Magnetic Field Tolerances for the TRIUMF 500 MeV H-Cyclotron

The mass of steel in the TRIUMF magnet will be approximately 4000 tons. In designing this magnet it has been found that there is considerable interplay between manufacturing methods and their tolerances on the one hand, and the tolerances required by beam dynamics on the. other. This paper reviews the magnet tolerances needed to achieve adequate isochronism and axial focusing, and limit first-harmonic induced radial oscillations and electric dissociation of H-ions. The possibility of separated turn acceleration is also considered.