HIGH-ENERGY CYCLOTRONS WITHOUT SPIRAL

This paper explores the possibility of reaching high energies in isochronous ring cyclotrons with radial sectors by using negative valley fields to increase the magnetic flutter. A simple model was used to generate field maps for 4-GeV and 13-GeV proton rings, whose orbit propert- ies were then studied using the CYCLOPS equilibrium orbit code. Field maps were also generated for two FFAG designs (both non-scaling, one isochronous and one not) and their orbit properties evaluated with CYCLOPS - the first time that a cyclotron code has been used on FFAGs.