnetic field corrections for independent tuning of betatron wave numbers and chromaticities in the CERN Proton Synchrotron

Precise control of the quadrupole and sextupole components of the magnetic fields in focusing and defocusing sectors respectively was achieved by the combined use of pole-face and yoke windings with three separate power supplies synchronously programmed by a computer. Experience of this technique led to a new philosophy in the design of pole-face windings, in which they become an integral and active part of the magnet. With the arrangement described, focusing and guiding functions are partially separated and an old combined-function accelerator can be transformed effectively into a more flexible separate-function machine without any decrease in available straight- section space. (5 refs).