The Focusing Air-Core Magnetic Channel for the M.S.U. 55-MeV Cyclotron

In variable-energy cyclotrons, saturation effects are always a problem; the use of air-core coils in lieu of iron as magnetic channels greatly reduces such difficulties. This paper describes the design of such a coil for the M.S.U. 55-MeV cyclotron. The coil includes the additional feature of incorporating a focusing gradient approximately equal in strength to a typical single-stage quadrupole.