Iron Dominated Mixed Multipole Magnets With Conventional or Superconducting Coils

Abstract

In low energy accelerators and beam lines such as those found in the Facility for Rare Isotope Beams (FRIB), it is desirable to have combined function magnets that are iron dominated (for the principle harmonic) with superconducting coils. The staff at FRIB has looked at a number of combined function magnets (such as quadrupole magnet with added sextupole and sextupoles with added octupole). There in fact is a whole class of combined function magnets that combine lower order multipole components with higher order multipole components. It is desirable for a magnet of this type to produce a pure component of each component along with an arbitrary mixture of the two multipole components. If the coils are superconducting, one can get enough ampere-turns in the coils for each multipole to fabricate a meaningful magnet. Specific examples for some of these magnets are given in this report.