CYCLOTRON AND FFAG STUDIES USING CYCLOTRON CODES

This paper describes the use of cyclotron codes to study the beam dynamics of both high-energy isochronous cyclotrons using AG focusing and non- scaling (NS) FFAGs. The equilibrium orbit code CYCLOPS determines orbits, tunes and period at fixed energies, while the general orbit code GOBLIN tracks a representative bunch of particles through the acceleration process. The results for radial-sector cyclotrons show that the use of negative valley fields allows axial focusing to be maintained, and hence intense cw beams to be accelerated, to energies >5 GeV. The results for FFAGs confirm those obtained with lumped-element codes, and suggest that cyclotron codes will prove to be important tools for evaluating the measured fields of FFAG magnets.